EXAMPLE #3 CITED IN PUBLIC COMMENT: 

EPA REGION IX WASTE MANAGEMENT DIVISION, RCRA ENFORCEMENT OFFICE, RCRA 

COMPLIANCE EVALUATION J NSPECTION REPORT FOR ASARCO INC. 

RAY COMPLEX HAYDEN SMELTER 

(APRIL 16, 2002) 

(UNOFFICIAL COPY) 
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UNITED STATES ENVIRONMENTAL PROTECTIO ;t.GENgj S _ff;:; ~ ~ REGION IX c:- _. -:> u ,:- · ~ ~ .~ 1 

75 Hawthorne Street · .-..::., .· •.;y 

San Francisco, CA 94105 '<c-.,. . </ z~ 

APR 1 5 ?OOZ 

Neil A. Gambell 

Environmental Services Manager 

Asarco Inc. Ray Complex Hayden Smelter 

P.O. Box 8 

Hayden, AZ 85235 

Certified Mail No. 7000 1670 0009 31229883 

Certified Receipt Requested 

In reply, refer to WST-3 

Warning Letter, Certification of Violation Correction. and Request for Infonnation 

On August 14-17, 2000, and September 20, 2000, a hazardous waste investigation was 

conducted by representatives of the United States Environmental Protection Agency ("EPA") at 

the Ray Complex in and ncar Hayden, AZ, EPA Identification Numbers AZD 008 397 127, AZD 

000 626 606, and AZD 008 397 184. During the course of this investigation, information was 

gathered in accordance with Section 3007 of the Resource Conservation and Recovery Act 

("RCRA"), as amended [42 U.S.C. 6927]. 

1\. copy of the investigation report is enclosed for your information and response. The 

report describes conditions at the facility at the time of the investigation, and identifies areas of 

noncompliance with RCRA regulations and potential violations of the Arizona authorized 

program under RCRA Subtitle C. Any omissions in the report shall not be construed as a 

determination of compliance with all applicable regulations. 

We apologize for the delay in issuing this report. Several of the regulatory issues 

addressed in this report were influenced by recent regulatory changes and court decisions, and 

were similar to issues affecting other industry facilities. While this effort contributed to the 

delay in issuing this report, we believe that it also contributed to the quality of our analysis. We 

welcome any updated information you wish to submit. 

Asarco 's actions during the investigation and your submittal, dated August 23, 2000, 

adequately address all of the violations noted during the inspection, and all but one of the issues 

discussed in tbc report. 

Under the provisions of Section 3007(a) of the Resource Conservation and Recovery Act 

(RCRA), 42 U.S.C. 6927(a), the EPA may require persons subject to RCRA to fumisb 
information necessary for EPA to administer the A1;t Pursuant to EPA's authority set fonh in 

Section 3007(a), you are requested to submit the following information: 

1) A copy of ~e one-time written notice submitted pursuant to 40 CFR § 266.1 00~!;); 

and, 

2) Documentation demonstrating that the spent refractory brick from Asarco's precious 

metals refinery in Amarillo, Texas does not significantly affect the residue, pursuant to 

40 CFR § 266.112(b ); or 

3) As an alternative to submitting the above information (1 and 2), a copy of the notice 

submitted pursuant to 40 CFR § 261.4(a)(J7)(v). lfthis option is used, please also submit 

certification signed by a duly authorized representative of Asarco's Amarillo, Texas precious 

metals refinery (the generator of the spent refractory brick) and your facility (the destination of 

the spent refrdctory brick) that the spent refrdctory brick is handled at aJJ times in compliance 

with 40 CFR § 261.4(a)(J7). 

Section 3008 ofRCRA, 42 U.S.C. 6928, authorizes the initiation of a civil enforcement 

proceeding for failure to respond fully to the information request set out in this letter. Section 

3008 also authorizes criminal prosecution for knowingly making a false statement or omitting 

material information. 

By copy of this letter, EPA is providing the State of Arizona with notice of the referenced 

violations of Subtitle C ofRCRA, and is providing the State with notice that it ·intends to take no 

further enforcement action for the violations that have been noted in the report. The State of 

Arizona may notify EPA of its intent to assume or decline responsibility to take further action to 

address the referenced violations. 

Pending receipt of the information requested above, EPA reserves the right to take 

fmther enforcement action as it deems appropriate. Violations of Subtitle C ofRCRA may be 

punishable by civil and criminal actions, including penalties of up to $27,500 per day for each 

violation as provided by Section 3008 ofRCRA. 

EPA routinely provides copies of investigation reports and related documents to state 

agencies. and upon request, to the public. Such releases are handled according to the Freedom of 

Information Act regulations (40 CFRPart 2). If you believe this report, or the information 

submitted in response to this letter, contains or will contain privileged or confidential 

information, you m~y make a claim within fifteen (15) calendar days from the date of this letter. 

EPA will construe your failure to furnish a timely claim as a waiver of the confidentiality claims. 

Your response to this Warning Letter, due within 15 calendar days of your receipt of this 

letter, shall be mailed to: 
Barry Cofer 

Mailcode: WST-3 

RCRA Enforcement Office 

U.S. EPA, Region 9 

75 Hawthorne Street 

San Francisco, CA 94105 

Jf you have questions or comments related to the technical aspects of the investigation 

report or this Jetter, please contact Bany Cofer at (415) 972-3303 or Kaoru Morimoto at (415) 

972-3306. 

Enclosure 

cc (w/o enclosure): 

Sincerely, 

___........-;· 

-~ ·. .... { ai .f_ ,_ .. --

/ 

./. / _t. '· r: 

Frances Schultz, Manager 

RCRA Enforcement Office 

Laura Malone, Arizona Depanment of Environmental Quality 

Greg Workman, Ari7.ona Department of Environmental Quality 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

REGION IX 

75 Hawthorne Street 

San Francisco, CA 94105 

WASTE MANAGEMENT DIVISION 

RCRAENFORCEMENTOFRCE 

COMPUANCE EVALUATION INSPECTION REPORT 

Purpose: 

Facility: 

Mailing Address: 

U.S. EPA ID Number: 

Date of Investigation: 

U. S. EPA Investigators: 

State Representative: 

RCRA Compliance Evaluation Inspection 

Asarco Incorporated 

Ray Complex - Hayden Smelter Plant 

640 Asarco A venue 

Hayden, AZ 

Asarco Incorporated - Ray Complex 

Box8 

Hayden, AZ 85235 

AZD 008 397 127 

August 14-17, 2000,and 

September 20, 2000 

Barry Cofer 

RCRA Enforcement Officer 

(415)947:3303 

co fer. bany@epa. go'' 

Kaoru Morimoto 

Environmental Engineer 

(415) 972-3306 

Frances Schultz 

Mr.nager, RCRA Enforcement Office 

(415) 972-3297 

Greg Workman 

Hazardous Waste Section Manager 

Arizona Department ofEnvironmcntal Quality 

(602) 207-4138 
Facility Representatives: 

Report Prepared Dy: 

Report Date: 

Neil A. Gambell 

Environmental Services Manager 

Ray Complex 

(520) 356-3284 

ngambell@asarco.com 

Joseph A. Wilhelm 

Manager of Metallurgy 

Ray Complex - Hayden Smelter 

(,?20) 356-3401 

Duane M. Y antomo 

Divisional Environmental Manager 

Copper Operations - Tucson Office 

(520) 798-7745 

Gary L. Lubers 

Manager 

- Hayllen Concentrator 

Ed A. Riege 

Senior Environmental Engineer 

Hayden Smelter 

Larry D. Hagy 

Environmental Engineer 

Asarco Ray Complex 

Neil Nebeker 

Senior Metallurgical Engineer 

Ray Mine 

Mike Benevidas 

Casting - Hayden Smelter 

Darry Cofer 

January 3 I, 2002 

2 
BACKGROUND 

Asarco Incorporated's Ray Co111plex (hereafter "Asarco" or the "facility") and assudated 

operations in and near Hayden, Arizona include: 

• The Hayden Smelter (EPA Identification Number AZD 008 397 127), a primary mineral 

processing facility (copper smelting); 

• TI1e Ray Mine (EPA ID # AZD 000 626 606), an open-pit copper mine located 

approximately 20 miles north ofllayden; 

• TI1e Hayden Concentrator (EPA ID # AZD 008 397 184), located near the Hayden 

Smelter; 

• The Ray Concentrator, located adjacent to the Ray Mine; 

• Heap leach pads, and associated barren and pregnant leach storage and handling systems 

at the Ray Mine; 

• A solvent extraction and copper electro-winning (SXIEW) plant adjacent to tbe Ray 

Mine; 

• An in-pit ore crusher and a primary grinding miJI at tbe Ray Mine; and, 

• A secondary mill for crushing and grinding copper ore, located near the Hayden 

Concentrator. 

TI1e combined operations at the Ray Complex produce approximately 300 million pounds 

of copper a year. Asarco also operates a wastewater treatment plant at the Ray Complex. 

Asarco provides sewage treatment for the town of Hayden, and provides approximately 1,000 

residents of Hayden and Winkleman, AZ with drinking water. 

According to Asarco's web pages and infonnational brochures (see Anachment #1 ofthis 

report), copper operations at what became the Ray Complex bega'n with the then-underground 

Ray Mine in 1880. The Hayden Smelter was constructed by Asarco's predecessor in 1912 to 

process ore for the owners of the Ray mine. In 1959, tbe Kennecott Copper Corporation, owners 

of the now open-pit Ray Mine, constructeQ their own smelter. Asarco purchased the Ray Mine 

operations in 1986, and combined them with Asarco's newly-modernized Hayden Smelter and 

Concentrator to fonn the Ray Complex. Effective November 11, 1999, Asarco Incorporated 

became a subsidiary ofGrupo Mexico S.A de C.V. 

Additional infonnation on Asarco's history and chronologies for the Ray Complex can be 

found in Attachment #1 . Facility maps, covering the approximately 700 acres of the smelter 

area, fonn Attacbrnenr #2. 

3 
REGULATORY HISTORY 

Asarco submitted their initial Notification of Hazardous Waste Activity for the Hayder. 

Smelter in August of 1980. Records available to EPA indicate the last hazardous waste 

inspection of the Hayden Smelter (EPA lOti AZD 008 397 127) was conducted by the Arizona 

Department of Environmental Quality (ADEQ) in November of 1994. Waste detennination 

violations were noted. Asarco bas subsequently returned to compliance. 

