U.S. EPA, Region LX

Planning Office, Air Division

75 Hawthorne Street (AIR-2)

San Francisco, CA 94105

U.S.P.S. Certified Mail 70111570 0000 2503 4277

Dear Mr. Webb:

This letter responds to your letter ofJanuary 10, 2013, in which you requested

information related to the Freeport-McMoRan Miami Inc. (“FMMI”) Smelter regarding potential

BART determinations for SO2and NON. As indicated in our January 18, 2013, letter to Ms.

McKaughan (attached for your convenience in Appendix S), FMMI has worked diligently to

provide as much ofthe requested information as practicable given the extremely tight timeframe.

In our letter, we also requested the opportunity to discuss these requests with EPA to assist

FMMI to better understand EPA’s need for the information so that we can evaluate practical

alternatives for responding that may provide EPA useful information on a timeframe that

reasonably accommodates EPA’s rulemaking schedule. In the interim, FMMI will continue its

best efforts to address the remaining information requested.

FMMI recognizes the importance of providing sufficient information for EPA to make an

informed evaluation ofthe sources that are potentially subject to BART at the FMMI Smelter.

We also understand the complexity of a BART determination for the Smelter and the data

necessary to make such a determination. We therefore invite EPA to contact FMMI staff with

any questions about the data FMMI is providing, so that EPA can develop a full understanding of

how a smelter operates. This maybe especially useful to EPA given the complexities associated

with smelter operations and the limited number oftechnical specialists who have practical

experience with the industry due to the fact that there are only three remaining copper smelters

United States, only two of which use a batch smelting process.

A discussion of FMMI’s responses to information requested and how that data are being

transmitted follows. Data have been provided in Excel format. When multiple years of data

have been requested, FMMI has provided the information in tabs for each calendar year.

Narrative responses will be provided within the body ofthis letter or as PDF’s contained in the

appendices. All appendices are attached to this letter on a Compact Disk.
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eager to work with EPA to help Region 9 personnel understand the complex operations ofthesmelter and FMMI’s understanding ofthe applicability of BART and available emissions

controls, and would be happy to speak with EPA’s staff and share FMIVIJ’s ongoing assessment

of BART at the smelter.

Response to Information Request

Information Needed to Make a BART Determination for SO2:

1. The average daily measurementfor the SO2continuous emission monitoring system

(CEMS)for the sulfuric acidplant since January], 2005 in per million (ppm)and the total tons

ofSO2per day recorded by the SO2CEMSfor the sulfuric acidplant since January 1, 2005.

Please provide this information in an electronicformat that may be edited by a spreadsheet

program such as Excel or comparable software. Please also provide all SO2stack test data and

relative accuracy test audits (RATA5) performedfor the sulfuric acidplantfor the periodfrom

January 2005 through December 2012.

In Appendix A, FMMI has provided the requested CEM data. This data presented are in

Excel format and were obtained from FMMI’s internal database.

Appendix B contains electronic copies of all annual compliance testing and RATA

Audits performed by FMMI’s contractors. The reports are in PDF format and include data from

the tests.2. The daily production ofsulfuric acid by the sulfuric acidplant since January 2005, intons. Describe the source ofthe data.

FMMI has provided monthly sulfuric acid production in Appendix C. Acid production

on a daily basis is not maintained in the ordinary course of business.3. The daily production ofcopper by the copper smelter since January 2005 in tons.

Describe the source ofthe data.

.4,’
ofthe data.

In Appendix E, FMMI provided the daily quantity of new copper bearing materials fed to

the smelter. FMMI analyzes each concentrated copper ore (or “concentrate”) shipment it

receives for copper, iron, sulfur and then builds a “bed” of concentrate for smelter feed.

Although the beds contain primarily concentrate, they also include other copper bearing

materials. The purpose of bedding the various materials is to provide a consistent feed to the

smelter. The source ofthe data is FMMI’s production records.

FMMI has provided the daily sulfur content ofthe smelter feed in Appendix F. The sulfur

content provided is inclusive of all materials in the bed. The sulfur content analysis is generated

within FMMI’s analytical laboratory.

5. Monthly material balances ofsulfur (as described in Specific Provision IV.B.2 and

Attachment D ofTitle V Operating Permit 29622) performed since January 2005, along with any

support documentsfor each monthly balance.

Appendix F contains a compilation ofmonthly sulfur balance information for the years

2005 to 2012 that has been submitted to ADEQ in the FMMI monthly reports.6. Copies ofall actual SO2emissions calculations performed since January 1, 2005for any

copper smelting equlpment that was submitted to any regulatory agency. Include with your

response a detailed description ofall equations relied upon, including the identflcation ofall

data inputs into the equation, a description ofall emissionsfactors (EFs) relied upon and their

source, and all other methods or data relied upon to perform the calculations;

Appendix G contains excerpts related to SO2emissions from the annual emissions

inventories submitted to ADEQ using their software for the years 2005 to 2011. FMMI has not

begun the process of calculating the 2012 Emissions Inventory because the ADEQ software for

that year has not yet been released.

FMMI submits monthly reports to ADEQ pursuant to Air Quality Permit 53592. The

data elements provided in the Monthly Report are addressed in Appendix A and Appendix F.

