Gila River Indian Community (GRIC) TIP Development 

Source Specific Emission Limitations & Standards 

Technical Support Document 

Section V71. Rule E -Nonmetallic Mineral Mining and Processing 

(I) Nonmetallic Mineral Mining and Processing 

(2) Concrete Batch Plants 

(3) Hot Mix Asphalt Plants 

(4) Vermiculite and Perlite Processing 

1.0 Introduction & Source Description 

Nonmetallic mineral mining and processing is a general source category including one or more 

of the following components: 

r Sand and gravel mining and processing (including crushed stone processing) 

Concrete batching 

Hot mix asphalt production 

Vermiculite / perlite processing 

Because of common raw materials, processing equipment, emission mechanisms, and control 

techniques, a single emission standard is proposed for nonmetallic mineral mining and 

processing with subsections to address specific processes as identified above. Several facilities 

cwently located and operating on GRIC land comprise this source category, All subcategories 

are cwently represented and expected to be potential candidates for expansion andor future new 

source siting. 

1.1 Sand and Gravel ~rocessin~',~~~ 

Deposits of sand and gravel are generally found in near surface alluvial deposits and in 

subterranean and sub aqueous beds. Such deposits are common on GRIC Land, Sand and gravel 

are typically mined in a moist or wet condition by open pit excavation or by dredging. Open pit 

excavation is carried out with power shovels, draglines, fiont-end loaders, and bucket wheel 

excavators. Mining by dredging involves mounting the equipment on boats or barges and 

removing the sand and gravel fiom the bottom of the body of water by suction or bucket-type 

dredges. After mhing, the materials are tramported to the processing plant by suction pump, 

earthmover, truck, belt conveyors, or other means. 

Sand and gravel may be used for fill, bedding, sub base, and base course without processing, but 

all current GRIC facilities include fbrther processing for concrete and or asphalt production. The 

processing of sand and gravel for a specific market involves the use of different combinations of 

washers, screens, and classifiers to segregate particle sizes; crushers to reduce oversized 

material; and storage and loading facilities. A process flow diagram for construction sand and 

gravel processing is included in Appendix A of this document. 

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After being transported to the processing plant, the wet sand and gravel raw feed is stockpiled or 

emptied directly into a hopper, which typically is covered with a "grizzly" of parallel bars to 

screen out large cobbles and boulders. From the hopper, the material is transported to fixed or 

vibrating scalping screens by gravity, belt conveyors, hydraulic pump, or bucket elevators. The 

scalping screens separate the oversize material from the smaller, marketable sizes. Oversize 

material may be directed to a crusher for size reduction, to produce crushed aggregate. Crushing 

generally is carried out in one or two stages, although three-stage crushing may also be 

performed. 

Following crushing, the material is returned to the screening operation for sizing. The material 

that passes through the scalping screen is fed into a battery of sizing screens, which generally 

consists of either horizontal or sloped, and either single or multideck, vibrating screens. Rotating 

trommel screens with water sprays are also used to process and wash wet sand and gravel. 

Screening separates the sand and gravel into different size ranges. Water is sprayed onto the 

material throughout the screening process. AfZer screening, the sized gravel is transported to 

stockpiles, storage bins, or, in some cases, to crushers by belt conveyors, bucket elevators, or 

screw conveyors. The sand is freed from clay and organic impurities by log washers or rotary 

scrubbers. Mer scrubbing, the sand typically is sized by water classification. Wet and dry 

screening is rarely used to size the sand. After classification, the sand is dewatered using screws, 

separatory cones, or hydroseparators. After processing, the sand is transported to storage bins or 

stockpiles by belt conveyors, bucket elevators, or screw conveyors. 

1.2 Concrete atc chin^^' 

Concrete is composed essentially of water, cement, sand (fine aggregate) and coarse aggregate. 

Coarse aggregate may consist of gravel, crushed stone or iron blast furnace slag. Some specialty 

aggregate products could be either heavyweight aggregate (of barite, magnetite, limonite, 

ilmenite, iron or steel) or lightweight aggregate (with sintered clay, shale, slate, diatomaceous 

shale, perlite, vermiculite, slag, pumice, cinders, or sintered fly ash). Concrete batching plants 

store, convey, measure and discharge these constituents into trucks for transport to a job site. In 

some cases, concrete is prepared at a building construction site or for the manufacture of 

concrete products such as pipes and prefabricated construction parts. A generalized process 

diagram for concrete batching is included in Appendix A of this document. 

The raw materials can be delivered to a plant by rail or truck, but in the case of existing sources 

on GFUC land, they are collocated with nonmetallic sand/gravel mining and processing facilities. 

The cement is transferred to elevated storage silos pneumatically or by bucket elevator. The 

sand and coarse aggregate are transferred to elevated bins by front-end loader, clamshell crane, 

belt conveyor, or bucket elevator. From these elevated bins, the constituents are fed by gravity 

or screw conveyor to weigh hoppers, which combine the proper amounts of each material. 