The Hayden Conceotrator (EPA lD # AZD 008 397 184) was inspected by ADEQ in 

September of 1998. No violations were noted (Att. #3). 

In January of 1998. the Department of Justice lodged two consent decrees to resolve 

alleged violations of the Clean Water Act (CW A) at the Ray Mjne and alleged violations of the 

CWA and the Resource Conservation and Recovery Act (RCRA) at Asarco's smelter facility 

(primarily lead) in East Helena, Montana. A third consent decree was filed in May of 1999 

resolving aUeged RCRA and CW A violations at the East Helena smelter and alleged RCRA 

violations at Asarco's smelting and recycling facilities in El Paso, Corpus Christi, and Amarillo. 

TX (all Att. #4). Further infonnation can be found on page 1 of Asarco's submittal to EPA (Att. 

#10)._ 

Penalties and_injunctive relief claims were estimated to total $56.3 million. Among other 

activities requjrcd under the consent decrees, Asarco agreed to: 

" .. .institllle improved materials screening and managemeut procedures at each of 

its four smelters nationwide ... "and; 

" ... impleme11t an enhanced corporate-wide environmental management and 

compliance auditing system at ASARCO's operating domestic facilities. " (Att. 

#4). 

The focus of this investigation was not to assess Asarco's compliance with the activities 

and schedules detailed in the consent decrees and related settlements. Asarco reported they were 

about mid-way through their consent decree schedule, and were preparing for an internal audit 

that was scheduled for October of2000. 

Some activities and procedures required by the consent decrees, however, had already 

been implemented at tt: ~ Hayden Smelter and thus were observed or reviewed during this 

investigation. For example. Asarco's "Procedure for Pre-Acceptance Review and Verification 

Upon Receipt of Secondary Materials at Asarco's Operating Smelting Facilities" (see the first of 

the two quotes above) was already part of the ongoing operations at the Hayden Smelter (Att. 

#5). We also briefly observed some of the construction activities at the Ray Mine which were 

conducted in response to the CW A consent decree. 

INVESTIGATION 

From August 14,2000 through August 17,2000, a RCRA Compliance Evaluation 

4 
lnspection (CEI) was conducted by inspectors from the United States Environmental Protection 

Agency (U.S. EPA). The purpose of this inspection was to detennine the facility's compliance 

with applicable federal environmental statutes and regulations, and in particular the Resource 

Conservation and Recovery Act (RCRA), as amended, the regulations provided in the Cou~ of 

Federal Regulations (CFR) Title 40, Parts 26 1-265, 268,270, and 279, and Arizona's authorized 

hazardous waste program j·n the Arizooa Revised Statutes (ARS) Title 49 and the Arizona 

Administrative Code (AAC) Title 18, Chapter 8, Article 2. 

As arco reponed generating approximately 14,739 pounds of hazardous waste in their 

1999 Facility Annual Report (FAR), including 12,285 pounds of •· ... spent vacuum truck hoses, 

gloves and personal protective equipment characteristically hazardous for lead and chrome ... " 

(An. #6, page 3 of8). Although tht; 1999 total would average less than 600 kilograms of 

hazardous waste per calendar month, Asarco indicated they were a large-quantity generator of 

RCRA hazardous wastes in the 1999 FAR (Att. #6, page 2 of8). 

A review ofUnifonn Hazardous Waste Manifests and discussions with Asarco 

representatives indicated Asarco occasionally generated greater than 1,000 kilograms of 

hazardous waste in a calendar month and was a large-quantity generator (see AAC Rl8-8-

262(A) and 40 CFR § 262.34}, especially during smelter shutdowns and equipment rebuilding 

" campaigns". Thus, Asarco was evaluated as a large-quantity generator during this 

investigation. 

On September 20, 2000, EPA collected samples of Asarco media and products and 

conducted preliminary screening using a portable x-ray fluorescence (XRF) instrument (Att. #7). 

The analysis res ults and XRF screening data form Attachment #8. 

PROCESSES 

In May of2000, EPA requested Asarco, under th~ provisions ofSection 3007(a) of 

RCRA, to provide information on their facilities' processes (An. #9). The process information 

provided below supplements the process information provided in the facility's July 14,2000 

response to EPA's 3007(a) information request (Att. # 10). The additional information detailed 

below includes clarifications and additional process infonnation obtained during and subsequent 

to the inspection. 

Based upon information gathered during the inspection, the Asarco process flowsheets 

submitted as the Appendix of their 3007(a) response (extracted into this report as Attachment 

#II) were modified to reflect current operations. The revised process Oowsheets created by 

EPA form Attachment #12 ofthis report. 

Ray Mine: 

Asarco partially owns the "Copper Basin Railway", which transports ground ore from the 

primary grinding mill at the Ray Mine to the secondary mills located near the Hayden 

5 
Concentrator, and also transports sulfuric acid from the Hayden Smelter acid plant to acid 

storage tanks at the Ray Mine. The CoppCJ: Basin Railway coMects to the nationwide rail 

system via a rail spur in Florence, AZ. 

Heap Leach Pads: 

lncomin2 Material; 

Crushed oxide ore and low-grade sulfide ores; purchased sulfuric acid; sulfuric acid from 

the Hayden Sme\ter acid plant (see discussion below); sulfuric acid from the acid plant cone 

settler overflow (CSO) tank (see discussion below); barren leach solution from the SXJEW plant. 

Outgoin2 Material: 

Pregnant leach solutions to the SX!EW plant. 

Additional Process Information: (Supplements information in Attachment# 10). 

• Unloading .from the rail cars is only done at night, so workers can avoid the heat while 

wearing the protective suits tequircd for unloading the cars. Approximately 24 acid cars 

are unloaded each twelve-hour shin. 

• Incoming purchased and produced sulfuric acid is air pumped into a 90,000 gallon 

storage tank The CSO is separately stored in two 20,000 gallon tanks. 

Heap Leach Regulatory lssues: 

Issue #1: 

Details: 

Clarified acid from the acid plant gas cleaning system drum filter and CSO is sent 

to Asarco's heap leach pads for its acid value (pH approximately 1.0) and also for 

its water value. This liquid is also characteristic for arsenic, cadmium, lead, and 

selenium (see the CSO acid discussion in the Gas Cleaning System and the 

Sulfuric Acid Plant section and Att. #8). Is this practice in violation of any 

RCRA regulations? 

Water and sulfuric acid are the primary ingredients used in the heap leach solutions. 

Heap leaching is beneficiation (40 CFR § 261.4(b){7)). During use, the acid and water solution 

is sprayed onto a mound ("heap") of ore. The solution dissolves ("leaches") copper and other 

metals from the ore. Copper in the metals-loaded ("pregnant") leach solution is then 

electro-plated onto copper anodes ("electro-winning"). After electro-winning, the spent 

pregnant leach ("barren leach") is returned to the heap leach motmd to dissolve more metals. 

Asarco is located in an arid or desert area of Arizona, and the capture of water from the 

acids, mine infiltration, equipment rinsing, rainwater runoff containment areas, etc. was common 

and economically necessary. The captured water is typically reused in the heap leach solution or 

6 
in the concentrdlor units. 

This copper ore contains sulfates. Exothermic sulfur reactions provide much of the heat 

used in the furnace and converters, and sulfur~laden gases from the smelter are coltected ty air 

pollution control devices and used to produce sulfuric acid. Asarco uses some of the sulfuric acid 

they produce in their heap leach solutions, but significant quantities of sulfuric acid arc sold as 

product. Asarco reported that the acid they produce is often of such high quality, and has sucb a 

high market value as a commodity, that they sell the sulfuric acid produced in their acid plants 

and purchase a lesser quality sulfuric acid from the open market for use on the heap leach. 

Particles from the smelter exhaust can be carried over into the sulfuric acid production 

vessels. The sulfuric acid process tanks are then "blown down .. to remove the paniculates. The 

particles are removed from the resulting acid plant blowdown liquids by a series of clarifiers, 

thickener tanks, filter presses. and the cone settler. 

"Acid plant blowdown slurry/sludge resulting from the thickening of blowdown slurry 

from primary copper. production" was formeFiy listed as hazardous waste number K064. On 

October 20, 1999 (64 FR 56470) EPA removed the listing for K064, after previously explaining 

that these wastes can be effectively regulated if they exhibit a hazardous characteristic (63 FR 

28600). 1 

The clarified liquid that overflows from the cone settler (both the cone settler tank and 

the liquid overflow are referred to as .. CSO" by Asarco), is variously referred to as "weak acid", 

"blowdown", ''weak acid blowdown" and "clarified acid" by other Arizona copper smelters. 

This "weak acid" is a strong corrosive with a pH of approximately 0.3 - 1.0. (Sulfuric acid from 

the gas scrubbing tower is weakened by the absorption of water vapor from the S02 gas, while 

tbe sulfuric acid sold as a product is strengthened by the absorption of so) gas.) 

Analysis and Interpretation: 

The reuse of the water at Asarco appears to be legitimate. The water was typically not 

characteristic, was not being stored in impoundments, and was being reused for its water value. 

Materials are not solid waste when recycled by being reused as ingredients in an industrial 

process to make a product or as effective substitutes for commercial products (40 CFR § 

261.2( e)( l)). Distinct components of the water are not recovered as separate end products (i.e. it 

is not reclaimed). See 40 CFR § 261 .1 ( c }(5)(i)) . 

. As noted, the CSO weak acid does display the hazardous waste charactcnstics. Asarco 

stated that: "[Tjhe gas cleaning systems are mineral processingjacilities because the materials 

resulting/rom operation of this equipment gain their chemical qualit.y primarily from 

constituents originating in the ore and copper concentrate. The acid plant, however, is not 

1 40 CFR § 261.4(b)(7)(ii) lists certain solid wastes from the processing of ores and 

minerals (i.e. "mineral processing wastes") that are not hazardous wastes. Although residues 

from the treatment of acid plant blowdown (calcium sulfate wastewater treatment plant sludge 

from primary copper processing) are included in the list (40 CFR § 261.4(b)(7)(ii)(H)), acid 

plant blowdown is not. 

7 
considered a mineral processingfacility. "(Page 16, Alt. #10) 

Asarco notes EPA's previous conclusion, discussed in the background documents 

incorporated into the LOR Phase IV docket, that acid plants are not uniquely associated to 

smelting. EPA reiterated this point in the LOR Phase IV final rule, defining "uniquely 

associated"1 and stating that the acid plant blowdown at copper smelters is subject to the RCRA 

hazardous waste regulations if it exhibits a hazardous characteristic (63 FR 28600). The acid 

plant blowdown used on the heap leach is characteristically hazardous. 