7. A summary and supporting documentation showing which units at the Facility comprise

the BART-eligible source under the Regional Haze Rule (40 CFR part 51, subpart P) and the

BART Guidelines (40 CFR part 51, appendix I’). Include any records that indicate which units at
Appendix I contains a list of equipment in the Smelter with installation date.

8. Provide the following information about the sulfuric acidplant.’

a. the volume (liters) ofcatalyst in each catalyst bed;

See Appendix J.

b. The diameter ofthe converter,’

48 feet, 5 inches.

c. the type ofcatalyst (including trade-name) in each catalyst bed;

See Appendix J.

d. the maximum volumetric capacity (liters) ofcatalyst,’

There was no maximum capacity specified by the original equipment

manufacturer. The manufacturer did specify a recommended catalyst loading for

each bed which is given below. Note that this loading results in very little excess

room remaining in each catalyst bed.

Bed 1 85,000 liters

Bed 2 140,000 liters

Bed 3 124,000 liters

Bed 4 155,000 liters

e. the amount and type ofcatalyst replaced during each turn around since 2005,’

See Appendix 3.

and

f [ASARCO is using cesium promoted catalyst, provide the date the facility began

using cesium catalyst.
Appendix K includes FMMI

s only available quotation for catalysts, including cesium

promoted catalyst. The catalyst vendors do not provide any emissions estimates.

10. Provide the following information aboutprocess gas capture and treatment:

a. Indicate the maximum capacity ofthe acidplant to acceptprocess offgases,

including both airflow and inlet SO2concentration;

FMMI does not have a ready way to calculate the “maximum” capacity ofthe acid plant

in terms of airflow and inlet SO2concentration. The nominal design capacity ofthe acid plant is

137,000 standard cubic feet per minute (scfm) at an SO2concentration of 10.5%. The maximum

process offgas flow rate to the acid plant is determined by the capacity ofthe blowers, which

direct 165,000 scfln of offgas to the acid plant.

b. Provide a detailed description ofwhat happens to captured excess gasflow that

would otherwise be vented to the acidplant when that total gasflow exceeds the capacity ofthe

acidplant;

The captured gas flow cannot exceed the capacity ofthe cold gas blowers, which is 165,000

scfm. During normal operations, gas flow generally does not exceed 150,000 scfm. Ifflow

approaches 165,000 scffii, an alarm informs the operator who then adjusts facility operations to

ensure flow remains below 165,000 scfm.

c. Provide a detailed analysis ofthe capture efficiency ofgases emittedfrom all

copper smelter process equipment;

Because all process gases are ducted to the acid plant from the Isa furnace, Electric

Furnace and Hoboken Converters, the capture efficiency ofthe collection system for SO2gasses

is intended to approach nearly 100%. Based on our review ofIndustry technical data, we have

identified SO2capture efficiency estimates ranging between 87 and 98% for similar collection

systems.

d. Provide a schematic diagram showing which equipment at the Facility are

captured and controlled or controllable by the acidplant;

See Appendix L for the Smelter Offgas Handling Overview flow diagram.
1, 2005;

ii. The total daily emissions ofS02 in tonsfrom the Secondary System since

January 1, 2005,

iii. The total daily amount oflime in tons injected into the Secondary System;

iv. An estimation, on a daily basis, ofthe control efficiency ofthe injected

lime for SO2;

v. For information provided under 8. c. i and 8. c. ii, a description ofthe

underlying measurement and/or data used and any calculations performed.

It is unclear what is meant by “Hoboken Converter Secondary System.” Presumably,

EPA is referring to “secondary capture systems” as that term is used under the National Emission

Standards for Hazardous Air Pollutants (NESHAP) for Primary Copper Smelters. The side flue

intake design ofthe Hoboken converters in use at the Smelter does not include a secondary

capture system.

f For any emergency bypass vent that is part ofthe acidplant line, please respond

to the following requests:

FMMI assumes that what EPA means by the “acid plant line” is the 90” duct that moves

process gases to the acid plant. Ifthis is incorrect, please clarify.

i. Describe the location ofthe bypass in regard to any particulate matter

(PM) controls (i.e. is it before or after each PM control);

The bypass stack is located just downstream ofthe acid plant hot gas fans which

are located at the inlet ofthe acid plant. There are no particulate matter controls

between the hot gas fans and the emergency bypass stack.

An electrostatic precipitator (ESP) is located downstream ofthe Isa furnace and

upstream ofthe converter and electric furnace tie in points to the 90” duct leading

to the acid plant. This ESP is dedicated to reducing particulate matter reporting to

the acid plant gas cleaning section while the Isa furnace is in operation. When the

bypass stack is opened during an emergency event, the Isa furnace and the

converters are shut down as expeditiously as practicable, in a controlled manner,
Process off-gases that go to the bypass are directly vented to atmosphere through

a stack.

Under normal shut down and startup operations when the bypass stack is in use,

there are no emissions being generated from processing concentrate as there is no

feed or blast air going to the Isa vessel, which means there are no active emissions

generated. However, there may be some residual emissions from the Isa furnace.

