# Air Emissions Permit Application for the Furnace 5 Reactivation Project
VOLUME I – Permit Application Forms, Regulatory Applicability Summary and BACT Analysis
Prepared for Northshore Mining Company Silver Bay, Minnesota

May 2, 2005

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## i 

# Volume I – Permit Application Forms, Re gulatory Applicability Summary and BACT Analysis

Contents
1 Introduc tion ................................................................................................................... ..................................... 1-1 2 Permit Applica tion Forms ....................................................................................................... ........................... 2-3 3 Project Desc ription ............................................................................................................ ................................. 3-1 3.1 Introduc tion ................................................................................................................... .............................. 3-1 3.2 Existing Op erations ............................................................................................................ ......................... 3-1 3.2.1 Concentrate Produc tion ......................................................................................................... ........... 3-2 3.2.2 Pellet Produ ction .............................................................................................................. ................ 3-2 3.2.3 Product Storage and Loadout.................................................................................................... ........ 3-3 3.2.4 Power Plant.................................................................................................................... ................... 3-3 3.2.5 Raw Materials Management....................................................................................................... ...... 3-4 3.2.6 Process Water and Tailing Disposal System. ................................................................................... 3- 4 3.3 The Furnace 5 Reac tivation Project ............................................................................................. ............... 3-4 3.3.1 Other Changes to Existing Fa cilitie s ........................................................................................... ..... 3-6 4 Regulatory Appli cability Su mmary

............................................................................................... ..................... 4-1 4.1 Introduc tion ................................................................................................................... .............................. 4-1 4.2 Ambient Air Qua lity Standards.................................................................................................. ................. 4-1 4.3 Emission Standards ............................................................................................................. ........................ 4-3 4.3.1 Federal New Source Performance Standards (NSPS)....................................................................... 4-4 4.3.2 National Emission Standards for Haza rdous Air Pollutants (NESHAP) .......................................... 4-4 4.3.2.1 40 CFR 61 NESHAP.......................................................................................................... 4-4 4.3.2.2 40 CFR 63 NESHAP.......................................................................................................... 4-4 4.3.3 State Standards of Performance................................................................................................. ....... 4-4 4.4 New Source Revi ew (NSR)........................................................................................................ ................. 4-5 4.4.1 Best Available Control Techno logy (BACT) Analysis .................................................................... 4-6 4.4.2 Air Quality Analys is........................................................................................................... .............. 4-6 4.4.3 Additional Imp acts Analysis.................................................................................................... ......... 4-7 4.4.3.1 Growth An alys is................................................................................................................ . 4-7 4.4.3.2 Ambient Air Quality Analysis............................................................................................ 4-8 4.4.3.3 Soils and Vegetati on Analysis............................................................................................ 4-8 4.4.3.4 Visibility Impairme nt Analysis .......................................................................................... 4-8 4.4.4 Class I Area Im pact Analysis ................................................................................................... ........ 4-8 4.5 References ..................................................................................................................... .............................. 4-9 5 BACT An alys is .................................................................................................................. ................................ 5-1

List of Tables
Table 4-1: National Ambient Air Quality Standards (NAAQS) Table 4-2: State Ambient Air Quality Standards (SAAQS) for Minnesota Table 4-3: New Source Review - Si gnificant Net Emissions Increases Table 4-4: New Source Review - PSD Increments
Table 5 1: Results of the BACT Analysis

Appendix

Section 5 Appendix A “Best Available Control Technology Review”, April 2005

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## 5-1 

# 5 BACT Analysis

Please refer to the separate report (“ Best Available Control Technology Revi ew” in Appendix A) that presents the findings of the BACT Analysis.

Table 5-1 summarizes the results for the completed BACT analysis for NSM’s Furn ace 5 Reactivation Project.



## Table 5-1: Results of the BACT Analysis

Emission Source BACT Pollutant(s) Controlled

Indurating Furnace Exhaust Wet ESP SO 2 

## , Particulate Matter
Indurating Furnace Exhaust No Controls NO x 

## Indurating Furnace Pellet Discharge Wet Scrubber Particulate Matter

Concentrator Silos Fabric Filter Particulate Matter
Ore Crushing Fabric Filter Particulate Matter

# Appendix A

# Northshore Mining Company Silver Bay, Minnesota

Appendix A

Best Available Control Technology Review for the Furnace 5 Reactivation Project

April 2005

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## A-5-3 

# Table of Contents

Table of Contents.............................................................................................................. ............................3

I. Executive Summary .............................................................................................................. ......5 A. Project Description............................................................................................................ ................5 B. Proposed BACT .................................................................................................................. ..............7

II. Introduction................................................................................................................... ..............8 A. Project Description............................................................................................................ ................8 B. BACT Methodology and Results................................................................................................... .13

III. Indurating Furn ace Exhaust ..................................................................................................... .14 A. Sulfur Dioxide (SO 2 

## ) Emission Controls ........................................................................................16 1. Step 1 – Identify all Control Technologies .................................................................. 16 2. Step 2 – Eliminate Technically Infeasible Options...................................................... 19 3. Step 3 – Rank Remaining Control Technologies by Control Effectiveness ................ 20 4. Step 4 – Evaluate Most Effective Control Technologies and Document Results........ 21 5. Step 5 – Select BACT .................................................................................................. 23 B. Nitrogen Oxide (NO x 

## ) Emission Controls ......................................................................................23 1. Step 1 – Identify all Control Technologies .................................................................. 23 2. Step 2 – Eliminate Technically Infeasible Options...................................................... 30 3. Step 3 – Rank Remaining Control Technologies by Control Effectiveness ................ 34 4. Step 4 – Evaluate Most Effective Control Technologies and Document Results........ 34 5. Step 5 – Select BACT .................................................................................................. 35 C. Particulate Matter (PM / PM 10 

## ) Emission Controls ........................................................................36 1. Step 1 – Identify all Control Technologies .................................................................. 36 2. Step 2 – Eliminate Technically Infeasible Options...................................................... 39 3. Step 3 – Rank Remaining Control Technologies by Control Effectiveness ................ 42 4. Step 4 – Evaluate Most Effective Control Technologies and Document Results........ 43 5. Step 5 – Select BACT .................................................................................................. 45

IV. Fine Crushing.................................................................................................................. ..........47 A. Particulate Matter (PM / PM 10 

## ) Emission Controls .......................................................................47 1. Step 1 – Identify all Control Technologies .................................................................. 47 2. Step 2 – Eliminate Technically Infeasible Options...................................................... 48 3. Step 3 – Rank Remaining Control Technologies by Control Effectiveness ................ 50 4. Step 4 – Evaluate Most Effective Control Technologies and Document Results........ 50 5. Step 5 – Select BACT .................................................................................................. 51

V. Concentrator Silos............................................................................................................. ........53 A. Particulate Matter (PM / PM 10 

## ) Emission Controls .......................................................................53 1. Step 1 – Identify all Control Technologies .................................................................. 53 2. Step 2 – Eliminate Technically Infeasible Options...................................................... 54 3. Step 3 – Rank Remaining Control Technologies by Control Effectiveness ................ 56 4. Step 4 – Evaluate Most Effective Control Technologies and Document Results........ 56 5. Step 5 – Select BACT .................................................................................................. 57

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## A-5-4 VI. Indurating Furnace Pe llet Discharge.........................................................................................59 A. Particulate Matter (PM / PM 10 

## ) Emission Controls .......................................................................59 1. Step 1 – Identify all Control Technologies .................................................................. 59 2. Step 2 – Eliminate Technically Infeasible Options...................................................... 60 3. Step 3 – Rank Remaining Control Technologies by Control Effectiveness ................ 62 4. Step 4 – Evaluate Most Effective Control Technologies and Document Results........ 62 5. Step 5 – Select BACT .................................................................................................. 63

BACT ATTACHMENT 1 .............................................................................................................. ............65

BACT ATTACHMENT 2 .............................................................................................................. ............83

BACT ATTACHMENT 3 .............................................................................................................. ..........111

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## A-5-5 

# I. Executive Summary

A. Project Description
Northshore Mining Co. (NSM) is proposing to reactiva te its Furnace 5 taconite production facilities. These facilities have been idle for some time due to a weak demand for taconite pellets. Recent
increases in market demand have prompted Northshore to re-activ e these production facilities in
order to increase iron concentrate and taconite pellet production.

Northshore Mining Co. is a major source of PSD pollu tants (Prevention of Signi ficant Deterioration). Because the project will be a major modifica tion under PSD rules, Best Available Control Technology (BACT) must be instal led. The purpose of this BACT study report is to submit information needed for the MPCA to establish BACT limits in the air quality permit for the project.

The following is a description of the equipm ent which Northshore proposes to reactivate and construct as part of the Furnace 5 Reactivation project:

• 

## Reactivate Fine Ore Crushi ng Facilities (2 lines)

• 

## Reactivate Concentrator Sections (9 lines)

• 

## Construct New Concentrate Storage Silos (2 silos)

• 

## Reactivate Indurating Furnace 5 (1 furnace)
Fine Ore Crushing

Fine ore crushing is the process of crushing taconite ore that is re ceived from the mine down to the size needed for ore concentration. Fine ore crushing is a dry process which generates dust. Dust emissions from the fine ore crushing equipment invo lved in the Furnace 5 Reactivation Project are to be routed to collection points currently equipped with baghouse emission controls.

Concentrator

Ore concentration is the process of concentrating the iron ore by separating the ore from the waste rock. Crushed ore entering the concentration process is dry. Particulate matter is emitted as the dry ore is transferred into the process. The ore transfer points will be equipped with fabric filters to

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## A-5-6 control particulate emissions. In the remainder of the ore concentration processing steps, the ore is wet, and there are no particulate matt er emissions from these operations.

Concentrate Storage Silos (2)

Concentrate for off site shipment used by NSM will be put in new storage silos. Use of the silos will not generate particulate emissions as the result of material transfers into and out of the silos due to its 9 to 10 percent moisture content. NSM is also pr oposing to equip the new storage silos with fabric
filter bin vents to control air flows in the silos.

Indurating Furnace Pellet Discharge

When the finished taconite pellets leave the induration furnace, particulate matter is emitted at the transfer point. The furnace discharge pellet transfer point is currently equipped with a rotoclone for particulate control. NSM is proposing to install a wet scrubber as BACT for control of particulate emissions from this source as part of the Furnace 5 Reactivation Project.

Indurating Furnace Exhaust

NSM is proposing to re-activate Furnace #5 as part of the Furnace 5 Reacti vation Project. Based on the estimated project emissions increase, the project will be a PSD major modification for SO 2 

## , NO x 

## , and particulate matter. All of these pollutants ar e emitted from this source . Furnace #5 is equipped
with a wet ESP which is used for Particulate and SO 2 

## emission controls. NSM proposes to use the existing wet ESP as BACT for these pollutants. None of the NOx emission c ontrol devices reviewed can be utilized due to technical or economic infeasibility.

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## A-5-7 

# B. Proposed BACT

The Best Available Control Tec hnologies for emissions from Northshore Mining Co.’s proposed Furnace 5 Reactivation Project are:



# Best Available Control Technology
Northshore Mining Co. Furnace 5 Re activation Project

Emission Source BACT Pollutant(s) Controlled

Indurating Furnace Exhaust Wet ESP SO 2 

## , Particulate Matter
Indurating Furnace Exhaust No Controls NO x 

## Indurating Furnace Pellet Discharge Wet Scrubber Particulate Matter

Concentrator Silos Fabric Fi lter Particulate Matter
Ore Crushing Fabric Filter Particulate Matter

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## A-5-8 

# II. Introduction

A. Project Description

Overview

Northshore Mining Company (NSM) plans to utiliz e its currently permitted, but idle, taconite processing and pellet production capacity to meet the growing dom estic and international demand for
iron ore concentrate and pellets in the production of finished iron and steel commodities. NSM expects the State of Minn esota and, in particular, Northeaste rn Minnesota to benefit through an increased tax base and employment increases directly at NSM an d in support infrastructure and industry throughout the state.

NSM plans to reactivate, over the next 6 months to 2 years, permitted ope rating equipment at its Silver Bay taconite processing plant. The reactivat ions in the proposed project include two permitted crushing lines, nine permitted concentrating lines a nd one permitted pelletizing furnace. The project will also involve the reactivation and/or upgrading of certain pollution cont rol equipment consistent with current USEPA and MPCA rules regarding em ission control requirements and standards. The project, although the equipment is currently permitted, may have th e potential to trigger Prevention of Significant Deterioration (PSD) and New Source Review (NSR) to assure compliance with BACT/MACT Technolog ies under current USEPA policy.

Proposed Reactivation

The reactivation of permitted but currently idle equipment at the Silver Bay facility includes the following equipment:

• Currently permitted fine crushing lines 4 and 104 including existing permitted baghouse emission control equipment. Lines 4 and 104 have the following MPCA equipment numbers:

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## A-5-9 Crushing Line # Emission Unit (EU) # St ack Vent (SV) # Control Equipment (CE) #

Line 4 Crusher EU 011 SV 011 CE 011

Line 104 Crusher EU 020 SV 020 CE 020

• Currently permitted concentrat ing lines 2 through 10. Existing multiclone emission control equipment will be upgraded with baghouse collectors to assure compliance with
BACT/MACT and New Source Re view requirements. The MPCA equipment numbers for the concentrator silos associated with lines 2 through 10 are as follows:

Concentrator Line # Em ission Unit (EU) # Stack Vent (SV) # Control Equipment (CE) #

Line 2 Concentrator Silo EU 033 SV 033 CE 033

Line 3 Concentrator Silo EU 034 SV 034 CE 034

Line 4 Concentrator Silo EU 035 SV 035 CE 035

Line 5 Concentrator Silo EU 036 SV 036 CE 036

Line 6 Concentrator Silo EU 037 SV 037 CE 037

Line 7 Concentrator Silo EU 038 SV 038 CE 038

Line 8 Concentrator Silo EU 039 SV 039 CE 039

Line 9 Concentrator Silo EU 040 SV 040 CE 040

Line 10 Concentrator Silo EU 041 SV 041 CE 041

• Currently permitted Furnace #5 is equipped with Wet Wall Electrostatic Precipitators (WWESP's). The MPCA equipment numbers for Furnace #5 are as follows

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## A-5-10 Source Emission Unit (EU) # Stack Ve nt (SV) # Control Equipment (CE) #

SV 266 CE 271

SV 267 CE 272 Furnace #5 EU 634

SV 268 CE 273

• A new wet scrubber will be installed at the di scharge end of Furnace #5 to assure compliance with the proposed BACT and Taconite MACT st andards for finished pellet handling emission sources. Furnace #5 pellet discharge has the following MPCA equipment numbers:

Source Emission Unit (EU) # Stack Ve nt (SV) # Control Equipment (CE) #

Furnace #5 Pellet Discharge EU 635 SV 269 CE 274

New Equipment

In addition to reactivating existing equipment, NSM proposes to install two (2) new concentrate storage silos. These silos will be used to store concentrate which is shipped off site. Concentrate shipped off site will be loaded directly out of th e silos into trucks and rail cars. MPCA equipment numbers have not been assigned to the storage silos. The silos will be equipped with fabric filter bin vents to control air flows as the silos are being lo aded. The concentrate has a moisture content of 9 to 10 percent, and no emissions are expected.

Equipment Descriptions

Concentrate Production

Concentrate production involves the following steps. The ore is received at Silver Bay by rail from the Babbitt mine and unloaded at the car dump station. The ore proceeds to fine crushing where it is reduced to a minus three fo urths-inch size. Following fine crushing, the

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## A-5-11 ore is directed to dry cobbing, a dry magnetic separation process, to reject the portion of the
ore that does not contain sufficient magnetic iron.

The ore not rejected during dry cobbing is sent to a series of wet grinding and concentrating processes to liberate, concentrate, and recover the iron. These processes include rod and ball mill grinding, particle sizing, magnetic separation, hydrau lic cleaning, froth flotation, and fine screening to produce a finely ground co ncentrate containing a pproximately 65 percent iron contained in a slurry. The iron concentrate slurry is thickened and vacuum filtered to reduce moisture to approximately 10 percent. After vacuum filtering, the concentrate is conveyed as a solid to pelletizing operations.

Concentrate production includes two types of em ission sources which are included in the Furnace 5 Reactivation Project:

• 

## Fine Crushing

Ore receipt, conveyance, crushing and dry cobbing produce dust. This equipment is currently equipped with baghouses for dust c ontrol. This BACT report will address emission controls for dust emissions from ore crushing at the two ore crushers associated with the Furnace 5 Reactivation Project.

• 

## Concentrator Silos

Dust emissions are generated at the feed conveyors prior to the wet processing operations and associated transfer points. The concentrators are currently equipped with cyclones (multiclones) to control dust at the feed conveyors. This BACT report will address
emission controls for dust emissions from the nine ore concentrators associated with the Furnace 5 Reactivation Project.

• 

## Concentrate Storage Silos

Ore concentrate that will not be immediately used by NSM will be put in new storage silos prior to use or shipment offsite. Use of the silos will not generate particulate
emissions as the result of mate rial transfers into and out of the silos. NSM is proposing to equip the new storage silos with fabric filter bin vents to control the air flows in the silos. This BAC T report will not address the concentrate storage silos because they are
not sources of emissions

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## A-5-12 Pellet Production

NSM produces standard and fluxe d (lime-containing) pellets from the concentrate using a number of processing steps as described below.

Following vacuum filtering, the concentrate is agglomerated. Agglom eration involves adding a small amount of binding agent (e.g., bentonite clay, starch) to the iron concentrate and passing the mixture through inclined rotating drum s where it is rolled into one-fourth to onehalf inch green balls suitable for the pelletizi ng furnaces. The green balls are placed onto a traveling grate that passes th rough the furnace. NSM has four permitted furnaces (#5 and #6 at 160 long tons per hour (LTPH) each and #11 an d #12 at 300 LTPH each). In the furnaces, the green balls are dried and heated to start an exothermic reaction that converts the magnetite (Fe 3 

## O 4 

## ) concentrate to hematite (Fe 2 

## O 3 

## ). During this process, the pellets are hardened. Pellets are then cooled and discharged from the furnace for subsequent handling. Fuels used at the furnaces include primarily natural gas, with fuel oil as a back-up fuel during periods of natural gas curtailment.

After leaving the furnaces, the pellets are directed to a series of screening and additional cooling steps. Undersized materi al is either sold as sinter or recycled. The final products are then transported to the storage yard for stockpiling or bin storage.

Pellet production includes two emission sources which are included in the Furnace 5 Reactivation Project:

• 

## Induration Furnace #5 Exhaust Gas

Particulate Matter, SO 2 

## and NO x 

## emissions are gene rated in the indurating furnace from fuel combustion, oxidation of sulfur compound s in the iron ore and attrition of pellets during material handling within the furnace. NSM’s Indurating furnaces are currently equipped with Wet Wall Electrostatic Precipitators (WWESPs) to control SO 2 

## and particulate matter emissions. This BACT report will address emission controls for particulate matter, SO 2 

## and NO x 

## emissions in the exhaust gases from Furnace #5.

• 

## Induration Furnace #5 Pellet Discharge

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## A-5-13 Dust emissions from pellet handling processes following the furnaces currently are controlled by rotoclones. This BACT re port will address emissi on controls for dust emissions from the pellet handling at the discharge of Furnace #5.


# B. BACT Methodology and Results
This BACT analysis was prepared in accordance with the “top-down” approach specified in EPA’s New Source Review Workshop Manual, (October 1990). The five basic steps of the top down approach to the BACT process are as follows:

Step 1 – Identify all Control Technologies The first step in a top down analysis is to identify all available control technologies for each emission
unit.

Step 2 – Eliminate Technically Infeasible Options In the second step, the technical feasibility of each control option identified in step one is evaluated with respect to source-specific factors.

Step 3 – Rank Remaining Control Te chnologies by Control Effectiveness In the third step, all remaining c ontrol technologies not eliminated in Step 2 are ranked and then
listed in order of overall control effectiveness for the pollutant under review, with the most effective control alternative at the top.

Step 4 – Evaluate Most Effective Control Technologies and Document Results In the fourth step, the energy, environmental, and economic impacts are considered for each of the control options.

Step 5 – Select BACT In the fifth step, the most effective control option, based on the impacts quantified in Step 4, is proposed as BACT for the pollutant and emission unit under review.

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## A-5-14 

# III. Indurating Furnace Exhaust

Taconite pellets are oxidi zed and heat-hardened in the induratio n furnace. Discha rged pellets are cooled, screened, and transferred on conveyor belts to bins or stockpiles for storage. The stored pellets are loaded to ships or trains for shipment to the steel mill.

The NSM Furnace #5 is a straight grate furnace. It is fueled by natural gas, with fuel oil as a back-up fuel. Figure 1 is a generic diagram of a typical st raight grate induration furn ace. A description of the induration process follows Figure 1.

Figure 1 General Diagram of a Straight Grate Induration Furnace.



## Drawing from MPCA Taconite BART Report, September, 2003

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## A-5-15 The induration process involves pell et pre-heating, drying, hardeni ng, oxidation and cooling. In a straight grate furnace, pellets ar e carried through the furnace on a con tinuous grate. Pellets are dried, and then heated to the proper temperatures for hardening and oxidation. The pellet hardening and oxidation section of the induration furnace is design ed to operate at 2,400 oF. This temperature is required to meet taconite pellet product specificat ions. Exhaust gas from the pelletizing process has a high moisture content.

NSM will use natural gas as the primary fuel in Furnace #5. The fuel is primarily combusted in the pellet hardening and oxidation section of the furnace.

The pelletizing process occurs at 300% to 400% excess air. The excess air is used for combustion, pellet cooling, and as a source of oxygen for pellet oxidation.

Due to the high-energy demands of the induration pr ocess, induration furnaces have been designed to recover as much heat as possible. Pellet preheat zones are heated with the hot gases generated in the pellet hardening/oxidation section. Each of these sections is designed to maximize heat recovery within process constraints.

PSD pollutants emitted from Furn ace #5 operation include, sulfur dioxide, nitrogen oxides and. particulate matter.

• 

## Sulfur dioxide (SO 2 

## ) emissions originate from both fuel combustion (depending on the sulfur content in the fuel used) and the oxidation of sulfur present in the green balls. SO 2 

## emissions are released to the atmosphere in the induration furnace flue gas.

• 

## Nitrogen oxides (NO x 

## ) are formed by both the thermal oxidation of nitrogen in the combustion air and the reduction and subsequent oxidatio n of fuel bound nitrogen. Furnace #5 uses natural gas and fuel oil as fuel sources. The majority of NO x 

## emissions from a pellet plant are from thermal oxidation due to the high oxygen leve ls and high operating temperatures present
in the induration furnaces. A small amount of fuel bound NO x 

## is generated when fuel oil is
used to fire the furnace. NO x 

## emissions are released to th e atmosphere in the induration furnace flue gas.

• 

## Particulate matter emissions emanate from both fuel combustion, and the attrition of particles (dust) in the taconite pellets. Particulate emissions from the pellets are caused by the abrasion of pellets rubbing against each other and against the equipment as the pellets move through

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## A-5-16 the induration furnace. Particul ates are released to the atmosphere in the induration furnace flue gas.



# A. Sulfur Dioxide (SO 2 

# ) Emission Controls

1. Step 1 – Identify all Control Technologies Four control technologies were evaluated for SO 2 

## emissions control from the indurating furnace. Two of the control technologies are technically infeasible.

EPA’s RACT, BACT, LAER Clea ringhouse (RBLC) database was checked for recent BACT
determinations in the mineral and me tallic processing industr ies. The results of this evaluation are in BACT Attachment 1, Tables 1 and 2. While most of the BACT determinations were for sources that are not directly applicable to this project, th e control technologies evaluated in this study are consistent with those found in the RBLC. The prop osed BACT limits are consistent with the level of
emission control found in RBLC for similar indust ries, after taking proce ss limitations and NSM’s site specific conditions in to account. The control technologies evaluated for SO 2 

## emissions control
from Furnace #5 as follows.

Table III A-1 SO2 Emission Control Technologies Considered for BACT Analysis Technology Description

Wet Scrubber A wet scrubber is a vessel which is used to contact the flue gas with a liquid sorbent. The scrubber is designed so that the liquid sorbent flows down through the scrubber while the flue gases flow both upwards and downwards. Liquid sorbent can be applied by spraying, and / or a packed tower may be used. The sorbent chemically reacts with SO 2 

### and removes it. Spent sorbent is a liquid waste. Sludge may also be a byproduct of wet scrubbing.

Spray Dryer Absorption A dry or semi-dry sorbent material is sprayed into a vessel where it contacts the flue gas. The sorbent chemically reacts with SO 2 

### and removes it. A fabric filter is used to collect the sp ent sorbent. Solid waste is a byproduct of this control device.

Wet Electrostatic Precipitator In applications where a wet electrostatic precipitator (ESP) is used for particulate removal, it may also be used for SO 2 

### removal. A wet ESP uses a water spray to remove particulate matter from the ESP collection plates. For SO 2 

### removal, caustic is added to the water spray system, allowing the spray system to function as an SO 2 

### absorber.

Dry Sorbent Injection Dry sorbent (pulverized lime or limestone) is directly injected into the duct upstream of the fabric filter. SO 2 

### reacts with sorbent and the solid particles are collected with a fabric filter. This process was developed as a lower cost option to conventional SDA technology

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## A-5-17 

# Wet Scrubbing / Flue-Gas Desulfurization

Wet scrubbing processes used to control SO 2 

## are generally termed flue-gas desulfurization (FGD) processes. FGD utilizes gas absorption technology, th e selective transfer of materials from a gas to a contacting liquid, to remove SO 2 

## in the waste gas. Lime, crushed limestone, or caustic may be used as scrubbing agents.

Limestone scrubbing introduces limes tone slurry with the flue gas in a spray tower. The sulfur dioxide is absorbed, neutralized, and partially oxidized to calcium sulfite and calcium sulfate. The overall reactions are shown in the following equations:



# Ca(OH) 2 

# +SO 2 

# → CaSO 3 

# • 1/2 H 2 

# O + 1/2 H 2 

# O Ca(OH) 2 

# + SO 2 

# + 1/2 O 2 

# + H 2 

# O → CaSO 4 

# •2 H 2 

# O

When lime (or limestone) is used as the reagent for SO 2 

## removal, additional equipment is needed for preparing the lime/limestone slurry and collecting and concentrating the resultant sludge. Calcium sulfite sludge is watery; it is typi cally stabilized with fly ash for land filling. The calcium sulfate sludge is stable and easy to dewater. To produce calc ium sulfate, an air inject ion blower is needed to supply the oxygen for the second reaction to occur.