Truck mixed (transit mixed) concrete is the process practiced at one of the existing GRIC 

concrete batch plants. At these plants, sand, aggregate, cement and water are all gravity fed from 

the weigh hopper into the mixer trucks. The concrete is mixed on the way to the site where the 

concrete is to be poured. Central mix facilities (including shrink mixed) constitute another 

concrete production process in use on GFUC lands. With these, concrete is mixed and then 

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transferred to either an open bed dump truck or an agitator truck for transport to the job site. 

Shrink mixed concrete is concrete that is partially mixed at the central mix plant and then 

completely mixed in a truck mixer on the way to the job site. Dry hatching, with concrete mixed 

and hauled to the construction site in dry form, is seldom, if ever, used. 

1.3 Hot Mix ~s~hall?' 

Hot mix asphalt (HMA) paving materials are a mixture of well graded, high quality aggregate 

(which can include reclaimed asphalt pavement w]), and liquid asphalt cement, which is 

heated and mixed in measured quantities to produce HMA. Aggregate and RAP (if used) 

constitute over 92 percent by weight of the total mixture. side hm the amount and grade of 

asphalt cement used, mix characteristics are determined by the relative amounts and types of 

aggregate and RAP used. A certain percentage of fine aggregate (less than 74 micrometers [pm] 

in physical diameter) is required for the production of good quality NMA. Hot mix asphalt 

paving materials can be manufactured by: (1) batch mix plants, (2) continuous mix (mix outside 

drum) plants, (3) parallel flow drum mix plants, and (4) counterflow drum mix plants. This order 

of listing generally reflects the chronological order of development and use within the HMA 

industry. An HMA plant can be constructed as a permanent plant, a skid-mounted (easily 

relocated) plant, or a portable plant. All plants can have RAP processing capabilities. Virtually 

all plants being manufactured today have RAP processing capability. A generalized process 

diagram for hot mix asphalt is included in Appendix A of this document 

1.4 Vermiculite and Perlite ~rocessin~~~~ 

Vermiculite - 

Vermiculite is the geological name given to a group of hydrated laminar minerals that are 

aluminum-iron-magnesium silicates and &at resemble mica in appearance. The chemical 

formula for vermiculite is (Mg,CaJC,Fe ) (Sifl,Fe ) 0 (ON) 4H 0. When subjected to heat, 

vermiculite has the unusual property of exfoliating, or expanding, due to the interlaminar 

generation of steam. Uses of unexpanded vermiculite include muds for oil-well drilling and 

fillers in fire-resistant wallboard. Vermiculite ore is mined using open-pit methods. Beneficiation 

includes screening, flotation, drying in rotary or fluid bed dryers, and expansion by exposure to 

high heat. All mined vermiculite is dried and sized at the mine site prior to exfoliation. A 

generalized process diagram for vermiculite processing is included in Appendix A of this 

document. 

Crude ore hm open-pit mines is brought to the mill by truck and is loaded onto outdoor 

stockpiles. Primary processing consists of screening the raw material to remove the waste rock 

greater than 518 inch and relmaing the raw ore to stockpiles. Blending is accomplished as 

material is removed &om stockpiles and conveyed to the mill feed bin. The blended ore is fed to 

the mill, where it is separated into hctions by wet screening and then concentrated by gravity. 

All concentrates are collected, dewatered, and dried in either a fluidized bed or rotary dryer. 

Drying reduces the moisture content of the vermiculite concentrate fkom approximately 15 to 20 

percent to approximately 2 to 6 percent. At most facilities, the dryer products are transported by 

bucket elevators to vibrating screens, where the material is classified. The dryer exhaust 

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generally is ducted to a cyclone for recoveriug the finer grades of vermiculite concentrate. The 

classified concentrate then is stored in bins or silos for later shipment or exfoliation. The rotary 

dryer is the more common dryer type used in the industry, although fluidized bed dryers also are 

used. Drying temperatures are 250 to 900 F, and he1 oil is the most commonly used hel. Natural 

gas and propane also are used to he1 dryers. 

After being transported to the exfoliation plant, the vermiculite concentrate is stored. The ore 

concentrate then is conveyed by bucket elevator or other means and is dropped continuously 

through a gas- or oil-fired vertical furnace. Exfoliation occurs after a residence time of less than 

8 seconds in the furnace, and immediate removal of the expanded material fiom the fimace 

prevents damage to the structure of the vermiculite particle. Flame temperatures of more than 

1000 F are used for exfoliation. Proper exfoliation requires both a high rate of heat transfer and a 

rapid generation of steam within the vermiculite particles. The expanded product falls through 

the hce and is air conveyed to a classifier system, which collects the vermiculite product and 

removes excessive fines. The furnace exhaust generally is ducted through a product recovery 

cyclone, followed by an emission control device. At some facilities, the exfoliated material is 

ground in a pulverizer prior to being classified. Finally, the material is packaged and stored for 

shipment 

Perlite - 

Perlite is a glassy volcanic rock with a pearl-like luster. It usually exhibits numerous concentric 

cracks that cause it to resemble an onion skin. A typical perlite sample is composed of 71 to 75 

percent silicon dioxide, 12.5 to 18.0 percent alumina, 4 to 5 percent potassium oxide, 1 to 4 

percent sodium and calcium oxides, and trace amounts of metal oxides. Crude perlite ore is 

mined, crushed, dried in a rotary dryer, ground, screened, and shipped to expansion plants. 