The clarified acid from the acid plant blowdown is used on an unlined heap leach, which 

may be a use constituting disposal. Materials used in a manner constituting disposal arc solid 

wastes even if they are legitimately recycled (40 CFR § 261.2(e)(2)(i) and Column I ofTable I 

in 40 CFR § 26 J .2).J As noted, the clarified acid used on the heap leach is characteristically 

hazardous. Hazardous wastes that are recycled are •'recyclable materials" ( 40 CFR § 

26 f .6(a)(l )). Recyclable materials used in a manner constituting disposal are required to comply 

with 40 CFR § 266.20. 40 CFR § 266.20 requires the recyclable material to meet the applicable 

Land Disposal Restrictions prior to placement on the land. The characteristically-hazardous 

clarified acid does not meet the treatment standards for the toxic metals. 

Asarco stated, however, that the use of the weak acid on the heap leach is legitimate 

because " ... the provisions of 40 C.F.R. 261.2(e)(J)(ii) and tire definition of solid waste under 40 

C.F.R. 261.2(c)(J)(i0 'allow for placement on the land that does not constitute disposal if that is 

the manner of their ordinary use. '"(page 20, Att. # 1 0). Additionally, Asarco noted ADEQ's 

interpretation of the 1997 military munitions rule (62 FR 6628): " ... use of a product for its 

intended purpose, even when the use of the product results in deposition on the land, does not 

constitute aiscard, 'and, therefore, the material is not necessarily a solid waste. "' (page 20, 

Att. #10). 

Actually, 40 CFR § 261.2(c)(l)(ii) states that: " ... commercial chemical products listed 

in§ 26/.33 are not solid wastes if they are applied to tire /anti and that is their ordinary manner 

of use. " While suJfuric acid is a commercial chemical product, it is not listed in 40 CFR § 

26 I .33. The Munitions Rule an~ previous EPA letters have recognized that commercial chemical 

2 " ... any wastefi·om ancillary operations are not "uniquely associated" because they 

are not properly viewed as being 'from" mining or mineral processing. In evaluating wastes 

from no11-ancil/ary operations, one must consider the extent to which the waste originates or 

derives from processes that serve to remove mineral values from the ground, conce11trate or 

otherwise enhance their characteristics or remove impurities, and the extent to which the 

mineral recovery process imparts its chemical characteristics to the waste. " (63 FR 28591) 

1 Unlike some of the recyclable materials discussed below, the clarified ac id is not a 

listed hazardous waste and is not reclaimed (i.e isn' t part of a furnace feedstock and is not 

retorted). The weak acid from the acid plant blowdown meets the definition of"sludge[s]" in 40 

CFR § 260.10, because the acid plant is connected to the smelter's air pollution control devices. 

It also can be considered a •'by-product., as defined in 40 CFR § 261.1(c)(3). The sulfuric acid 

produced for sale by the acid plant is a .. co-product", not a solid waste sludge or by-product (50 

FR625). 

8 
products may still be legitimately recycled when they are applied to the land and that is their 

ordinary manner of use, even if the chemical products are not specifically listed in 40 CFR § 

261.33,, 

Asarco must purchase or produce sulfuric acid, a chemical product, for use in the heap 

leach solution. The clarified sulfuric acid replaces some of the acid product that is ordinarily 

used. Thus, the clarified acid can be considered a "commercial product'~ that is nonnally 

"applied to the land" during use on tbe heap leach. Wben legitimately recycled into the heap 

leach solution, the clarified acid is not a solid waste (40 CFR § 26 1.2(c)(l )(ii)). 

- The question now becomes: Is the use of the characteristically-hazardous clarified acid 

from the acid plant blowdown in the heap leach solution legitimate recycling? Given its strong 

acid value, the "weak" acid blowdown appears to be an effective replacement for some of the 

sulfuric acid normally used in the heap leach solution. Asarco stated that " ... The pH of the 

solulion is 1.0 1naking it a suitable commercial product substilute for I he normal raffinale, which 

has a pH of approximately 2.0 ... "(Page 20, An. #I 0). As discussed in the Revert Scree'ning Area 

· and Revert Handling section, one criterion in determining the legitimacy of recycling is whether 

there are ''toxics along for the ride" ~ Although some of the lead in the weak acid may 

eventually be recovered as ·a lead concentmte after electro-winning, the characteristically-high 

levels of cadmium, selenium, and arsenic are non-contributing hazardous constituents.$ 

Situations likely to be deemed sham recycling would involve low amounts of recoverable 

material plus the presence of non-contributing hazardous constituents in the waste, 

" ... particularly hazardous constituenls not olhenvise present in the normal feed'itock of the 

process ... " (63 FR 28587). The clarified acid has large amounts of recoverable material 

(sulfuric acid). 

The normal feedstocks of the heap leaching process are water, acid, and ore. A detailed 

review of the processes indicates that Asarco was correct in determining the weak acid derives 

all of its acid value and toxic metals from the sulfates and metals originally in the ore (Page 16, 

Att. #10). We did not find any other sources of materials that ·would account for the hazardous 

characteristics (either toxic metals or corrosivity) of the acid. Thus, the usc of the clarified acid 

in the heap leach solution would not introduce hazardous constituents not already present in the 

feedstock 

The acid in the heap leach solution (including the clarified acid portion) leaches the toXlc 

metals present in the ore along with the copper. The use ofthe clarified acid removes toxic 

metals from the heap leach. Thus, the clarified acid portion will gain toxic metals, not dispose of 

them. Although the toxic metals are "along for the ride", the weak acid is used on the heap leach 

primarily to leach copper, not as sham means of disposing of toxic metals. Thus, the usc of acid 

• See 53 FR 522 (1/8/88), 52 FR 17013 (5/6/87), and 50 FR 638 ( 1/4/85) for examples 

of recycling legitimacy criteria. The clarified acid is not speculati vely accumulated. 

5 We believe that the cadmium, selenium, and arsenic are also removed from the 

electro-winning process in the lead concentrate, but because this line of inquiry was developed 

after our inspections at the copper smelters, we do not have confirmation from the facilities. 

9 
in the heap leach is not use constiruting disposal, and the clarified acid from the acid plant 

blowdown used in the heap leach solution is being legitimately recycled. 

Solvent Extraction and Copper Electro-Winning (SXIEW) Plant: 

Incoming Material: 

Copper starter sheets from Asarco's refinery in Amarillo, TX; lead anodes; pregnant 

leach solution. 

Outgoing Material: 

~opper cathodes (at 99.999% copper); barren leach; used lead anodes; lead flake; lead 

sulfate residue. 

Additional Process Information: (Supplements information in Attac~ment #I 0) 

• The SX!EW Plant generates "lead flake" and lead sulfate residues. The lead flake is 

shipped to Asarco's East Helena lead smelter. 

• A printout from Asarco's intranet Material Safety Data Sheet (MSDS) system for lead 

flake and lead sulfate indicates the lead Oake contains 10-50% lead, and would be a 

hazardous waste (0008) if discarded (Att. #13). 

• Spent lead anodes are rehlmed to the vendor that provides the new anodes. 

SX!EW Plant Regulatory ssues: ~ 

A 20-yard bin marked as containing "beads.only" actually held lead flake. Asarco 

representatives stated that all outgoing bins are properly placarded before they are transported to 

East Helena. 

The SX!EW Plant receives pregnant leach solutions from the Heap Leach. See the 

discussion on the use ofCSO weak acid in the Heap Leach section above. 

Hayden Mills: 

The mills were constructed in 191\. Copper ore from the Ray Mine is unloaded into a 

crusher (for secondary and tertiary crushing with cone crushers) and then passes through four 

rod mills and four ball mills. The milled ore is then fed into the flotation series in the 

Concentrator. 

Incoming Material: 

10 
Approximately 30,000 tons of ore per day (300 ore cars at 100 tons/car) brought in by 

rail (see Attachment 1143, photo J); oversized slag; water. 

Outeoing Materia l: 

Slurried ore to concentrator; approximately 50 gallons per minute of water flows to 

tailings impoundment via a gravity ditch. 

Additional Process Infonnation: (Supplements infonnation in Attachment #10) 

• The ore crusher area is shown in photos 3-6. 

• Mill crushing and grinding operations are shown in photos 7-8. 

• The crushed and ground ore is conveyed to the concentrator via overhead conveyer belts 

(photos 9-1 0). 

• EPA samples collected from under the ore conveyer belts did not display any of the 

Toxicity Characteristics (Att._ #8). 

• Approximately 30,000 tons of finely crushed ore (a one-day supply) is stored in the fine 

ore building. 

"H igh chrome" s hot balls, bought used from cement plants, are used in the ball mills. 

Mills Regulatory Issues: 

None. 

Hayden Concentrator: 

Incoming Material: 

Fihely ground ore; crushed refractory brick (approximately 15% copper); fresh water; 

flotation reagents. 

Outgoing Material: 

Copper concentrate to the bedding plant; tailings (water and non-copper solids) to the 

tailings impoundment; solids from the gravity bins to the filter plant. 

Additional Process Jnfoonation: (Supplements infonnation in Attachment #10) 

• The three-story Concentrator has ten froth flotation rows, with each row consisting of a 

series of tanks ("banks"). Each row has eight ''rougher" banks (about 15% copper, one 

scavenger bank, one fina l cleaner (25-30% copper) (photos I I -12). The concentrate goes 

11 
through a re-grind mill between flotation banks. 

• The froth flotation reagents jnclude milk of lime, pine oil, alcohol, and potassium amyl 

xanthate. 

• Liquids and solids that leak or spill from the flotation banks and wash down water flow 

to channels below the Concentrator {the ''subway" flows to the "Grand Canyon" or "Salt 

ruver Canyon") (photo 13). Overflow from the "Canyons" is pumped through a filter 

plant and thickener at the concentrator and goes back into. the flotation circuits. 

• Copper recovery in the Concentrator averages about 86%, and is measured every fi ve 

minutes or so by the Head Operator. 

• The tailings are normally pumped to the top of the tailings impoundments, but can 

gravity flow to the toe of tailings during upsets. 