The normal SO 2 

## control efficiency range for SO 2 

## scrubbers is 80% to 90% for low efficiency scrubbers and 90% to 95% for high efficiency scrubbers


# Spray Dryer Absorption

Spray dryer absorption (SDA) systems spray lime slurry into an absorption tower where SO 2 

## is absorbed by the slurry, forming CaSO 3 

## /CaSO 4 

## per the reactions described in wet scrubbing. The liquid-to-gas ratio is such that the water evaporates before the droplets reach the bottom of the tower. The dry solids are carried out with the gas and collected with a fabric filter. Further SO 2 

## removal occurs as the flue gas flows through the lime powder adhered filter cake on the bags.

The normal SO 2 

## control efficiency range for dry SO 2 

## scrubbers is 70% to 90%.

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## A-5-18 

# Wet Walled Electrostatic Precipitator (WWESP)

In applications where a wet electrostatic precipitator (ESP) is used for particulate removal, it may
also be used for SO2 removal. A wet ESP uses a water spray to remove particulate matter from the ESP collection plates. For SO 2 

## removal, caustic is added to the water spray system, allowing the spray system to function as an SO 2 

## absorber. The SO 2 

## removal reactions are as follows:



# Na + 

# + OH- + SO 2 

# + → Na 2 

# SO 3 

# 2Na + 

# + 2OH- + SO 2 

# + → Na 2 

# SO 3 

# + H 2 

# O

A caustic scrubbing solution produces a liquid waste.

The SO 2 

## control efficiency for a WWESP is approximately 80%.


# Dry Sorbent Injection

Dry sorbent injection is a post-combustion SO 2 

## control technology in which pulverized lime or limestone is directly injected into the duct upstream of the fabric filter. Dry sorption of SO 2 

## onto the lime or limestone particle occurs and the solid particles are collected with a fabric filter. This process was developed as a lower cost option to co nventional SDA technology. Since the sorbent is injected directly into the exha ust gas stream, the mixing offered by the dry scrubber tower is not
realized.

The maximum efficiency for this SO 2 

## control technology is estimated to be 50 percent.

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## A-5-19 

# 2. Step 2 – Eliminate Tec hnically Infeasible Options Two of the proposed technologies discussed in Step 1 are infeasible. The fe asibility analysis is
summarized as follows:

Table III A-2
SO2 Emission Control Technology Feasibility Analysis



## Technology Description Feasible? Yes or No Typical % Efficiency

Wet Scrubber A wet scrubber is a vessel which is used to contact the flue gas with a liquid sorbent. Liquid sorbent can be applied by spraying, and / or a packed tower may be used. The sorbent chemically reacts with SO 2 

## and removes it. Yes 70% - 95%

Spray Dryer Absorption A dry or semi-dry sorbent material is sprayed into a vessel where it contacts the flue gas. The sorbent chemically reacts with SO 2 

## and removes it. A fabric filter is used to collect the spent sorbent. No 70% - 90%

Wet Electrostatic Precipitator In applications where a wet electrostatic precipitator (ESP) is used for particulate removal, it may also be used for SO 2 

## removal. A wet ESP uses a water spray to remove particulate matter from the ESP collection plates. For SO 2 

## removal, caustic is added to the water spray system, allowing the spray system to function as an SO 2 

## absorber. Yes 80%



## Dry Sorbent Injection Dry sorbent (pulverized lime or limestone) is directly injected into the duct upstream of the fabric filter. SO 2 

## reacts with sorbent and the solid particles are collected with a fabric filter. This process was developed as a lower cost option to conventional SDA technology No 50%



# Wet Scrubbing / Flue-Gas Desulfurization

A wet scrubber is technically fe asible in this application.

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## A-5-20 

# Spray Dryer Absorption

A spray dryer absorption system is technically infeasible in this application.

Spray dryer absorption requires use of a filter baghouse to collect the spent sorbent. Use of a fabric filter is technically infeasible for collection of sp ent spray dryer sorbent in this application due to potential filter blinding associated with water c ondensation. Exhaust gases from the pelletizing process have a high moisture content. Currently, no taconite plants in th e United States use fabric filters for particul ate control on induration furnaces. The process designs for induration furnaces include provisions for energy recovery by using hot process gas to pre-heat and dry the incoming green taconite pellets. To maxi mize energy recovery, the furnaces were designed so that gases leaving the induration furnac e are typically in the 100 °F to 150 F range. This leaves the stack gases at or very near their dew points. Any free water present in the induration furnace waste gas or water
condensation on the filter media woul d create a wet and stic ky filter cake that would not be easily
removed from the filters.



# Wet Electrostatic Precipitator

A Wet ESP is feasible in this application. The NSM ta conite plants currently employ this technology.


# Dry Sorbent Injection

Dry Sorbent Injection (SDI) is infeasible in this application.

Since this technology is similar to SDA, it is also technically infeasible.



# 3. Step 3 – Rank Remain ing Control Technologies by Control Effectiveness The SO2 emission control rankings are summarized as follows:

Table III A-3 SO2 Control Technology Ranking

Rank Technology Typical % Efficiency Estimated Furnace #5 % Control Efficiency
1 Wet Scrubber 70% - 95% 80% Vendor Information

2 Wet Electrostatic Precipitator 80% 80% NSM Wet ESP

performance

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## A-5-21 

# Wet Scrubbing / Flue-Gas Desulfurization

The normal control efficiency range for SO 2 

## scrubbers is 70% to 95%. Given the relatively low SO 2 

## concentrations in the Furnace #5 exhaust gas, a cont rol efficiency of 80% is expected. The scrubber
vendor verified that 80% control was feasib le for this application. Since the SO 2 

## emission rate is relatively low, a higher control efficiency will not make a significant change in the pollution control cost ($/ton removed).



# Wet Walled Electrostatic Precipitator

The SO 2 

## control efficiency for a WWESP is approximately 80%. This efficiency is based on NSM’s operating experience with wet ESP technology.



# 4. Step 4 – Evaluate Most Effecti ve Control Technolog ies and Document Results

Emissions control effectiveness was evaluated for the top two c ontrol technologies, wet scrubbing and wet ESP’s. The control equipment effectiveness analysis can be summarized as follows:

Table III A-4
SO 2 

### Control Technology Emission Control Cost Analysis



## Rank Technology Control Cost $/ton 1 Wet Scrubber $9,073/ton 2 Wet ESP $13,385/ton



## A summary of the control cost analysis is located in BACT Attachment 2, Table 1. The control cost analyses for each control system are located in BACT Attachment 2 Tables 2 and 3. Please note that
both evaluations have not accounted for the additio nal expense of demolition and site specific installation costs associated with construction at an existing facility which will increase the $/ton
control cost.

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## A-5-22 A. Economic impacts

The control cost analysis suggests that in stallation of new control equipment for both technologies is economically infeasible at this ti me. Therefore the existing controls should be
considered BACT for SO 2 

## .

Wet scrubber and wet ESP control cost calculations were prepared using caustic as the base in the scrubbing liquor. Lime and lime stone are potential alternatives , but additional equipment will be needed for slurry preparation and for solids separation from the sludge generated in the
scrubber. Construction materials must also be suitable for caustic, lime, or limestone . This could add to the cost of wet scrubbing of SO 2 

## .
Both wet scrubbing and the Wet ESP’s also have the option of being used to control PM.

B. Environmental impacts

The primary environmental impact of wet sc rubbers and wet ESP’s is the generation of wastewater and sludge. Waste from the scrubber will increase the sulfate and solids loading in the facility’s wastewater. This places additional burdens on a facility’s wa stewater treatment and solid waste management capabilities.

Scrubber and Wet ESP exhaust gases are saturate d with water, thus cr eating a visible plume. Plume visibility may be a local/community concern. Once the exhaust mixes with sufficient air, the moisture droplets evaporate, a nd the plume is no longer visible.

Given that NSM currently uses wet ESP’s these impacts are not significant and restarting Furnace 5 is not likely to cause an adverse environmental impact.

C. Energy impacts

A scrubber operates with a high pr essure drop, resulting in a sign ificant amount of electricity required to operate the blower and pump. In comparison, the Wet ESP has a lower pressure drop requirement than the scrubber and the cost to operate the electrical field is not as significant as
the electrical costs for the wet scrubber.

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## A-5-23 

# 5. Step 5 – Select BACT
A wet ESP is selected as BACT for control of SO 2 

# from Furnace #5. A wet ESP was selected because it is one of top control technologies for SO 2 

# control in this applic ation, and Furnace #5 is currently equipped with a wet E SP. Performance test data for similar equipment at NSM show
that wet ESP’s control SO2 concentrations to very low levels (1 ppm to 3 ppm), and a wet scrubber will not perform any better in this app lication. In addition, the control cost analysis
shows that installation of new control e quipment is economically infeasible (SO 2 

# control costs are close to or above $10,000/ton) . Therefore, NSM proposes cont inued use of the existing wet ESP control system as BACT.

The proposed BACT limits are 12.7 lb/hr SO 2 

# on a 24 hour average basis and a performance standard of 8 ppm SO 2 

# . Test for SO 2 

# using EPA Method 6 or 6C. The proposed emission limits represent SO2 concentrations of 8 ppm in the cont rol equipment exhaust. This concentration is at the limit of concentrations which any type of SO 2 

# control technology can attain.

The proposed BACT limit is based on the highest level of emission control that can be achieved with existing equipment. Performance test data from NSM induration furnaces 6, 11 and 12
show emission rates of 0.6 lb/h r to 2.4 lb/hr per stack while combusting natural gas. Since Furnaces 11 and 12 are of a different design th an Furnace 5, the mass emission rates are not equivalent. SO 2 

# stack concentrations were in the 1 ppm to 3 ppm range. The proposed BACT
limits are based on the tested emi ssion rate plus 7.97 lb/hr of SO 2 

# from fuel oil firing.

The historical performance test data used as the basis for the proposed BACT are summarized in Attachment 3, Table 1.



# B. Nitrogen Oxide (NO x 

# ) Emission Controls

1. Step 1 – Identify all Control Technologies

Seven different cont rol technologies were evaluated for NO x 

## emissions from Furnace #5. All of these technologies have been dete rmined technically in feasible for Furnace #5, because operating conditions are not consistent with the process requirements of the control equipment.

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## A-5-24 EPA’s RACT, BACT, LAER Clea ringhouse (RBLC) database was checked for recent BACT
determinations in the mineral and me tallic processing industr ies. The results of this evaluation are in BACT Attachment 1, Tables 1 and 2. While most of the BACT determinations were for sources that are not directly applicable to this project, th e control technologies evaluated in this study are consistent with those found in the RBLC. The prop osed BACT limits are consistent with the level of
emission control found in RBLC for similar indust ries, after taking proce ss limitations and NSM’s site specific conditions in to account. The control technologies evaluated for NO x 

## emissions control
from Furnace #5 are as follows.

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## A-5-25 Table III B-1
NO x 

### Emission Control Technologies Considered for BACT Analysis Technology Description

Selective Catalytic Reduction Selective catalytic reduction (SCR) is a post-combustion NOx control technology in which ammonia (NH3) is injected into the flue gas stream in the presence of a catalyst. NOx is removed through chemical reaction. SCR requires a temperature range of 500 ° F – 800 ° F.

Selective Non-Catalytic Reduction In the selective non-catalytic reduction (SNCR) process, urea or ammonia-based chemicals are injected into the flue gas stream to convert NO to N2 and water. Without the participation of a catalyst, the reaction requires a high temper ature range to obtain activation energy. The optimum operating temperature for SNCR is 1,600 ° F to 2,000 ° F.

Non-Selective Catalytic Reduction Non-selective catalytic reduction (NSCR) system is a post combustion add-on exhaust gas treatment system. NOx and CO react in the presence of NSCR catalyst to form nitrogen (N2) and carbon dioxide (CO2). It is typically employed in clean gas services such as natural gas fired turbines.

External Flue Gas Recirculation External flue gas recirculation (EFGR) uses flue gas as an inert material to reduce flame temperatures. In an external flue gas recirculation system, flue gas is collected from the heater or stack and returned to the burner via a duct and blower. The flue gas is mixed with the combustion air and this mixture is introduced into the burner. The lower oxygen level in the combustion zone reduces flame temperatures; which in turn reduces NOx .

Low-NOx Burners and Induced Flue Gas Recirculation Burners Low-NOx burner (LNB) technology utilizes advanced burner design to reduce NOx formation through the restriction of oxygen, flame temperature, and/or residence time. Staged fuel combustion is typically the most effective method.
Induced flue gas recirculation burners, also called ultra low-NOx burners, combine the benefits of flue gas recirculation and low-NOx burner control technologies. The burner is designed to draw flue gas to dilute the fuel in order to reduce the flame temperature. These burners also utilize staged fuel combustion to further reduce flame temperature.

Low Excess Air (LEA) Low Excess is a combustion control method which is used to reduce the amount of oxygen in the combustion zone of a furnace or boiler. This limits the amount of oxygen available for NOx formation.

Other Combustion Controls These combustion control methods are typically employed on existing sources. They inexpe nsive, but have limited control efficiencies. Combusti on controls include Overfire Air (OFA), Burners Out of Service (BOOS) and Load Reduction and Reduced Combustion Air Temperature.

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## A-5-26 

# Selective Catalytic Reduction

Selective catalytic reduction (SCR) is a post-com bustion NOx control technology in which ammonia (NH 3 

## ) or urea is injected into the flue gas stream in the presence of a catalyst. NOx is removed through the following chemical reaction:



# 1) (NH 2 

# )2CO + H 2 

# O 2 NH 3 

# + CO 2 

# 2) 4 NO + 4 NH 3 

# + O 2 

# → 4 N 2 

# + 6 H 2 

# O 3) 2 NO 2 

# + 4 NH 3 

# + O 2 

# → 3 N 2 

# + 6 H 2 

# O

A catalyst bed containing metals in the platinum family is used to lower the activation energy required for NOx decomposition. SCR requires a temperat ure range of 500 ° F – 800 ° F for a normal catalyst. The optimum operat ing temperature range is 700 ° F to 750 ° F. A high temperature zeolite catalyst is also available; it can operate in the 600 ° F – 1000 ° F temperature range. However, these catalysts are very expensive.

The normal NOx control efficiency range for SCR is 70% to 90%.


# Selective Non-Catalytic Reduction

In the selective non-catalytic re duction (SNCR) process, urea or ammonia-based chemicals are injected into the flue gas stream to convert NO to N 2 

## and water. Without the participation of a catalyst, the reaction requires a high temperature range to obtain activati on energy. The relevant
reactions are as follows:



# NO + NH 3 

# + 1/4 O 2 

# → N 2 

# + 3/2 H 2 

# O NH 3 

# + 1/4 O 2 

# → NO + 3/2 H 2 

# O

The optimum operating temperature for SNCR is 1,600 ° F to 2,000 ° F. Under these conditions reaction (1) dominates, and a significant reduc tion in NOx occurs. At temperatures above 2,000 ° F reaction (2) begins to dominate and NOx control efficiency decreases rapidly.

The normal NOx control efficiency range for SNCR is 50% to 70%.


# Non-Selective Catalytic Reduction

A non-selective catalytic reduction (NSCR) syst em is a post combustion add-on exhaust gas treatment system. It is of ten referred to as “three-way convers ion” catalyst since it reduces NOx,

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## A-5-27 unburdened hydrocarbons (UBH), and CO simultaneously. NOx and CO react in the presence of NSCR catalyst to form nitrogen (N 2 

## ) and carbon dioxide (CO 2 

## ). In order to operate properly, the combustion process must be near-stoichiometric conditions. SCONOxTM is a commercially available example of an NSCR system. SCONOxTM employs a single catalyst that simultaneously oxidizes CO
to CO 2 

## and NO to NO 2 

## . NO 2 

## formed by the oxidation of NO is subsequently absorbed onto the catalyst surface through the use of a potassium carbonate absorber coating. CO 2 

## produced by these reactions is released to the atmosphere. The potassium carbonate catalyst coating reacts with NO 2 

## to form potassium nitrites and nitr ates. Prior to saturation of the potassium carbonate coating, the catalyst must be regenerated.

SCONOxTM is typically employed in clean gas services such as natural gas fired turbines. The SCONOxTM catalyst is very sensitive to contaminants in the waste gas and would not be viable in induration waste gas service.

NOx control efficiency for NSCR is approxima tely 90% in clean combustion applications.



# External Flue Gas Recirculation

External flue gas recirculation (EFGR) uses flue gas as an inert material to reduce flame temperatures. In an external flue gas recirculation system, flue gas is collected from the heater or
stack and returned to the burner via a duct and blow er. The flue gas is mixed with the combustion air
and this mixture is introduced into the burner. Th e addition of flue gas reduces the oxygen content of the “combustion air” (air + flue gas) in the burner. The lower oxygen level in the combustion zone reduces flame temperatures; which in turn reduces NOx emissions.

The normal NOx control efficiency range for EFGR is 30% to 50%.



# Low-NOx Burners

Low-NOx burner (LNB) technology utilizes a dvanced burner design to reduce NOx formation through the restriction of oxygen, flame temperat ure, and/or residence time. LNB is a staged combustion process that is designed to split fuel combustion into two zone s, primary combustion and secondary combustion. This analysis utilizes the staged fuel design in the cost analysis because lower emission rates can be achieved with staged fu el burner than with a staged air burner.

In the primary combustion zone of a staged fuel burner, NOx formation is limited by a rich (high fuel) condition. Oxygen levels and fl ame temperatures are low; this results in less NOx formation. In

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## A-5-28 the secondary combustion zone, incomplete combustion products formed in the primary zone act as reducing agents. In a reducing atmosphere, nitrog en compounds are preferentially converted to molecular nitrogen (N 2 

## ) over nitric oxide (NO).

The estimated NOx control efficiency for Low NOx bur ners in high temperature applications is 25%.



# Induced Flue Gas R ecirculation Burners

Induced flue gas recircul ation burners, also called ultra low-NOx burners, combine the benefits of flue gas recirculation and low-NOx burner control technologi es. The burner is designed to draw flue gas to dilute the fuel in order to reduce the flame temperature. These burners also utilize staged fuel combustion to further reduce flame temperature.

The estimated NOx control efficiency for IFGR bur ners in high temperature applications is 50%.



# Low Excess Air (LEA)

Due to the oxidizing atmosphere of indurating furnaces, the low excess air option cannot be employed for Furnace 5.



# Combustion Controls

Overfire Air (OFA) - The OFA option is primarily geared to fuel-bound NOx reductions, which are no the major source of NOx in this process. Fuel is combusted in an oxygen deficient atmosphere to
inhibit NOx formation. Overfire ai r is added after the burner to complete the fuel combust process.

Burners Out of Service (BOOS) and Load Reduction -The BOOS and load reduction options incorporate a reduction in the furnace load, thereby reducing the formation of NOx emissions.

Reduced Combustion Air Temperature – Reducing combustion air te mperature inhibits thermal NOx production. This option is limited to proc esses with combustion air pre-heaters that allow reduced process temperatures.

Low Temperature Oxidation - Low temperature oxidation (LTO) is an emerging NO x 

## control technology. There are very few applications of this technology, and there are currently no applications of this technology at a taconite plan ts in the US. LTO requires a supply of pure oxygen to operate. In most cases this would require construction of an air refrigeration plant to produce oxygen for the LTO process. So, in addition to limited application of LTO technology; LTO is

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## A-5-29 generally economically infeasible. Therefore, it wa s not given additional consideration as a viable technology for the Furnace 5 Restart Project

LTO utilizes ozone as a medium to oxidize variou s pollutants including NOx. In the system, NOx in the flue gas is oxidized by means of ozone to form nitrogen trioxide or nitrogen pentoxide. These compounds react with water vapor to form nitric acid. The nitric acid vapor is then absorbed as
dilute nitric acid and is neutralized by the sodium hydroxide in the scrubbing solution to form sodium nitrate. The sodium nitrate is separated and discharged to the wastewater system. LTO is typically employed at locations where the nitrat e byproduct and be used or recycled.

BOC Gases’ Lo-TOx is an example of a commercially available version of an LTO system that was evaluated by Barr in 2001 for a potential new taco nite plant. Lo-TOx technology uses ozone to
oxidize NO to NO 2 

## and NO 2 

## to N 2 

## O 5 

## in reactor. The N 2 

## O 5 

## is converted to HNO 3 

## in a scrubber, and is
removed with caustic. The LTO reactions are as follows:



# O 3 

# + NO → O 2 

# + NO 2 

# NO 2 

# + O3 → 2 N 2 

# O 5 

# N 2 

# O 5 

# + H 2 

# O → 2 HNO 3 

# NaOH + HNO 3 

# → NaNO 3 

# + H2O

The normal NOx control efficiency range for Lo-TOx is 80% to 95%.

Lo-TOx would require a minimum of two process columns, a reactor for NOx oxidation, and a
scrubber for nitrate removal. In a ddition, an ozone generator with a supply of liquefied oxygen would be required. As a result of equi pment requirements, this is a ra ther expensive control technology. Nitrates are produced as a byproduct of this control te chnology. At a taconite plant, there is no place to utilize these nitrates, so this wastewater would be routed to the tailings basin. Nitrates in the tailings basin would pose a thre at to ground and surface water.

Table 13, BACT Attachment 2 c ontains cost estimates for applic ation of Lo-TOx technology to Furnace #5. The estimated control cost is $14,500/ ton. The estimate is based on a paper presented by BOC gases “LoTOx Process Flexibility and Multi –Pollutant Control Capability”. Supplemental information from a BOC bid for a 2001 BACT analys is conducted by Barr Engineering Company for a proposed new taconite processing facility.

During the 2001 BACT analysis, Barr contacted Tr i-Mer Corporation, the manufacturer of the TriNOx® LTO system, to determine the applicability of LTO at a potential new taconite plant in 2001.

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## A-5-30 The vendor stated that Tri-NOx® LTO system is not commercially availabl e for use on a taconite pellet induration furnace. Tri-Mer stated that th e magnitude of the air streams from an induration furnace is too large for the chemistry used in the Tri-NOx® system to reduce NOx effectively.

LTO is not considered for further review in this BACT analysis.



# 2. Step 2 – Eliminate Tec hnically Infeasible Options

Seven different cont rol technologies were evaluated for NO x 

## emissions from the Furnace #5. All of these have been determined technically infeasible for Furnace #5 because its operating conditions are not consistent with the process requirements of the control equipment. The control technology feasibility analysis is summarized as follows.

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## A-5-31 Table III B-2

NO x 

### Emission Control Technology Feasibility Analysis

Technology Description Feasible? Yes or No Typical % Efficiency

Selective Catalytic Reduction Selective catalytic redu ction (SCR) is a postcombustion NOx control technology in which ammonia (NH3) is injected into the flue gas stream in the presence of a catalyst. SCR requires a temperature range of 500 ° F – 800 ° F. No 70% - 90%.

Selective Non-Catalytic Reduction The Selective non-catalytic reduction (SNCR) process injects urea or ammonia-based chemicals into the flue gas stream to convert NO to N2 and water.. The optimum operating temperature for SNCR is 1,600 ° F to 2,000 ° F. No 50% - 70%

Non-Selective Catalytic Reduction Non-selective catalytic reduction (NSCR) system is a post combustion add-on exhaust gas treatment system. NOx and CO react in the presence of NSCR catalyst to form nitrogen (N2) and carbon dioxide (CO2). It is typically employed in clean gas services such as natural gas fired turbines. No 90%

External Flue Gas Recirculation External flue gas recirculation (EFGR) uses flue gas as an inert material to reduce flame temperatures. The flue gas is mixed with the combustion. The lower oxygen level in the combustion zone reduces flame temperatures; which in turn reduces NO x 

### . No 30% - 50%

Low-NOx Burners and Induced Flue Gas Recirculation Burners Low-NOx burner (LNB) technology utilizes advanced burner design to reduce NOx formation through the restriction of oxygen, flame temperature, and/or residence time.

Induced flue gas recirculation burners are designed to draw flue gas into the burner to dilute the fuel. This reduces flame temperature and NO x 

### formation. No 25% - 50%

Low Excess Air (LEA) Low Excess is a combustion control method which is used to reduce the amount of oxygen in the combustion zone of a furnace or boiler. This limits the amount of oxygen available for NOx formation. No NA

Other Combustion Controls These combustion control methods are typically employed on existing sources. They inexpensive, but have limited control efficiencies. Combustion controls include Overfire Air (OFA), Burners Out of Service (BOOS) and Load Reduction and Reduced Combustion Air Temperature. No NA

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## A-5-32 

# Selective Catalytic Reduction

Selective catalytic reduction (SCR) is not te chnically feasible in this application.

The first issue in the application of SCR is achieving the appropriate temperatures for NO x 

## reduction reactions to occur. SCR requires a temperature range of 500 ° F – 800 ° F. There are no access points for installation of an SCR reactor in Northshore Mining Co.’s Furnace #5 where these temperatures exist. Process temperatures dow nstream of the existing wet ESP or a wet scrubber are too cold for
SCR.

The last concern in application of SCR is catalyst poisoning. Catalyst poisons include arsenic, lead alkali earth metals, SO 2 

## and halogens. Particulate matter ca n block catalyst por es, and water vapor also adversely affects NOx conversion. All of these materials are present in the Furnace #5 exhaust gas SCR is technically infeasible.



# Installation of SCR in conjunction with a reheat system after a wet emission control systems is generally not considered practical . This is due to high energy de mands for reheating exhaust gas up to SCR catalyst operating temperatures. Rehe at costs also make this option economically
infeasible. The estimated NO x 

# control cost of SCR with reheat for Furnace 5 is $25,982 per ton
NO x 

# removed.

Selective Non-Catalytic Reduction

SNCR is not technically feasible in this application.

The main issue in the application of SNCR is achieving the appropriate temperatures for NO x 

## reduction reactions to occur. The oper ating temperature range for SNCR is 1,600 ° F to 2,000 ° F. Temperatures at the outlet of the furnace are 2,400o F; well above SNCR temperature range. There are no access points for installation of an SCR reactor within NSM’s Furnace #5 pellet preheat train where SNCR operating temperatures occur. The furnace exhaust gas temperature as it leaves the furnace 140oF; so, the minimum design temperature of 1,700 ° F for SNCR cannot be met.



# Non-Selective Catalytic Reduction

Non-Selective Catalytic Reduction is not feasible in this application.

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## A-5-33 Non-selective catalytic re duction (NSCR) catalysts are very sensitive to catalyst poisoning. For that reason, they are only used in clean combustion applications such as natural gas fired turbines. NSCR is not feasible in this application due the catalyst poisons present in the Furnace #5 exhaust gas.



# External Flue Gas Recirculation

External Flue Gas Recirculation is not feasible in th is application.

Northshore Mining Co.’s Indurating Furn aces operate at temper ature of 2,400° F. External Flue Gas Recirculation (EFGR) uses flue gas as an inert material to reduce flame temperatures in order to
reduce NO x 

## emissions. EFGR is not feasible in this application because the reduced flame temperatures associ ated with EFGR would adversely affe ct taconite pellet product quality.



# Low-NOx Burners and Induced Fl ue Gas Recirculation Burners

Low-NOx Burners and Induced Flue Gas Recirculation Burners are not feasible in this application.

Northshore Mining Co.’s Indurating Furnaces oper ate at temperature of 2,400° F. Low-NO x 

## burner (LNB) technology and induced flue gas recirculati on burners both reduce flame temperatures in order
to reduce NO x 

## emissions. Low NO x 

## burners are not feasible in this application because the reduced flame temperatures would adversely af fect taconite pellet product quality.



# Low Excess Air (LEA)

Low Excess Air combustion controls are infeasible in this application.