Horizontal rotary or vertical stationary expansion furnaces are used to expand the processed 

perlite ore. Crude perlite is mined using open-pit methods and then is moved to the plant site 

where it is stockpiled. A generalized process diagram for perlite processing is included in 

Appendix A of this document 

The kt processing step is to reduce the diameter of the ore to approximately 0.6 inch in a 

primary jaw crusher. The crude ore is then passed through a rotary dryer, which reduces the 

moisture content from between 4 and 10 percent to less than 1 percent After drying, secondary 

grinding takes place in a closed-circuit system using screens, air classifiers, hammer mills, and 

rod mills. Oversized material produced from the secondary circuit is returned to the primary 

crusher. Large quantities of fines, produced throughout the processing stages, are removed by air 

classification at designated stages. The desired size processed perlite ore is stored uatil it is 

shipped to an expansion plant. At the expansion plants, the processed ore is either preheated or 

fed directly to the hrnace. Preheating the material to approximately 800 F reduces the amount of 

fines produced in the expansion process, which increases usable output and controls the 

uniformity of product density. 

In the furnace, the perlite ore reaches a temperature of 1400 to 1800 F, at which point it begins to 

soften to a plastic state where the entrapped combined water is released as steam. This causes the 

hot perlite particles to expand 4 to 20 times their original size. A suction fan draws the expanded 

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particles out of the furnace and transports them pneumatically to a cyclone classifier system to be 

collected. The air-suspended perlite particles are also cooled as they are transported to the 

collection equipment. The cyclone classifier system collects the expanded perlite, removes the 

excessive fines, and discharges gases to a baghouse or wet scrubber for air pollution control. The 

grades of expanded perlite produced can also be adjusted by changing the heating cycle, altering 

the cutoff points for size collection, and blending various crude ore sizes. All processed products 

are graded for specific uses and are usually stored before being shipped. Most production rates 

are less than 2 tomdhr, and expansion bace temperatures range fiom 1600 to 1 800 F. Natural 

gas is typically used for fuel, although No. 2 fuel oil and propane are occasionally used. 

2.0 GRIC Source Profile 

Four sources currently located and operating on GRIC land comprise the nonmetallic minerals 

mining and processing source category. Those sources are: 

United Metro #4 1 

United Metro #48 

Rock Solid 

Thermo-Rock Inc. 

United Metro # 4 1 

This facility includes a sand and gravel mining operation, two concrete batch plants, and a hot 

mix asphalt plant. The facility is subject to NSPS Subpart 000 (Nonmetallic Mineral 

Processing) and NSPS Subpart I (Hot Mix Asphalt). Appendix A of this document includes site 

visit notes providing further details on this facility as well as a generalized process flow diagram. 

United Metro #48 

This facility is another sand and gravel mining and processing operation with a concrete batch 

plant. United Metro No. 48 does not operate a hot mix asphalt plant. The facility is subject to 

NSPS Subpart 000 (Nonmetallic Mineral Processing). 

Rock Solid 

Rock Solid is a concrete batch plant without associated mineral mining and processing stages. 

Aggregate and other raw materials are delivered to the site and loaded to hoppers prior to 

weighing, mixing, and truck loading. Concrete is loaded to trucks in dry form and water is added 

directly to the concrete trucks on site prior to departure. Rock Solid plans to move and expand its 

operations on GRIC land. 

Thermo-Rock Lnc. 

Thermo-Rock, Inc, is a vermiculate and perlite processing facility. Operations include 

vermiculite and perlite expansion fbmaces, potting soil manufacture, and fire retardant 

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production. One of the facility fimaces is subject to NSPS Subpart UUU (Calciners and Dryers 

in Mineral Industries). Two other facility furnaces predate the NSPS applicability date. 

3.0 Technical Review - Emission Units, Pollutants, and Control Technologies 

3.1 Emissions and Controls 

Sand and Gravel Miningl~rocessin~'~ 

Emissions from the production of sand and gravel consist primarily of particulate matter (PM) 

and particulate matter less than 10 micrometers (PM- 1 0) in aerodynamic diameter, which are 

emitted by many operations at sand and gravel processing plants, such as conveying, screening, 

crushing, and storing operations. Generally, these materials are wet or moist when handled, and 

process emissions can be negligible. A substantial portion of these emissions may consist of 

heavy particles that settle out within the plant. Other potentially significant sources of PM and 

PM-10 emissions are haul roads. Emissions from dryers include PM and PM-10, as well as 

typical combustion products including CO, COz , and Na. In addition, dryers may be sources of 

volatile organic compounds (WC) or sulfur oxides (S&) emissions, depending on the type of 

%el used to fire the dryer. 