• Asarco used to operate a molybdenum recovery circuit at the Concentrator. The current 

market price of molybdenum, however, is about one-half of what Asarco estimates it 

costs to produce and handle at the Concentrator, so the circuit remains idle. 

• Liquids discharged from the Concentrator had puddled on the roadway (photos 14-1 5). 

Further inspection, however. showed it was condensate {clean water) from the water 

coolers and air conditioners. 

• Approximately 300-400 tons of a dark material was piled near the roadway {photos 16-

17). Facility representatives stated that solids are generated during upset conditions, 

when solids from the .. 9-bin pump tails" settle in gravity bins. The solids arc collected 

with a long-reach excavatoT and the resulting "low-grade concentrate" Lc; moved within 

two weeks to the filter plant, and then to the bedding plant. 

EPA samples collected from under the fence line shown to the left in photo t 7 did not 

display any of the Toxicity Characteristics (Att. #8). 

Concentrator Regulato!)' Issues: 

See Brick; Revert Screening Area and Reverts Handling. 

Bedding Plant Area, Delumper, and Dryer: 

Incoming Material: 

According to Asarco's submittal (see page 6 of Attachment #10) each 6,000 ton bin holds 

about 5,200-5,.300 tons concentrate, 500 tons silica flux {occasionally includes used silica 

beads and quartz rock from acid plant), and about 200-300 tons of other materials and 

byproducts. 

12 
The other materials and byproducts include: crushed reverts and matte, dusts removed 

from flash furnace and converter off-gases (acid plant dust, converter hood dust, spray 

chamber dust and flash furnace filter cake); Cottrell and secondary hood baghouse du!'t, 

dust from the concentrate dryer baghouse; filter rock from the fluidized bed concentrate 

dryer; delumper rejects from the wet screens. 

Out2oing Material: 

Furnace feed; delumper rejects 6

; filter rock; used baghouse bags; fluidized bed dryer offgas; water to evaporation. 

Additional Process Information: (Supplements information in Attachment #10) 

• TI1e concentrate, primarily from the Ray, Hayden, and Mission concentrators, is 

delivered in bottom dump rail cars or trucks (photo 18) and passes through the reclaim 

hopper (photos 19-22). An auger is used to collect six assay samples from each rail car. 

Asarco normally bas about 20,000 tons of concentrate on hand. At tlle time of 

inspection, Asarco estimated they bad approximately I 00,000 tons of concentrate on 

hand (photos 23·27). Much of the additional supply was identified as Mission 

concentrate (photos 28-29). 

• The Bedding Plant has four 6,000-ton beds in concrete walled and floored bunkers 

(photos 30·32). 

• The Hayden smelter uses 2,500 tons/day of concentrate, so each 6,000 ton bin is smelted 

in about 2.1 to 2.3 days. 

• The concentrate is inventoried monthly. 

• The "Ray and Mission concentrate" contains approximately 27% copper (Att. #14). The 

Mission concentrate displays the Toxicity Characteristic for lead (6 mg/L TCLP, Att. #8). 

• The bags from the Dryer baghouse contain approximately 17% copper, and display the 

Toxicity Characteristics for cadmium and lead (Att. #15). 

Bedding Plant Area Regulatory Issues: · 

See discussions in: Gas Cleaning and Sulfuric Acid Plant; Filter Plant; Revert Screening 

Area and Reverts Handling; Brick; CP-1 Sump and Impoundment. 

" After drying in the fluidized bed dryer, the smelter feed is raised into the smelter by 

air pressure. Feed particles too large to be blown into the smelter ("delumper rejects") are 

ground to a - 10 mesh, about the size of beach sand, and then returned to the bedding plant 

13 
Oxygen (01) Plant: 

Incoming Material ~ 

Air; water; electricity. 

Outgoing Material: 

500 tons oxygen per day to the Jnco flash furnace; nitrogen vented to atmosphere; 

maintenance wastes. 

Additional Process Jnfonnation: (Supplements information in Attachment #10) 

• The Oxygen Plant underwent a major rebuild in 19.83. 

• Can also make liquid 0 1 for backup storage or sale. 

Q1 Plant Regulatory lssues: - ~ 

A container of used oil was marked as containing ••waste oil". The container WdS placed 

under a Used Oil sign. The label was promptly corrected (Att. 34). 

Inco Flash Furnace: 

According to Asarco's submittal to EPA: 

"As area's Hayden smelter processes copper concentrate into copper anodes 

using an Inca flash fum ace, five Pierce Smith converter vessels. two anode 

furnaces and two anode castiflg wheels." (page 5, Att. #10). 

Incoming Material: 

Furnace feed from the bedding plant; oxygen from the oxygen plant; naturnl gas; s1lica; 

bone ash. 

Outgoing Material: 

Matte; slag; used furnace refractory brick; lander brick; lnco flash furnace off-gas; 

fugitive gases; approximately 200 tons/day flue dust, other reverts. 

Additional Process lnfonnatjon; (Supplements information in Attachment #10) 

• The furnace chambers are lined with silica flux_, purchased from a nearby mine. 

14 
• Bone ash, purchased from South America, is used as a releasing agent in the launders, 

spoons, ladles, etc. 

• The smelter operates continually, with a shut down occurring once every two years. 

• The smelter's stack is 1000 feet tall. 

• Bricks from the launders were noted in the converter aisle ncar the suspended bumping 

block, which is made of 30 tons of copper. 

• The matte is tapped three times per hour, into 200 cubic foot ladles. Slag is tapped once 

per hour into a 600 cubic foot ladle. 

Inco Flasb Furnace RegulatorY Issues: 

The outlets of the flue dust bins arc nonnally sealed with silica. During inspection, 

Asarco representatives noted two bins that were scaled with flue dust, not silica (photo 33). The 

bins were promptly scaled properly (photo 34). 

See discussions in: Gas Cleaning and Sulfwic Acid Plant; Filter Plant; Revert Screening 

Area and Reverts Handling; Brick; CP- 1 Sump and Impoundment. 

Converters: 

Asarco operates five Pierce-Smith converters. 

Incoming Material: 

Matte from the furnace, silica; 3-inch ceramic saddles from the acid plant for use as 

silica; reverts for use as cold dope; used baghouse bags; blister copper.bars; "foul" anodes. 

Outgoing Material: 

Blister copper, converter slag; reverts; used brick; off-gas particulates (converter dusts); 

ofT-gases to the gas cleaning system and acid plant; converter slag. 

Additional Process Information: (Supplements information in Attachment #10) 

• The converter aisle, with ladles, skulls and reverts material, is shown in photos 35-38 and 

41-42. Bunker #1, holding mainly cold dope reverts, is shown in photos.39-40. 

• The matte contains about 65% copper, 15% sulfur, 20% iron. 

• Each converter receives about 150 tons/day matte, and produces about 100 tons of blister 

copper. 

15 
• Approximately 30 ladles of converter slag per day go into the furnace. 

• Asarco's MSDS for matte and slag shell shows they contain approximately 30-40% 

copper, 1-3% lead (Att. #16). 

• Asarco analysis of matte from Asarco's El P.aso facility shows the matte displays the 

Toxicity Characteristics for lead at 47.5 ppm TCLP (Att. #17). 

• The converters receive about 10 baghouse bags per week. 

• Each 150-ton converter charge contains about five ladles of cold reverts. 

Converter Regulatory Issues: 

See discussions in: Gas Cleaning and Sulfuric Acid Plant; Revert Screening Area and 

Reverts Handling; Brick. 

Anode Barrel Furnace, Remelt Vessel, and Casting Wheel: 

Asarco operates two Fuller anode furnaces and fluid bed dryers, and two anode casting 

wheels (photos 43-47). 

incoming Material: 

Blister copper from converters; blister bars from Mexico; natural gas; steam; barite slurry 

used as a mold release; contact cooling water. 

Outgoing Material: 

Anode copper; anode slag (to the converters); used refrdctory brick; reverts from minor 

splashes and spills; reject anodes (to the converters); off-gases (to atmosphere); contact 

cooling water (reused at the casting wheel). 

Additional Process Infonnation: (Supplements infonnation in Attachment #10) 

• Each of the two anode furnaces receives a 300 ton charge of blister copper. 

• About 25 tons per blow of anode skimmer slag goes to the converter . 

. • The anode casting wheels are made of copper, and cast about 60 tons/hour ofanodes 

(photos 44-46). 

• The cast anode contains about 825 pounds of99.4% copper (photo 47). The anodes go to 

the Asarco refinery in Amarillo, Texas. 

16 
37. Training Plan, undated, circa 1997. 

38. Arizona Department of Health Services Environmental Laboratory Licenses for J/20199-

1/20/00 and 5/22/00 - 5/22101. 

39. Asarco Analysis and hazardous waste detenninations for: 

Ace Pipe Cleaning PPE 

Used gloves 

Used work boots 

40. Weekly Container Inspection Log for Plastic Hose RolloffBin dated 2/15/00 though 

8/14/00. 

41. Selected Unifonn Hazardous Waste Manifests. 

42. MineraJ Processing Materials Inventory as submitted to ADEQ dated 5/31/00. 

43. 1nspection photographs. 

44 
20. Asarco Assay/Analysis for Acid Plant Filters (mist eliminators) dated 5/6/97. 

21. Asarco Assay/ Analysis for WTP drum .filter cake dated 7/12198. 

22. Asarco Assay/ Analysis for WTP plate filter cake dated 7/12198. 

23. Asarco Assay/Analysis for filter cake plastic and filter plant tank rubber dated I 0/3/96 

and associated Laidlaw Environmental Services material profile. 

24. Asarco Assay/Analysis for: 

Converter cyclone dust dated 7/30/98; 

Delumper reject dated 1217/98; 

Converter hood dust dated 7/3Q/98; 

Converter spray chamber dust dated 7/1 0/98; 

"Revert in aisle" dated 7/9/98; 

Ace baghouse bags dated 7/21/00; 

Filter rock dated 7 I I 0/98. 

Crucibles and cupels dated 717/00; 

Silica blasting abrasive dated 7/14/00. 

25. Material Safety Data Sheets for refractory bricks. 

26. Asarco Assay/Analysis for "N 3 Brick Converter'' dated 6/4/97 and anode brick dated 

4/ 15/98. 

2 7. Material Safety Data Sheet for precious metals used refractory brick dated 3/20/97. 

28. Unifonn Hazardous Waste Manifest for precious metals used refractory brick dated 

8/2/00. 