Indurating Furnaces must operate at high levels of excess air. Therefore LEA controls cannot be used because they are not cons istent with the requirements of the induration process.



# Combustion Controls

The following combustion controls are not te chnically feasible in this application

.
Overfire Air (OFA) – To control NOx emissions using OF A, fuel is combusted in an oxygen deficient atmosphere to inhibit NOx formation. Overfire air is added after the burner to complete the fuel combust process. In the induration process, high oxygen levels must be maintained to ensure proper oxidation of the taconite iron ore. Use of OFA would adversely affect product quality

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## A-5-34 because the use of OFA would not match the need for high oxygen content throughout the furnace to meet taconite pellet product quality specifications.

Burners Out of Service (BOOS) and Load Reduction -The BOOS and load reduction options incorporate a reduction in the furnace load, thereby reducing the formation of NOx emissions. This technique is only applicable fo r existing sources operating well below capacity. The Furnace #5 design does not contain sufficient exce ss capacity to use this method.

Reduced Combustion Air Temperature – Reducing combustion air te mperature inhibits thermal
NO x 

## production by reducing flame temp eratures. This is not possi ble in an indurating furnace because it must operate at temperatures near 2,400 ° F. Reducing the level of air preheat would drop the combustion temperatures needed to maintain product quality due to incomplete oxidation. Therefore, reducing combustion air temp erature is not tec hnically feasible.



# 3. Step 3 – Rank Remain ing Control Technologies by Control Effectiveness The emission control effectiveness ranking of NO x 

## control technologies are as follows:

Table III B-3
NO x 

### Control Technology Ranking



## Rank Technology Typical % Efficiency Furnace #5 Estimated % Control Efficiency

1 No controls NA NA



## As noted in step 2, all control te chnologies are technically infeasible.



# 4. Step 4 – Evaluate Most Effecti ve Control Technolog ies and Document Results At this time, there is no viable control technology in this application. The control effectiveness analysis is summarized as follows.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-35 Table III B-4
NO x 

### Control Technology Emission Control Cost Analysis



## Rank Technology Control Cost $/ton

1 No controls NA



## As noted in step 2, all control te chnologies are technically infeasible.

The control cost for use of SCR in conjunction with re-heating the furnace exhaust was examined to ensure that the BACT analysis is complete. This analysis shows that this combination is economically infeasible. In ad dition, this option uses a significant amount of energy.



# 5. Step 5 – Select BACT The technical feasibility analysis shows that installation of control equipment is technically infeasible. Therefore NSM proposes to set BACT limits based on actual emissions from a similar source at NSM’s Silver Bay facilit y. The proposed BACT limits are 45.7 lb/hr NO x 

# on a 24 hour average basis and a perf ormance standard of 40 ppm NO x 

# for Furnace 5. Test for NO x 

# using EPA Method 7 or 7E.

The proposed BACT limit is based on actual emissions test data as measured in Furnace 6, an induration furnace of the same design as Furnace 5. Performance test data from NSM induration
Furnace 6 show NO x 

# emissions of 13.23 lb/hr NO x 

# on a per stack basis, and NO x 

# concentrations of 32 ppm and 36 ppm. Since te st data are limited, the propose d BACT limits are based on the
tested emission rate of 39.7 lb/hr of NO x 

# plus a 15% safety factor and the maximum NO x 

# concentration plus a 15% safety factor.

The historical performance test data used as the basis for the proposed BACT are summarized in Attachment 3, Table 1.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-36 

# C. Particulate Matter (PM / PM 10 

# ) Emission Controls
Five different control technologies were evaluated for particulate em issions from Furnace #5. One of these has been determined technically infeasible for Furnace #5 due to operating conditions which are not consistent with the process requirements of the control equipment.

As noted in the introduction to this section, pa rticulate matter from Furnace #5 comes from the taconite pellet induration process and from comb ustion byproducts. This combination of sources yields both filterable and c ondensable particulate matter.

EPA’s RACT, BACT, LAER Clea ringhouse (RBLC) database was checked for recent BACT
determinations in the mineral and me tallic processing industr ies. The results of this evaluation are in BACT Attachment 1, Tables 1 and 2. While most of the BACT determinations were for sources that are not directly applicable to this project, th e control technologies evaluated in this study are consistent with those found in the RBLC. The prop osed BACT limits are consistent with the level of
emission control found in RBLC for similar indust ries, after taking proce ss limitations and NSM’s site specific conditions into acc ount. The control technologies ev aluated for particulate matter
emissions control from Furnace #5 are as follows.



# 1. Step 1 – Identify all Control Technologies The following control technologies were evalua ted for PM emissions control from Furnace #5.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-37 Table III C-1
PM / PM 10 

### Emission Control Technologies Considered for BACT Analysis 

## Technology Description

Fabric Filter (Baghouse) A fabric filter, or baghouse, cons ists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags.

Wet Scrubber Wet scrubbers, remove particles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream.

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the fl ue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal



## .

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates.

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to c entrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone.



# Fabric Filter

A fabric filter, or baghouse, consists of a number of fabric bags placed in parallel inside of an
enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodical ly removed from the bags and collected in hoppers located beneath the bags. A number of methods are employed to fa cilitate the removal of pa rticulate from the bags, including shaking, reverse air flow, and pulse air flow.

The normal PM control efficiency range for a fabric filter is 98% to 99+% for filterable particulate matter. The control of condensable particulate matt er by fabric filters is limited by the operating

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-38 temperature of the filt er vs. the condensation temperatures of the compounds present in the condensable particulate matter.



# Wet Scrubbers

Wet scrubbers remove particles from waste gas by capturing the particles with liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream.

Scrubbers capture the particulates through the following mechanisms:

1. Impaction of the particle directly into a target droplet

2. Interception of the particle by a target dropl et as the particle comes near the droplet

3. Diffusion of the particle through the gas surrounding the target droplet until the particle is close enough to be captured

Scrubbers are generally classified according to the liquid contacting mechanism used. The most common scrubber designs are spray-chamber scrubbe rs, cyclone spray chambers, orifice and wetimpingement scrubbers, and ventur i and venturi jet scrubbers.

The normal PM control efficiency range for a scrubber is 90% to 95% for a low efficiency scrubber
and 95% to 99+% for a hi gh efficiency scrubber. A wet scrubber is relatively effective in controlling condensable particulate matter due to its low op erating temperature and the solubility of some
condensable materials in the scrubbing water.



# Electrostatic Precipitator

An electrostatic precipitator (ESP) is a potential control method for particulates in the Furnace 5 exhaust. An electrostatic precipitator applies electrical forces to separate suspended particles from the flue gas stream. The suspended particles are given an electrical charge by passing through a highvoltage DC corona region in whic h gaseous ions flow. The charged particles are attracted to and collected on oppositely charged collec tor plates. Particles on the coll ector plates are released by rapping and fall into hoppers for collection and removal.

The normal PM control efficiency range for an ESP is 98% to 99+%. The control of condensable particulate matter by ESP’s is limited by the operating temperature of the filter vs. the condensation temperatures of the comp ounds present in the conden sable particul ate matter.

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## A-5-39 

# Wet Electrostatic Precipitator

A Wet WESP operates on the same collection prin ciples as a dry ESP, and uses a water spray to remove particulate matter from the collection plates.

The normal PM control efficiency range for a WWESP is 98% to 99+%. A wet ESP may also be relatively effective in controlling condensable particulate matter due to its low operating temperature and the solubility of some condensable materials in the scrubbing water.


# Centrifugal (Cyclone) Separator

Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to centrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they ar e removed. The cleaned gas flows out of the top the cyclone.

There are two principal types of cyclones: tangential entry and axial entry. In tangential entry cyclones, the exhaust gas enters an opening located on the tangent at the top of the unit. In axial flow cyclones, the exhaust gases enter at the middle of one end of a cylinder and flows through vanes that cause the gas to spin. A peripheral stream removes collected particles, while the cleaned gas exits at the center of the opposite end of the cylinder.

A typical emission control rate for a multiclone is 50% to 80%. The control of condensable particulate matter by centrifugal se paration is limited by the operating temperature of the filter vs. the condensation temperatures of the compounds pres ent in the condensabl e particulate matter.

The control efficiency for cyclone separators is less for small particles than larger particles. Particle size distribution data is necessary to properly determine the control efficiency for a specific application.



# 2. Step 2 – Eliminate Tec hnically Infeasible Options Five different control technologies were evaluated for particulate em issions from Furnace #5. One of these has been determined technically infeasible for Furnace #5 due to Furnace #5 operating conditions which are not consistent with the proc ess requirements of the control equipment. The technical feasibility analysis is summarized as follows.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-40 Table III C-2

PM / PM 10 

### Emission Control Technology Feasibility Analysis
Technology Description Feasible? Yes or No Typical % Efficiency

Fabric Filter (Baghouse) A fabric filter, or baghouse, consists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags. No 98 - 99%

Wet Scrubber Wet scrubbers, remove pa rticles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream. Yes 95%-99+%

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the flue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal

. Yes 98% - 99+%

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates. Yes 98% - 99+%

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to centrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone. Yes 50% - 80%

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## A-5-41 

# Fabric Filter

A fabric filter (baghouse) is in feasible in this application.

Fabric filters are infeasible in this application due to filter blinding associated with water condensation. The exhaust gas from Furnace 5 has a high moisture content. Currently, no taconite plants in the United States u se fabric filters for pa rticulate control on i nduration furnaces. The process designs for induration furnaces include prov isions for energy recovery by using hot process gas to pre-heat and dry the incoming green taconite pellets. To maximize energy recovery, the furnaces were designed so that gases leaving the in duration furnace are typica lly in the 100 °F to 150 °F range. This leaves the stack gases at or ve ry near their dew points. Any free water present in the induration furnace waste gas or water condensation on the filter media would create a wet and sticky filter cake that would not be easily be removed from the filters.



# Wet Scrubbers

A wet scrubber is feasible in this application

Scrubbers are generally classified according to the liquid contacting mechanism used. The most common scrubber designs are spray-chamber scrubbe rs, cyclone spray chambers, orifice and wetimpingement scrubbers, and vent uri and venturi jet scrubbers.

The normal PM control efficiency range for a scrubber is 90% to 95% for a low efficiency scrubber and 95% to 99+% for a high efficiency scrubber.



# Electrostatic Precipitator

An electrostatic precipitator (ESP) is feasible in this application. The two taconite plants in the upper Michigan peninsula currently use ESP’s for particulate matter control.

An electrostatic precipitator applies electrical forces to separate particulate matter from flue gas. The charged particles are attr acted to and collected on oppositely charged collecto r plates. Particles on the collector plates are released by rapping and fall into hoppers for co llection and removal. For an ESP to work, the rapping system must be able to remove the material collected on the plates. Highly
conductive materials tend to retain their electrical charge and ar e difficult to remove from the

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-42 collection plates. Given the magnetic nature of some iron ores, this might pose a problem in some cases. Since ESP’s are currently used on taconite pl ants in Michigan, this study will assume that they are technically feasible.

The normal PM control efficiency range for an ESP is 98% to 99+%.



# Wet Electrostatic Precipitator

A wet electrostatic precipitator (ESP) is feasible in this application.

A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates. A water spray system is more effective than rapping systems in removing particulates. Therefore, a wet ESP may not have the problems that a standard ESP has in removing conductive material. Wet ESP’ s are currently used at this facility.

The normal PM control efficiency range for a WWESP is 98% to 99+%.


# Centrifugal (Cyclone) Separator

Centrifugal separators are feasib le in this application.

A typical emission control rate for a multiclone is 50% to 80%. The control efficiency for cyclone separators is less for small particles than larger particles.



# 3. Step 3 – Rank Remain ing Control Technologies by Control Effectiveness Emissions control effectiveness was evaluated for the top four control technologies. Due to the configuration of NSM’s induration furnaces, cont rol equipment inlet concentrations cannot be measured. So, actual control effici encies cannot be determined. Ther efore this analysis is based on typical control efficiencies found in literature data. The control equi pment effectiveness analysis can
be summarized as follows:

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-43 Table III C-3 PM / PM 10 

### Control Technology Ranking



## Rank Technology Typical % Efficiency

1 Wet Electrostatic Precipitator 98% - 99+%

2 Wet Scrubber 95% - 99+%

3 Dry Electrostatic Precipitator 98% - 99+%

4 Centrifugal Separation (e.g. Cyclones) 50% - 80%



# 4. Step 4 – Evaluate Most Effecti ve Control Technolog ies and Document Results

Emissions control effectiveness wa s evaluated for the top three control technologies, wet scrubbing and Wet ESP controls. Control cost estimates are based on meeting the MACT standard; the control device was sized to meet this standard. The control equipment effectiveness analysis can be
summarized as follows:

Table III C-4
PM / PM 10 

### Control Technology Emission Control Cost Analysis



## Rank Technology Control Cost $/ton 1 Wet ESP $4796 2 Dry ESP $2139 3 Wet Scrubber $3166



## A summary of the control cost analysis is located in BACT Attachment 2, Table 1. The control cost analyses for individual controls are located in BACT Attachment 2 Tables 6, 7 and 8.



# Wet Walled Electrostatic Precipitator

Performance of the wet ESP’s has been proven in practice at Nort hshore Mining. The particulate matter control cost for a new precipitator is $4,796 

## /ton. The control cost for the existing wet ESP

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-44 will be considerably less, since no capital expenses will be required and onl y operational and repair expenses will be incurred. In addition, NSM already has the infrastructure needed to accommodate operation of wet walled ESP’s. See Attachment B for the control cost analysis.

The non-air environmental impact of a wet ESP is the need to treat the wastewater discharged from the wet ESP. NSM currently has the wastewater treatment capacity to treat water from the #5
Furnace

A wet walled ESP has a moderate energy use rate. ESP’s have a low pressure drop, so, a modest electricity use rate is needed to operate the air blower. Operation of the electric grids does not add significantly to the overall electrical consumption.



# Dry Electrostatic Precipitator

A dry ESP has a moderate energy use rate. ESP’s have a low pressure drop, so, a modest electricity use rate is needed to operate the air blower. Oper ation of the electric grids in the EPS does not add significantly to the overall electrical consumption.

Performance of the ESP’s has been proven in practice at the Michigan taconite plants. The particulate matter control cost for a new precipitator is $2139 

## /ton. See Attachment B for the control cost analysis.

The non-air environmental impact of a ESP is the need to dispose of the solid waste collected in the
ESP.

A dry ESP has a moderate energy use rate. ESP’s have a low pressure drop, so, a modest electricity use rate is needed to operate the air blower. Operation of the electric grids does not add significantly to the overall electrical consumption.


# Wet Scrubbing

The particulate matter control cost for a wet scrubber is $3,166 

## /ton. See Attachment B for the control cost analysis.

The non-air environmental impact of a wet scrubber is the need to treat the wastewater discharged
from the scrubber.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-45 A wet scrubber has the highest energy use rate of th e control technologies stud ied. A high efficiency wet scrubber operates with a high pressure drop in or der to achieve high collec tion efficiency. This results in a higher electricity use rate than the other controls to operate the air blower.



# 5. Step 5 – Select BACT The proposed BACT limit for Furnace 5 is a performance limit of 0.01 gr PM/dscf on a 24 hour average basis. To establish compliance limits, NS M will test for filterable + organic condensable PM using EPA Method 5 and MN 7011.0725 using th ree (3) one-hour test runs. During the performance test, the facility will measure emission control equipment process parameters. Process parameter limits for operating the Furnace 5 emission control equipment will be set using the data collected during the performance test. The facility will demonstrate ongoing compliance based on the 24 hour average(s) of th e process parameters established during the performance test.

NSM is proposing a concentration of 0.01gr/dscf fo r Furnace 5 because it is essentially the limit of particulate emission control technology removal capability in this serv ice as demonstrated by
stack test data for similar sour ces at NSM. Furnace 5 is equi pped with a fixed speed fan for moving exhaust gas through the control equipment. Since Furnace 5 has a constant exhaust flow rate, setting a PM concentration limit for BACT also limits the maximum mass emission rate from this source. So, additional emission limits are not needed.

The proposed BACT limit is based on the highest level of emission control that can be achieved with Wet ESP’s in this applic ation. Performance test data from NSM induration furnaces 6, 11 and 12 show post control stack concentrations of 0.006 gr/dscf to 0.01 gr/dscf. while combusting natural gas. Stack testing included methods us ed to measure filterable PM and condensable organic PM. The tests also include operation of the wet EPS’s with and without electric power. The proposed BACT limits are based on the high est tested concentration of 0.01 gr/dscf.

The proposed BACT limit is consistent with r ecent RBLC determinations for sources in the mineral processing industries (metallic and non- metallic). The RBLC database shows BACT determinations for mineral processing sources in the 0.003 – 0.01 gr/dscf range. Since these determinations are for several different types of processing equipment, they are indicative of the level of emission control that is possible in the industries covered by this source category.

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## A-5-46 

# However, differences in conditions at individual sources affect the level of emission controls possible at a particular source

NSM cannot propose a control effici ency based BACT limit for this source. No test data are
available for the uncontrolled emission rate from th is source due to the duct configuration on the
inlet to the wet ESP’s. Theref ore, control efficiency cannot be determined for this source.

The “typical” control efficiencies listed in the pr evious section are literature values which are
consistent with control efficiencies found in a wi de variety of applicatio ns. They may represent conditions which include higher uncontrolled emission rates, and in some cased higher
controlled emission rates.

The historical performance test data used as the basis for the proposed BACT are summarized in Attachment 3, Table 1.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-47 

# IV. Fine Crushing

Fine crushing of the iron ore is a dry process. Both the crushing operations and material movement
within the crushing section produce dust. This BACT report will address emission controls for dust
emissions from ore crushing associated wi th the Furnace 5 Reactivation Project.



# A. Particulate Matter (PM / PM 10 

# ) Emission Controls

1. Step 1 – Identify all Control Technologies
EPA’s RACT, BACT, LAER Clea ringhouse (RBLC) database was checked for recent BACT
determinations in the mineral and me tallic processing industr ies. The results of this evaluation are in BACT Attachment 1, Tables 1 and 2. While most of the BACT determinations were for sources that are not directly applicable to this project, th e control technologies evaluated in this study are consistent with those found in the RBLC. The prop osed BACT limits are consistent with the level of
emission control found in RBLC for similar indust ries, after taking proce ss limitations and NSM’s site specific conditions into acc ount. The control technologies eval uated for PM emissions control from dryers are as follows.

The following control technologies were evaluate d for PM emissions control from fine crushing:

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-48 Table IV A-1
PM / PM 10 

### Emission Control Technologies Considered for BACT Analysis 

## Technology Description

Fabric Filter (Baghouse) A fabric filter, or baghouse, cons ists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags.

Wet Scrubber Wet scrubbers, remove particles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream.

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the fl ue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal



## .

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates.

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to c entrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone.



# 2. Step 2 – Eliminate Tec hnically Infeasible Options The particulate matter control te chnologies evaluated for the dryer exhaust streams are technically feasible. The technical feasibility is summarized as follows:

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-49 Table IV A-2

PM / PM 10 

### Emission Control Technology Feasibility Analysis



## Technology Description Feasible? Yes or No Typical % Efficiency

Fabric Filter (Baghouse) A fabric filter, or baghouse, consists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags. Yes 98% - 99+%

Wet Scrubber Wet scrubbers, remove particles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream. Yes 95%-99+% (high efficiency scrubbers)

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the flue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal



## . Yes 98% - 99+%

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates. Yes 98% - 99+%

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to centrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone. Yes 50% - 80%



## All listed control technologies ar e technically feasible for partic ulate emission control for fine grinding/crushing.

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## A-5-50 

# 3. Step 3 – Rank Remain ing Control Technologies by Control Effectiveness

Fabric filters are the most effective control technology in this application. The control technology rankings are as follows:

Table IV A-3
PM / PM 10 

### Control Technology Ranking



## Rank Technology Typical % Efficiency

1 Fabric Filter (Baghouse) 98% - 99+%

2 Wet Scrubber 95% - 99+%

3 Wet Electrostatic Precipitator 98% - 99+%

4 Centrifugal Separation (e.g. Cyclones) 50% - 80%



## The fine crushing exhaust streams contains only dry particulate matter. Under these conditions, fabric filters have the highest particulate matter control efficiency.



# 4. Step 4 – Evaluate Most Effecti ve Control Technolog ies and Document Results The fine crushing equipment associated with the Furnace 5 Restart project at Northshore Mining Co. currently has fabric filters (baghou ses) for control equipment. Sinc e fabric filters have the highest particulate matter control efficiency in this a pplication, additional anal ysis is not required.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-51 Table IV A-4
PM / PM 10 

### Control Technology Emission Control Cost Analysis



## Rank Technology Control Cost $/ton

1 Fabric Filter (Baghouse) Top Emission Controls Selected

2 Wet Scrubber NA

3 Wet Electrostatic Precipitator NA

4 Centrifugal Separation (e.g. Cyclones) NA



# 5. Step 5 – Select BACT Fabric filters are selected as BACT for control of particulate emissions from crushing. Fabric filters were selected because they are the top control technology in this application.

The only non-air environmental impa ct of this technology is the ge neration of solid waste. Wet scrubbing or Wet ESP’s would al so generate waste water.

The use fabric filters has minimal energy use impacts. The only particulate matter control device with significant energy impacts, in this circumstance, is wet scrubbing.



# The proposed BACT limit for fine crushing is a performance limit of 0.003 gr PM/dscf on a 24 hour average basis. To establish compliance limits, NSM will test for filterable + organic condensable PM using EPA Method 5 and MN 7011.0725 using three (3) one-hour test runs. During the performance test, the facility will measure emission control equipment process parameters. Process parameter limits for opera ting fine crushing emission control equipment will be set using the data collected during the performance test. The facility will demonstrate ongoing compliance based on the 24 hour average(s) of the process para meters established during the performance test.

Fine crushing is equipped with a fixed speed fans for moving exhaus t gas through the control equipment. Since fine crushing has a constant exhaust flow rate, setting a PM concentration

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-52 

# limit for BACT also limits the maximum mass emission rate from this source. So, additional
emission limits are not needed.

The proposed BACT limit is consistent with r ecent RBLC determinations for sources in the mineral processing industries (metallic and non- metallic). The RBLC database shows BACT determinations for mineral processing sources in the 0.003 – 0.01 gr/dscf range. Since these determinations are for several different types of processing equipment, they are indicative of the level of emission control that is possible in th e industries covered by th is source category. However, differences in conditions at individual sources affect the level of emission controls possible at a particular source.

The proposed BACT limits are more stringent than the new source MACT limit (40 CFR 63 Subpart RRRRR) of 0.005 gr/dscf filterable particul ate for ore handling e quipment at taconite facilities. The new source MACT standard repr esents the highest level of emission controls which can be expected for these sources; not the av erage of the top 12% of existing sources. The
evaluation criteria for new source MACT is similar to the criteria for BACT determinations. The taconite MACT standard was promulgated Oc tober 30, 2003, so the analysis is current;
consistent with the re quirements of BACT.

The proposed BACT limit is based on the highest level of emission control that can be achieved
with fabric filters in this application. The proposed BACT limits are based on a particulate matter concentration of 0.003 gr/dsc f after controls. Performance test data from NSM fine crushing sources equipped with fabric filters show particulate concentrations of 0.0010 gr/dscf to 0.0031 gr/dscf.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-53 

# V. Concentrator Silos

The Concentrator Silos receive the upgraded cr ude ore the dry cobbing process and stores the upgraded ore for direct tran sfer to the rod mills, which are a we t process. Crushed ore entering the concentration process is dry. Particulate matter is emitted as the dry ore is transferred into the process. The ore transfer point will be equipped with a fabric filter to control particulate emissions. In the remaining balance of the concentration processing steps, the ore is wet, and there are no particulate matter emissions from these operations.

Ore concentration equipment associated with the Furnace 5 Restart project is currently equipped with multiclones. NSM proposes to install baghouses for improved PM emissions control on these sources as part of the project



# A. Particulate Matter (PM / PM 10 

# ) Emission Controls

1. Step 1 – Identify all Control Technologies
EPA’s RACT, BACT, LAER Clea ringhouse (RBLC) database was checked for recent BACT
determinations in the mineral and me tallic processing industr ies. The results of this evaluation are in BACT Attachment 1, Tables 1 and 2. While most of the BACT determinations were for sources that are not directly applicable to this project, th e control technologies evaluated in this study are consistent with those found in the RBLC. The prop osed BACT limits are consistent with the level of
emission control found in RBLC for similar indust ries, after taking proce ss limitations and NSM’s site specific conditio ns into account.

The following control technologies were evaluated for PM emissions control from ore concentration

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-54 Table V A-1
PM / PM 10 

### Emission Control Technologies Considered for BACT Analysis 

## Technology Description

Fabric Filter (Baghouse) A fabric filter, or baghouse, cons ists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags.

Wet Scrubber Wet scrubbers, remove particles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream.

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the fl ue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal



## .

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates.

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to c entrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone.



# 2. Step 2 – Eliminate Tec hnically Infeasible Options All of the particulate matter cont rol technologies examined for concen tration are technically feasible. The technical feasibility is summarized as follows.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-55 Table V A-2

PM / PM 10 

### Emission Control Technology Feasibility Analysis



## Technology Description Feasible? Yes or No Typical % Efficiency

Fabric Filter (Baghouse) A fabric filter, or baghouse, consists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags. Yes 98% - 99+%

Wet Scrubber Wet scrubbers, remove particles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream. Yes 95%-99+% (high efficiency scrubbers)

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the flue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal



## . Yes 98% - 99+%

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates. Yes 98% - 99+%

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to centrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone. Yes 50% - 80%



## All listed control technologies ar e technically feasible for part iculate emission control for ore
concentration.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-56 

# 3. Step 3 – Rank Remain ing Control Technologies by Control Effectiveness

Fabric filters are the most effective control technology in this application. The control technology rankings are as follows:

Table V A-3
PM / PM 10 

### Control Technology Ranking



## Rank Technology Typical % Efficiency

1 Fabric Filter (Baghouse) 98% - 99+%

2 Wet Scrubber 95% - 99+%

3 Wet Electrostatic Precipitator 98% - 99+%

4 Centrifugal Separation (e.g. Cyclones) 50% - 80%



## The exhaust streams from this source contain only dry particulate matter. Under these conditions, fabric filters have the highest particulate matter control efficiency.



# 4. Step 4 – Evaluate Most Effecti ve Control Technolog ies and Document Results Northshore Mining Co. has elected to install fabric filters on the concentrator silo exhaust streams. Fabric filters have the highest particulate matter control efficiency in this application. Since the top control option was chosen, additiona l analysis is not required.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-57 Table V A-4
PM / PM 10 

### Control Technology Emission Control Cost Analysis



## Rank Technology Control Cost $/ton

1 Fabric Filter (Baghouse) Top Emission Controls Selected

2 Wet Scrubber NA

3 Wet Electrostatic Precipitator NA

4 Centrifugal Separation (e.g. Cyclones) NA



# 5. Step 5 – Select BACT The proposed BACT limit for the concentrator silos is a performance limit of 0.003 gr PM/dscf on a 24 hour average basis. To establish co mpliance limits, NSM will test for filterable + organic condensable PM using EPA Method 5 and MN 7011.0725 using three (3) one-hour test runs. During the performance test, the facility will measure emission control equipment process parameters. Process parameter limits for operati ng the concentrator silo emission control equipment will be set using the data collected during the performance test. The facility will demonstrate ongoing compliance based on the 24 hour average(s) of the process parameters established during the performance test.