With the exception of drying, emissions fiom sand and gravel operations primarily are in the 

form of fugitive dust, and control techniques applicable to fugitive dust sources are appropriate. 

Some successful control techniques used for haul roads are dust suppressant application, paving, 

route modifications, and soil stabilization; for conveyors, covering and wet suppression; for 

storage piles, wet suppression, windbreaks, enclosure, and soil stabilizers; for conveyor and 

batch transfer points, wet suppression and various methods to reduce freefall distances (e. g., 

telescopic chutes, stone ladders, and hinged boom stacker conveyors); and for screening and 

other size classification, covering and wet suppression. Wet suppression techniques include 

application of water, chemicals and/or foam, usually at crusher or conveyor feed and/or 

discharge points. Such spray systems at transfer points and on material handling operations have 

been estimated to reduce emissions 70 to 95 percent. Spray systems can also reduce loading and 

wind erosion emissions from storage piles of various materials 80 to 90 percent. Control 

efficiencies depend upon local climatic conditions, source properties and duration of control 

effectiveness. Wet suppression has a carryover effect downstream of the point of application of 

water or other wetting agents, as long as the surface moisture content is high enough to cause the 

fines to adhere to the larger rock particles. 

In addition to figitive dust control techniques, some facilities use add-on control devices to ' 

reduce emissions of PM and PM-1 0 from sand and gravel processing operations. Controls in use 

include cyclones, wet scrubbers, venturi scrubbers, and fabric filters. These types of controls are 

rarely used at construction sand and gravel plants, but are more common at industrial sand and 

gravel processing facilities. 

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Concrete Batch plants4 

Particulate matter, consisting primarily of cement dust but including some aggregate and sand 

dust emissions, is the only pollutant of concern fiom concrete batch operations. All but one of 

the emission points are fugitive in nature. The only point source is the transfer of cement to the 

silo, and this is usually vented to a fabric filter or "sock." 

FugiGve sources include the transfer of sand and aggregate, truck loading, mixer loading, vehicle 

traffic, and wind erosion fiom sand and aggregate storage piles. The amount of fugitive 

emissions generated during the transfer of sand and aggregate depends primarily on the surface 

moisture content of these materials. The extent of fugitive emission control varies widely from 

plant to plant. Types of controls used may include water sprays, enclosures, hoods, curtains, 

shrouds, movable and telescoping chutes, and the like. A major source of potential emissions, the 

movement of heavy trucks over unpaved or dusty surfaces in and around the plant, can be 

controlled by good maintenance and wetting of the road surface. 

Hot Mix ~s~halt' 

As with most sources in the mineral products industry, batch mix HMA plants have two major 

categories of emissions: ducted sources (those vented to the atmosphere through some type of 

stack, vent, or pipe), and fugitive sources (those not confined to ducts and vents but emitted 

directly fiom the source to the ambient air). Ducted emissions are usually collected and 

transported by an industrial ventilation system having one or more fans or air movers, eventually 

to be emitted to the atmosphere through some type of stack. Fugitive emissions redt fiom 

process and open sources and consist of a combination of gaseous pollutants and PM. 

The most significant ducted source of emissions fiom batch mix HMA plants is the rotary drum 

dryer. Emissions fiom the drum consist of water (as steam evaporated fiom the aggregate); PM; 

products of combustion (carbon dioxide [Ca], nitrogen oxides [N&], and sulfiu oxides [SOx]); 

carbon monoxide (CO); and small amounts of organic compounds of various species (including 

volatile organic compounds [VOC], methane [Ca], and hazardous air pollutants [HAP]). The 

organic compound emissions result fiom incomplete combustion of the fuel and fiom heating 

and mixing of the liquid asphalt cement inside the dm. The CO emissions result from 

incomplete combustion of the fuel. Processing of RAP materials may increase organic compound 

emissions because of an increase in mixing zone temperature during processing. Once the 

organic compounds cool after discharge hm the process stack, some condense to form a fine 

organic aerosol or "blue smoke" plume. Because liquid asphalt cement, aggregate, and 

sometimes RAP, are mixed in a zone not in contact with the hot exhaust gas stream, counterflow 

dm mix plants will likely have lower organic compound emissions than parallel flow drum mix 

plants. 

Other potential process sources include the hot-side conveying, classifling, and mixing 

equipment, which are vented to either the primary dust collector (along with the dryer gas) or to 

a separate dust collection system. The vents and enclosures that collect emissions from these 

sources are commonly called "fugitive air" or "scavenger" systems. The scavenger system may 

or may not have its own separate air mover device, depending on the particular facility. The 

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emissions captured and transported by the scavenger system are mostly aggregate dust, but they 

may also contain gaseous organic compounds and a fine aerosol of condensed organic particles. 