29. Asarco Assay/Analysis and handling records for concrete sump sediment removal dated 

211 I /99 through 1/21/00. 

30. Asarco Analysis for plastic vacuum hose dated 9/17/98. 

3 I. Material Safety Data Sheets for Nalco flocculants dated 2117/97 and 2/23/99. 

32. Kennecott tracking sheet for Moberg algicide dated 8/17/00. 

33. Asarco letter t9 EPA with attachments and photos dated 8/23/00. 

34. Asarco photos taken 8/16/00. 

35. Asarco Hazard Recognitionffraining card dated 8/15/00. 

36. Example of Asarco R.CRA hazardous waste training materials. 

. 43 
AIT ACHMENTS 

I . Facility brochure and selected web site pages. 

2. Facility maps. 

3. ADEQ Report for the September 22, I 998 inspection. 

4. 63 FR 8473, dated 2/19/98, 64 FR 23858-9, dated 5/9/99, and associated press releases. 

5. Procedure for Pre-Acceptance Review and Verification Upon Receipt of Secondary 

Materials at Asarco's Operating Smelting facilities dated 12/l 6/98. 

6. l999 facility Annual Report.(FAR). 

7. EPA field Sampling Plan dated 9/ 15/00. 

8. EPA Region 9 Laboratory- Richmond, CA: Summaries of Analytical Results and XRF 

Preliminary Screening Data. 

9. EPA 3007(a) Information request dated 5111/00; 

Asarco letter to EPA dated 5/19/00; 

EPA e-mail to Asarco dated 6/6/00; 

EPA letter to Asarco dated 6/8/00. 

10. Asarco's 7/14/00 submittal(s) in response to the 3007(a) request. 

I I. Asarco process flowsbeets dated 717/00. 

12. EPA's revised process flowsbeets. 

13. Material Safety Data Sheet for lead flake, lead sulfate, EW plant residue dated 9/1/93. 

14. Material Safety Data Sheet for Mission and Ray Concentrate dated 7/2/96. 

15. Asarco Assay/Analysis for silica blasting abrasive, dryer baghouse, and benn dirt dated 

7/00. 

16. Material Safety Data Sheet for matte and slag shell dated 5/ 19/95. 

I 7. Asarco Assay/Analysis for El Paso matte dated 8/13/98. 

18. Asarco Assay/Analysis for Acid Plant used silica beads and quartz rock (ceramic saddles 

and V205 fines) dated 6-7/00. • 

19. Asarco Assay/Analysis for polypropylene saddles dated 8/98. 

42 
AAC Rl8-8-262(A) 

and 

40 CFR § 262.34(a)(4) 

The training plan did not describe the type and amount of botb 

introductory and continuing ttaining of each employee with 

duties related to hazardous waste management, as required by 

40 CFR § 265.J6(d)(3). 

The violation bas been corrected. 

41 
POTENTIAL VIOLATIONS 

AAC, Title 18, Chapter 8, Article 2, Section RlS-8-262, states in pertinent part: . All of 40 CFR 262 and the accompanying appendices, as amended as of July 1, 1999 ... are 

incorporated by reference and modified by the following subsections c:>fRJS-8-262 ... 

ARS, Chapter 49, Artfcle 7, Section 49-802, states In pertinent part: 

.. .40 Code of Federal Regulations part 279, as amended on January L, 1997, is adopted by 

reference. 

AAC Rl8-.8-262(A) 

and 

40 CFR § 262.34(a)( l)(i) 

AAC RI8-8-262(A) 

and 

40 CFR § 262.34(a)(4) 

AAC Rl8-8-262(A) 

and 

40 CFR § 262.34(a)(4) 

ARS49-802 

and 

40 CFR § 279.22(c)( I) 

AAC Rl&-8-262(A) 

and 

40 CFR § 262.34(a)(4) 

A roll-off bin of hazardous waste in the Ace Pipe Cleaning yard 

and a 55-gallon drum by the Environmental Engineering Office 

were not stored closed, except when necessary to add or remove 

waste, as required by 40 CFR § 265.173(a) 

The violations have been corrected 

The Ace Pipe Cleaning storage area were not equipped with fire 

extinguishers, as required by 40 CFR § 265.32(c). 

The violation has been corrected. 

The fire extinguisher in the 90-day accumulation area was not 

tested or inspected to assure its proper operation in an 

emergency, as required by 40 CFR § 265.33. 

The violation has been corrected 

A 500-gallon used oil tank in tbe Ace Pipe Cleaning yard, a 

500-gallon used oil collection tank near the Truck Shops, the fill 

pipes to the oil tank at the oil-water separator, a 55-gallon drum 

holding used oil and used oil filters near the truck shop, a I 50-

gallon container at tbe locomotive shop, two 55-gallon drums of 

ustd oil at the Oxygen Plant, and a 5-gallon bucket of used oil . 

outside of the Tool Room all were not labeled or marked clearly 

with the words "Used Oil." 

The violations have been corrected. 

The contingency plan did not list the name addresses of all 

persons qualified to act as emergency coordinators, as required 

by 40 CFR § 265.52(d). 

The violation has been corrected. 

40 
used work boots arsenic, cadmium, chromiu:n 

waste paint F003, DOOI 

parts cleaner {prior to 2000) D039 

filter cake weighing dishes cadmium, lead 

drilling grease lead 

Used clothing an~ personal protective equipment are collected in special lockers to 

prevent exposure to dust {photo 120). 

According to Asarco representatives, the Safety-Klecn parts cleaners used on site since 

1999 are not hazardous wastes. Other materials determined not to be hazardous wastes include: 

filters from the furnace air and room conditioners; spent respirator cartridges (pass TCLP); 

fluorescent lights; sewage sludge {pass TCLP, are conveyed to off-site sewers by the "honey 

wagon"); and used oil (has always been on-specification). 

Biohazard wastes from the medical clinic are shipped to Stericycle as medical waste. 

Supersacks containing new vanadiwn pentoxide arc reportedly rendered RCRA-empty by 

shaking and are then sent to the solid waste landfill. 

Other Records: 

Weekly inspection records for the 90-day storage area were complete from September 

1999 to August 2000. 90-day storage area records dating back to 1994 were available for 

review. Examples of the satellite accumulation area inspection records form Attachment #40. 

Biennial Reports and Facility Annuai.Reports dating back to the 1980's were available 

for review. Uniform Hazardous Waste Manifests dated back to September of 1999 were 

reviewed (Att. #4 1 ). No deficiencies were noted. 

39 
Recordkeeping and Reporting 

Training: 

Initial Hazard Recognition training was provided by Jody Schwingle, of the Safety Office 

(Att. #35). Asarco has developed detailed RCRA hazardous waste training, including RCRA 

training materials and videotapes prepared by Asarco's corporate offices and facility-specific 

training prepared by the Ray Complex (see example in Attachment #36). According to Asarco 

representatives, updated RCRA trainin&requirements were instituted in 1999. Under the new 

schedule, every employee will receive an initial four hours of training, followed by a two-hour 

annual refresb~r. During the August inspection, approximately 700 ofAsarco's 1400-1500 

employees had completed the 2000 aMual refresher. 

Tbese training requirements, however, were not reflected in Asarco's Training Plan (Att. 

#37). The plan bas since been modified to "reflect the current training and recordkeeping 

requirements (Att. #33 ). 

Fire training is also provide<ko Asarco personnel. According to Asarco representatives, 

they have open bum pennits which specify what can be burned during the fire training exercises. 

Waste petroleum products such as used oil and solvents, and empty hazardous materials 

containers, tires, wire, etc. are not burned. 

Contingency Plan: 

The Contingency Plan, dated 8/11/00, did not include the home addresses of the primary 

emergency responders or a list of emergency equipment. The. Contingency Plan was 

subsequently modified (Att. #33). · 

Waste Analysis: 

Asarco's Hayden Laboratory is licensed by the Arizona Department of Health Services to 

perform a variety of hazardous waste analysis, including the Toxicity Characteristics leaching 

Procedure (TC:LP) (Att. #38). Asarco conducted a number of hazardous waste determinations, 

particularly in 1996 ·and 1998, and appears to have thoroughly characterized the potentially 

hazardous materials produced at the Ray Complex. 

In addition to the materials and wastes previously discussed in this report, Asar..;o 

analysis results indicates the following materials are hazardous wastes (see Att. #39): 

MATERIAL HW CHARACTERISTIC 

laboratory assay crucibles and cupels lead at 3000 ppm 

used personal protective equipment used by the Ace Pipe lead 

Cleaning employees 

used gloves cadmium, lead 

38 
wa~ last punched in 1998. Asarco representatives promptly had the extinguisher inspected 

(photo I 03). The 90-day area did not have a.n eyewash station. An eyewash unit has been added 

(see photo in Attachment #33). 

Environmental Engineering Accumulation: The lid on a 55-gallon drum, about 3/4 full of spray 

paint cans, could not be closed (photos l 04-1 05). The lid was promptly fixed (see photo I 06 and 

Att. #34). 

Ace Pipe Cleaning. Inc. Yard: As noted, Ace Pipe Cleaning (Kansas City, MO) uses vacuum 

trucks to collect metal bearing dusts and sludges. The used plastic flex hoses exceed the 

Toxicity Characteristics for cadmium and lead (Att. #30). The bin holding the hoses was not 

securely closed (photo 107), there was no fire extinguisher near the hazardous waste 

accumulation area, and an approximately 500-gallon used oil tank was not marked with the 

words .. Used Oil" (photo I 08). The bin was promptly closed, and the tank, which was about !12 

full, was marked with the words "Used Oil" (An. #34). A fire extinguisher was subsequently 

installed (Att. #33). 

Water Filter Plant Control Room: This area contained used personal protective equipment (see 

Waste Analysis, below). No violations were noted. 

Empty Container and Used Oil Storage Yard: Constructed in 1994, this area has a sloped and 

bermed concrete pad with a concrete-lined blind sump. Used oil containers are serviced by 

Mesa Oil, and were stored on containment pallets. The area is also used to store spill equipment. 

See photos 108-110. · 

Oil Collection Tank and Oil-Water Separator: A 500-gallon used oil collection tank near the 

Truck Shops was not marked with the words .. Used Oil" (photo l 1 1 ). The tank was promptly 

labeled {Photo 112). 