The concentrator silos are equipped with a fixe d speed fans for moving exhaust gas through the control equipment. Since each concentrator ha s a constant exhaust flow rate, setting a PM
concentration limit for BACT also limits the maxi mum mass emission rate from this source. So,
additional emission limits are not needed.

The proposed BACT limit is consistent with r ecent RBLC determinations for sources in the mineral processing industries (metallic and non- metallic). The RBLC database shows BACT determinations for mineral processing sources in the 0.003 – 0.01 gr/dscf range. Since these determinations are for several different types of processing equipment, they are indicative of the level of emission control that is possible in th e industries covered by th is source category.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-58 

# However, differences in conditions at individual sources affect the level of emission controls possible at a particular source.

The proposed BACT limits are more stringent than the new source MACT limit (40 CFR 63 Subpart RRRRR) of 0.005 gr/dscf filterable particul ate for ore handling e quipment at taconite facilities. The new source MACT standard repr esents the highest level of emission controls which can be expected for these sources; not the av erage of the top 12% of existing sources. The
evaluation criteria for new source MACT is similar to the criteria for BACT determinations. The taconite MACT standard was promulgated Oc tober 30, 2003, so the analysis is current;
consistent with the re quirements of BACT.

The proposed BACT limit is based on the highest level of emission control that can be achieved
with fabric filters in this application. The proposed BACT limits are based on a particulate matter concentration of 0.003 gr/dsc f after controls. Performance test data from NSM fine crushing sources equipped with fabric filters show particulate concentrations of 0.0010 gr/dscf to 0.0031 gr/dscf.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-59 

# VI. Indurating Furn ace Pellet Discharge

This emission source is the material handling and screening point for finished taconite pellets as they leave the taconite furnace. When the finished taconite pellets leave the induration furnace, particulate matter is emitted from the transfer to the screens and the screening process. Water is added at the pellet discharge to cool the pellets to levels acceptable for s ubsequent pellet handling equipment, and to control dust from pellet screening. The exhaust stream is saturated with water. The furnace discharge pellet transfer point is currently equipped with a rotoclone for particulate control. NSM is proposing to install a wet scrubb er as BACT for control of particulate emissions from this source as part of the Furnace 5 Restart Project.



# A. Particulate Matter (PM / PM 10 

# ) Emission Controls

1. Step 1 – Identify all Control Technologies
EPA’s RACT, BACT, LAER Clea ringhouse (RBLC) database was checked for recent BACT
determinations in the mineral and me tallic processing industr ies. The results of this evaluation are in BACT Attachment 1, Tables 1 and 2. While most of the BACT determinations were for sources that are not directly applicable to this project, th e control technologies evaluated in this study are consistent with those found in the RBLC. The prop osed BACT limits are consistent with the level of
emission control found in RBLC for similar indust ries, after taking proce ss limitations and NSM’s site specific conditions into acc ount. The control technologies eval uated for PM emissions control from Furnace #5 pellet discharge are as follows.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-60 Table VII A-1
PM / PM 10 

### Emission Control Technologies Considered for BACT Analysis 

## Technology Description

Fabric Filter (Baghouse) A fabric filter, or baghouse, cons ists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags.

Wet Scrubber Wet scrubbers, remove particles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream.

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the fl ue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal



## .

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates.

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to c entrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone.



# 2. Step 2 – Eliminate Tec hnically Infeasible Options Two of the particulate matter control technologies for the pellet discharge exhaust are technically infeasible. The technical feasibility is summarized as follows:

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-61 Table VII A-2

PM / PM 10 

### Emission Control Technology Feasibility Analysis



## Technology Description Feasible? Yes or No Typical % Efficiency

Fabric Filter (Baghouse) A fabric filter, or baghouse, consists of a number of fabric bags placed inside an enclosure. Particulate matter is collected on the surface of the bags as the gas stream passes through them. The particulate is periodically removed from the bags and collected in hoppers located beneath the bags. No 98% - 99+%

Wet Scrubber Wet scrubbers, remove particles from waste gas by capturing the particles in liquid droplets (usually water) and separating the droplets from the gas stream. The droplets transport the particulate out of the gas stream. Yes 95%-99+% (high efficiency scrubbers)

Electrostatic Precipitator An electrostatic precipitator applies electrical forces to separate particles from the flue gas stream. Particles are given an electrical charge. The charged particles are attracted to and collected on oppositely charged collector plates. Particles on the collector plates are released by rapping and fall into hoppers for collection and removal



## . No 98% - 99+%

Wet Electrostatic Precipitator A Wet ESP operates on the same collection principles as a dry ESP, and uses a water spray to remove particulate matter from the collection plates. Yes 98% - 99+%

Centrifugal Separation (e.g. Cyclones) Cyclone separators are designed to remove particles by causing the exhaust gas stream to flow in a spiral pattern inside of a tube. Owing to centrifugal forces, the larger particles slide down the wall and drop to the bottom of the cyclone where they are removed. The cleaned gas flows out of the top the cyclone. Yes 50% - 80%



## As noted in the process descripti on, the exhaust from this source is saturated with water due to the water sprays used for cooling and dust control. Due to the high moisture content of this stream, fabric filters and dry ESP’s are inf easible. Wet particulate matter would clog the particulate matter

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-62 collection and removal systems in each of these technologies. Th e remaining control technologies are technically feasible for particulate emission control of the pellet discharge exhaust.



# 3. Step 3 – Rank Remain ing Control Technologies by Control Effectiveness This study assumes that the top 3 technically f easible technologies can m eet the Taconite MACT particulate standards. Control cost estimates are based on meeting the MACT standard; the control
device was sized to meet this standard.

Table VII A-3

PM / PM 10 

### Control Technology Ranking



## Rank Technology Typical % Efficiency

1 Wet Electrostatic Precipitator 98% - 99+%

2 Wet Scrubber 95% - 99+%

3 Dry Electrostatic Precipitator 98% - 99+%

4 Centrifugal Separation (e.g. Cyclones) 50% - 80%



# 4. Step 4 – Evaluate Most Effecti ve Control Technolog ies and Document Results

Emissions control effectiveness wa s evaluated for the top two cont rol technologies, wet scrubbing, baghouses, ESP’s and Wet ESP contro ls. The control equipment ef fectiveness analysis can be
summarized as follows:

Table VII A-4
PM / PM 10 

### Control Technology Emission Control Cost Analysis



## Rank Technology Control Cost $/ton 1 Wet Scrubber $3,390 2 Wet Electrostatic Precipitator $19,792

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-63 A summary of the control cost analysis is located in BACT Attachment 2, Table 9. The control cost analyses for individual controls are locate d in BACT Attachment 2 Tables 10 and 11.


# Wet Scrubbing

The particulate matter control cost for a wet scrubber is $3,390 

## /ton. This cost makes it economically
feasible. NSM has the infrastructure to handle the liquid waste from the wet scrubber. So, it may be advantageous for the facility to use a wet scrubbe r instead of a baghouse. See Attachment B for the control cost analysis.

The non-air environmental impact of a wet scrubber is the need to treat the wastewater discharged
from the scrubber.

A wet scrubber has the highest energy use rate of th e control technologies stud ied. A high efficiency wet scrubber operates with a high pressure drop in or der to achieve high collec tion efficiency. This results in a higher electricity use rate than the other controls to operate the air blower.



# Wet Walled Electrostatic Precipitator

Application of a wet ESP’s is economically infeasible. The particulate matter control cost for a new precipitator is $19,792 

## /ton.

The non-air environmental impact of a wet ESP is the need to treat the wastewater discharged from
the wet ESP.

A wet ESP has a moderate energy use rate. ESP’s ha ve a low pressure drop, so, a modest electricity use rate is needed to operate the air blower. Oper ation of the electric grids in the EPS does not add significantly to the overall electrical consumption.



# 5. Step 5 – Select BACT

A wet scrubber is selected as BACT for control of particulate emissions from Furnace #5 pellet discharge. The other control techno logies are economically infeasible.



# The proposed BACT limit for the Furnace 5 pellet discharge is a performance limit of 0.005 gr PM/dscf on a 24 hour average basis. To establis h compliance limits, NSM will test for filterable + organic condensable PM using EPA Met hod 5 and MN 7011.0725 using three (3) one-hour test runs. During the performance test, the fa cility will measure emission control equipment

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-64 

# process parameters. Process parameter limits for operating the Furnace 5 pellet discharge emission control equipment will be set using the data collected during the performance test. The facility will demonstrate ongoing compliance base d on the 24 hour average(s) of the process parameters established during the performance test.

The Furnace 5 pellet discharge is equipped with a fixed speed fans for moving exhaust gas through the control equipm ent. Since the pellet discharge has a constant exhaust flow rate, setting a PM concentration limit for BACT also limits the maximum mass emission rate from this source. So, additional emission limits are not needed.

The proposed BACT limit is consistent with r ecent RBLC determinations for sources in the mineral processing industries (metallic and non- metallic). The RBLC database shows BACT determinations for mineral processing sources in the 0.003 – 0.01 gr/dscf range. Since these determinations are for several different types of processing equipment, they are indicative of the level of emission control that is possible in the industries covered by this source category. However, differences in conditions at individual sources affect the level of emission controls possible at a particular source.
The proposed BACT limits are equal to the 0.005 gr/dscf new source MACT limit (40 CFR 63 Subpart RRRRR) for finished pellet handling equipment at taconite facilities. NSM is planning to install new control equipment for the pellet discharge to meet Taconite MACT. Although this source is subject to the existing source MACT, NSM is proposing to meet the new source standard since new control equipment is being installed. The new source MACT standard is more stringent that the existing source standard and represents the hi ghest level of emission controls which can be expected for new sources . The evaluation criteri a for new source MACT
is similar to the criteria for BACT determin ations. The taconite MACT standard was promulgated October 30, 2003, so the analysis is current; consistent with the requirements of
BACT.

### P:\23\38\107 NSM Furnace 5 Rest art\Air Permit App\Submittal\050502 to MPCA (P SD App)\Original Files\Vol I Sect 5 App A (BACT).doc 

## A-5-65 

# BACT ATTACHMENT 1

RBLC BACT DataP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-66BACT Attachment 1 Table 1 RBLC Search Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeMO-0011PEA RIDGEIRON ORE CO.0895-012 8/9/1995ADDITION OFDIRECTREDUCTIONFURNACE&COALHANDLINGSO2USES A #6 RESIDUAL FUELOIL SPRAY DRYER\ FABRICFILTER104 LB/HR BACT-PSDMO-0011PEA RIDGEIRON ORE CO.0895-012 8/9/1995ADDITION OFDIRECTREDUCTIONFURNACE&COALHANDLINGNO2#6 RESIDUAL FUEL OIL,SNCR52 LB/HR BACT-PSDMO-0011PEA RIDGEIRON ORE CO.0895-012 8/9/1995ADDITION OFDIRECTREDUCTIONFURNACE&COALHANDLINGPM10USES A #6 RESIDUAL FUELOIL. SPRAY DRYER \FABRIC FILTER0.01 GR/DSCF BACT-PSDAK-0033COMINCORED DOGMINE9932-AC00512/10/1999ROCK CRUSHER,READ SCREENALL, PORTABLEPM10MEET REQUIREMENTS OF40 CFR 60.673(B), (C), & (E).0.05 G/DSCM BACT-OTHERAK-0033COMINCORED DOGMINE9932-AC00512/10/1999CRUSHER,GYRATORYPM10 BAGHOUSE 0.01 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-67BACT Attachment 1 Table 1 RBLC Search Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeAK-0033COMINCORED DOGMINE9932-AC00512/10/1999METALLICMINERALPROCESSINGEQUIPMENT,VARIOUSPM10MEETS REQUIREMENTS OF40 CFR 60.382(A) & (B).BAGHOUSE, WATERINGAND CHEMICAL CONTROLS.0.05 G/DSCM NSPSAK-0033COMINCORED DOGMINE9932-AC00512/10/1999METALLICMINERALPROCESSINGEQUIPMENT,VARIOUSVEMEET REQUIREMENTS OF40 CFR 60.382 (A) AND (B).BAGHOUSE7 % OPACITY NSPSAK-0033COMINCORED DOGMINE9932-AC00512/10/1999HEATERS, ABCO,3 UNITSNOX LOW NOX BURNERS 0.084 LB/MMBTU BACT-PSDAK-0033COMINCORED DOGMINE9932-AC00512/10/1999HEATERS, ABCO,3 UNITSVE LOW NOX BURNERS 20 % OPACITY BACT-PSDMN-0036ISPAT INLANDMINING CO.13700062-0011/14/2000METAL OREMINING,TACONITE,INDURATINGFURNACENO2FUEL USE IS LIMITED TO270 MMBTU/HR FOR ALLEU26 BURNERS COMBINED(4 STACKS) IN ADDITION TOTHE USE OF EXISTING LOWNOX BURNERS. 11CONTROL OPTIONSEXAMINED.1088 LB/H BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-68BACT Attachment 1 Table 1 RBLC Search Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit Type*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL55W825BAGHOUSE, #31VEBAGHOUSE IS THECONTROL DEVICE20 % OPACITY SIP*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL55W825BAGHOUSE, #31PMBAGHOUSE IS THECONTROL DEVICE0.01 GR/DSCF BACT-PSD*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL55W825BAGHOUSE, #31PBBAGHOUSE IS THECONTROL DEVICE0.0006 GR/DSCF BACT-PSD*AK-0040RED DOGMINE9332-AA0037/27/1994EMTROL 66W40#1 SCRUBBERVEBAGHOUSE IS THECONTROL DEVICE20 % OPACITY SIP*AK-0040RED DOGMINE9332-AA0037/27/1994EMTROL 66W40#1 SCRUBBERPMBAGHOUSE IS THECONTROL DEVICE0.01 GR/DSCF BACT-PSD*AK-0040RED DOGMINE9332-AA0037/27/1994EMTROL 66W40#1 SCRUBBERPBBAGHOUSE IS THECONTROL DEVICE0.0006 GR/DSCF BACT-PSD*AK-0040RED DOGMINE9332-AA0037/27/1994EMTROL 66W40#2 SCRUBBERVESCRUBBER IS CONTROLDEVICE20 % OPACITY SIP*AK-0040RED DOGMINE9332-AA0037/27/1994EMTROL 66W40#2 SCRUBBERPMSCRUBBER IS THECONTROL DEVICE0.01 GR/DSCF BACT-PSD*AK-0040RED DOGMINE9332-AA0037/27/1994EMTROL 66W40#2 SCRUBBERPBSCRUBBER IS THECONTROL DEVICE0.0006 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-69BACT Attachment 1 Table 1 RBLC Search Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit Type*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL 49S8-20 BAGHOUSE,#34VEBAGHOUSE IS A CONTROLDEVICE20 % OPACITY SIP*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL 49S8-20 BAGHOUSE,#34PMBAGHOUSE IS A CONTROLDEVICE0.01 GR/DSCF BACT-PSD*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL 49S8-20 BAGHOUSE,#34PBBAGHOUSE IS A CONTROLDEVICE0.0006 GR/DSCF BACT-PSD*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL 48N4-B BAGHOUSEVETHE BAGHOUSE IS ACONTROL DEVICE20 % OPACITY SIP*AK-0040RED DOGMINE9332-AA0037/27/1994MIKROPUL 48N4-B BAGHOUSEPMTHE BAGHOUSE IS ACONTROL DEVICE0.01 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-70BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeOR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER1/CALCINER 1PMBAUMCO MODEL 2-5116-4.510P PULSE-JETBAGHOUSE, AIR TO CLOTHRATIO IS 1.7:10.1 GR/DSCF SIPOR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER1/CALCINER 1SO2OXIDIZED, LOW SULFURORES CAN BE OBTAINED BYSELECTIVE MINING OF THEUPPER STRATA OF THEDEPOSITS. SULFUR ISPRESENT IN RAW DE ORESAT VARYING LEVELSDEPENDING ON THEPARTICULAR GEOLOGICFORMATION.60%REDUCTIONBACT-OTHEROR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER1/CALCINER 1NOXGOOD COMBUSTIONCONTROL6.6 LB/H BACT-OTHEROR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER1/CALCINER 1COGOOD COMBUSTIONCONTROL19.7 LB/H BACT-OTHEROR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER1/CALCINER 1VEBAUMCO MODEL 2-5116-4.510P PULSE-JETBAGHOUSE, AIR TO CLOTHRATIO IS 1.7:120 % OPACITY SIPOR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER2/CALCINER 2PMFABRIC FILTER MODEL 289-10 PULSE-JET BAGHOUSEWITH AIR TO CLOTH RATIOOF 2.0:10.1 GR/DSCF SIPOR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER2/CALCINER 2PMFILTERABLEBAGHOUSE 0.04 GR/DSCF NSPSP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-71BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeOR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER2/CALCINER 2SO2OXIDIZED, LOW SULFURORES CAN BE OBTAINED BYSELECTIVE MINING THEUPPER STRATA OF THEDEPOSITS. SULFUR ISPRESENT IN RAW DE ORESAT VARYING LEVELSDEPENDING ON THEPARTICULAR GEOLOGICFORMATION PROCESS60%SO2REDUCTIONBACT-OTHEROR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER2/CALCINER 2NOXGOOD COMBUSTIONPRACTICES7.1 LB/H BACT-OTHEROR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER2/CALCINER 2COGOOD COMBUSTIONPRACTICES21.4 LB/H BACT-OTHEROR-0042EAGLEPICHER VALE,OREGONPLANT23-0007 5/23/2003DRYER2/CALCINER 2VEFABRIC FILTER MODEL 289-10 PULSE-JET BAGHOUSEWITH AIR TO CLOTH RATIOOF 2:110 % OPACITY NSPSIL-0084VULCANMATERIALS96020014 10/28/2002 LIME KILN SO2 BAGHOUSE AND SCRUBBER 2.76 LB/T BACT-PSDIL-0084VULCANMATERIALS96020014 10/28/2002 LIME KILN NOXBEST COMBUSTIONPRACTICES4.5 LB/T BACT-PSDIL-0084VULCANMATERIALS96020014 10/28/2002 LIME KILN PM BAGHOUSE 0.134 LB/T BACT-PSDIL-0084VULCANMATERIALS96020014 10/28/2002 LIME KILN COBEST COMBUSTIONPRACTICE43.2 LB/T BACT-PSDNC-0099PCSPHOSPHATE04176R15 7/14/2000SULFURIC ACIDPLANT, NO. 3SO2FIBERGLASS PACKED MISTELIMINATORS AND A MESHPAD INSTALLED ON THEFINAL ABSORBING TOWER4 LB/T BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-72BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeNC-0099PCSPHOSPHATE04176R15 7/14/2000SULFURIC ACIDPLANT, NO. 3H2SO4MISTFIBERGLASS PACKED MISTELIMINATORS AND A MESHPAD INSTALLED ON THEFINAL ABSORBING TOWER0.15 LB/T BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000 MINE VENT (E1) CO 0.26 LB/H BACT-OTHERWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000 MINE VENT (E1) NMHC 130 LB/H BACT-OTHERWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000 MINE VENT (E1) NOX 1.7 LB/H BACT-OTHERWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000ROM OREHANDLING DUSTCOLLECTOR (E2)PM10ELECTROSTATICPRECIPITATOR. ADDITIONALALT.EMISSION 8.2 T/YR.0.005 GR/DSCF BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000ROM ORESTORAGE DUSTCOLLECTOR (E3)NOX LOW NOX BURNER 8.1LB/H(PHASE 1)BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000ROM ORESTORAGE DUSTCOLLECTOR (E3)PM10ELECTROSTATICPRECIPITATOR. ADDITIONALALT. EMISSION 9.2 T/YR0.005 GR/DSCF BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000BENETRON OREUPGRADEFACILITY STACK(E4)PM10ELECTROSTATICPRECIPITATOR.0.0025 GR/DSCF BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000BENETRON OREUPGRADEFACILITY STACK(E4)NOX LOW NOX BURNER 8.1LB/H(PHASE 1)BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000TRONA ORECALCINER STACK(E5) (E15)NOXLOW NOX BURNER. ALT.EMISSION LIMIT: PHASE 2 -16.1 LB/H.0.038 LB/MMBTU BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000TRONA ORECALCINER STACK(E5) (E15)PM10 WET SCRUBBER. 0.003 GR/DSCF BACT-PSDWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000SODA ASHPRODUCTHANDLING DUSTCOLLECTOR (E6)PM10ELESTROSTATICPRECIPITATOR.0.005 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-73BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeWY-0055WOLD TRONACOMPANY, INC.MD-455 4/27/2000ROM ORESTORAGE DUSTCOLLECTORPM10 ESP 2.1 LB/H BACT-OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999 SPRAY DRYER #2 PM10CYCLONE PRECOLLECTORS& ESP0.07 LB/T OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999DEAGGLOMERATOR CPM10 CYCLONE, FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999CONVEYINGSYSTEM,PRODUCT SILOPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999FLASH DRYERSYSTEM #1, #2AND #3PM10 FABRIC FILTERS 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999FLASH DRYERSYSTEM #1, #2AND #3SO2LIMIT ON DISTILLATE FUELSULFUR CONTENT: < .3% SBY WT0.7 LB/H OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999CONVEYINGSYSTEM, FLASHDRYER PROD 1, 2& 3PM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999SURFACETREATER, A & CPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999CONVEYINGSYSTEM,SURFACETREATER A, B &C PRODPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999SURFACETREATER BPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999PRODUCTCONVEYINGSYSTEM,DEAGGLOMERATOR CPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999TRANSFERHOPPER, BULKBAGGINGPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999BULK BAGGERSTATIONS/SILOSPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999HOUSE VACUUMSYSTEMPM10 FABRIC FILTER 0.01 GR/DSCF OTHERVT-0016OMYA /VERPOLAOP-98-015A10/26/1999 ROTOPACKERS PM10 FABRIC FILTERS 0.01 GR/DSCF OTHERP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-74BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeVT-0016OMYA /VERPOLAOP-98-015A10/26/1999BOILER, FIRETUBEPM10LOW SULFUR FUEL, GOODOPERATING PRACTICE.0.35 LB/MMBTU OTHERAR-0028ARKANSASLIMECOMPANY45-AOP-R1 9/14/1999 KILN, LIME SO2RESTRICTION ON THESULFUR CONTENT OF THEFUEL USED TO FIRE THELIME KILN (MAX 4% ON ADAILY BASIS AND 3% ON AROLLING 30 DAY AVERAGE).65.2 LB/H BACT-PSDAR-0028ARKANSASLIMECOMPANY45-AOP-R1 9/14/1999 KILN, LIME NOXPROPER DESIGN ANDOPERATION OF LIME KILN91.2 LB/H BACT-PSDCO-0040AMERICANSODA, LLP,PARACHUTEFACILITY98-GA08585/6/1999INDUSTRIALBOILER,NATURAL GASNOXLOW NOX COMBUSTIONSYSTEM. CAPITAL COSTSARE INCLUDED INEQUIPMENT COSTS;ANNUALIZED COSTS AREINCLUDED IN OPERATIONAND MAINTENANCE0.05 LB/MMBTU BACT-PSDCO-0040AMERICANSODA, LLP,PARACHUTEFACILITY98-GA08585/6/1999INDUSTRIALBOILER,NATURAL GASCOGOOD COMBUSTIONMANAGEMENT. CAPITAL ANDANNUALIZED COSTS AREINCLUDED IN OPERATIONAND MAINTENANCE0.09 LB/MMBTU BACT-PSDCO-0040AMERICANSODA, LLP,PARACHUTEFACILITY98-GA08585/6/1999SODIUMCARBONATEPROD., SODAASH DRYER, NATGASPM10ELECTROSTATICPRECIPITATOR (ESP) ANDGOOD COMBUSTIONPRACTICES.0.01 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-75BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeCO-0040AMERICANSODA, LLP,PARACHUTEFACILITY98-GA08585/6/1999SODIUMCARBONATEPROD., SODAASH DRYER, NATGASCOGOOD COMBUSTIONMANAGEMENT.CONTAMINATION OF THEPRODUCT IS OF PRIMARYCONCERN. REFRACTORIESCANNOT BE USED IN THECOMBUSTION SYSTEM.CAPITAL AND ANNUALIZEDCOSTS ARE INCLUDED INOPERATION ANDMAINTENANCE2.02 LB/MMBTU BACT-PSDCO-0040AMERICANSODA, LLP,PARACHUTEFACILITY98-GA08585/6/1999SODIUMCARBONATEPROD., SODAASH DRYER, NATGASNOXGOOD COMBUSTIONMANAGEMENT.CONTAMINATION OF THEPRODUCT IS OF PRIMARYCONCERN. REFRACTORIESCANNOT BE USED IN THECOMBUSTION SYSTEM.CAPITAL AND ANNUALIZEDCOSTS ARE INCLUDED INOPERATION ANDMAINTENANCE0.15 LB/MMBTU BACT-PSDCO-0041AMERICANSODA, LLP,PINEANCEFACILITY98-RB-0831 5/6/1999BOILER NO.2,TEST MINE HOTWATER (1)NOXLOW NOX COMBUSTIONSYSTEM. NO ADD-ON COSTS.COSTS PART OFOPERATION.0.05 LB/MMBTU BACT-PSDCO-0041AMERICANSODA, LLP,PINEANCEFACILITY98-RB-0831 5/6/1999BOILER NO.2,TEST MINE HOTWATER (1)CO GOOD COMBUSTION 0.09 LB/MMBTU BACT-PSDCO-0041AMERICANSODA, LLP,PINEANCEFACILITY98-RB-0831 5/6/1999BOILER NO.2,TEST MINE HOTWATER (1)PM10 COMBUSTION CONTROL 0.009 LB/MMBTU BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-76BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeCO-0041AMERICANSODA, LLP,PINEANCEFACILITY98-RB-0831 5/6/1999BOILER NO.1,MAIN HOTWATER, (2)PM10USE OF PIPELINE QUALITYNATURAL GAS, ANDAPPLICATION OF GOODCOMBUSTION MANAGEMENTPRACTICES0.0075 LB/MMBTU BACT-PSDCO-0041AMERICANSODA, LLP,PINEANCEFACILITY98-RB-0831 5/6/1999BOILER NO.1,MAIN HOTWATER, (2)VOC GOOD COMBUSTION 0.0054 LB/MMBTU BACT-PSDCO-0041AMERICANSODA, LLP,PINEANCEFACILITY98-RB-0831 5/6/1999BOILER NO.1,MAIN HOTWATER, (2)NOXLOW NOX COMBUSTIONSYSTEMS TO MINIMIZEFORMATION AND EMISSIONSOF OXIDES OF NITROGEN0.038 LB/MMBTU BACT-PSDCO-0041AMERICANSODA, LLP,PINEANCEFACILITY98-RB-0831 5/6/1999BOILER NO.1,MAIN HOTWATER, (2)COGOOD COMBUSTIONMANAGEMENT PRACTICESTO MINIMIZE FORMATIONAND EMISSION OF CARBONMONOXIDE0.09 LB/MMBTU BACT-PSDCA-0851CELITECORPORATION(LOMPOCPLANT)10023 1/21/1999BAGHOUSE,GENERAL WASTEMATERIALPM10GENERAL WASTEBAGHOUSE. MFGR/MODEL:MIKOPUL/611R-10-30-TRC""0.0045 GR/DSCF BACT-OTHERCA-0851CELITECORPORATION(LOMPOCPLANT)10023 1/21/1999BAGHOUSE,GENERAL WASTEMATERIALVEGENERAL WASTEBAGHOUSE. MFGR/MODEL ISMIKOPUL/ 611R-10-30-TRC""10 % OPACITY BACT-OTHERWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998CALCINER,NATURAL GASFIRED TRONAPMELECTROSTATICPRECIPITATOR 264,000ACFM0.015 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-77BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998CALCINER,NATURAL GASFIRED TRONANOXBURNER DESIGNED FORLOW NOX" PERFORMANCE"0.05 LB/MMBTU BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998CALCINER,NATURAL GASFIRED TRONAVOC 533.5 LB/H BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998SODA ASHNATURAL GAS,DRYERNOXBURNER DESIGNED FORLOW NOX" PERFORMANCE"NORTH AMERICAN FLAMEGRID" UNIT"0.15 LB/MMBTU BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998SODA ASHNATURAL GAS,DRYERPMELECTROSTATICPRECIPITATOR 130,000 ACFM0.01 GR/SCF BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998BOILER,NATURAL GASPMMINIMAL PARTICULATEEMISSIONS AND LOWEMITTING FUEL5 LB/MMBTU BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998BOILER,NATURAL GASNOX LOW NOX" BURNER SYSTEM" 0.038 LB/MMBTU LAERWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998PRIMARYSCREENS,TRONA OREPMBAGHOUSE AND INDUSTRIALVENTILATION SYSTEM0.01 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-78BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998PRIMARYSCREENS,TRONA OREVE 7 % OPACITY NSPSWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998CONVEYORDISCHARGE,RECLAIM TRONAOREPMBAGHOUSE AND INDUSTIRALVENTILATION SYSTEM0.01 GR/DSCF BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998CONVEYORDISCHARGE,RECLAIM TRONAOREVE 7 % OPACITY NSPSWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998PRODUCTHANDLING AREA,SODA ASHDRYER PRODUCTPMBAGHOUSE & INDUSTRIALVENTILATION SYSTEM0.01 GR/DSCF BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998PRODUCTHANDLING AREA,SODA ASHDRYER PRODUCTVE 7 % OPACITY NSPSWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998DIN VENTS &PRODUCTTRANSFERPOINTS, (2) SODAASHPMBAGHOUSE AND INDUSTRIALVENTILATION SYSTEM0.01 GR/DSCF BACT-PSDWY-0034SOLVAY SODAASH JOINTVENTURETRONAMINE/SODAASHCT-1347 2/6/1998DIN VENTS &PRODUCTTRANSFERPOINTS, (2) SODAASHVE 7 % OPACITY NSPSP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-79BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeCA-0808CELITECORPORATION9757 12/5/1997DIATOMACEOUSEARTH CALCINERSOXGAS ABSORPTION TOWER(AKA. SCRUBBER). PACKEDBED COUNTER-CURRENTDESIGN USING CAUSTIC ASTHE SOLVENT.98% MASSREMOVALLAERWY-0031GENERALCHEM SODAASHPARTNERS -GEN CHEMSODAMD-340 11/21/1997CALCINER,TRONA, 5 EACHVOC 0 BACT-PSDWY-0031GENERALCHEM SODAASHPARTNERS -GEN CHEMSODAMD-340 11/21/1997CALCINER,TRONA, 2 EACHVOC 0 BACT-PSDWY-0031GENERALCHEM SODAASHPARTNERS -GEN CHEMSODAMD-340 11/21/1997DRYER, TRONA, 6EACHVOC 0 BACT-PSDWY-0031GENERALCHEM SODAASHPARTNERS -GEN CHEMSODAMD-340 11/21/1997DRYER, TRONA, 6EACHVOC 0 BACT-PSDWY-0035TEXASGULFSODA ASHPLANTCT-1321 10/13/1997ROTARY DRYER,SODA ASHPMELECTROSTATICPRECIPITATOR 124,000 ACFM0.01 GR/DSCF BACT-PSDWY-0035TEXASGULFSODA ASHPLANTCT-1321 10/13/1997ROTARY DRYER,SODA ASHVE 0.07 OPACITY NSPSWY-0035TEXASGULFSODA ASHPLANTCT-1321 10/13/1997ROTARY DRYER,SODA ASHNOXLOW NOX BURNERS - NORTHAMERICAN BURNER0.15 LB/MMBTU BACT-PSDWY-0035TEXASGULFSODA ASHPLANTCT-1321 10/13/1997SCREENING/SIZING AREA, SODAASHPMVENTURI SCRUBBER ANDINDUSTRIAL VENTILATIONSYSTEM0.01 GR/DSCF BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-80BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeWY-0035TEXASGULFSODA ASHPLANTCT-1321 10/13/1997BOILER,NATURAL GASNOXLOW NOX" BURNERS WITH16% FLUE GASRECIRCULATION"0.05 LB/MMBTU BACT-PSDWY-0035TEXASGULFSODA ASHPLANTCT-1321 10/13/1997BOILER,NATURAL GASPM NATURAL GAS FUEL 0 NEGLIGIBLE BACT-PSDWY-0035TEXASGULFSODA ASHPLANTCT-1321 10/13/1997BOILER,NATURAL GASSO2 NATURAL GAS FUEL 0 NEGLIGIBLE BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 CALCINER NO. 4 VE ESP, BAGHOUSE. 10 % OPACITY BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 CALCINER NO. 4 PM ESP 0.04 GR/DSCF BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 CALCINER NO. 4 SOXSULFUR CONTENT OF FUELOIL LIMITED TO 0.5 WT %40TONS/12CONSEC.MOS.BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 CALCINER NO. 4 NOXLIMITED FUELCONSUMPTION40TONS/12CONSEC.MOS.BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995CALCINERCOOLEROPACITY BAGHOUSE. 7 % OPACITY BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995CALCINERCOOLERPM BAGHOUSE 0.03 GR/DSCM BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 SILOS (5) VE BAGHOUSE. 7 %OPACITY BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 SILOS (5) PM BAGHOUSE 0.03 GR/DSCM BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 PULVERIZERS (8) VE BAGHOUSE 7 % OPACITY BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 PULVERIZERS (8) PM BAGHOUSE 0.03 GR/DSCM BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 TRUCK LOADING VE BAGHOUSE 7 % BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 TRUCK LOADING PM BAGHOUSE 0.03 GR/DSCM BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995RAILCARLOADINGVE BAGHOUSE 7 % OPACITY BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995RAILCARLOADINGPM BAGHOUSE 0.03 GR/DSCM BACT-PSDP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-81BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 BIN VENTS (3) VE BAGHOUSE. 7 % BACT-PSDGA-0074DRY BRANCHKAOLIN CO.3295-143-1108111/6/1995 BIN VENTS (3) PM BAGHOUSE 0.03 GR/DSCM BACT-PSDCA-0670 U.S. BORAXA/C NO.1004207A9/28/1995BORATETAILINGS PONDS(FUGITIVE DUSTCONTROL)PM10APPLICATION OF DLR-MS-40ACRYLIC COPOLYMER ANDRECLAMATION OF DRYPONDS68.49 LBM/DAY BACT-OTHERCA-0672U.S. BORAX,INC.1004207A 9/28/1995BORATESTAILING PONDSPM10APPLICATION OF DUSTRETARDANT68.5699 LBM/DAY BACTWY-0038WOLD TRONACO.CT-1148 5/2/1995MATERIALHANDLING, OREPMELECTROSTATICPRECIPITATOR0.005 GR/DSCF BACT-PSDWY-0038WOLD TRONACO.CT-1148 5/2/1995MATERIALHANDLING, OREVE 7 % OPACITY NSPSWY-0038WOLD TRONACO.CT-1148 5/2/1995MATERIALSTORAGE, ORE,(2)PMELECTROSTATICPRECIPITATOR0.005 GR/DSCF BACT-PSDWY-0038WOLD TRONACO.CT-1148 5/2/1995MATERIALSTORAGE, ORE,(2)VE 7 % OPACITY NSPSWY-0038WOLD TRONACO.CT-1148 5/2/1995BENETRON OREUPGRADEFACILITY 2 EAPMELECTROSTATICPRECIPITATOR, 4 INPARALLEL0.0025 GR/DSCF BACT-PSDWY-0038WOLD TRONACO.CT-1148 5/2/1995BENETRON OREUPGRADEFACILITY 2 EAVE 7 % OPACITY NSPSWY-0038WOLD TRONACO.CT-1148 5/2/1995MATERIALHANDLING, SODAASH PRODUCTPMELECTROSTATICPRECIPITATOR0.005 GR/DSCF BACT-PSDWY-0038WOLD TRONACO.CT-1148 5/2/1995MATERIALHANDLING, SODAASH PRODUCTVE 7 % OPACITY NSPSWY-0038WOLD TRONACO.CT-1148 5/2/1995CALCINER &CALCINERBOILER, (2)PMWET SCRUBBER (VENTURI)AND PACKED TOWERCONDENSER ON CALCINER0.005 GR/DSCF BACT-PSDWY-0038WOLD TRONACO.CT-1148 5/2/1995CALCINER &CALCINERBOILER, (2)VE 20 % OPACITY NSPSP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-82BACT Attachment 1 Table 2 RBLC Search Non-Metallic Mineral ProcessingRBLC ID # Facility NamePermitNumberPermitDateProcess Name PollutantControl EquipmentDescriptionEmissionLimitUnits Permit TypeWY-0038WOLD TRONACO.CT-1148 5/2/1995CALCINER &CALCINERBOILER, (2)NOXMONOWALL FURNACECONSTRUCTION LOW NOXBURNERS WITH FUELSTAGING, 15% EXCESS AIRFLUE GASRECIRCULATION(FGRS 15%)ON CALCINER BOILER0.048 LB/MMBTU BACT-PSDWY-0038WOLD TRONACO.CT-1148 5/2/1995CALCINER &CALCINERBOILER, (2)CO 15.12 LB/H BACT-PSDTN-0097TENNLUTTRELLCOMPANY938511P 9/23/1994VERTICAL SHAFTLIME KILNNOXINHERENT DESIGN OF THEVERTICAL SHAFT KILN31.14 LB/H BACT-PSDTN-0097TENNLUTTRELLCOMPANY938511P 9/23/1994VERTICAL SHAFTLIME KILNPM10 BAGHOUSE 1.85 LB/H BACT-PSDTN-0097TENNLUTTRELLCOMPANY938511P 9/23/1994VERTICAL SHAFTLIME KILNSO23 PERCENT SULFUR LIMIT INFUEL7.71 LB/H BACT-PSDTN-0097TENNLUTTRELLCOMPANY938511P 9/23/1994VERTICAL SHAFTLIME KILNTSP BAGHOUSE 3.24 LB/H BACT-PSDTN-0097TENNLUTTRELLCOMPANY938511P 9/23/1994VERTICAL SHAFTLIME KILNVE BAGHOUSE 10 % OPACITY OTHERTN-0097TENNLUTTRELLCOMPANY938511P 9/23/1994VERTICAL SHAFTLIME KILNVOC NONE LISTED IN PERMIT 6.3 LB/H OTHERTN-0097TENNLUTTRELLCOMPANY938511P 9/23/1994VERTICAL SHAFTLIME KILNCO NONE LISTED IN PERMIT 41.63 LB/H BACT-PSDTN-0098TENNLUTTRELLCOMPANY938513P 9/23/1994MATERIALHANDLINGOPERATIONSTSPBAGHOUSE ON LIMECRUSHING/SCREENINGOPERATION0.05 GR/DSCM BACT-PSDTN-0098TENNLUTTRELLCOMPANY938513P 9/23/1994MATERIALHANDLINGOPERATIONSVE BAGHOUSE 7 % OPACITY OTHER