This organic aerosol is created by the condensation of gas into particles during cooling of 

organic vapors volatilized from the asphalt cement in the mixer (pug mill). The amount of 

organic aerosol produced depends to a large extent on the temperature of the asphalt cement and 

aggregate entering the pug mill. Organic vapor and its associated aerosol are also emitted 

directly to the atmosphere as process fugitives during truck loadout, fiom the bed of the truck 

itself during transport to the job site, and hm the asphalt storage tank. Both the low molecular 

weight organic compounds and the higher weight organic aerosol may contain small amounts of 

HAP. The ducted emissions fiom the heated asphalt storage tanks may include gaseous and 

aerosol organic compounds and combustion products fiom the tank heater. 

There are also a number of fugitive dust sources associated with batch mix HMA plants, 

including vehicular traffic generating fbgitive dust on paved and unpaved roads, aggregate 

material handling, and other aggregate processing operations. Fugitive dust may range fiom 0.1 

pm to more than 300 pm in aerodynamic diameter. On average, 5 percent of cold aggregate feed 

is less than 74 pm (minus 200 mesh). Fugitive dust that may escape collection before primary 

control generally consists of PM with 50 to 70 percent of the total mass less than 74 pm. Process 

fugitive emissions associated with batch plant hot screens, elevators and the mixer (pug mill) are 

not present in the drum mix processes. However, there are fugitive PM and VOC emissions fiom 

transport and handling of the HMA from the drum mixer to the storage silo and also fiom the 

load-out operations to the delivery trucks. Since the drum process is continuous, these plants 

have surge bins or storage silos. The fugitive dust sources associated with drum mix plants are 

similar to those of batch mix plants with regard to truck traffic and to aggregate material feed 

and handling operations. 

Applicable PM emission controls for HMA plant dryers and vent lines include dry mechanical 

collectors, scrubbers, and fabric filters. Attempts to apply electrostatic precipitators have met 

with little success. Practically all plants use primary dust collection equipment such as large 

diameter cyclones, skimmers, or settling chambers. These chambers are often used as classifiers 

to return collected material to the hot elevator and to combine it with the drier aggregate. To 

capture remaining PM, the primary collector effluent is ducted to a secondary collection device. 

Most plants use either a fabric filter or a venturi scrubber for secondary emissions control. As 

with any combustion process, the design, operation, and maintenance of the burner provides 

opportunities to minimize emissions of NOx , COY and organic compounds. 

A number of process modifications or restrictions have been introduced to reduce blue smoke 

hm rotary drum dryers, including installation of flame shields, rearrangement of flights inside 

the drum, adjustments of the asphalt injection point, and other design changes. 

Vermiculite ~rocessing~ 

The primary pollutants of concern in vermiculite processing are particulate matter (PM) and PM 

less than 10 micrometers (PM-10). Particulate matter is emitted fiom screening, drying, 

exfoliating, and materials handling and transfer operations. Emissions &om dryers and 

exfoliating furnaces, in addition to filterable and condensable PM and PM-10, include products 

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of combustion, such as carbon monoxide (CO), carbon dioxide (C02), nitrogen oxides (NOx), 

and sulfur oxides (SOx). Wet scrubbers are typically used to control dryer emissions. The 

majority of expansion baces are ducted to fabric filters for emission control. However, wet 

scrubbers also are used to control the furnace emissions. Cyclones and fabric filters also are used 

to control emissions fiom screening, milling, and materials handling and transfer operations. 

Perlite ~rocessin~' 

The major pollutant of concern emitted fiom perlite processing facilities is particulate matter 

(PM). The dryers, expansion fusnaces, and handling operations can all be sources of PM 

emissions. Emissions of nitrogen oxides fiom perlite expansion and drying generally are 

negligible. When sulfur-containing fuels are used, sulfur dioxide (SO2) emissions may result 

from combustion sources, However, the most common type of fie1 used in perlite expansion 

Eumaces and dryers is natural gas, which is not a significant source of SO2 emissions. To control 

PM emissions fiom both dryers and expansion furnaces, the majority of perlite plants use 

baghouses, some use cyclones either alone or in conjunction with baghouses, and a few use 

scrubbers. Frequently PM emissions fiom material handling processes and fiom the dryers are 

controlled by the same device. J~I most plants, fabric filters are preceded by cyclones for product 

recovery. Wet scrubbers are also used in a small number of perlite plants to control emissions 

fiom perlite milling and expansion sources. 

3.2 Emission UnitPollutant Matrix 

Emission units and pollutants associated with nonmetallic mineral mining and processing, as 

defined in this document, are presented in Table 3-1. This matrix is based on available EPA 

literature on source category emissions and emission htors. 