Also near the Truck Shops was an oil-water separator (photos 113-115) that serves the 

maintenance areas. The separator sends oily water through a sand-trap filter. The water goes to 

CP-1, and the oil is collected in a tank. The fill pipes to the oil-water separator oil tank were not 

marked with the words "Used Oil'' (photo 115), and one oftwo 55-gallon drums holding used oil 

and used oil filters was not marked as containing used oil (photo 116). The drum was promptly 

labeled, and oil sump tank and fill pipes were subsequently marked with the words .. Used Oil'' 

(photos 117-118 and Att. #33). 

Ux::omotive Shop: Maintenance of Asarco's diesel/electric locomotives is directed by Hugh 

Alexander, Main Manager. According to Asarco representatives, the locomotive oil filters are 

ROt teme plated. One uwnarked container, with a capacity of approximately 150 gallons, was 

about half full of used oil (photos 119). 

Auto Shop: The auto shop is managed by Mike Fialla, shop foreman. No violations were 

noted. 

Landfill: The solid waste landfill was briefly toured. No hazardous wastes were noted. 

37 
Kennecott Smelter: 

Additional Process Jnfonnation: (Supplements information in Attachment #I 0) 

• The smelter formerly operated by Kennecott was shut down in April of 1982. The 

reverb and anode furnace were tom down for their brick., and the remaining units were rebricked with new brick pending a future start-up of the smelter. 

• Approximately three years ago, Asarco began cleaning out all copper-bearing materials, 

and began seeking markets for the re-bricked converters and other equipment. 

• The old converter aisle bas been cleaned of almost all of tlte accumulated reverts (photo 

94). Brick removal dusts, clay. and some remaining revert-like materials were noted. 

EPA XRF screening results indicated that some copper-bearing materials remained (Att. 

#8). 

• Four 55-gallon drums identified only with "Aqua Phos'' spray-painted on the lid were 

noted in the rear ofthe converter aisle (photo 95). Asarco representatives stated the 

containers were not present during a walk-through inspection three weeks earlier, and 

could not positively identify the contents. Asarco stated they believed the contents may 

be Nalco floc.culants suitable for use in water treatment (Alt. #31 ). 

• In the Spare Parts room, two unmarked 35-gallon fiber containers bolding an unidentified 

purple material were noted (photo 96). Using an old Kennecott container tracking 

system, Asarco identified the contents as a Moberg-brand algicide used in water 

treatment (Att. #32). 

• Asarco subsequently identified the four 55-gallon drums ac; containing polyphosphate, 

and confirmed the two 35-gallon containers held an algicide. Doth chemicals are cooling 

tower water treatment chemicals, and would be evaluated for usability (Att. #33). 

Material identified as " fume" was noted piled under the balloon flue dust bins (photos 

97-98). Asarco promptly containerized (photos 99-100) and assayed the material, 

determined it contained approximately 12.6% copper, and removed it to the bedding 

plant. · 

Kennecott Smelter Regulatory Issues: 

Issue # 1: Used. oil spiiJs were noted in the \oodiog area outside the Kennecott smelter, and a 

five·gallon bucket of used oil in the Tool room was not marked "Used Oil" (photo 

10 I). Asarco promptly corrected the problem. See photo I 02 and Attachment 

#33. 

Waste Accumulation Areas: 

Less Than 90-Day Hazardous Waste Accumulation Area: The fire extinguisher inspection tag 

36 

\ 
CFR § 261.1(c)(l-3). 

Because the soil is not one of the materials listed in 40 CFR § 261.2(c), it is a solid waste 

when recycled. Because the soil is nota spent material, sludge, or byproduct as defined u. 40 

CFR § 261.1(c)(l -3), it cannot qualify for any of the reduced requirements for the reclamation of 

solid wastes in CFR § 261.2(c)(3). 

Because the soil is a solid waste that exhibits the toxicity characteristics for lead and 

cadmjum, it.is also a hazardous waste prior to recycling or reclamation. Hazardous wastes that 

will be recycled are defined as "recyclable materials" in 40 CFR § 261.6(a)(l). Gener.uors of 

recyclable materials must comply with the requirements for generators of hazardous wastes (40 

CFR § 261.6(b)). Owners or operators of facilities that store recyclable materials before they are 

recycled are regulated as treatment and storage facilities (except that the recycling process itself 

is exempt from regulation) (40 CFR § 261.6(c)(l)). 

RCRA hazardous waste storage requirements apply once hazardous wastes are 

generated.22 The pertinent question now becomes: When is the hazardous waste/recyclable 

material (soil) generated? 

EPA has consistently maintained that contaminated soils (that are not the result of illegal 

disposal) such as this copper-bearing soil are generated when they are excavated and removed 

from the area of contamination13• EPA recently reiterated this point in the LDR Phase IV Final 

Rule, noting that: " ... if contaminated soil is not removed from the land (i.e. ge11erated), LDR.s 

cannot apply ... in other words, LDR.s do not apply to contaminated soil in situ or force 

exca\,ation of contaminaled soil." (63 FR 28617) 

We were also concerned that road work adjacent to the dirt wall or routine maintenance 

of the wall could mix the characteristically-hazardous copper-bearing soil with non-hazardous 

soil, rendering the combined soil both non-characteristic and unsuitable for reclamation. The 

LDR Phase IV Final Rule, however, indicate this activity is not prohibited: "The Agency notes 

tlzat the normal mixing of contaminated soil from various portions of a site that typically occurs 

during the course of remedial activities or in the course ofnonna/ earthmoving and grading 

activities is not considered intentional mixing of soil with non-media or prohibited soil with nonprohibited soil and, therefore, is not a type of impennissib/e dilution. " ( 63 FR 28621) 

Thus, the characteristically-hazardous copper-bearing soil is a RCRA-regulated 

hazardous waste (and subject to the hazardous waste generation and storage requirements) when 

excavated and removed Deliberate mixing of the characteristic soil wich non-characteristic soil 

to render the combined soils non-hazardous is prohibited dilucion. The mixing that typically 

occurs during normal road work or wall maintenance activities, however, is not prohibited. 

n Storage is defined in 40 CFR § 260.10 as the ", .. holding of hazardous waste for a 

temporary period, at the end of which the hazardous waste is treated, disposed of, or stored 

elsewhere." 

' 3 See the National Oil and Haiardous Substances Contingency Plan (NCP) and 

subsequent amendments, EPA guidance letters, etc. 

35 
Issue # I: 

Details: 

Contaminated soils at the Hayden copper smelter ( .. Hayden") display the tox.icity 

characteristics for lead and cadmium (0006 and D008) and contain significant 

quantities of copper (Atts. #8 and 15). If excavated or subsequently managed, 

would ~sarco have to manage the soil as a hazardous waste? 

No recent spills or releases of hazardous waste were noted in this area. The smelter has 

been operating for almost a century. Contaminates from the furnace stack, water run-off or dust 

from the road supported by the dirt wall, windblown copper concentrate, etc. may have 

accumulated in the soil over time. If subsequently mffilaged, the soil would probably be 

introduced into the bedding plant as a concentrate or revert to recover its copper value. 

Analysis and Interpretation: 

Because the actual source of the lead, cadmium, and ~opper in the soil could not be 

detennined, we are not attempting to interpret whether the soil is characteristically hazardous 

because of hazardous waste ''contained in" the soil, or if the toxic constituents came from raw 

materials that have been absorbed or deposited in or on tbe soil. Following EPA's established 

policy1

, we are thus assuming the contaminated soil does not contain untreated hazardous 

wastes placed after the effective dates of the applicable land disposal prohibitions. We are also 

not attempting to determine whether the soil would meet the RCRA statutory elements noted in 

40 CFR § 261.1 (b)(2), but restricting our analy~is to how the recycling of the soil may be 

regulated in 40 CFR Parts 261 through 268. 

The introduction of materials into the bedding plant that contain characteristicallyhazardous quantities of toxic metals along with substantial amounts of copper was discussed in 

detail in the reverts issue. Tbe copper content of the soil ( 15-2 1% copper) approaches that of -the 

concentrate (approximately 32%). As previously noted, some smelter operators consider reverts 

containing as little as 3% copper suitable for use in the bedding plant. 

Using the same rationale already applied to the fine reverts in the reverts issue, it would 

appear that the introduction of the soil into the bedding plant would not constitute treatment of 

the toxic metals in the soil, but would be legitimate recovery of the copper. Thus, under the 

conditions discussed m the precious metals brick issue, the high-copper soil could be considered 

legitimately reclaimed by the smelting process upon introduction into the bedding plant. 

Unlike the reverts, however, the soil is not primarily .netallic in composition, is not 

directly generated by the smelting process, docs not have an established market value, and bas 

been left in place for an extended period of time. Thus the soil is not "used or reused" as defined 

in 40 CFR § 26l.l(c)(5), because it would be recl.airned in the smelter and it is not a commercial 

chemical product. The soil is also not a spent materi!ll, sludge, or byproduct as defined in 40 

:u "As discussed in the April 29, 1996 proposal, the Agency continues to believe that, if 

infonnation is not available or inconclusive, it is generally rea s~mable to assume that 

contaminated soils do not contain untreated hazardous wastes placed after the effective dates of 

applicable land disposal prohibitions." (63 FR 286 19) 

34 
Arizona's Aquifer Protection Program. 

• Sediments are cleaned from the sump quarterly. 

• EPA analysis indicates the CP-1 sediments exceed the Toxicity Characteristics for 

cadmium at 5.2 mgll and lead at 5.0 mg/L. Total mercury was 160 mglkg, TCLP at .02 

mg!L (Att. #8). 

• CP-1 sediments are typically collected with a bucket loader and hauled to the bedding 

plant, where they are air dried ~d then blended with the filter cake. 

• Asarco assay results and sediment handling records indicate the CP-1 sediments can vary 

from 12 to 54% copper and .92 to 35% lead (An. #29). 

• An Asarco contractor, Ace Pipe Cleaning, uses vacuum trucks to collect metal bearing 

dusts and sludges. Wash waters an<J liquids are sent to CP-l. Asarco bas determined the 

used plastic flex hoses exceed the Tox.kity Characteristics for cadmium at 2.2 mg/L and 

lead at 10.4 mg/L (Att. #30). 

- - ...:. 

CP-1 Sump and Impoundment Regulatory Issues: 

See discussion under Revert Screening Area and Reverts HandJing. 

ADDITIONAL AREAS INSPECTED: 

Berm Dirt: 

Additional Process lnfonnation: (Supplements information in Attachment #10) 

• Analysis and assay results reviewed during the investigation included TCLP analysis for 

.. berm dirt .. (Att. #J 5). 