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## A-5-83 

# BACT ATTACHMENT 2

Emission Control Cost Analysis

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-84 BACT Attachment 2 Table 1: Furnace 5 Control Cost Summary

NSM Line 5 Restart BACT Emission Control Cost Analysis

SO2 Control Cost Summary

Control Technology Control Eff % Emissions T/y Emission Reduction T/yr Installed Capital Cost $ A nnualized Operating Cost $/yr Pollution Control Cost $/ton Air Toxic's & AQRV's? Energy Impacts? Non-Air Env Impacts?

Wet Wall ElectroStatic Precipitator (WWESP) 80% 63 253 8,372,201 3,380,395 13,385 None Low Waste-water

Wet Scrubber 80% 63 253 7,970,886 2,291,431 9,073 None High Waste-water

NOx Control Cost Summary

Control Technology Control Eff % Emissions T/y Emission Reduction T/yr Installed Capital Cost $ A nnualized Operating Cost $/yr Pollution Control Cost $/ton Air Toxic's & AQRV's? Energy Impacts? Non-Air Env Impacts? SCR with Re-heat of furnace exhaust gas 90% 25.5 229 10,868,371 5,957,963 25,982 NH3 Slip High Catalyst Waste
PM Control Cost Summary

Control Technology Control Eff % Emissions T/y Emission Reduction T/yr Installed Capital Cost $ A nnualized Operating Cost $/yr Pollution Control Cost $/ton Air Toxic's & AQRV's? Energy Impacts? Non-Air Env Impacts?

Wet Wall ElectroStatic Precipitator (WWESP) 94% 43 668 8,372,201 3,203,603 4,796 None Low Waste-water

Dry ElectroStatic Precipitator (ESP) 94% 43 668 8,128,350 1,428,618 2,139 None Low Solid Waste Wet Scrubbers High Efficienc y 94% 43 668 7,970,886 2,114,639 3,166 None High Waste-water

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## A-5-85 BACT Attachment 2 Table 2: Furnace 5 SO2 Control - Wet Wall ESP NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1)

ESP + auxillary equipment 3,090,000 Instrumentation 10% of control device cost (A) 309,000 MN Sales Taxes 6.5% of control device cost (A) 200,850 Freight 5% of control device cost (A) 154,500 Purchased E q ui p ment Total (B) 22% 3,754,350

Direct Installation Costs

Foundations & supports 4% of purchased equip cost (B) 150,174 Handling & erection 50% of purchased equip cost (B) 1,877,175 Electrical 8% of purchased equip cost (B) 300,348 Piping 1% of purchased equip cost (B) 37,544 Insulation for ductwork 2% of purchased equip cost (B) 75,087 Painting 2% of purchased equip cost (B) 75,087 Direct Installation Costs 2,515,415

Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA

Total Direct Ca p ital Costs, DC 67% 6,269,765

Indirect Capital Costs Engineering 20% of purchased equip cost (B) 750,870 Construction & field expenses 20% of purchased equip cost (B) 750,870 Constractor fees 10% of purchased equip cost (B) 375,435 Start-up 1% of purchased equip cost (B) 37,544 Performance Tes t 1% of purchased equip cost (B) Model Stud y 2% of purchased equip cost (B) 75,087 Contingencies 3% of purchased equip cost (B) 112,631 Total Indirect Capital Costs 57% 2,102,436 Total Ca p ital Investment (TCI) = DC + IC 8,372,201



### OPERATING COSTS

Direct Operating Costs Operator 32.00 $/Hr, 1.0 hr/8 hr shift, 8000 hr/yr 32,000 Supervisor 15% of operator costs 4,800 Coordinator 33% of operator costs 10,560 Operating materials

Maintenance Labor 0.1155 $/ft2 collector area; $5775 if < 50,000 ft2 39,149 Maintenance Materials 1% of purchased equipment costs 37,544 Utilities Electricity 0.05 $/kW-hr, 387.2 kW-hr, 8000 hr/yr 141,622 Water 0.22 $/Mgal, 2,115.0 gpm, 8000 hr/yr 221,867 Solid Waste Disposal NA - Wastewater Treatment 1.50 $/Mgal, 2,115.0 gpm, 8000 hr/yr 1,522,800 Reagent (Caustic) 280.00 $/Ton, 157.9 lb/hr, 8000 hr/yr, 62 lb/lbmole, 50 w 176,792 Total Annual Direct O p eratin g Costs, DC 2,187,135

Indirect Operating Costs Overhead 60% of oper, maint & supv labor + maint mtl costs 68,096 Administration (2% total capital costs) 2% of total capital costs (TCI) 167,444 Property tax (1% total capital costs) 1% of total capital costs (TCI) 83,722 Insurance (1% total capital costs) 1% of total capital costs (TCI) 83,722 Captial Recover y 9% for a 20- year equipment life and a 7% interest rat 790,277 Total Indirect O p eratin g Costs, IC 1,193,260

Total Annual Cost (Annualized Ca p ital Cost + O p eratin g Cost) 3,380,395 Pollutant Removed (tons/yr) B 252.6 Cost p er ton of PM Removed 13,385 Notes & Assumptions 1 Equipment cost estimates assumed to be 3% higher than that of dry ESP. 2 Capital cost estimated from 2001 Wheelabrator costs for ESP on propos ed taconite processing facilit y 3 EPA Cost Manual 6th Ed. 2002

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## A-5-86 BACT Attachment 2 Table 2: Furnace 5 SO2 Control - Wet Wall ESP (Continued)

Capital Recovery Factors Enter Data in Blue Highlighted Cells Primary Installation Data to Summary Table in Yellow Highlighted Cells Interest Rate 7.0% Equipment Life 20 years CRF 0.0944

Catalyst Replacement Cost Catalyst Life 2 years CRF 0.5531 Catalyst cost per unit 0 $/ft 3 Amount Required 0 ft 3 Catalyst Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 0 $ each Amount Required 0 Number Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Catalyst 0

Design Flow 207,240 scfm

235,000 acf m

Operating Cost Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0% Unit Unit of Use Unit of Annual Annual Comments Ite m Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 1 hr/8 hr shift 1,000 32,000 $/Hr, 1.0 hr/8 hr shift, 8000 hr/yr Supervisor NA NA NA Calc'd as % of labor costs Maint Labor 0.1155 $/ft 2 collect o 71,423 ft 2 collector area 8,249 $/ft 2 collector area; $5775 if < 50,000 ft 2 Maint Mtls NA NA 1% of purchased equipment costs Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 387 kW-hr 3,097,549 141,622 $/kW-hr, 387.2 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/yr Water 0.22 Mgal 2115 gpm 1,015,200 221,867 $/Mgal, 2,115.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Ca u 280 Ton 157.9 lb/hr 631 176,792 $/Ton, 157.9 lb/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH Reagent #2 300 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH SW Disposal 25.00 Ton 0.000 ton/hr 0 0 $/Ton, NA, 8000 hr/yr Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/Ton, NA, 8000 hr/yr WW Treat 1.50 Mgal 2115 gpm 1,015,200 1,522,800 $/Mgal, 2,115.0 gpm, 8000 hr/yr

Catalyst 0 ft 3 0 ft 3 2 yr life 0 $/ft3, 0.0 ft3, 2 yr life, 8000 hr/yr Rep Parts 0 $/bag 0 b ags 2 yr life 0 $/$/bag, 0.0 bags, 2 yr life, 8000 hr/yr *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation Uncontrolled Emission Rate

Emission Unit of Flow Unit of Control Eff. Emis Rate Factor Measure Rate Measure % T/yr Comments/Notes

N A NA N A NA N A 315.70 Unit P to E from Title V Permit Application Form GI-07 Controlled Emission Rate Perf Unit of Flow Unit of Control Eff. Emis Rate Guarantee Measure Rate Measure % T/yr Comments/Notes

N A NA N A NA 80% 63.14 Calculated basis control efficienc y Emission Reduction T/yr 252.6

Electrical Consumption Requirements Kilowatts
Flow acfm D P in H2O Blower-Motor Eff kW Blower 235,000 5 0.65 211.5 OAQPS Cost Cont Manual 6th ed - Eq 3.46 Flow gpm D P ft H2O Pump Eff Motor Eff Pump 1 2115 60 0.8 0.9 33.1 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Pump 2 0 60 0.8 0.9 0.0 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Area sqft TR pwr # Hoppers Htr Pwr ESP 71,423 138.6 2 4 142.6 OAQPS Cost Cont 5th ed - Eq 6.29 & 6.30

Caustic Use 63.14 lb/hr SO2 2.50 lb NaOH/lb SO2 157.9 lb/hr Caustic Lime Use 0.00 lb/hr SO2 1.53 lb Lime/lb SO2 0.000 T/hr Lime

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-87 BACT Attachment 2 Table 3: Furnace 5 SO2 Control - Wet Scrubber NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1)

Purchased Equipment Costs - Absorber + packing + auxillary equipment, EC (2) 2,982,000 Instrumentation 10% of control device cost (A) 298,200 MN Sales Taxes 6.5% of control device cost (A) 193,830 Freight 5% of control device cost (A) 149,100 Purchased Equipment Total (B) 22% 3,623,130

Installation (3)

Foundations & supports 12% of purchased equip cost (B) 434,776 Handling & erection 40% of purchased equip cost (B) 1,449,252 Electrical 1% of purchased equip cost (B) 36,231 Piping 30% of purchased equip cost (B) 1,086,939 Insulation 1% of purchased equip cost (B) 36,231 Painting 1% of purchased equip cost (B) 36,231 Installation Total 85% 3,079,661

Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA

Total Direct Capital Cost, DC 6,702,791

Indirect Capital Costs Engineering, supervision 10% of purchased equip cost (B) 362,313 Construction & field expenses 10% of purchased equip cost (B) 362,313 Construction fee 10% of purchased equip cost (B) 362,313 Start-up 1% of purchased equip cost (B) 36,231 Performance tes t 1% of purchased equip cost (B) 36,231 Contingencies 3% of purchased equip cost (B) 108,694 Total Indirect Capital Costs, IC 35% 1,268,096

Total Capital Investment (TCI) = DC + IC 7,970,886


### OPERATING COSTS

Direct Annual Operating Costs, DC

Operating Labor

Operator 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 14,400 Supervisor 0.15 15% of Operator Costs 2,160 Operating Materials

Reagent #1 280 $/Ton, 157.9 lb/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH 176,792 Lime NA - Packing 0.00 ft3/5 yr - Wastewater Treatment 1.50 $/Mgal, 423.0 gpm, 8000 hr/yr, 274,104 Maintenance

Maintenance Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 14,400 Maintenance Materials 100% of Maint Labor, 0.0 , 8000 hr/yr 14,400 Electricity - Fan, Pump 0.05 $/kW-hr, 955 kW-hr, 8000 hr/yr 314,249

Total Annual Direct Operating Costs 810,505

Indirect Operating Costs Overhead 60% of total labor and material costs 27,216 Administration (2% total capital costs) 2% of total capital costs (TCI) 159,418 Property tax (1% total capital costs) 1% of total capital costs (TCI) 79,709 Insurance (1% total capital costs) 1% of total capital costs (TCI) 79,709 Capital Recover y 14.24% for a 10- year equipment life and a 7% interest rate 1,134,875 Total Annual Indirect Operating Costs Sum indirect oper costs + capital recovery cos t 1,480,926

Total Annual Cost (Annualized Capital Cost + Operating Cost) 2,291,431

Pollutant Removed (tons/yr) B SO 2 253

Cost per ton of Pollutant Removed SO 2 9,073

Notes & Assumptions 1) Sept 2004 Cost Estimates from Ceilcote 2) Cost factors for packed bed scrubber, unit is a combined ventrui/packed bed system 3) EPA Air Pollution Control Cost Manual 6th Ed 2002

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-88 BACT Attachment 2 Table 3: Furnace 5 SO2 Control - Wet Scrubber (Continued)

Capital Recovery Factors Primary Installation Interest Rate 7.0% Equipment Life 10 years CRF 0.1424

Stainless Steel Packing Replacement Cost Packing Life 5 years CRF 0.0000 Packing cost per unit 35.86956522 $/ft 3 Amount Required 0 ft 3 Packing Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 33.72 $ eac h Amount Required 0 Numbe r Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Packing 0
Design Flo w 207,240 dscf m 235,000 acf m

Operating Cost Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0%

Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 0.5 hr/8 hr shift 450 14,400 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor 15% of Op. NA 2,160 15% of Operator Costs Maint Labor 32.00 Hr 0.5 hr/8 hr shift 450 14,400 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maint Mtls 100% of Maint Labor NA 14,400 of Maint Labor, 0.0 , 8000 hr/yr Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 954.6 kW-hr 6,873,212 314,249 $/kW-hr, 955 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/y r Water 0.22 Mgal 423.0 gpm 182,736 39,936 $/Mgal, 423.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Caustic) 280 Ton 157.85 lb/hr 631 176,792 $/Ton, 157.9 lb/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH Reagent #2 (Lime) 300 Hr 0.00 lb/h r 0 0 $/Hr, 0.0 lb/hr, 8000 hr/y r SW Disposal 25.00 Ton 0.000 ton/h r 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/y r Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/yr WW Treat 1.50 Mgal 423.0 gpm 182,736 274,104 $/Mgal, 423.0 gpm, 8000 hr/yr, Catalyst 0 ft 3 0 ft 3 0 0 $/ft3, 0.0 ft3, 0, 8000 hr/y r Rep Parts 0 b ag 0 b ags 2 yr life 0 $/bag, 0.0 bags, 2 yr life, 8000 hr/y r *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation Uncontrolled Emission Rate Emission Unit of Flow Unit of Control Eff. Emis Rate Factor Measure Rate Measure % T/yr Comments/Notes

NA NA NA NA NA 315.70 Unit P to E from Title V Permit Application Form GI-07 Controlled Emission Rate Perf Unit of Flow Unit of Control Eff. Emis Rate Guarantee Measure Rate Measure % T/yr Comments/Notes

NA NA NA NA 80% 63.14 Calculated basis control efficienc y Emission Reduction T/yr 252.6

Flow acfm ∆ P in H2O Blower Eff Motor Eff kW Blower 235,000 12 0.55 0.7 857.0 OAQPS Cost Cont Manual 6th ed - Eq 1.48 Flow gpm P ft H2O Pump Eff Motor Eff Circ Pump 2,115 125 0.8 0.7 88.8 OAQPS Cost Cont Manual 6th ed - Eq 1.49 H2O WW Disch 423.0 62.5 0.8 0.7 8.9 OAQPS Cost Cont Manual 6th ed - Eq 1.49

Caustic Use 63.14 lb/hr SO2 2.50 lb NaOH/lb SO2 157.85 lb/hr Caustic Lime Use 0.00 lb/hr SO2 1.53 lb Lime/lb SO2 0.00 lb/hr Lime Water Makeup Rate/WW Disch = 20% of circulating water rate Utility use rates basis: 8000 hr/yr

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-89 NSM Line 5 NOx Control - Duct Burner for SCR & Flue Gas Re-Heat BACT Emission Control Cost Analysis

CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1)

Control Device (A) Instrumentatio n 10% of control device cost (A) See SCR MN Sales Taxes 6.5% of control device cost (A) Freight 5% of control device cost (A) Auxiliary equipment (not included in CD cost) 0% of control device cost (A) Purchased Equipment Total (B) 18% Installation

Foundations & supports 8% of purchased equip cost (B) Handling, erection 14% of purchased equip cost (B) Electrical 4% of purchased equip cost (B) Piping 4% of purchased equip cost (B) Insulation 1% of purchased equip cost (B) Painting 1% of purchased equip cost (B) Expenses not covered by items listed above 0% of purchased equip cost (B) Site Preparation, as required Site Specific Buildings, as require d Site Specific Installation Total 30% Total Direct Ca p ital Cost

Indirect Capital Costs Engineering, supervision 10% of purchased equip cost (B) Construction, field exp. 5% of purchased equip cost (B) Construction fee 10% of purchased equip cost (B) Startup 2% of purchased equip cost (B)

Tests 1% of purchased equip cost (B) Contingencies 3% of purchased equip cost (B) Total Indirect Capital Costs 31% Total Ca p ital Investment (TCI) 11,393,580 Adjust TCI for Replacement Parts 525,209 10,868,371 Total Annualized Ca p ital Costs 1,025,897

OPERATING COSTS

Direct O p eratin g Costs Operating Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor 15% of oper labor costs Maintenance Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maintenance Materials 100% of maint labor costs Utilities, Reagents, Waste Management & Replacements Electricity 0.05 $/kW-hr, 1,225 kW-hr, 8000 hr/yr Natural Gas (Fuel) NA Water NA Compressed Air NA Reagent #1(Anhydrous Ammonia) 405.00 $/Ton, 27.1 lb/hr, 8000 hr/yr, Ammonia Reagent #2 (Urea 50% Solution) NA Solid Waste Disposal 25.00 $/Ton, 36.9 ton/yr Hazardous Waste Disposal NA Wastewater Treatment NA Catalyst 64.71 $/ft3, 6,329.4 ft3, 3, 8000 hr/yr Replacement Parts NA Total Annual Direct O p eratin g Costs Fixed + Variable O&M 907,667

Indirect Operating Costs Overhead 60% of o p er, maint & su p v labor + maint mtl costs ( fixed O&M ) 45,119 Property tax (1% total capital costs) 1% of total capital costs (TCI) 113,936 Insurance (1% total capital costs) 1% of total capital costs (TCI) 113,936 Administration (2% total capital costs) 2% of total capital costs (TCI) 227,872 Capital Recover y 9.44% for a 20- year equipment life and a 7% interest rate 1,025,897 Total Indirect O p eratin g Costs Sum indirect oper costs + capital recovery cos t 1,526,759

SCR Total Annual Cost (Annualized Capital Cost + Operating Cost) 2,434,426 Re-Heat Total Annual Cost (Annualized Capital Cost + Operating Cost) See App B Table 5 3,523,537 Combined Total Annual Cost (Annualized Capital Cost + Operating Cost) 5,957,963 Pollutant Removed (tons/ y r) 229 Cost p er ton of NOx Removed 25,982 Notes & Assumptions Basis for SCR control cost: 1 The SCR capital investment is from vendor estimates (Babcok Power Inc, 2005). 2 SCR catalyst quote based on information obtained from Cormetech, Inc. Sept 2004. It is used for catalsyt replacement costs. 3 The total direct and indirect operating costs are based on operation and maintenance costs in the

"Pwr Plt SCR $" tab per EPA correlation of SCR costs for power plants. 4 The emission rate used in the control cost analysis is based on the RHF NOx P to E of 847 t/yr (193.4 lb/hr), and is adjusted to account for

normal hours of operation and utilization rates as allowed by EPA BACT protocol. See pg B-37 and B-38 in the New Source Review Workshop Manual , October 1999 (puzzle book). Flue Gas Reheat Control Cost 5 Capital cost of TO unit $750,000 per John Zink, Feb 2005. 6 EPA control cost guideline for catalytic oxidizers used for operating cost analysis . EPA Air Pollution Control Cost Manual 6th Ed 2002 7 The re-heat total annual cost (annualized capital cost + operating cost) is from the "RHF Flue Gas Reheat" tab total annual co st per 

### Attachment 2 Table 4

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-90 NSM Line 5 NOx Control - Duct Burner for SCR & Flue Gas Re-Heat (Continued)

Capital Recovery Factors Primary Installation Interest Rate 7.00% Equipment Life 20 years CRF 0.0944 200k - 300 k Catalyst Replacement Cost Catalyst Cost per EPA Control Cost Manaul Section 4.2 Catalyst Life 3 years Catalyst Disposal Amount in Tons/yr at 35 lb/ft 3 CRF 0.3811 Amount Yrs Service T/yr Waste Catalyst cost per unit 64.71 $/ft 3 110.8 3 36.9 Amount Required 6329.4 f t 3 333,086 Catalyst Cost $456,703 Cost adjusted for freight & sales tax Installation Labor 68,505 Assume Labor = 15% of catal yst cost (basis labor for baghouse replacement) Total Installed Cost 525,209 Annualized Cost 200,132

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per uni t 33.72 $ eac h Amount Required 0 Number Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Catalyst 525,209

Design Flow 207,000 scfm 454,773 acf m @700 Deg F

Operating Cost Calculations Utilization Rate 90.0% Annual hours of operation: 8,000 Unit Unit of Use Unit of Annual Annual Comments Ite m Cost $ Measure Rate Measure Use* Cost Op Labor 32.00 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor NA NA NA 15% of Operator Costs Maint Labor 32.0 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maint Mtls NA NA NA of purchased equipment costs Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 1225.4 kW-hr 9,803,251 448,212 $/kW-hr, 1,225 kW-hr, 8000 hr/yr Natural Gas 5.50 Mf t 3 0 scf m 0 0 $/Mft3, 0.0 scfm, 8000 hr/yr Water 0.22 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(An h 405 Ton 27.1 lb/hr 198,574 40,211 $/Ton, 27.1 lb/hr, 8000 hr/yr, Ammonia Reagent #2 (Ur e 0.085 Lb 0.0 lb/hr 0 0 $/Lb, 0.0 lb/hr, 8000 hr/yr, 50 wt% Urea Soln. SW Disposal 25.00 Ton 36.9 ton/yr 37 923 $/Ton, 36.9 ton/yr Haz W Disp 273.18 Ton 0.000 ton/3-yr period 0.00 0 $/Ton, 0.0 ton/3-yr period WW Treat 1.50 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr Catalyst 64.7 f t 3 6329.4 f t 3 3 200,132 $/ft3, 6,329.4 ft3, 3, 8000 hr/y r Rep Parts 33.72 $/bag 0 b ags 2 0 $/$/bag, 0.0 bags, 2, 8000 hr/yr *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation Uncontrolled Emission Rate

Emission Unit of Rate % Max Control Eff. Emis Rate Factor Measure Hrs Capacity % T/yr Comments/Notes 70.8 lb/hr 8,000 90.0% NA 254.79 Hourly P to E based on 952.8 t/yr from Permit Application. Annual Controlled Emission Rate emissions adjusted for normal operating hours and utilization. Perf Unit of Flow Unit of Control Eff. Emis Rate Guarantee Measure Rate Measure % T/yr Comments/Notes

NA NA NA NA 90% 25.48 Calculated basis control efficiency Emission Reduction T/yr 229

Flow acfm D P in H2O Blower Eff Motor Eff kW Blower 454,773 11.4 0.55 0.9 1225.4 OAQPS Cost Cont Manual 5th ed - Eq 3.37 Flow gpm D P ft H2O Pump Eff Motor Eff Reagent Pump 0.04 50 0.8 0.9 0.0 OAQPS Cost Cont Manual 5th ed - Eq 9.49

Total Electricity 1225.4

Ammonia 63.7 lb/hr NOx 0.370 lb NH3/lb NOx 27.1 lb/hr NH3; inlcudes 3.5 lb/hr for NH3 slip Urea 50% Sol'n 63.7 lb/hr NOx 1.317 lb Urea Sol'n/lb NOx 96.4 lb/hr Urea Sol'n; inlcudes 12.5 lb/hr for NH3 slip

Estimating amount of catalyst required Vol. #1 5000 ft3 Flow #1 359256 acfm Basis SCR Bids for proposed 2001 Taconite Plant Flow #2 454,773 acfm Vol #2 6329.4 ft3 

### Attachment 2 Table 4 Continued

BACT Emission Control Cost Analysis

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-91 NSM Line 5 NOx Control - Duct Burner for SCR & Flue Gas Re-Heat - SCR Costs 

### BACT Emission Control Cost Analysis

EPA SCR Cost Worksheet for Coal Fired Power Plants
Determine Comparable Boiler Size Based on Flue Gas Exhast Rate RHF exhast flow scfm 207,000 Moisture Content 10% Ind furnace exhast flow dcfm 186,300 Coal F Factor dscf/MMBtu 10,000 Equivalent Duty MMBtu/hr 1,118 Est Power Plant Efficiency 35% Watt per Btu/hr 0.29307 Equivalent Power Plant kW 114,658 Uncontrolled NOx t/yr 310 Annual Operating Hours 8,000 Uncontrolled NOx lb/MMBtu 0.069
Plant Capacity kW A 114,658 Uncontrolled NOx lb/MMBtu B 0.069 Nox Reduction Efficiency C 90 Capital Cost $/kW D 99.37 Total Capital Cost $11,393,580
D= 75*(300,000*((B/1.5)^0.05*(C/100)^0.04)/A)^0.35
Plant Capacity kW A 114,658 Capital Cost $/kW D $99.37 Fixed O&M Cost, $/yr E $75,198

E = D*A*0.0066
Plant Capacity kW A 114,658 Uncontrolled NOx lb/MMBtu B 0.07 Nox Reduction Efficiency C 90 Capital Cost $/kW D $99.37 Annual Capacity Factor G 0.82 Heat Input MMBtu/hr H 6000 Variable O&M Cost $/yr F $832,469
F = G*(225(0.37*B*H*C/100*8760/2000)*1.005+0.075* D*A*((B/1.5)^0.05*(c/100)^.4)+1.45*A) Note: used worst case factor for catalyst replacement Note: Capital Cost kW is estimate from Tom Robinson @ Babcock Power Inc. 

# Attachment 2 Table 4 Continued

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-92 NSM Line 5 NOx Control - Duct Burner for SCR & Flue Gas Re-Heat - Duct Burner BACT Emission Control Cost Analysis

CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1)

Control Device (A) 864,355 Instrumentation 10% of control device cost (A) 86,436 MN Sales Taxes 6.5% of control device cost (A) 56,183 Freight 5% of control device cost (A) 43,218 Auxiliary equipment (not included in CD cost) 0% of control device cost (A) 0 Purchased Equipment Total (B) 18% 1,050,192
Installation

Foundations & supports 8% of purchased equip cost (B) 84,015 Handling, erection 14% of purchased equip cost (B) 147,027 Electrical 4% of purchased equip cost (B) 42,008 Piping 2% of purchased equip cost (B) 21,004 Insulation 1% of purchased equip cost (B) 10,502 Painting 1% of purchased equip cost (B) 10,502 Expenses not covered by items listed above 0% of purchased equip cost (B) 0 Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA Installation Total 30% 315,057 Total Direct Capital Cost 1,365,249

Indirect Capital Costs Engineering, supervision 10% of purchased equip cost (B) 105,019 Construction, field exp. 5% of purchased equip cost (B) 52,510 Construction fee 10% of purchased equip cost (B) 105,019 Startup 2% of purchased equip cost (B) 21,004 Tests 1% of purchased equip cost (B) 10,502 Contingencies 3% of purchased equip cost (B) 31,506 Total Indirect Capital Costs 31% 325,559 Total Capital Investment (TCI) 1,690,808 Adj ust TCI f or R ep l acement P arts 0 1 , 690 , 808 Total Annualized Capital Costs 159,600

OPERATING COSTS

Direct Operating Costs Operating Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/y r 16,000 Supervisor 15% of oper labor costs 2,400 Maintenance Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 16,000 Maintenance Materials 100% of maint labor costs 16,000 Utilities, Reagents, Waste Management & Replacements Electricity 0.05 $/kW-hr, 360 kW-hr, 8000 hr/yr 131,637 Natural Gas (Fuel) 5.50 $/Mft3, 1,168 scfm, 8000 hr/yr 3,084,027 Water NA - Compressed Air NA - Reagent #1(Caustic) NA - Reagent #2 NA - Solid Waste Disposal NA - Hazardous Waste Disposal NA - Wastewater Treatment NA - Catalyst NA - Replacement Parts NA - Total Annual Direct Operating Costs 3,266,064

Indirect Operating Costs Overhead 60% of oper, maint & supv labor + maint mtl costs 30,240 Property tax (1% total capital costs) 1% of total capital costs (TCI) 16,908 Insurance (1% total capital costs) 1% of total capital costs (TCI) 16,908 Administration (2% total capital costs) 2% of total capital costs (TCI) 33,816 Capital Recovery 9.44% for a 20- year equipment life and a 7% interest ra t 159,600 Total Indirect Operating Costs Sum indirect oper costs + capital recovery cos t 257,473

Total Annual Cost (Annualized Capital Cost + Operating Cost) 3,523,537 Pollutant Removed (tons/yr) B

- Cost per ton of PM Removed

- Notes & Assumptions 1 EPA control cost guideline for thermal oxidizers for cost analysis. 2 EPA Air Pollution Control Cost Manual 6th Ed 2002 3 Capital cost estimate from John Zink 4 Heat capacity from Perry's 5th Edition Chemical engineers Handbook 

### Attachment 2 Table 4 Continued

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-93 NSM Line 5 NOx Control - Duct Burner for SCR & Flue Gas Re-Heat - Duct Burner (Continued)

Capital Recovery Factors Primary Installation Interest Rate 7.00% Equipment Life 20 years CRF 0.0944

Catalyst Replacement Cost Catalyst Life 2 years CRF 0.5531 Catalyst cost per unit 650 $/f t 3 Amount Required 0 ft 3 Catalyst Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 33.72 $ each Amount Required 0 Numbe r Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag ( 13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Catalyst 0
Design Flow 207,000 scf m 235,140 acf m

Operating Cost Calculations Utilization Rate 90.0% Annual hours of operation: 8,000 Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor 15% NA 2400 15% of Operator Costs Maint Labor 32 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maint Mtls NA NA NA of purchased equipment costs Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 359.9 kW-hr 2,879,147 131,637 $/kW-hr, 360 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 1,168 scfm 560,732 3,084,027 $/Mft3, 1,168 scfm, 8000 hr/yr Water 0.22 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Ca u 280 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, Ammonia Reagent #2 100 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 50 wt% Urea Soln. SW Disposal 25.00 Ton 0.000 ton/hr 0 0 $/Ton, 0.000 , 8000 hr/yr Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/Ton, 0.000 , 8000 hr/yr WW Treat 1.50 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr Catalyst 650 ft 3 0 ft 3 2 yr life 0 $/ft3, 0.0 ft3, 2 yr life, 8000 hr/yr Rep Parts 33.72 $/bag 0 b ags 2 yr life 0 $/$/bag, 0.0 bags, 2 yr life, 8000 hr/y r *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation Uncontrolled Emission Rate

Emission Unit of Flow Unit of Emis Rate Factor Measure Rate Measure T/yr Comments/Notes

Controlled Emission Rate Perf Unit of Flow Unit of Emis Rate Guarantee Measure Rate Measure T/yr Comments/Notes

Emission Reduction T/yr

Flow acfm D P in H2O B lower Ef f Motor Eff kW Blower 304,525 5 0.55 0.9 359.9 OAQPS Cost Cont Manual 5th ed - Eq 3.37 

## Attachment 2 Table 4 Continued

BACT Emission Control Cost Analysis

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-94 NSM Line 5 NOx Control - Duct Burner for SCR & Flue Gas Re-Heat - Duct Burner (Continued)

Capital Recovery Factors Primary Installation Interest Rate 7.00% Equipment Life 20 years CRF 0.0944

Catalyst Replacement Cost Catalyst Life 2 years CRF 0.5531 Catalyst cost per unit 650 $/f t 3 Amount Required 0 ft 3 Catalyst Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 33.72 $ each Amount Required 0 Numbe r Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag ( 13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Catalyst 0
Design Flow 207,000 scf m 235,140 acf m

Operating Cost Calculations Utilization Rate 90.0% Annual hours of operation: 8,000 Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor 15% NA 2400 15% of Operator Costs Maint Labor 32 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maint Mtls NA NA NA of purchased equipment costs Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 359.9 kW-hr 2,879,147 131,637 $/kW-hr, 360 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 1,168 scfm 560,732 3,084,027 $/Mft3, 1,168 scfm, 8000 hr/yr Water 0.22 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Ca u 280 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, Ammonia Reagent #2 100 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 50 wt% Urea Soln. SW Disposal 25.00 Ton 0.000 ton/hr 0 0 $/Ton, 0.000 , 8000 hr/yr Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/Ton, 0.000 , 8000 hr/yr WW Treat 1.50 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr Catalyst 650 ft 3 0 ft 3 2 yr life 0 $/ft3, 0.0 ft3, 2 yr life, 8000 hr/yr Rep Parts 33.72 $/bag 0 b ags 2 yr life 0 $/$/bag, 0.0 bags, 2 yr life, 8000 hr/y r *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation Uncontrolled Emission Rate

Emission Unit of Flow Unit of Emis Rate Factor Measure Rate Measure T/yr Comments/Notes

Controlled Emission Rate Perf Unit of Flow Unit of Emis Rate Guarantee Measure Rate Measure T/yr Comments/Notes

Emission Reduction T/yr

Flow acfm D P in H2O B lower Ef f Motor Eff kW Blower 304,525 5 0.55 0.9 359.9 OAQPS Cost Cont Manual 5th ed - Eq 3.37 

## Attachment 2 Table 4 Continued

BACT Emission Control Cost Analysis

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-95 Attachment 2 Table 4 Continued NSM Line 5 NOx Control - Duct Burner for SCR & Flue Gas Re-Heat - Duct Burner (Continued) BACT Emission Control Cost Analysis

Duct Burner Cost Estimate

Auxiliary Fuel Use Equation 3.19 T wi 150 Deg F - Temperature of waste gas into heat recovery T fi 750 Deg F - Temperature of Flue gas into of heat recovery T ref 77 Deg F - Reference temperature for fuel combustion calculations FER 70% Factional Heat Recovery % Heat recovery section efficiency

T wo 570 Deg F - Temperature of waste gas out of heat recovery 152292 scfm
359 scf/lbmole
T fo 330 Deg F - Temperature of flue gas into of heat recovery mw flue gas (air) Flow Calculator mw flue gas (H2O) -h caf 21502 Btu/lb Heat of combustion auxiliary fuel (methane) Design Flow 207,000 scfm 28 mw CO 0 v % 0 -h w g 0 Btu/lb Heat of combustion waste gas 150 Temp Deg F 44 mw CO2 15 v % 279979.72 22.0% 0.24 0.0528 C p wg 0.2684 Btu/lb - Deg F Heat Capacity of waste gas (air) na % Moisture 18 mw H2O 10 v % 76358.106 6.0% 0.46 0.0276
p wg 0.0739 lb/scf - Density of waste gas (air) at 77 Deg F 235,140 acfm 28 mw N2 60 v % 712675.65 56.0% 0.27 0.1512
p af 0.0408 lb/scf - Density of auxiliary fuel (methane) at 77 Deg F 32 mw O2 15 v % 203621.62 16.0% 0.23 0.0368 Q w g 207,000 scfm - Flow of waste gas 330 100 v % 1272635.1 100.0% 0.2684 304,525 Q af 1,168 scfm - Flow of auxiliary fuel

Year 2005 Inflation Rate 3.0% Cost Calculations 208,168 scfm Flue Gas Cost in 1988 $'s $455,868 Current Cost @ 3% inflation $753,480 Heat Rec % A B 0 10,294 0.2355 Exponents per equation 3.24 0.3 13,149 0.2609 Exponents per equation 3.25 0.5 17,056 0.2502 Exponents per equation 3.26 0.7 21,342 0.2500 Exponents per equation 3.27

Reference: OAQPS Control Cost Manual 5th Ed Feb 1996 - Cha p ter 3 Thermal & Catal y tic Incinerators (EPA 453/B

- 96

- 001)

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-96 BACT Attachment 2 Table 6: Furnace 5 PM Control - Wet Wall ESP NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1 & 2)

ESP + auxillary equipment 3,090,000 Instrumentation 10% of control device cost (A) 309,000 MN Sales Taxes 6.5% of control device cost (A) 200,850 Freight 5% of control device cost (A) 154,500 Purchased E q ui p ment Total (B) 22% 3,754,350

Direct Installation Costs

Foundations & supports 4% of purchased equip cost (B) 150,174 Handling & erection 50% of purchased equip cost (B) 1,877,175 Electrical 8% of purchased equip cost (B) 300,348 Piping 1% of purchased equip cost (B) 37,544 Insulation for ductwork 2% of purchased equip cost (B) 75,087 Painting 2% of purchased equip cost (B) 75,087 Direct Installation Costs 2,515,415

Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA

Total Direct Ca p ital Costs, DC 67% 6,269,765

Indirect Capital Costs Engineering 20% of purchased equip cost (B) 750,870 Construction & field expenses 20% of purchased equip cost (B) 750,870 Constractor fees 10% of purchased equip cost (B) 375,435 Start-up 1% of purchased equip cost (B) 37,544 Performance Test 1% of purchased equip cost (B) Model Study 2% of purchased equip cost (B) 75,087 Contingencies 3% of purchased equip cost (B) 112,631 Total Indirect Capital Costs 57% 2,102,436 Total Ca p ital Investment (TCI) = DC + IC 8,372,201



### OPERATING COSTS

Direct Operating Costs Operator 32.00 $/Hr, 1.0 hr/8 hr shift, 8000 hr/y r 32,000 Supervisor 15% of operator costs 4,800 Coordinator 33% of operator costs 10,560 Operating materials

Maintenance Labor 0.1155 $/ft2 collector area; $5775 if < 50,000 ft2 39,149 Maintenance Materials 1% of purchased equipment costs 37,544 Utilities Electricity 0.05 $/kW-hr, 387.2 kW-hr, 8000 hr/yr 141,622 Water 0.22 $/Mgal, 2,115.0 gpm, 8000 hr/yr 221,867 Solid Waste Disposal NA - Wastewater Treatment 1.50 $/Mgal, 2,115.0 gpm, 8000 hr/yr 1,522,800 Reagent (Caustic) 280.00 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 5 - Total Annual Direct O p eratin g Costs, DC 2,010,343

Indirect Operating Costs Overhead 60% of oper, maint & supv labor + maint mtl costs 68,096 Administration (2% total capital costs) 2% of total capital costs (TCI) 167,444 Property tax (1% total capital costs) 1% of total capital costs (TCI) 83,722 Insurance (1% total capital costs) 1% of total capital costs (TCI) 83,722 Captial Recover y 9% for a 20- year equipment life and a 7% interest rat 790,277 Total Indirect O p eratin g Costs, IC 1,193,260

Total Annual Cost (Annualized Ca p ital Cost + O p eratin g Cost) 3,203,603 Pollutant Removed (tons/yr) B 667.9 Cost p er ton of PM Removed 4,796 Notes & Assumptions 1 Equipment cost estimates assumed to be 3% higher than that of dry ESP. 2 Capital cost estimated from 2001 Wheelabrator costs for ESP on proposed taconite processing facilit y 3 EPA Cost Manual 6th Ed. 2002

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-97 BACT Attachment 2 Table 6: Furnace 5 PM Control - Wet Wall ESP (Continued)

Capital Recovery Factors Enter Data in Blue Highlighted Cells Primary Installation Data to Summary Table in Yellow Highlighted Cells Interest Rate 7.0% Equipment Life 20 years CRF 0.0944

Catalyst Replacement Cost Catalyst Life 2 years CRF 0.5531 Catalyst cost per unit 0 $/ft 3 Amount Required 0 ft 3 Catalyst Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 0 $ each Amount Required 0 Number Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Catalyst 0

Design Flow 207,240 scfm

235,000 acf m

Operating Cost Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0% Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 1 hr/8 hr shift 1,000 32,000 $/Hr, 1.0 hr/8 hr shift, 8000 hr/yr Supervisor NA NA NA Calc'd as % of labor costs Maint Labor 0.1155 $/ft 2 collect o 71,423 ft 2 collector area 8,249 $/ft 2 collector area; $5775 if < 50,000 ft 2 Maint Mtls NA NA 1% of purchased equipment costs Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 387 kW-hr 3,097,549 141,622 $/kW-hr, 387.2 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/yr Water 0.22 Mgal 2115 gpm 1,015,200 221,867 $/Mgal, 2,115.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Ca u 280 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH Reagent #2 300 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH SW Disposal 25.00 Ton 0.000 ton/hr 0 0 $/Ton, 0.100 gr/dscf, 8000 hr/yr Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/Ton, 0.100 gr/dscf, 8000 hr/yr WW Treat 1.50 Mgal 2115 gpm 1,015,200 1,522,800 $/Mgal, 2,115.0 gpm, 8000 hr/yr

Catalyst 0 ft 3 0 ft 3 2 yr life 0 $/ft3, 0.0 ft3, 2 yr life, 8000 hr/yr Rep Parts 0 $/bag 0 b ags 2 yr life 0 $/$/bag, 0.0 bags, 2 yr life, 8000 hr/yr *annual use rate is in same units of measurement as the unit cost facto r Emission Control Rate Calculation Uncontrolled Emission Rate

Emission Unit of Flow Unit of Control Eff. Emis Rate Factor Measure Rate Measure % T/yr Comments/Notes 0.1 gr/dsc f 207,240 dscf m NA 710.54 Controlled Emission Rate Perf Unit of Flow Unit of Control Eff. Emis Rate Guarantee Measure Rate Measure % T/yr Comments/Notes 0.006 gr/dscf 207,240 dscfm 94% 42.63 Calculated basis in and out grain loadings Emission Reduction T/yr 667.9

Electrical Consumption Requirements Kilowatts
Flow acfm D P in H2O Blower-Motor Eff kW Blower 235,000 5 0.65 211.5 OAQPS Cost Cont Manual 6th ed - Eq 3.46 Flow gpm D P ft H2O Pump Eff Motor Eff Pump 1 2115 60 0.8 0.9 33.1 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Pump 2 0 60 0.8 0.9 0.0 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Area sqft TR pwr # Hoppers Htr Pwr ESP 71,423 138.6 2 4 142.6 OAQPS Cost Cont 5th ed - Eq 6.29 & 6.30

Caustic Use 0.00 lb/hr SO2 2.50 lb NaOH/lb SO2 0.000 T/hr Caustic Lime Use 0.00 lb/hr SO2 1.53 lb Lime/lb SO2 0.000 T/hr Lime

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-98 BACT Attachment 2 Table 7: Furnace 5 PM Control - Dry ESP

NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1)