Table 3- 1. Emission UnitPollutant Matrix 

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4.0 Regulatory Review 

4.1 Tribal Programs/Rules 

PollutantJParameter 

Opacity, PWM- 10, COY N&, 

so*, voc, HAP 

VOC, HAP 

Opacity, PMIPM- 10 

Opacity, PWM- 10, COY NOx, 

SO*, VOC, HAP 

Opacity, PWM- 10 

Opacity, PWM- 10 

Opacity, PWM-10, COY NOx, 

S02, VOC, HAP 

Opacity, PMIPM- 10 

Opacity, PWM-10, SO*, HAP 

Opacity, PMIPM- 10 

Source Subcategory 

Hot Mix Asphalt 

Vermiculite Processing 

Perlite Processing 

A review of U.S. tribal air quality programs was performed to define the baseline of existing 

tribal rules and source specific standards. This review was conducted jointly between RTP and 

the GRIC. At the time of this retriew, no tribal programs or rules were identified that specifically 

pertained to nonmetallic minerals mining and processing source categories. 

Emission Unit1 Process 

Dryer 

Hot Oil Heater 

Loadout 

Rotary Dryer 

Concentrate Screening 

Concentrate Conveyor Transfer 

Exfoliation (Vertical Furnace) 

Product Grinding 

Expansion Furnace 

Dryer 

4.2 Federal Programs and Regulations 

4.2.1 New Source Performance Standards (NSPS) 

Three NSP Standards were identified as applicable to the nonmetallic mineral mining and 

processing industry as defined in this document. Those standards are: 

NSPS Subpart 000 - Standards of Performance for Nonmetallic Mineral Processing Plants 

NSPS Subpart I - Standards of Performance for Hot mix Asphalt Facilities 

NSPS Subpart UUU - Standards of Perfomance for Calciners and Dryers in Mineral 

Industries 

Table 4- 1 presents a summary of identified NSPS provisions by Subpart and equipment/process 

unit. 

Table 4- 1. NSPS Summary 

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Subpart 

000 

Emission Limitfstandard (Units) 

0.05 g/dscm 

7 % (unless scrubber controlled) 

10 % 

Equipment/Process Unit 

Transfer point on belt conveyors or 

my other affected facility - stack 

emissions 

Transfer point on belt conveyors or 

any other affected facility - fugitive 

emissions 

Pollutant/ 

Parameter 

PM 

Visible 

Emissions 

Visible 

Emissions 
4.2.2 National Emission Standards for Hazardous Air Pollutants 

(NESHAP)/Maximum Available Control Technology (MACT) Standards 

A single listed MACT development source category was identified as potentially applicable to 

the nonmetallic mineral mining and processing source category as defined in this document. 

However, this source category, Asphalt Concrete Manufacturing, will be delisted per information 

obtained fiom the EPA Unified Air Toxics (UATW) web site. No further analogous standards 

were identified as a resource for GRIC standard development for this source category. No GRIC 

sources within this category are major sources of HAP (i.e., emissions > 10 tpy for a single HAP 

or > 25 tpy for total combined HAP). 

Subpart 

I 

UZTU 

4.2.3 Reasonably Available Control Technology/Best Available Control 

Technology/Lowest Achievable Emission Rate (RACTBACT/LAER) 

Clearinghouse 

'~ected facilities include dryers; systems for screening, handling, storing and weighing hot aggregate; systems for loading 

trausfening, and storing mineral filler; systems for mixing hot mix asphalt; and the loading, transfer, and storage systems 

associated with emission control systems. 

Pollutant/ 

Parameter 

PM 

Visible 

Emissions 

Visible 

Emissions 

Visible 

Emissions 

PM 

Opacity 

PM 

Opacity 

Equipment/Process Unit 

Transfer point on belt conveyors or 

any other affected Edcility - inside 

building, building vents 

Crusher (without capture system) - 

Wtive emissions 

Wet Screening ops and subsequent, 

screening ops, bucket elevators, belt 

conveyors 

Any affected facility' 

Calciners and dryers 

An EPA RACTBACTILAER Clearinghouse (RBLC) search for entries after 1990 was 

conduced for the following source categories: 

Emission Limitlstandard (Units) 

0.05 gldscm 

0% 

15 % 

0% 

0.04 grldscf 

20 % 

0.040 grldscf / 0.025 grldscf 

10 % (unless scrubber controlled) 

r 90.024: Nonmetallic Mineral Processing 

90.006: Cement Manufacturing 

90.003 : Asphalt Concrete Manufacturing 

90.017: Calciners & Dryers and Mineral Processing Facilities 

Tables 4-2 through 4-5 (Attached to this document) present a summary of RBLC entries relevant 

to the nonmetallic mineral mining and processing source category as defined in this document. 

4.2.4 Accidental Release Prevention [Sec. 1 12(r)] 

No materials expected to be stored or processed at nonmetallic mineral mining and processing 

facilities are regulated under the EPA accidental release prevention rule (40 CFR Part 68). Fuels, 

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including liquefied petroleum gas (LPG), were removed fiom the list of regulated materials 

under 1 12(r) in 1999. 