Further, all converters are positioned so that process air is not introduced to the

bath for oxidation purposes, which means that there will be no emissions from

these units directed to the acid plant. The residual emissions escape to the ambient

air. Depending on the temperature ofthe bath in the electric furnace, there may be

some low level residual sulfur dioxide emissions going to the stack. Prior to

commencing operations (feeding concentrate, blowing converters and raising

power on the electric furnace), the acid plant must be up to temperature and the

bypass stack valve must be closed.

In the case of a sudden emergency bypass (due to a malfunction), all feed to the

Isa vessel is stopped, the Isa lance is pulled from the molten matte/slag bath, the

converters are positioned so that process air is not introduced to the bath for

oxidation purposes and the power to the electric furnace is turned off as soon as

the bypass stack valve opens. The only process emissions going to the stack are

those in the duct work between the time the valve is opened and the process

equipment operations are curtailed.

iii. Describe how the gasflow exiting the bypass is measured;

Gas flow and SO2concentrations are measured through the 90 inch duct CEMS.

The system includes an AMETEK 919 CEM and an anubar for measuring flow in the

duct. Temperature monitOring is located just prior to the hot gas fans downstream ofthe

CEMS.

iv. In a chartformat, since January 1, 2005, spec5’ the total amount ofgas

vented through the bypass on a daily basis. Describe the source ofthe data.
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d EPA will need to discuss

EPA’s data needs to ensure a full package that meets the intended use ofthe data.

g. Provide a detailed description ofS02-laden gasflow emittedfrom all copper

smelterprocess equipment at the Facility (e.g. maximum and lypicalfiow rates in actual cubic

feetper minute (acfin), temperature, and SO2concentration in ppm), and whether it is currently

vented to the acidplant, to other controls in place, or to the atmosphere uncontrolled.

SO2laden gas is emitted from the following smelter process equipment to the acid plant:

• Isa smelting vessel

• Electric furnace

• Hoboken converters

FMMI cannot calculate the maximum or typical flow rate in such areas reliably.

While there is some process instrumentation that could provide a rough estimate ofthese

flows, they are not accurately measured until the 90” duct. FMN’fl is providing a diagram

(Smelter Offgas Handling Overview) in Appendix L.

Information Needed to Make a BART Determination for NO,j

1. A description ofexisting NOsources and controls all copper smelter process equipment

at the Facility.

FMMI is not certain what EPA means by “all copper smelter process equipment.”

For purposes ofthis response, FMMI interprets it to mean the Hoboken Converters and

the Isa Furnace. The principal NO sources from this equipment include the Isa Lance

and the Isa Auxiliary Boiler, which both use natural gas.

2. The average NOx emissionsfrom any copper smelter process equipment at the Facility

since January, 2005 calculated in tons per calendar month and the assumptions and emission

factors relied upon to perform the calculations. Please provide all NO stack tests performed on

any ofthis equipment.

There are no continuous emissions monitoring system(s) for NO emissions from

this equipment. FMMI performs testing of each stack semi-annually. This data is

presented in Appendix N, and was derived from NOx performance stack testing (found

in Appendix B).
4. A detailed description ofallfuel burners associated with any copper smelter process

equipment at the Facility including the manufacturer, model number, type offuel combusted,

maximumfuel combustion rate, and guaranteedNO emission rate.

As noted above, FMMI is not certain what EPA means by “all copper smelter

process equipment.” For purposes ofthis response, FMMI interprets it to mean the

Hoboken Converters and the Isa Furnace. The principal N0 sources from this

equipment include the Isa Lance and the Isa Auxiliary Boiler, which both use natural gas.

There are no ratings for the Isa lance. The manufacturer’s information for the Isa

Auxiliary Boiler is found in Appendix G. Air Quality Permit 53592 (page 54) has a NO

limit for the Isa Auxiliary Boiler listed at 1.8 lb./hr. and 97.5 Ib./hr. for Process Gasses

from exiting the Tailstack (Air Quality Permit 53592, page 25). This limit was included

in the 1998 NO PSD permit issued by ADEQ.

5. Records and summaries ofeach type offuel, including sulfur content and higher heating

value, combusted in each piece ofcopper smelter process equipment at the Facility, on a

monthly basis.

Based on FMMI’s understanding of “copper smelter production equipment,” the only

available information is the natural gas used in the Isa furnace (used as supplementary fuel.)

Appendix Q contains the natural gas usage in the Isa.

Appendix R contains El Paso Natural Gas’ Federal Energy Regulatory Commission filing

for 2011. In this filing, natural gas is listed as not to exceed 5 grains total sulfur /100 cubic feet

of natural gas. The higher heating values are only available for the calendar years 2010, 2011 and

2012 at this time. Previous years will need to be obtained by El Paso Natural Gas.

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FMMI appreciates the opportunity to provide the information to facilitate EPA’s

evaluation ofBART issues related to the Smelter. Should EPA require clarification on any of

the data presented in this response, please feel free to call Mr. Chris West, Chief Environmental
Derek Cooke

General Manager

Attachment (CD with Appendices)

CC: Eric Massey, ADEQ

FMI Distribution