• Upon questioning, Asarco representatives stated the berm dirt contained approximately 

15% copper, and identified the sample as soil from several locations along a dirt wall 

("berm") down-gradient from the copper smelting furnace and up-gradient from a copper 

concentrate storage pile. 

• The Asarco analysis indicates the berm dirt displays the Toxicity Characteristics for 

cadmium at 4.6 ppm, and lead at 33 ppm (Att. # 15). 

• EPA also sampled soils from the earthen benn. XRF data indicated the berm dirt 

contained 16-21 % copper, and EPA analysis results indicated the benn dirt displays the 

Toxicity Characteristics for cadmium at 1.1 and 4.2 mg!L, and lead at 17 and It mg!L 

(Alt. #8). 

Benn Dirt Regulatory Issues: 

33 
Asarco's "Procedure for Pre-Acceptance Review and Verification Upon Receipt of 

Secondary Materials at Asarco's Operating Smelting Facilities .. includes procedures for the 

acceptance of precious metals-bearing hazardous wastes, including compliance with the 

requirements of 40 CFR § 266.112 (page 13, Att #5).20 

Thus, although the selenium contributed by the precious metals bricks could be 

considered a "toxic along for the ride", Asarco is required to detcnnine that tbc selenium in the 

bricks does not "significantly affect'' the furnace residues (i.e. doeS not sib'Ilificantly increase the 

concentration of toxic constituents of concern in the Bcvill-cxempt smelting slag). 

As noted, with the transmittal of this report Asarco is being given the opportunity to 

demonstrate their compliance with 40 CFR § 261.4(a)( 17). If Asarco does not avail themselves 

of this opportunity, the transmittal requests Asarco submit a copy of their one-time written notice 

submitted pursuant to 40 CFR § 266.100(g) and their documentation, pursuant to 40 CFR § 

266.112(b), demonstrating that the spent refractory brick from Asarco 's precious metals refinery 

in AmariiJo, Texas does not significantly affect the Hayden residue. 

Pending receipt of this documentation, Asarco appears to be processing the precious 

metals brick to recover economicaUy-significant amounts of precious metals, not as a sham 

means of disposing of the selenium present in the brick. The recycling of the precious metals 

brick into the copper concentrate, if Asarco can demonstrate their current practices do not 

significantly affect the residue, appears to be a legitimate means of recovering the silver and 

gold values in the brick. 

CP-1 Sump and Impoundment: 

Incoming Material: 

Run-off water; wash water; process drains. 

Outgoing Material: 

Water to processes; sediments to bedding plant pad. 

Additional Process lnfonnation: (Supplements infonnation in Attachment #I 0) 

• Asarco refers to "CP-1" as both the 100,000 gallon concrete sump and the lined basin/ 

impoundment that contains any sump overflow (photos 88~93). 

• Prior to the lining being installed, the impoundment was the "Containment Pond". The 

concrete walled and floored sump was constructed, the impoundment lined, and the 

impoundment designated as overflow for the sump (not routine storage) to comply with 

20 The 40 CFR § 266 Appendix VU limits are referenced under the legitimate recycling 

criteria in this procedure (page II, All #5). 

32 
At 6-14% silver, the value ofthe precious metals the bricks contribute to the slimes 

should more than off-set the costs of transporting and crushing the bricks. Thus, introducing 

Amarillo's precious metals brick into Hayden's furnace feed is an economical way for Asarco to 

retrieve the value of the precious metals in the brick. 

The valueofthe material, combined with the fact that it is shipped to the Hayden smelter 

on a hazardous waste manifest, should serve to ensure that the precious metals brick is properly 

managed and prevent the brick from becoming a part of the RCRA disposal problem. Thus, the 

precious metals brick contains economicaJly significant quantities of silver, is handled as a 

material that has value, is transported to the copper smelter on a Hazardous Waste Manifest (AU. 

#28), and is neither stored nor speculatively accumulated prior to reclamation. 

19 Asarco thus 

appears to be in compliance with the requirements of 40 CFR § 266.70. 

As discussed in the Revert Screening Area and Revert Handling section, a primary 

copper smelting furnace (which is an industrial furnace) is a Boiler or Industrial Furnace (BIF) if 

it processes hazardous waste ( 40 CFR § 266.1 00( a)). 40 CFR § 266.1 OO(g) states that owners 

and operators of smelting furnaces that process hazardous wastes for recovery of economicallysignificant amounts of precious metals '' ... are conditionally exempt from regulation under this 

subpart, except for§ 266.11 2 ... " if the smelter submits a one-time notification that the owner or 

operator c1aims the exemption, samples the waste as necessary to document the economica11y 

significant amounts of metals, and maintain records of the analysis results. 

40 CFR § 266.112 requirements include demonstrating that the hazardous waste does not 

significantly affect the residue by conforming with selected sampling and analysis criteria. 40 

CFR § 266.11 2 also states that the residue standards must be met for the furnace residues (i.e the 

copper smelting slag) to remain Bevill-exempt under 40 CFR § 261.4(b)(7). 

The precious metals brick amounts to a very small percentage of the smelter feedstock, 

and Asarco is unquestionably complying with the 40 CFR § 266.112(a)(2) requirement that at 

Jeast 50% of the feed be normal, nonhazardous raw materials. It would appear unlikely that such 

relatively small amounts of precious metals brick would significantly affect the smelter slag. 

However, Asarco's precious metals used refractory brick displays the Toxicity 

Characteristic for selenium (Att. #27). Selenium is not found in significant amounts in the 

normal smelting furnace feedstock, and thus any detectable amount of selenium in the resulting 

smelting furnace slag could "significantly affect" the slag (and its Bevill-exempt status). 40 

CFR § 266.112(b )(I) states: "The waste-derived residue must not contain appendix VIII, part 

261 constituents (toxic constituents) that could reasonably be attributable io .-:,e ha~ardous 

waste ... " Selenium is an appendix VIII, part 261 toxic constituent 

19 Precious metals brick that is stored prior to crushing, or is left on the ground after 

the crushing procedure, would subject the smelter to the speculative accumulation record 

keeping requirements in 40 CFR § 266.70(c). The purpose of the bedding plant is to blend 

various materials together to ensure a uniform feed for the furnaces. Thus the blending is an 

integral part of the smelting process, and the reclamation of the brick would commence when the 

crushed precious metals brick is mixed into the copper concentrate at the bedding plant. 

31 
reclaimed (except as provided under 40 CFR § 261.4(a){l7)). "17 

With the transmittal of this report, Asarco is being given the opportunity to provide a 

copy of their notice submitted pursuant to 40 CFR § 261.4(a)( 17)(v), and to demonstrate tb:tt De 

spent refractory brick is handled at all times in compliance with 40 CFR § 261.4(a)(l7) at both 

their Amarillo and Hayden facilities. lf Asarco does not avail themselves of this opportunity, the 

solid waste exemption for the reclamation for spent materials (the used precious metal brick) a: 

40 CFR § 261.2(c)(3) would not apply, and the spent bricks from the precious metals smelter 

would be solid wastes prior to recycling. Because the spent bricks also contain 

characteristically-hazardous levels of toxic metals, the solid waste bricks would also be 

hazardous wastes. 

The question now becomes: Is the Hayden copper smelter legitimately recycling the 

characteristically-hazardous spent precious metals brick? Hazardous wastes that will be recycled 

are defined as .. recyclable materials" in 40 CFR § 261.6(a)(l). 40 CFR § 261.6(a)(2)(iii) 

provides that recyclable materials from which precious metals are reclaimed arc subject to the 

Recyclable Materials Utilized For Precious Metal Recovery regulations in 40 CFR Subpart F (40 

CFR § 266.70). 40 CFR § 266.70(a) states that "The regulations in this subpart apply to 

recyclable materials that are reclaimed to recover economically-significant amounts of gold, 

silver ... " 18 

Whether the process is economical is also one criterion in determining the legitjmacy of 

recycling. That is, whether the costs of transporting the spent brick from Texas to Hayden, 

crushing and smelting the spent brick at Hayden, and then smelting the electro-refming slimes 

back at the Amarillo precious metals smelter would consistently exceed or be less than the value 

of the precious metals in the spent brick. 

As previously discussed, slimes containing precious metals are products normally 

produced by the copper smelting industry during the electro-refining of copper anodes, and 

Hayden's anodes (with or without the enhanced silver value from the precious metals brick) are 

routinely electro-refined at Amarillo. Increasing the silver value of the anodes by introducing 

the precious metals brick into the Hayden furnace feed increases the market value of Amarillo's 

slimes without changing the routine cost of transporting the anodes to Amarillo, electro-refining 

the anodes, and smelting the precious metals slimes. 

17 As previously noted in the reverts issue, 40 CFR § 261.4(a)(J7) requires certain 

handling and storage practices for mincrnl processing secondary materials. The .. Battery" 

decision (Association of Battery Recyclers, Inc. et al v. United States Environmental Protection 

Agency, (D.C. Cir. No. 98-1368), decided April 21, 2000) set aside the reference to 40 CFR § 

261.4(aX1 7) for characteristic-only byproducts and sludges (such as the fine reverts and acid 

plant blowdown) that are not solid wastes when reclaimed, but left intact the potential exclusion 

for spent materials that m solid wastes when reclaimed. 

19 And " ... platinum, pa/adium, iridium, osmium, rhodium, ruthenium. or any 

combination qf these. " Although small amounts of these platinum group metals are smelted 

from the slimes produced from Arizona copper ore, they were not noted in the MSDS for the 

precious metals brick and thus their value was not considered in this analysis. 

30 
arsenic, chromium, and selenium (0004, 0007, and DO 1 0). 15 The spent refractory brick makes 

up an extremely small fraction of the copper smelter feedstock. Incoming spent refractory brick 

is immediately crushed and mixed with the copper concentrate (to prevent pilferage, according 

to a smelter representative), and then goes directly into the bedding plant, where it is mixc:J with 

other feedstock and furnace ingredients (sand fluxes, lime, etc.) From the front gate of the 

Hayden smelter to the furnace takes approximately nine to ten days. 16 

Hayden only accepts the spent brick if the precious metal value is high enough (Att. #5). 

The brick is shipped to Hayden on a hazardous waste manifest (Att. #28). 