4.2.5 Other 

No other federal air quality regulatory programs or standards were identified as applicable or 

potentially applicable to the nonmetallic mineral mining and processing source category. 

4.2.6 Summary of Identified Federal RulesPrograms - Testing, Monitoring, 

Recordkeeping & Reporting Provisions 

Presented in Table 4.6 is a summary of applicable Federal rule monitoring, source testing, 

recordkeeping and reporting requirements relevant to the nonmetallic mineral mining and 

processing source category as defined in this document. 

Table 4-6. Federal Rule Monitoring, Testing, Recordkeeping and Reporting 

I Rule ( Subject 1 Monitoring 62 Testing Provisions I RecordkeepingReporting Provisions 

1 NSPS 

000 

Equipment/Pollutant 

Affected hility Test methods 6om 40 CFR 60 I Replacement equipment: rated 

I I Written report of all compliance test 

Appendix A or specified in Subpart 

000 

I results within 30 days - 

Wet scrubber PM I Continuous monitoring devices - I Daily - record measurements of 

capacity, swface area of screens, 

width of conveyor belts, capacity of 

storage bins 

Control pressure drop and sc&bing liquid drop and liquid flow. I flow Semiannual report of deviations 

I +- 30% of last-performance test 

Compliance I EPA Method 5 or 17 1 Written report of all compliance test 

deterkination: PM I I results within 30 days 

Compliance 1 EPA Method 9, distance to source = I Written report of all comvliance test 

determination: 15 ft. Minimize fugitive interference. results within 30 days a 

Opacity Water mist not included Alternate 

Compliance 

determination: 

Opacity 6om storage 

bin baghouse 

Compliance 

determination: 

Opacity fiom fugitive 

method provided in 60.675(e) 

EPA Method 9, duration of 1 hour I Written report of all compliance test 

(1 0 6-minute averages) results wit& 30 days 

emissions 

Compliance ( EPA Method 22,75 minute duration I Written report of all compliance test 

EPA Method 9, duration may be 

reduced to 1 hour if certain 

conditions are met 

determination: 

Opacity fiom 

processes enclosed in 

building 

Written report of all compliance test 

results within 30 days 

results within 30 days - 

NMMTroc TSD 6-14-02 Created on 6/18/2002 9:39:00 AM 12 
NMMProc TSD 6-14-02 Created on 6/18/2002 9:39:00 AM 13 

Monitoring & Testing Provisions RecordkeepingReporting Provisions 

Test methods fiom 40 CFR 60 

Appendix A or specified in Subpart I 

EPA Method 9 

EPG Method 5, sampling time and 

volume at least 60 mb, 3 1.8 d~cf. 

Facility shall monitor dry control 

device exhaust with continuous 

emissions monitoring system, or 

For the sources listed below with a 

dry control device: 

Certiiied visible emissions 

observer - measure and record 

tbree 6-minute averages of the 

opacity of visible emissions each 

day of operation in accordance 

with Method 9 of appendix A of 

part 60. 

Sources: 

ball clay vibrating grate dryer 

bentonite rotary dryer 

diatomite flasb dryer 

3 diatomite rotary calciner 

feldspar rotary dryer 

fire clay rotary dryer 

industrial sand fluid bed dryer 

r kaolin rotary calciner 

perlite rotary dryer 

roofing granules fluid bed dryer 

roofing granules rotary dryer 

talc rotary calciner 

titanium dioxide spray dryer 

titanium dioxide fluid bed dryer 

vermiculite fluid bed dryer 

vermiculite rotary dryer 

Sources exempt fiom monitoring 

provisions (if equipped with dry 

control device): 

ball clay rotary dryer 

diatomite rotary dryer 

feldspar fluid bed dryer 

fuller's earth rotary dryer 

gypsum rotary dryer 

r gypsum flash calciner 

gypsum kettle calciner 

industrial sand rotary dryer 

kaolin rotary dryer 

kaolin multiple hearth furnace 

perlite expansion furnace 

talc flash dryer 

, talc rotary dryer 

Rule 

NSPS 

1 

NSPS 

UlTU 

Subject 

Equipment/Pollutant 

Affected facility 

Compliance 

determination: 

Opacity 

Compliance 

determination: PM 

Dry control device: 

PM andopacity 

monitoring 
4.3 State/RegionaVLocal Regulations 

To define State, regional, and local air quality rules applicable to the source categories present or 

expected to potentially site on GRIC land, all U.S. State air quality rules and select regionaVlocal 

district rules were screened using Internet resources. This screening identified sets of air quality 

rules with source specific regulations matching the matrix of GRIC source categories. The 

summary results of this study are contained in a separate electronic file titled 

STATEMATRTX.xls. From this research, specific rule provisions applicable to the nonmetallic 

mineral mining and processing source category, including emission limitations, standards, 

RecordkeepinglReporting Provisions 

Determine and record once each day 

an arithmetic average over a 2-hour 

period of botb the change in pressure 

of the gas stream across the scrubber 

and the flow rate of the scrubbing 

liquid. 