ESP + auxillary equipment 3,000,000 Instrumentation 10% of control device cost (A) 300,000 MN Sales Taxes 6.5% of control device cost (A) 195,000 Freight 5% of control device cost (A) 150,000 Purchased Equipment Total (B) 22% 3,645,000

Direct Installation Costs

Foundations & supports 4% of purchased equip cost (B) 145,800 Handling & erection 50% of purchased equip cost (B) 1,822,500 Electrical 8% of purchased equip cost (B) 291,600 Piping 1% of purchased equip cost (B) 36,450 Insulation for ductwork 2% of purchased equip cost (B) 72,900 Painting 2% of purchased equip cost (B) 72,900 Direct Installation Costs 2,442,150

Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA

Total Direct Capital Costs, DC 67% 6,087,150

Indirect Capital Costs Engineering 20% of purchased equip cost (B) 729,000 Construction & field expenses 20% of purchased equip cost (B) 729,000 Constractor fees 10% of purchased equip cost (B) 364,500 Start-up 1% of purchased equip cost (B) 36,450 Performance Test 1% of purchased equip cost (B) Model Study 2% of purchased equip cost (B) 72,900 Contingencies 3% of purchased equip cost (B) 109,350 Total Indirect Capital Costs 57% 2,041,200 Total Capital Investment (TCI) = DC + IC 8,128,350



### OPERATING COSTS

Direct Operating Costs Operator 32.00 $/Hr, 1.0 hr/8 hr shift, 8000 hr/yr 32,000 Supervisor 15% of operator costs 4,800 Coordinator 33% of operator costs 10,560 Operating materials

Maintenance Labor 0.1155 $/ft2 collector area; $5775 if < 50,000 ft2 38,249 Maintenance Materials 1% of purchased equipment costs 36,450 Utilities Electricity 0.05 $/kW-hr, 354.1 kW-hr, 8000 hr/yr 129,503 Water NA - Solid Waste Disposal 25.00 $/Ton, 0.100 gr/dscf, 8000 hr/yr 17,763 Wastewater Treatment NA - Reagent (Caustic) 280.00 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 5 - Total Annual Direct Operating Costs, DC 269,326

Indirect Operating Costs Overhead 60% of oper, maint & supv labor + maint mtl costs 66,900 Administration (2% total capital costs) 2% of total capital costs (TCI) 162,567 Property tax (1% total capital costs) 1% of total capital costs (TCI) 81,284 Insurance (1% total capital costs) 1% of total capital costs (TCI) 81,284 Captial Recover y 9% for a 20- year equipment life and a 7% interest ra t 767,259 Total Indirect Operating Costs, IC 1,159,292

Total Annual Cost (Annualized Capital Cost + Operating Cost) 1,428,618 Pollutant Removed (tons/yr) B 

### 667.9 Cost per ton of PM Removed 2,139 Notes & Assumptions 1 Capital cost estimated from 2001 Wheelabrator costs for ESP on proposed taconite processing facility
2 

### EPA Cost Manual 6th Ed. 2002

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-99 BACT Attachment 2 Table 7: Furnace 5 PM Control - Dry ESP (Continued)

Capital Recovery Factors Enter Data in Blue Highlighted Cells Primary Installation Data to Summary Table in Yellow Highlighted Cells Interest Rate 7.0% Equipment Life 20 years CRF 0.0944

Catalyst Replacement Cost Catalyst Life 2 years CRF 0.5531 Catalyst cost per unit 0 $/ft 3 Amount Required 0 ft 3 Catalyst Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 0 $ each Amount Required 0 Number Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Catalyst 0

Design Flow 207,240 dscfm

235,000 acf m

Operating Cost Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0% Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 1 hr/8 hr shift 1,000 32,000 $/Hr, 1.0 hr/8 hr shift, 8000 hr/yr Supervisor NA NA NA Calc'd as % of labor costs Maint Labor 0.1155 $/ft 2 collect o 71,423 ft 2 collector area 8,249 $/ft 2 collector area; $5775 if < 50,000 ft 2 Maint Mtls NA NA 1% of purchased equipment costs Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 354 kW-hr 2,832,480 129,503 $/kW-hr, 354.1 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/yr Water 0.22 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Ca u 280 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH Reagent #2 300 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH SW Disposal 25.00 Ton 0.089 ton/hr 711 17,763 $/Ton, 0.100 gr/dscf, 8000 hr/yr Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/Ton, 0.100 gr/dscf, 8000 hr/yr WW Treat 1.50 Mgal 0 gpm 0 0 $/Mgal, 0.0 gpm, 8000 hr/yr

Catalyst 0 ft 3 0 ft 3 2 yr life 0 $/ft3, 0.0 ft3, 2 yr life, 8000 hr/yr Rep Parts 0 $/bag 0 b ags 2 yr life 0 $/$/bag, 0.0 bags, 2 yr life, 8000 hr/yr *annual use rate is in same units of measurement as the unit cost facto r Emission Control Rate Calculation Uncontrolled Emission Rate

Emission Unit of Flow Unit of Control Eff. Emis Rate Factor Measure Rate Measure % T/yr Comments/Notes 0.1 gr/dsc f 207,240 dscf m NA 710.54 Controlled Emission Rate Perf Unit of Flow Unit of Control Eff. Emis Rate Guarantee Measure Rate Measure % T/yr Comments/Notes 0.006 gr/dscf 207,240 dscfm 94% 42.63 Calculation basis in and out grain loadings Emission Reduction T/yr 667.9

Electrical Consumption Requirements Kilowatts
Flow acfm D P in H2O Blower-Motor Eff kW Blower 235,000 5 0.65 211.5 OAQPS Cost Cont Manual 6th ed - Eq 3.46 Flow gpm D P ft H2O Pump Eff Motor Eff Pump 1 0 60 0.8 0.9 0.0 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Pump 2 0 60 0.8 0.9 0.0 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Area sqft TR pwr # Hoppers Htr Pwr ESP 71,423 138.6 2 4 142.6 OAQPS Cost Cont 5th ed - Eq 6.29 & 6.30

Caustic Use 0.00 lb/hr SO2 2.50 lb NaOH/lb SO2 0.000 T/hr Caustic Lime Use 0.00 lb/hr SO2 1.53 lb Lime/lb SO2 0.000 T/hr Lime

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-100 BACT Attachment 2 Table 8: Furnace 5 PM Control - Wet Scrubber NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1)

Purchased Equipment Costs - Absorber + packing + auxillary equipment, EC (2) 2,982,000 Instrumentation 10% of control device cost (A) 298,200 MN Sales Taxes 6.5% of control device cost (A) 193,830 Freight 5% of control device cost (A) 149,100 Purchased Equipment Total (B) 22% 3,623,130

Installation (3)

Foundations & supports 12% of purchased equip cost (B) 434,776 Handling & erection 40% of purchased equip cost (B) 1,449,252 Electrical 1% of purchased equip cost (B) 36,231 Piping 30% of purchased equip cost (B) 1,086,939 Insulation 1% of purchased equip cost (B) 36,231 Painting 1% of purchased equip cost (B) 36,231 Installation Total 85% 3,079,661

Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA

Total Direct Capital Cost, DC 6,702,791

Indirect Capital Costs Engineering, supervision 10% of purchased equip cost (B) 362,313 Construction & field expenses 10% of purchased equip cost (B) 362,313 Construction fee 10% of purchased equip cost (B) 362,313 Start-up 1% of purchased equip cost (B) 36,231 Performance test 1% of purchased equip cost (B) 36,231 Contingencies 3% of purchased equip cost (B) 108,694 Total Indirect Capital Costs, IC 35% 1,268,096

Total Capital Investment (TCI) = DC + IC 7,970,886


### OPERATING COSTS

Direct Annual Operating Costs, DC

Operating Labor

Operator 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 14,400 Supervisor 0.15 15% of Operator Costs 2,160 Operating Materials

Reagent #1 NA - Lime NA - Packing 0.00 ft3/5 yr - Wastewater Treatment 1.50 $/Mgal, 423.0 gpm, 8000 hr/yr, 274,104 Maintenance

Maintenance Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 14,400 Maintenance Materials 100% of Maint Labor, 0.0 , 8000 hr/yr 14,400 Electricity - Fan, Pump 0.05 $/kW-hr, 955 kW-hr, 8000 hr/yr 314,249

Total Annual Direct Operating Costs 633,713

Indirect Operating Costs Overhead 60% of total labor and material costs 27,216 Administration (2% total capital costs) 2% of total capital costs (TCI) 159,418 Property tax (1% total capital costs) 1% of total capital costs (TCI) 79,709 Insurance (1% total capital costs) 1% of total capital costs (TCI) 79,709 Capital Recover y 14.24% for a 10- year equipment life and a 7% interest rate 1,134,875 Total Annual Indirect Operating Costs Sum indirect oper costs + capital recovery cost 1,480,926

Total Annual Cost (Annualized Capital Cost + Operating Cost) 2,114,639

Pollutant Removed (tons/yr) B PM10 Filterable 668

Cost per ton of Pollutant Removed PM10 Total 3,166

Notes & Assumptions 1) Sept 2004 Cost Estimates from Ceilcote 2) Cost factors for packed bed scrubber, unit is a combined ventrui/packed bed system 3) EPA Air Pollution Control Cost Manual 6th Ed 2002

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-101 BACT Attachment 2 Table 8: Furnace 5 PM Control - Wet Scrubber (Continued)

Capital Recovery Factors Primary Installation Interest Rate 7.0% Equipment Life 10 years CRF 0.1424

Stainless Steel Packing Replacement Cost Packing Life 5 years CRF 0.0000 Packing cost per unit 35.86956522 $/ft 3 Amount Required 0 ft 3 Packing Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 33.72 $ eac h Amount Required 0 Numbe r Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Packing 0

Design Flo w 207,240 dscf m 235,000 acf m

Operating Cost Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0%

Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 0.5 hr/8 hr shift 450 14,400 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor 15% of Op. NA 2,160 15% of Operator Costs Maint Labor 32.00 Hr 0.5 hr/8 hr shift 450 14,400 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maint Mtls 100% of Maint Labor NA 14,400 of Maint Labor, 0.0 , 8000 hr/yr Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 954.6 kW-hr 6,873,212 314,249 $/kW-hr, 955 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/y r Water 0.22 Mgal 423.0 gpm 182,736 39,936 $/Mgal, 423.0 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Caustic) 280 Ton 0.00 lb/hr 0 0 $/Ton, 0.0 lb/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH Reagent #2 (Lime) 300 Hr 0.00 lb/h r 0 0 $/Hr, 0.0 lb/hr, 8000 hr/y r SW Disposal 25.00 Ton 0.000 ton/h r 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/y r Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/yr WW Treat 1.50 Mgal 423.0 gpm 182,736 274,104 $/Mgal, 423.0 gpm, 8000 hr/yr, Catalyst 0 ft 3 0 ft 3 0 0 $/ft3, 0.0 ft3, 0, 8000 hr/y r Rep Parts 0 b ag 0 b ags 2 yr life 0 $/bag, 0.0 bags, 2 yr life, 8000 hr/y r *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation Uncontrolled Emission Rate Emission Unit of Flow Unit of Control Eff. Emis Rate Factor Measure Rate Measure % T/yr Comments/Notes 0.1 gr/dscf 207,240 dscf m NA 710.54 Controlled Emission Rate Perf Unit of Flow Unit of Control Eff. Emis Rate Guarantee Measure Rate Measure % T/yr Comments/Notes 0.006 gr/dscf 207,240 dscf m 94% 42.63 Calculation basis in and out grain loadings Emission Reduction T/yr 667.9

Flow acfm ∆ P in H2O Blower Eff Motor Eff kW Blower 235,000 12 0.55 0.7 857.0 OAQPS Cost Cont Manual 6th ed - Eq 1.48 Flow gpm P ft H2O Pump Eff Motor Eff Circ Pump 2,115 125 0.8 0.7 88.8 OAQPS Cost Cont Manual 6th ed - Eq 1.49 H2O WW Disch 423.0 62.5 0.8 0.7 8.9 OAQPS Cost Cont Manual 6th ed - Eq 1.49

Caustic Use 0.00 lb/hr SO2 2.50 lb NaOH/lb SO2 0.00 lb/hr Caustic Lime Use 0.00 lb/hr SO2 1.53 lb Lime/lb SO2 0.00 lb/hr Lime Water Makeup Rate/WW Disch = 20% of circulating water rate Utility use rates basis: 8000 hr/yrP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-102BACT Attachment 2 Table 9: Furnace 5 Pellet Discharge Control Cost SummaryNSM Line 5 Restart BACT Emission Control Cost AnalysisPM Control Cost SummaryControl TechnologyControlEff %EmissionsT/yEmissionReductionT/yrInstalledCapital Cost $AnnualizedOperatingCost $/yrPollutionControl Cost$/tonAir Toxic's& AQRV's?EnergyImpacts?Non-Air EnvImpacts?Wet Scrubbers HighEfficiency92% 5 52 133,650 177,067 3,390 None High Waste-waterWet Wall ElectroStaticPrecipitator (WWESP)92% 5 52 4,744,247 1,033,809 19,792 None Low Waste-water

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-103 BACT Attachment 2 Table 10: Furnace 5 PM Control - Wet Wall ESP NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1 & 2)

ESP + auxillary equipment 1,751,000 Instrumentation 10% of control device cost (A) 175,100 MN Sales Taxes 6.5% of control device cost (A) 113,815 Freight 5% of control device cost (A) 87,550 Purchased E q ui p ment Total (B) 22% 2,127,465

Direct Installation Costs

Foundations & supports 4% of purchased equip cost (B) 85,099 Handling & erection 50% of purchased equip cost (B) 1,063,733 Electrical 8% of purchased equip cost (B) 170,197 Piping 1% of purchased equip cost (B) 21,275 Insulation for ductwor k 2% of purchased equip cost (B) 42,549 Painting 2% of purchased equip cost (B) 42,549 Direct Installation Costs 1,425,402

Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA

Total Direct Ca p ital Costs, DC 67% 3,552,867

Indirect Capital Costs Engineering 20% of purchased equip cost (B) 425,493 Construction & field expenses 20% of purchased equip cost (B) 425,493 Constractor fees 10% of purchased equip cost (B) 212,747 Start-up 1% of purchased equip cost (B) 21,275 Performance Tes t 1% of purchased equip cost (B) Model Study 2% of purchased equip cost (B) 42,549 Contingencies 3% of purchased equip cost (B) 63,824 Total Indirect Capital Costs 57% 1,191,380 Total Ca p ital Investment (TCI) = DC + IC 4,744,247



### OPERATING COSTS

Direct Operating Costs Operato r 32.00 $/Hr, 1.0 hr/8 hr shift, 8000 hr/yr 32,000 Supervisor 15% of operator costs 4,800 Coordinator 33% of operator costs 10,560 Operating materials

Maintenance Labor 0.1155 $/ft2 collector area; $5775 if < 50,000 ft2 21,635 Maintenance Materials 1% of purchased equipment costs 21,275 Utilities Electricity 0.05 $/kW-hr, 56.2 kW-hr, 8000 hr/yr 20,549 Water 0.22 $/Mgal, 288.0 gpm, 8000 hr/yr 30,212 Solid Waste Disposal NA - Wastewater Treatment 1.50 $/Mgal, 288.0 gpm, 8000 hr/yr 207,360 Reagent (Caustic) 280.00 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 5 - Total Annual Direct O p eratin g Costs, DC 348,390

Indirect Operating Costs Overhead 60% of oper, maint & supv labor + maint mtl costs 47,826 Administration (2% total capital costs) 2% of total capital costs (TCI) 94,885 Property tax (1% total capital costs) 1% of total capital costs (TCI) 47,442 Insurance (1% total capital costs) 1% of total capital costs (TCI) 47,442 Captial Recover y 9% for a 20- year equipment life and a 7% interest rat 447,823 Total Indirect O p eratin g Costs, IC 685,419

Total Annual Cost (Annualized Ca p ital Cost + O p eratin g Cost) 1,033,809 Pollutant Removed (tons/ y r) 52.2 Cost p er ton of PM Removed 19,792 Notes & Assumptions 1 Equipment cost estimates assumed to be 3% higher than that of dry ESP. 2 Capital cost estimated from 2001 Wheelabrator costs for ESP on proposed taconite processing facilit y 3 EPA Cost Manual 6th Ed. 2002

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-104 BACT Attachment 2 Table 10: Furnace 5 PM Control - Wet Wall ESP (Continued)

Capital Recovery Factors Enter Data in Blue Highlighted Cells Primary Installation Data to Summary Table in Yellow Highlighted Cells Interest Rate 7.0% Equipment Life 20 years CRF 0.0944

Catalyst Replacement Cost Catalyst Life 2 years CRF 0.5531 Catalyst cost per unit 0 $/ft 3 Amount Required 0 ft 3 Catalyst Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cos t 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per uni t 0 $ each Amount Required 0 Numbe r Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag ( 13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cos t 0

Total Cost Replacement Parts & Catalyst 0

Design Flow 27,700 scfm

32,000 acfm

t Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0% Unit Unit of Use Unit of Annual Annual Comments Cost $ Measure Rate Measure Use* Cost 32 Hr 1 hr/8 hr shift 1,000 32,000 $/Hr, 1.0 hr/8 hr shift, 8000 hr/yr NA NA NA Calc'd as % of labor costs 0.1155 $/ft 2 collect o 9,726 ft 2 collector area 4,125 $/f t 2 collector area; $5775 if < 50,000 ft 2 NA NA 1% of purchased equipment costs

e nts, Waste Management & Replacements 0.046 kW-hr 56 kW-hr 449,436 20,549 $/kW-hr, 56.2 kW-hr, 8000 hr/yr 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/yr 0.22 Mgal 288 gpm 138,240 30,212 $/Mgal, 288.0 gpm, 8000 hr/yr 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr 280 Ton 0 lb-mole/hr 0 0 $/Ton, 0.0 lb-mole/hr , 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH 300 Ton 0 lb-mole/h r 0 0 $/Ton, 0.0 lb-mole/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH 25.00 Ton 0.000 ton/h r 0 0 $/Ton, 0.060 gr/dscf, 8000 hr/yr 273.18 Ton 0.000 ton/hr 0 0 $/Ton, 0.060 gr/dscf, 8000 hr/yr

1.50 Mgal 288 gpm 138,240 207,360 $/Mgal, 288.0 gpm, 8000 hr/yr

0 ft 3 0 ft 3 2 yr life 0 $/ft3, 0.0 ft3, 2 yr life, 8000 hr/y r 0 $/bag 0 b ags 2 yr life 0 $/$/bag, 0.0 bags, 2 yr life, 8000 hr/y r *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation E mission Rate Unit of Flow Unit of Control Eff. Emis Rate Measure Rate Measure % T/yr Comments/Notes gr/dscf 27,700 dscf m NA 56.98 i ssion Rate Unit of Flow Unit of Control Eff. Emis Rate Measure Rate Measure % T/yr Comments/Notes gr/dscf 27,700 dscfm 92% 4.75 Calculated basis in and out grain loadings

c tion T/yr 52.2

Electrical Consumption Requirements Kilowatts
Flow acfm D P in H2O Blower-Motor Eff kW Blower 32,000 5 0.65 28.8 OAQPS Cost Cont Manual 6th ed - Eq 3.46 Flow gpm D P ft H2O Pump Eff Motor Eff Pump 1 288 60 0.8 0.9 4.5 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Pump 2 0 60 0.8 0.9 0.0 OAQPS Cost Cont Manual 5th ed - Eq 9.49 Area sqft TR pwr # Hoppers Htr Pwr ESP 9,726 18.9 2 4 22.9 OAQPS Cost Cont 5th ed - Eq 6.29 & 6.30

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-105 BACT Attachment 2 Table 11: Furnace 5 Pellet Discharge PM Control - Wet Scrubber NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A) , (1)

Purchased Equipment Costs - Absorber + packing + auxillary equipment, EC (2) 50,000 Instrumentation 10% of control device cost (A) 5,000 MN Sales Taxes 6.5% of control device cost (A) 3,250 Freight 5% of control device cost (A) 2,500 Purchased Equipment Total (B) 22% 60,750

Installation

Foundations & supports 12% of purchased equip cost (B) 7,290 Handling & erection 40% of purchased equip cost (B) 24,300 Electrical 1% of purchased equip cost (B) 608 Piping 30% of purchased equip cost (B) 18,225 Insulation 1% of purchased equip cost (B) 608 Painting 1% of purchased equip cost (B) 608 Installation Total 85% 51,638

Site Preparation, as required Site Specific NA Buildings, as required Site Specific NA

Total Direct Capital Cost, DC 112,388

Indirect Capital Costs Engineering, supervision 10% of purchased equip cost (B) 6,075 Construction & field expenses 10% of purchased equip cost (B) 6,075 Construction fee 10% of purchased equip cost (B) 6,075 Start-up 1% of purchased equip cost (B) 608 Performance test 1% of purchased equip cost (B) 608 Contingencies 3% of purchased equip cost (B) 1,823 Total Indirect Capital Costs, IC 35% 21,263

Total Capital Investment (TCI) = DC + IC 133,650


### OPERATING COSTS

Direct Annual Operating Costs, DC

Operating Labor

Operator 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 14,400 Supervisor 0.15 15% of Operator Costs 2,160 Operating Materials

Reagent #1 NA - Lime NA - Packing 0.00 ft3/5 yr - Wastewater Treatment 1.50 $/Mgal, 57.6 gpm, 8000 hr/yr, 37,325 Maintenance

Maintenance Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 14,400 Maintenance Materials 100% of Maint Labor, 0.0 , 8000 hr/yr 14,400 Electricity - Fan, Pump 0.05 $/kW-hr, 130 kW-hr, 8000 hr/yr 42,791

Total Annual Direct Operating Costs 125,476

Indirect Operating Costs Overhead 60% of total labor and material costs 27,216 Administration (2% total capital costs) 2% of total capital costs (TCI) 2,673 Property tax (1% total capital costs) 1% of total capital costs (TCI) 1,337 Insurance (1% total capital costs) 1% of total capital costs (TCI) 1,337 Capital Recover y 14.24% for a 10- year equipment life and a 7% interest rate 19,029 Total Annual Indirect Operating Costs Sum indirect oper costs + capital recovery cos t 51,591

Total Annual Cost (Annualized Capital Cost + Operating Cost) 177,067

Pollutant Removed (tons/yr) PM10 Filterable 52

Cost per ton of Pollutant Removed PM10 Total 3,390

Notes & Assumptions 1) Oct 2004 Cost Estimate from Ducon 2) Cost factors for packed bed scrubber, unit is a combined ventrui/packed bed system 3) EPA Air Pollution Control Cost Manual 6th Ed 2002

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-106 BACT Attachment 2 Table 11: Furnace 5 Pellet Discharge PM Control - Wet Scrubber (Continued)

Capital Recovery Factors Primary Installation Interest Rate 7.0% Equipment Life 10 years CRF 0.1424

Stainless Steel Packing Replacement Cost Packing Life 5 years CRF 0.0000 Packing cost per unit 35.86956522 $/ft 3 Amount Required 0 ft 3 Packing Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Replacement Parts & Equipment Equipment Life 2 CRF 0.5531 Rep part cost per unit 33.72 $ eac h Amount Required 0 Numbe r Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Packing 0

Design Flo w 27,700 dscf m 32,000 acf m

Operating Cost Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0%

Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32 Hr 0.5 hr/8 hr shift 450 14,400 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor 15% of Op. NA 2,160 15% of Operator Costs Maint Labor 32.00 Hr 0.5 hr/8 hr shift 450 14,400 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maint Mtls 100% of Maint Labor NA 14,400 of Maint Labor, 0.0 , 8000 hr/yr Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 130.0 kW-hr 935,927 42,791 $/kW-hr, 130 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/y r Water 0.22 Mgal 57.6 gpm 24,883 5,438 $/Mgal, 57.6 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1(Caustic) 280 Ton 0.00 lb/hr 0 0 $/Ton, 0.0 lb/hr, 8000 hr/yr, 62 lb/lbmole, 50 wt% NaOH Reagent #2 (Lime) 300 Hr 0.00 lb/h r 0 0 $/Hr, 0.0 lb/hr, 8000 hr/y r SW Disposal 25.00 Ton 0.000 ton/h r 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/y r Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/yr WW Treat 1.50 Mgal 57.6 gpm 24,883 37,325 $/Mgal, 57.6 gpm, 8000 hr/yr, Catalyst 0 ft 3 0 ft 3 0 0 $/ft3, 0.0 ft3, 0, 8000 hr/y r Rep Parts 0 b ag 0 b ags 2 yr life 0 $/bag, 0.0 bags, 2 yr life, 8000 hr/y r *annual use rate is in same units of measurement as the unit cost factor Emission Control Rate Calculation Uncontrolled Emission Rate Emission Unit of Flow Unit of Control Eff. Emis Rate Factor Measure Rate Measure % T/yr Comments/Notes 0.06 gr/dscf 27,700 dscf m NA 56.98 Controlled Emission Rate Perf Unit of Flow Unit of Control Eff. Emis Rate Guarantee Measure Rate Measure % T/yr Comments/Notes 0.005 gr/dscf 27,700 dscf m 92% 4.75 Calculation basis in and out grain loadings Emission Reduction T/yr 52.2

Flow acfm ∆ P in H2O Blower Eff Motor Eff kW Blower 32,000 12 0.55 0.7 116.7 OAQPS Cost Cont Manual 6th ed - Eq 1.48 Flow gpm P ft H2O Pump Eff Motor Eff Circ Pump 288 125 0.8 0.7 12.1 OAQPS Cost Cont Manual 6th ed - Eq 1.49 H2O WW Disch 57.6 62.5 0.8 0.7 1.2 OAQPS Cost Cont Manual 6th ed - Eq 1.49

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-107 BACT Attachment 2 Table 12: Line 5 Restart - Summary of Utility, Chemical and Supply Costs NSM Line 5 Restart BACT Emission Control Cost Analysis

Utilities Chemicals Etc Unit Cost Units Information Source A ssumptions/Comments

Electricity 0.046 $/kwh Energy Information Administration - Minnesota, Average Electrical Costs for MN in 2002 http://www.eia.doe.gov/emeu/states/sep_prices/ind/pr_ind_mn.html#foot notes , Conversion factor: 3412 BTU/kWh. Natural Gas 5.50 $/mscf Northshore Mining Co. 2004 Gas pricing in NE Minnesota Wate r 0.22 mgal OAQPS Manual '98 cost adjusted for 3% inflation Compressed Air 0.27 $/mscf OAQPS Manual Dried & Filtered, Section 5.4.1.8. '98 cost adjusted for 3% inflation Oxygen 17.45 $/mscf Air Products Web Site Budgetary Price Quote 4/8/05

Wastewater Disposal 1.50 $/mgal EPA Air Pollution Control Cost Manual, 6th ed Used Av g, Section 1.0, Chapter 2 p 2-32. '02 cost estimate Wastewater Biotreat 5.38 $/mgal OAQPS Manual Used Avg, Section 9.6.8 p 9-55. '92 cost adjusted for 3% inflation Solid Waste Disposal (ESP) 25.00 $/ton OAQPS Manual EPA Cost Manual 6th ed. 1/2002, Range $20-$30. Used Average Solid Waste Disposal (Baghouse) $45 25.00 $/ton OAQPS Manual Used $25/ton EPA Cost Manual 6th ed. For Fab Filters 1/2002, Range $35-$55. Average is $45 Haz Waste Disposal 273.18 $/ton OAQPS Manual 10 x's SW, Section 6.4.1.8 p 6-53. '98 cost adjusted for 3% inflation Waste Transport 0.55 $/ton-mi OAQPS Manual Travel Distance 0.5 mi. '98 cost adjusted for 3% inflation Internal Waste Recycle 1.00 $/ton Corus Study Study use$1/ton to cover cost of materials movement
Chemicals & Supplies Ammonia 405 $/ton Hawkins Chemical Anhydrous; includes delivery Urea 0.085 $/lb Hawkins Chemical 50% solution of urea in water; includes delivery Caustic 280 $/ton Hawkins Chemical 50% solution (50 Deg Be); includes delivery Lime 100 $/ton Corus Study SCR Catalyst CO Catalyst Baghouse Filter Bags 35 $/bag Engineering Estimate

Other Annual Op. Hrs 8000 Engineering Estimate Utilization Rate 90% Engineering Estimate Operating Labor 32 $/hr Northshore Mining Co. Taconite Industry Labor Rates Supervisor 15% of Op. Labor cost EPA Cost Manual 6th ed. 1/2002 Maintenance Labor 32.00 $/hr Northshore Mining Co. Taconite Industry Labor Rates

Maintenance Labor - ESP's 0.1155 $/ft2 If area <50,000 ft 2 , then constant $5775 EPA Cost Manual 6th ed. 1/2002, was $12.5/h in 1987. Assumed to be $17.50/h in 2003. Use ratio to estimate factor. ((17.50*0.0825/12.50)=0.1155. Also for Area <50,000 ft2, fixed cost was $4125 in 1987. Used ratio to get $5775 to account for inflation ((17.5*4125)/12.50 = 5775. Maintenance Materials 100% Sales Tax 6.50% Mn Sales Tax Rate Interest Rate 7.0% % Estimated prime rate plus 3% Equipment Life (scrubbers) 10 yrs Engineering Estimate Equipment Life (all other equip. except scrubbers) 20 yrs Engineering Estimate

Note: Reviewed by Northshore Mining Co for consistency with local prices.