Submit written reports semiannually 

of exceedauces of control device 

operating parameters reed to be 

monitored. 

Exceedances: 

(1) All 6-minute periods during 

which the average opacity l?om dty 

control devices is greater than 10 

percent; or 

(2) Any daily 2-hour average of the 

wet scrubber pressure drop that is 

less than 90 percent of the average 

value recorded during the most 

recent performance test that 

demonstrated compliance with the 

particulate matter standard; or 

(3) Each daily wet scrubber liquid 

flow rate recorded that is less than 80 

percent or greater than 120 percent of 

the average value recorded during the 

most recent performance test that 

demonstrated compliance with the 

particulate matter standard. 

NMMProc TSD 6-14-02 Created on 6/18/2002 9:39:00 AM 14 

Monitoring & Testing Provisions 

= titanium dioxide direct or 

indirect rotary dryer or a 

vermiculite expansion furnace 

Wet scrubber controlled sources: 

Install, calibrate, maintain, and 

operate continuous monitoring 

devices for scrubber pressure 

drop and liquid flow to scrubber 

Scrubber monitoring device accuracy 

spec: 5% based on manufacturer 

certification 

Initial performance test of a wet 

scrubber: 

Use the monitoring devices to 

determine the average change in 

pressure of the gas stream across the 

scrubber and the average flow rate of 

the scrubber liquid during each of the 

particulate matter nms. The 

arithmetic averages of the three runs 

shall be used as the baseline average 

values. 

EPA Method 5, sampling time and 

volume for each test run at least 2 

hours and 1.70 dscfin. 

EPA Method 9 

Rule Subject 

EquipmentJPollutant 

Wet scrubber control: 

PMIOpacity 

Parameter monitoring 

Compliance 

detemhtion: PM 

Compliance 

determination: 

Opacity 
monitoring, recordkeeping and reporting were documented to form a baseline of analogous 

StateRegional rules. 

4.3.1 Summary of Identified Rules - Emission Limitations & Standards 

This section presents a summary of existing StateRegional air quality rules applicable to the 

nonmetallic mineral mining and processing source category as defined in this document. Five 

StateRegional program standards were identified as relevant and of potential value in 

developing the GRIC emission limits and standards for this source category. The identified rule 

provisions, including applicability, emission limits/standards, monitoring, recordkeeping and 

reporting are summarized in Table 4-7. 

Table 4-7. Summary StateIRegional Rule Emission Limits and Standards 

NMMProc TSD 6-14-02 Created on 6/18/2002 9:39:00 AM 15 

State Rule 

Arizona 

Rule 722 

Arizona 

Rule 723 

Arizona 

Rule 708 

Maricopa 

County 

Rule 3 16 

Applicability 

Existing Gravel and 

Crushed Stone 

Processing Plants 

Existing Concrete 

Batch Plants 

Existing Asphalt 

Concrete Plants 

Liquid Fuel 

Solid Fuel 

Nonmetallic Mineral 

Processing Plants 

Pollutant/ 

Parameter 

PM Emissions 

PM Control 

PM: Fugitive 

Dust 

PM Emissions 

s (sod 

s (so21 

PM: Stack 

Emissions 

Opacity: Stack 

Emissions 

Opacity; 

Emission Limit/Standard (Units) 

For process rates <30 tph: 

Max. allowable PM emissions 

(E) = 4.1 OPO.~' 

For process rates >30 tph: 

Max. allowable PM emissions 

@) = 55.0p0." - 40, 

Where: P = Process weight rate (tph) 

Spray bar pollution controls in accordance with EPA 

"Control of Air emissions From Process Operations in the 

Rock Crushing Inch~~try" (EPA 34011-79-002). Placement 

of spray bars and nozzles as required by Director 

Shall be controlled in accordance with R18-2-604 through 

607 

NOTE: Rules 604-607 include gend requirements for 

fugitive dust sources including open areas, dry washes, and 

riverbeds, Roadways and streets; Material handling; and 

Storage Piles. Requirements are limited to "reasonable 

precautions" including chemical or wet suppression, 

covering, etc. 

For process rates <30 tph: 

Max. allowable PM emissions 

(E) = 4.1 OPO.~' 

For process rates >30 tph: 

Max. allowable PM emissions 

(E) = 55.0p0." - 40, 

Where: P = Process weight rate (tph) 

Total process weight of all similar units employing a 

similar process type shall be used in determining max. 

allowable PM emissions 

Shall not exceed 0.9 % S by weight 

Shall not exceed 0.5 % S by weight 

Stack emissions shall not exceed 0.02 grldscf 

Stack emissions shall not exceed 7 % opacity 

Emissions fiom any crusher shall not exceed 15 % opacity