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## A-5-108 BACT Attachment 2 Table 13: Furnace 5 NOx Control - Low Temperature Oxidation (LTO) NSM Line 5 Restart BACT Emission Control Cost Analysis
CAPITAL COSTS

Direct Capital Costs

Purchased Equipment (A)

Purchased Equipment Costs - Absorber + packing + auxillary equipment, EC (2) Instrumentation 1% of control device cost (A) MN Sales Taxes 6.5% of control device cost (A) Freight 5% of control device cost (A) Auxiliary equipment (not included in CD cost) 5.0% of control device cost (A) Purchased E q ui p ment Total (B) 18%

Installation (3)

Foundations & supports 12% of purchased equip cost (B) Handling & erection 40% of purchased equip cost (B) Electrical 1% of purchased equip cost (B) Piping 30% of purchased equip cost (B) Insulation 1% of purchased equip cost (B) Painting 1% of purchased equip cost (B) Installation Total 85%

Site Preparation, as required Site Specific Buildings, as required Site Specific

Total Direct Ca p ital Cost, DC

Indirect Capital Costs Engineering, supervision 10% of purchased equip cost (B) Construction & field expenses 10% of purchased equip cost (B) Construction fee 10% of purchased equip cost (B) Start-up 1% of purchased equip cost (B) Performance test 1% of purchased equip cost (B) Contingencies 3% of purchased equip cost (B) Total Indirect Capital Costs, IC (4) 35% Total Capital Investment (TCI) per BOC Paper 6,932,459 Total Annualized Capital Costs (capital recovery) 654,375

OPERATING COSTS

Direct Annual Operating Costs, DC

Operating Labor

Operator 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 16,000 Supervisor 0.15 15% of Operator Costs 2,400 Operating Materials

Reagent #1 (O2) 17 $/Mscf, 10.6 Mscfh, 8000 hr/yr, 1,326,487 Water 0.22 $/Mgal, 124.3 gpm, 8000 hr/yr 13,044 Packing 0.00 ft3/5 yr - Wastewater Treatment 5.38 $/Mgal, 124.3 gpm, 8000 hr/yr, 320,847 Maintenance

Maintenance Labor 32.00 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr 16,000 Maintenance Materials 100% of Maint Labor, 0.0 , 8000 hr/yr 16,000 Electricity ozone gen, pumps & fan 0.05 $/kW-hr, 1,852 kW-hr, 8000 hr/yr 677,527

Total Annual Direct O p eratin g Costs 2,388,305

Indirect O p eratin g Costs Overhead 60% of total labor and material costs 30,240 Administration (2% total capital costs) 2% of total capital costs (TCI) 138,649 Property tax (1% total capital costs) 1% of total capital costs (TCI) 69,325 Insurance (1% total capital costs) 1% of total capital costs (TCI) 69,325 Capital Recover y 9.44% for a 20- year equipment life and a 7% interest rate 654,375 Total Annual Indirect O p eratin g Costs Sum indirect oper costs + capital recovery cost 961,913

Total Annual Cost (Annualized Capital Cost + Operating Cost) 3,350,218

Pollutant Removed (tons/yr) B NOx 231

Cost per ton of Pollutant Removed NOx 14,500

Notes & Assumptions
1) July 2001 Cost Estimates from BOC 2) Cost factors for packed bed scrubber, unit is a combined ventrui/packed bed system 3) EPA Air Pollution Control Cost Manual 6th Ed 2002 4) LoTOx cost of $60/kW ($52/kW adjusted for inflation) Table 5, Paper #147 Adrian Day and Naresh Suchak BOC Gases

### P:\23\38\107 NSM Furnace 5 Restar t\Air Permit App\Submittal\050502 to MPCA (PSD Ap p)\Original Files\Vol I Sect 5 App A (BACT).d oc 

## A-5-109 BACT Attachment 2 Table 13: Furnace 5 NOx Control - Low Temperature Oxidation (LTO) (Continued)

Capital Recovery Factors Primary Installation Interest Rate 7.0% Equipment Life 20 years CRF 0.0944

Stainless Steel Packing Replacement Cost Packing Life 5 years CRF 0.0000 Packing cost per unit 35.86956522 $/ft 3 Amount Required 0 ft 3 Packing Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 Assume Labor = 15% of catalyst cost (basis labor for baghouse replacement) Total Installed Cost 0 Annualized Cost 0

Re p lacement Parts & E q ui p ment Equipment Life 2 CRF 0.5531 Rep part cost per unit 33.72 $ each Amount Required 0 N umber Total Rep Parts Cost 0 Cost adjusted for freight & sales tax Installation Labor 0 10 min per bag (13 hr total) Labor at $29.65/hr Total Installed Cost 0 Annualized Cost 0

Total Cost Replacement Parts & Packing 0

Design Flow 207,240 dscfm 235,500 acf m

Operating Cost Calculations Annual hours of operation: 8,000 Utilization Rate: 90.0%

Unit Unit of Use Unit of Annual Annual Comments Item Cost $ Measure Rate Measure Use* Cost Op Labor 32.00 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Supervisor 15% of Op. NA 2,400 15% of Operator Costs Maint Labor 32.00 Hr 0.5 hr/8 hr shift 500 16,000 $/Hr, 0.5 hr/8 hr shift, 8000 hr/yr Maint Mtls 100% of Maint Labor NA 16,000 of Maint Labor, 0.0 , 8000 hr/yr Utilities, Reagents, Waste Management & Replacements Electricity 0.046 kW-hr 1852.3 kW-hr 14,818,792 677,527 $/kW-hr, 1,852 kW-hr, 8000 hr/yr Natural Gas 5.50 Mft 3 0 scfm 0 0 $/Mft3, 0.0 scfm, 8000 hr/yr Water 0.22 Mgal 124.3 gpm 59,685 13,044 $/Mgal, 124.3 gpm, 8000 hr/yr Comp Air 0.27 Mscf 0 Mscfm 0 0 $/Mscf, 0.0 Mscfm, 8000 hr/yr Reagent #1 (O2) 17.45 Mscf 10.6 Mscfh 76,016 1,326,487 $/Mscf, 10.6 Mscfh, 8000 hr/yr, Reagent #2 0 Ton 0.00 lb/hr 0 0 $/Ton, 0.0 lb/hr, 8000 hr/yr SW Disposal 25.00 Ton 0.000 ton/hr 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/yr Haz W Disp 273.18 Ton 0.000 ton/hr 0 0 $/ton, 4 gr/scf, 50 Mscfm, 8460 hr/yr WW Bio Treat 5.38 Mgal 124.3 gpm 59,685 320,847 $/Mgal, 124.3 gpm, 8000 hr/yr, Catalyst 0 ft 3 0 ft 3 0 0 $/ft3, 0.0 ft3, 0, 8000 hr/yr Rep Parts 0 b ag 0 b ags 2 yr life 0 $/bag, 0.0 bags, 2 yr life, 8000 hr/yr *annual use rate is in same units of measurement as the unit cost factor

Emission Control Rate Calculation Uncontrolled Emission Rate

Emission Unit of Rate % Max Emis Rate Factor Measure Hrs Ca p acit y T/ y r Comments/Notes 48.0 p p m 207,240 dscf m 257 Annual emission rate from hourly P to E adjusted for Controlled Emission Rate normal hours of operation and untilzation Perf Unit of Flow Unit of Emis Rate Guarantee Measure Rate Measure T/ y r Comments/Notes 90% Pct Red 26 Basis:8000 hr/yr, 0.0% of capcity Emission Reduction T/yr 231

Flow acfm P in H2O Blower Eff Motor Eff kW Blower OAQPS Cost Cont Manual 5th ed - Eq 3.37 Flow gpm P ft H2O Pump Eff Motor Eff Circ Pump 622 Estimated from Vendor Data (gpm= mscfh gas * 3) H2O WW Disch 124 Water Makeup Rate/WW Disch = 20% of circulating water rate LTO Electric Use 1,852 Estimated from Table 5 LoTOx Paper #147

BOC LoTox Bid July 2001 Rate scfm Bid Basis 200,805 Design close to NSM; don't adjust cost numbers O2 required mscf/Hr 10.6 Adj H2 Use BOC Estimate 608 scfm for 222 lb/hr NOx NSM 64.25 lb/hr July 2001 BOC BID

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## A-5-111 

# BACT ATTACHMENT 3

Summary of NSM Emission Testing DataP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-112Attachment 3, Table 1. NSM Stack Test ResultsLine 5 Restart Project, Northshore Mining CompanyGrain Loading ConcentrationTemp Flow Flow(gr/dscf) (ppm, d)(F) (acfm) (dscfm)in Col V as notedFine Crushing PM Stack Test Data with Fabric Filter ControlsPM gr/dscfSV 013 EU 013 Fine Crusher Line 2 Crush 7/20/04 [18] PM Dry Catch + Organic Wet Catch 80 14,433 13,600 0.22 0.96 0.0277 620.3 0.0019SV 014 EU 014 Fine Crusher Line 1 Crush 7/20/04 [18] PMDry Catch + Organic Wet Catch -Note - EU did not meet permit79 15,733 14,600 0.39 1.69 0.0488 574.7 0.0031SV 017 EU 017 No. 2 Fine Crusher Stack (EP11) Crush 06/27/95 [6] PM Dry Catch + Organic Wet Catch 75 16,553 15,596 0.31 1.34 0.0385***N/A N/A***0.0023SV 017 EU 017 No. 2 Fine Crusher Stack (EP11) Crush 06/27/95 [6] PM Dry + Method 202 75 16,479 15,595 0.31 1.38 0.0397***N/A N/A***0.0024SV 017 EU 017 No. 2 Fine Crusher Stack (EP11) Crush 06/27/95 [6] PM Dry + organic wet catch 75 16,457 15,460 0.14 0.63 0.0182***N/A N/A***0.0011SV 017 EU 017 No. 2 Fine Crusher Stack (EP11) Crush 01/13/95 [7] PM68 16,098 15,393 0.62 2.70 0.0776***N/A N/A***0.0047 Not Included in Stats,SV 017 EU 017 No. 2 Fine Crusher (EP11) Crush 05/25/94 [8] PM Dry catch + organic wet catch 65 16,658 15,820 0.41 1.78 0.0513***N/A N/A***0.0030 Testing Control SystemSV 017 EU 017 No. 2 Fine Crusher Stack (EP11) Crush 06/27/95 [6] PM10 Dry + Method 202 76 17,214 16,155 0.35 1.53 0.0441***N/A N/A***0.0025 Operational ParametersSV 017 EU 017 No. 2 Fine Crusher Stack (EP11) Crush 06/27/95 [6] PM10 Dry + organic wet catch 76 17,208 16,206 0.14 0.61 0.0177***N/A N/A***0.0010SV 017 EU 017 No. 2 Fine Crusher Stack (EP11) Crush 06/27/95 [6] PM10 Dry + Method 202 76 16,654 15,626 0.23 1.00 0.0288***N/A N/A***0.0017Average Test Result0.280.0021Maximum Test Result0.410.0031Safety Factor0.000.0000 Max test value = Proposed BACTProposed BACT0.390.003 gr/dscfIndruation Hood Exhaust Stack Test Data with Wet ESP Controls. For Reference OnlySV 113 EU 110 Furnace 12 Hood Exhaust (1203) Hood 12/20/00 [15] Natural Gas NOx115 83,000 66,533 10.80 47.30 1.3620 219.022.7000 0.0880SV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] NOx Electronics on2.50 10.95 0.3153 N/A N/A N/A 5.6667SV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] NOx Electronics off2.40 10.51 0.3027 N/A N/A N/A 5.3333Hood Exhaust Stack Hood 01/07/92 [10] NOx76,764 60,155 8.66 37.91 1.0916 N/A N/A N/AHood Exhaust Stack Hood 01/09/92 [10] NOx81,270 62,497 9.98 43.71 1.2586 N/A N/A N/ASV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] PM Dry catch + organic wet catch, electronics on 129 79,603 61,803 4.87 21.32 0.6137 N/A N/A N/A 0.0092SV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] PM Dry catch only, electronics on 129 79,603 61,803 4.63 20.29 0.5843 N/A N/A N/A 0.0087SV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] PM Dry catch + organic wet catch, electronics off 121 79,418 62,574 5.07 22.21 0.6394 N/A N/A N/A 0.0095SV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] PM Dry catch only, electronics off 121 79,418 62,574 4.78 20.92 0.6024 N/A N/A N/A 0.0089SV 011 EU 110 No. 1202 Line 12 Hood Exhaust Hood 04/29/04 [19] PM Dry catch + organic wet catch, electronics on 120 77,000 62,000 2.90 12.70 0.36570.0540SV 011 EU 110 No. 1202 Line 12 Hood Exhaust Hood 04/29/04 [19] PM Dry catch + organic wet catch+ aq phase, electronics on 120 77,000 62,000 6.00 26.28 0.75670.0115SV 011 EU 110 No. 1202 Line 12 Hood Exhaust Hood 04/29/04 [19] PM Dry catch + organic wet catch, electronics off 118 79,000 64,000 3.20 14.02 0.40360.0059SV 011 EU 110 No. 1202 Line 12 Hood Exhaust Hood 04/29/04 [19] PM Dry catch + organic wet catch+ aq phase, electronics off 118 79,000 64,000 6.70 29.35 0.84490.0123SV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] SO2 Electronics on2.07 9.05 0.2606 N/A N/A N/A 3.3333SV 111 EU 110 No. 12 Pelletizer Hood Exhaust Stack (EP101) Hood 05/24/94 [8] SO2 Electronics off1.68 7.34 0.2114 N/A N/A N/A 2.6667Hood Exhaust Stack Hood 01/07/92 [10] SOx76,764 60,155 0.66 2.88 0.0828 N/A N/A N/AHood Exhaust Stack Hood 01/09/92 [10] SOx81,270 62,497 1.12 4.92 0.1417 N/A N/A N/AIndruation Furnace Waste Gas NOx Stack Test DataNOx PPMSV 262 EU 262 Furnace 6 HE/WG (602) Waste 12/20/00 [15] Natural Gas NOx120 73,300 57,700 13.30 58.25 1.6773 120.032SV 263 EU 262 No. 601 Pelletizer Stack (EP97) Waste 10/10/95 [5] NOx13.23 57.96 1.6689***N/A N/A N/A 35Average Test Result13.23 On Per Stack Basis34Maximum Test Result35Safety Factor15%5 15% Safety FacProposed BACT45.7 Furnace Total (3 stacks)40 ppm NOxIndruation Furnace Waste Gas PM Stack Test Data with Wet ESP Controls.PM gr/dscfSV 104 EU 104 Furnace 11 Waste Gas (EP104) Waste 7/31/96 [4] PM Dry + organic wet catch 142 87,139 61,383 4.13 18.09 0.5208***N/A N/A***0.0078SV 105 EU 105 Furnace 11 Waste Gas (EP105) Waste 7/31/96 [4] PM Dry + organic wet catch 141 86,623 61,778 3.22 14.09 0.4057***N/A N/A***0.0061SV 114 EU 114 Furnace 12 Waste Gas (EP106) Waste 7/30/96 [4] PM Dry + organic wet catch 139 84,510 59,783 3.70 16.21 0.4666***N/A N/A***0.0072SV 115 EU 115 Furnace 12 Waste Gas (EP107) Waste 7/30/96 [4] PM Dry + organic wet catch 138 78,597 56,336 3.07 13.46 0.3876***N/A N/A***0.0064SV 263 EU 262 No. 601 Pelletizer Stack (EP97) Waste 10/10/95 [5] PM Dry + organic wet catch 137 73,289 52,802 3.74 16.40 0.4721***N/A N/A***0.0083SV 104 EU 104 No. 1104 Pelletizer Waste Gas Stack (EP104) Waste 01/10/95 [7] PM Dry 132 93,253 69,282 5.32 23.30 0.6710***N/A N/A***0.0090SV 105 EU 105 No. 1105 Pelletizer Waste Gas Stack (EP105) Waste 01/10/95 [7] PM Dry 128 94,711 71,079 6.58 28.82 0.8297***N/A N/A***0.0108SV 114 EU 114 No. 1204 Waste Gas Stack (EP106) Waste 01/11/95 [7] PM Dry 139 90,456 63,312 3.95 17.32 0.4986***N/A N/A***0.0073SV 115 EU 114 No. 1205 Waste Gas Stack (EP107) Waste 01/11/95 [7] PM Dry 139 89,678 63,868 5.22 22.86 0.6582***N/A N/A***0.0095SV 114 EU 114 No. 12 Pelletizer Waste Gas Stack (EP107) Waste 05/25/94 [8] PM Dry + organic wet catch 137 89,748 63,113 18.02 78.94 2.2729***N/A N/A***0.0333 Not Included in Stats;SV 114 EU 114 No. 12 Pelletizer Waste Gas Stack (EP107) Waste 05/25/94 [8] PM Dry catch only, electronics on 137 89,748 63,113 17.26 75.602.1767***N/A N/A***0.0319 Not Represenative ofSV 114 EU 114 No. 12 Pelletizer Waste Gas Stack (EP107) Waste 05/25/94 [8] PM Dry + organic wet catch 138 89,428 61,560 19.93 87.28 2.5130***N/A N/A***0.0378 Current OperationsSV 114 EU 114 No. 12 Pelletizer Waste Gas Stack (EP107) Waste 05/25/94 [8] PM Dry catch only, electronics off 138 89,428 61,560 22.20 97.22 2.7992***N/A N/A***0.0421SV 104 EU 104 No. 1104 Pelletizer Waste Gas Stack Waste 05/26/94 [8] PM Dry catch + organic wet catch, electronics on 144 93,066 68,002 22.20 97.22 2.7992***N/A N/A***0.0381SV 105 EU 104 No. 1105 Pelletizer Waste Gas Stack Waste 05/26/94 [8] PM Dry + organic wet catch 151 98,063 72,647 9.69 42.44 1.2220***N/A N/A***0.0156SV 105 EU 104 No. 1105 Pelletizer Waste Gas Stack Waste 04/29/04 [19] PM Dry catch + organic wet catch, electronics on 135 81,000 59,0003.60 15.77 0.4540*** ***0.0071SV 105 EU 104 No. 1105 Pelletizer Waste Gas Stack Waste 04/29/04 [19] PM Dry catch + organic wet catch, electronics off 135 83,000 59,000 3.30 14.45 0.4162*** ***0.0065Average Test ResultNA Not same desgn as Furnace 50.0078Maximum Test ResultNA Not same desgn as Furnace 50.0108Safety FactorNA0.0000 Max test value = Proposed BACTProposed BACT18.4 Furnace 5 Max Flow & 0.01 gr/dscf 0.01 gr/dscf Dry + Organic CondensableIndruation Furnace Waste Gas SO2Stack Test Data with Wet ESP Controls.SO2 PPMSV 263 EU 262 No. 601 Pelletizer Stack (EP97) Waste 10/10/95 [5] SO21.6133 7.07 0.2035***N/A N/A***2.1SV 115 EU 114 No. 1205 Waste Gas Stack (EP107) Waste 01/11/95 [7] SO20.7500 3.29 0.0946***N/A N/A***1.0SV 114 EU 114 No. 12 Pelletizer Waste Gas Stack (EP107) Waste 05/25/94 [8] SO2 Electronics on0.8500 3.72 0.1072***N/A N/A***1.3SV 114 EU 114 No. 12 Pelletizer Waste Gas Stack (EP107) Waste 05/25/94 [8] SO2 Dry + organic wet catch0.6200 2.72 0.0782***N/A N/A***1.0SV 104 EU 104 No. 1104 Pelletizer Waste Gas Stack Waste 05/26/94 [8] SO2 Electronics on1.1500 5.04 0.1450***N/A N/A***1.7SV 105 EU 104 No. 1105 Pelletizer Waste Gas Stack Waste 05/26/94 [8] SO2 Dry catch only, electronics on2.4000 10.51 0.3027***N/A N/A***3.3No. 12 Waste Gas Stack Waste 01/08/92 [10] SOx82,613 58,708 0.5900 2.58 0.0744***N/A N/A***1.0Average Test Result4.78 Furnace total lb/hr1.7Maximum Test Result0.0147 lb/ton of pellets based on stack test EF, natural gas as fuel 3.3Safety Factor7.97 Adjust emission rates for fuel oil comb0.7 ppm+4 ppm for oil Max+15% + OilProposed BACT12.75 Furnace Total (3 stacks)8 ppm*** NSM to collect production data to calculate lb/ton emission rateMiscellaneous(lb/tongreen(lb/tonpellets)(lb/ton ore)Controlled Emission Factor(calculated from Test Results)Stack Test ResultsDate Pollutant CommentsFuel(if applicable)(lb/hr)(ton/yr)(g/s)Measured T/putTest Parameters Measured Emission Rate(LT greenballs/hr)(LTpellets/hr)(LT ore/hr)TypeSource InformationEmission UnitStack IDID DescriptionP:\23\38\107 NSM Furnace 5 Restart\Air Permit App\Submittal\050502 to MPCA (PSD App)\Original Files\Vol I Sect 5 App A (BACT).docA-5-113Notes:[1] "Results of the May 19-21, 1998 Trace Metals Emission Engineering Tests at the Northshore Mining Facility in Silver Bay, Minnesota", June 24, 1998, Interpoll Laboratories, Inc. Report number 8-11183M.[2] "Results of the October 23, 1997 Particulate Emission Compliance Test at the Northshore Mining Plant in Silver Bay, Minnesota", December 1, 1997, Interpoll Laboratories, Inc. Report number 7-10191.[3] "Results of the August 19, 1997 Particulate and Visible Emission Compliance Tests at the Northshore Mining Plant in SilverBay, Minnesota", September 4, 1997, Interpoll Laboratories, Inc. Report number 7-9908.[4] "Results of the July 30 & 31, 1996 Air Emission Testing at the Northshore Mining Facility in Silver Bay, Minnesota", August 30, 1996, Interpoll Laboratories, Inc. Report number 6-8063.[5] "Results of the October 10-12, 1995 EPA-Required Emission Compliance Testing at the Northshore Mining Facility in Silver Bay, Minnesota", November 3, 1995, Interpoll Laboratories, Inc. Report number 5-6648.[6] "Results of the June 27 - 29 and July 13,1995 Air Emission Testing at the Northshore Mining Facility in Silver Bay, Minnesota", August 1, 1995, Interpoll Laboratories, Inc. Report number 5-5897.[7] "Results of the January 10 - 13, 1995 Air Emission Compliance Testing at the Northshore Mining Facility in Silver Bay, Minnesota", January 25, 1995, Interpoll Laboratories, Inc. Report number 5-4664.[8] "Results of the May 24 - 27, 1994 Air Emission Testing at the Cyprus Northshore Mining Facility in Silver Bay, Minnesota", July 6, 1994, Interpoll Laboratories, Inc. Report number 4-2971.[9] "Results of the June 2 - 3, 1993 Particulate and PM-10 Emission Tests on the North and South Rotoclones at the Cyprus Northshore Mining Facility in Silver Bay, Minnesota", July 21, 1993, Interpoll Laboratories, Inc.Report number 3-8983.[10] "Results of the January 7 - 9, 1992 Engineering Scrubber Performance Tests at the Cyprus Northshore Mining Facility in Silver Bay, Minnesota", Febuary 6, 1992, Interpoll Laboratories, Inc. Report number 2-3480.[11] "Results of the September 16-17, 1998 Northshore Mining Company Metals Emission Engineering Testing on the No. 12 Pelletizer Hood Exhaust and Waste Gas Exhaust" by Barr Engineering Company, Project No. 2338041TMR300.[12] The rest of the three runs reported more metal HAP in blank than in sample.[13] The result for run 1 is currently under review with the contract laboratory.[14] "Results of the November 23, 1999 Northshore Mining Company Ore Transfer Bins PM Emission Tests" by Barr Engineering Company, Project No. 2338052TAK003.[15] "Results of the December 20-21, 2000 Nitrogen Oxides Engineering Tests on the Furnace 12 Waste Gas and Hood Exhaust (1203and 1205) and Furnace 6 hood Exhaust/Waste Gas Stack (602) at the Northshore Mining Company E.W. Davis Works Facility" by Barr[16] "Results of the March 6, 2003 Formaldehyde Emission Testing of Furnace No. 11 Waste Gas Stack (1105) and Hood Exhaust Stack (1103) at Northshore Mining Co." by Barr Engineering Company, Project No. 2338081[17] "Results of the April 22-23, 2003 Hexavalent Chrome Emission Testing Performed on Furnace No. 11 Waste Gas Stack (105) and Hood Exhaust Stack (1103) at Northshore Mining Co." by Barr Engineering Company, Project No. 2338082[18] "Results of the July 20-22, 2004 Title V Air Emissions Performance Testing Performed at Northshore Mining Company" by Barr Engineering, Project No. 23/38-104 MTP 002Revised since 1999 DRI PSD Permit ApplicationNote: shading denotes that the test result is below the detection limit (BDL). The detection limit is reported.