Analysis and lnterpretation: 

The spent refractory brick from Hayden's copper smelting furnace and convertors absorb 

copper during the smelting process. These spent bricks are then finely ground and introduced 

into the Hayden smelter feed to recover their copper value. These bricks directly contribute 

copper to the copper anodes at Hayden, and are best considered "by-products" as defined in 40 

CFR § 26l .l(cX3) and .fine reverts, as previously discussed in the Revert Screening Area and 

Revert Handling issue. Hayden's resulting product, anode copper, is not only "commodity-like" 

(see 50 FR 655, 1/4/85) but is a commodity commonly listed on the metals exchange markets. 

Based on our understanding of the copper smelting process, the majority of the silver and 

gold in the incoming spent precious metals brick would be concentrated into the copper anodes 

along with the copper, thus increasing the value of the anode copper. Unlike the copper in the 

Hayden spent refractory brick, however, the silver and gold in the spent precious metals brick 

are not fully recovered at Hayden. As previously noted, the Hayden anodes are sent to Amarillo, 

which electro-refines the anodes and generates the precious-metal bearing slimes. AmariJio then 

smelts the slimes to recover the silver and gold. Thus, the Hayden copper smelter concentrates 

the silver from the precious metals brick into the copper anOdes, but the enhanced silver values 

arc actually recovered in Amarillo. Hayden only partially reclaims the silver by making it 

amenable for full reclamation by electro-refining and smelting at Amarillo. 

Thus, unlike the "byproduct" finely-ground copper refractory brick Hayden produces and 

reclaims onsite, the spent precious metals brick produced at Amarillo and transported to l:Iayden 

for partial reclamation are best classified as a "spent material" as defined in 261.l(c)(l). 40 CFR 

§ 261.2( c )(3) and Table 1 of subpart 261 states that spent materials, " ... are solid wastes when 

15 Asarco's Ray Complex licensed laboratory routinely analyzes for selenium (see the 

various attached assay/analytical results, and the Waste Analysis discussion below). We noted, 

however, that the list of target TCLP metals in Appendix 7 of Asarco's corporate-wide 

"Procedure for Pre-Acceptance Review and Verification Upon Receipt of Secondary Materials at 

Asarco's Operating Smelting Facilities" does not include selenium (Att. #5). 

16 Asarco smelts 2,500 tons/day, so each 6,000 ton bin at the bedding plant takes a 

around 2.1 to 2.3 days to smelt. With four ·bins (one being smelted, one waiting, two being 

built), the bricks would pass into the smelter in about 9 days. 

29 
• The furnace brick is composed of60-75% chrome ore and magnesium chromium oJCide 

(An. #25). 

• The furnace brick passes the TCLP for chrome (An. #10, and Asarco assays and 311l!ly3is 

reviewed during the inspection). 

• Asarco analysis of the converter and anode refractory brick do not display any of the 

Toxicity Characteristics (An. #26). 

Brick Regulatory Issues: 

Issue #1 : 

Issue #2: 

Details: 

Sec discussion under Revert Screening Area and Reverts Handling. 

Asarco's Ray Complex Hayden Smelter ("Hayden") is a primary copper 

processing facility that accepts spent refractory brick from Asarco's precious 

metals refinery in Amarillo, Texas ("Amarillo"). Hayden immediately crushes 

the incoming brick (in the "Smithco" crusher) and mixes it with other incoming 

raw materials destined for the copper furnace. Is the use of this brick legitimate? 

The same grinding, flotation, and smelting processes that concentrate the copper present 

in the ore also concentrate the gold and silver present in the ore. The copper ore contains a bout 

0.3% copper. The smelting process produces copper anodes containing 99.9% to 99.99% 

copper. Most copper smelters then electro-refine the anodes. In electro-refining, the copper in 

the anodes is electroplated onto copper cathodes (99.999<'/o pure copper). The 0.1% to 0.01% of 

non-copper metals in the copper anodes collect in the electrolyte and are removed as "slimes". 

The slimes had a market value of about $8-$15 a gallon during our investigation in August of 

2000 (price varies with assay results and gold and silver prices), and are the way gold and silver 

arc nonnally produced and sold by copper smeJters. 

The Hayden primary copper smelter does not operate an electro-refining unit. Asarco 

sends the Hayden copper anodes to tbeir Amarillo facility. Amarillo docs the electro-refining, 

and also has a precious metals refming unit that refines the clectro·refining slimes along with 

other compounds containing gold and silver (dore'). This sister facility's precious metals unit 

generates spent refrac\ory brick from inside the bottom blown cupels. According to facility 

representatives, the Amarillo precious metals refinery cannot recover precious metals fTom the 

spent brick, but the Eayden copper smelter can. The copper smelting process concentrates the 

precious metals into the anodes, where they can later be recovered by electro-refining and 

precious metals smelting. 

The material safety data sheet for the spent precious metals refractory brick (Att. #27) 

indicates that it contains approx.imately 6-14% silver, l-4% selenium, 1-2% copper, "less than 

l%"1cad and arsenic, some .. mixed oxides" of other toxic metals, and is characteristic for 

28 
cadmium and lead. 

A copper smelting furnace (which is an industrial furnace) is a Boiler or Industrial 

Furnace (BIF) if it processes hazardous waste (40 CFR § 266.IOO(a)). "Taxies along for lite 

ride., are evaluated at BlFs by determining if the taxies .. significantly affect" the furnace 

residues (i.e. the BeviJJ-exempt smelting slag) (see 40 CFR § 266.112{a)(2) and (b)(l)). 

Although the smelter is not processing a hazardous waste if the reclamation is legitimate, the 

BIF regulations arc stilt useful in determining the affect of the toxic metals on the Bevill-exempt 

slag.

14 

The toxic metals· in Asarco's.fine reverts appear to have originated in the nonnal copper 

concentrate and smelter feed. Since cadmium is already present in the smelter feed, "e ha\·c 

determined that the re-introduction and recycling of the relatively small quantities of 

characteristically hazardous .fine reverts into the concentrate and smelter feed is unlikely to 

"significantly affect" the slag. Thus, the fine reverts are being legitimately reclaimed in the 

smelter. 

Brick: 

Bricks generated at the Hayden Smelter are handled in a portion of the reven screening 

area. 

·Incoming Material: 

Refractory brick from the flash furnace, fu01ace launders, conveners; and anode furnace; 

used a~id plant brick; used refractory brick from Asarco's Amarillo, Texas precious metals 

refmery. 

Outgoing Material: 

Revert copper to the converters (via Bunker# 1 ); crushed brick to the concentrator: 

launder bricks to the converter aisle (photo 86). 

Additional Process Information: (Supplements information in Attachment # I 0) 

• Bricks are accumulated in 50-ton piles, then sorted by hand for visible copper. 

• For the purposes of this investigation. bricks with visible "ribbons" of copper 

(absorption) used in the converters were considered analogous to large reverts (photo 

87). 

• MSDSs for a variety of Asarco refractory bricks form Attachment #25. 

11 The reverts appear to meet the BIF limits in 40 CFR § 266. J 00( d)(2}, contain less 

than 590 ppm cyanide, and comprise less than 50% of the feedstock. 

27 
of the material are recovered as separate end products (as wllen metals are recovered/rom 

metal-containing secondary materials) ... " (40 CFR § 261.l(c)(5)(i), emphasis added). 40 CFR § 

261.l(c)(4) defines "reclaimed" as: "A material is "reclaimed" if it is processed to recover a 

usable product, or if ills regenerated. Examples are recovery of lead values from spent 

batteries ... ". Thus, because Asarco recovers copper from the re.verts as a separate end product, 

and also because this recovery constitutes reclamation, the fine reverts do not qualify for the 

"used or reused" solid waste exclusion in 40 CFR § 261 .2(c)(l )(i). 

Tbefine reverts could also be considered ''used or reused" if they are used as an effective 

substitute for a commercial product, i.e. copper concentrate (40 CFR § 261.l(c)(5)(ii) and§ 

261 .2( e)( 1 )(ii)). However, EPA has previously indicated in guidance documents and preamble 

language (50 FR 619) that the same reclamation issues applicable to ingredients can apply to 

product substitutes. 

Therefore, the .fine reverts do not qualify for the "used or reused" exclusion (40 CFR § 

261 . l(c)(5)(ii) and§ 261 .2(e){l )(ii)) because the smelting process itself constitutes reclamation 

(see 40 CFR § 261.1(c)(4)). The fine reverts, however, are not listed hazardous wastes. Because 

the fine reverts are not listed hazardous wastes and are not speculatively accumulated, whether 

they are considered "by-products" as.de.ftf!.ed in 40 CFR § 26l.l(c)(3), "sludge(s]" as defined in 

40 CFR § 260.10, or mineral processing "secondary materials" (see 40 CFR § 261 .4(a)(17)), 

they are not solid wastes when legitimately reclaimed by the smelting process ( 40 CFR § 

26l.2(c)(3)). 

The question now becomes: Are the fine reverts legitimately reclaimed by the smelting 

process? The smelting process clearly recovers the copper value in the reverts. One criterion in 

determining the legitimacy of reclamation is whether there are "toxics along for the ride".

12 

EPA has stated: ''Situations most likely to be deemed sham recycling would, thus, be those 

involving low amounts of recoverable maten·al plus the presence of non-contributing hazardous 

constituents in the waste (particularly hazardous constituents not otherwise present in the 

nonnalfeedstock of the process)." {63 FR 28587) 

As noted, the fine reverts contain significant amounts of copper. A portion (if not the 

majority) of the lead in the .fine reverts will be removed in the drum filter cake and sold to 

Asarco's lead smelter. Cadmium, which some of the fine reverts contain in concentrations that 

exceed the Toxicity Characteristics, is a non-contributing hazardous constituent. However, 

cadmium appears to be present in tbe normal feedstock of the processes, and the same smelting 

processes that concentrate copper into the reverts also concentrate the heavy metals.

1 3 Although 

the cad .. 1ium is .. along for the ride", the .fine reverts are being introduced into the smelting 

process primarily to reclaim their high copper content, not as a sham means of disposing of 

u Sec 53 FR 522 (1/8/88), 52 FR 1701.3 (5/6/87), and 50 FR 638 (1/4/85) for examples 

of recycling legitimacy criteria. 

11 Unlike some of the secondary materials reportedly utilized in the smelting of other 

metals (cathode ray tubes being crushed at lead smelters, etc.), the fine reverts are generated 

during the copper smelting process and the toxic metals found in the fine reverts appear to have 

primarily originated from the ore. 

26 
re-introduction of reverts as a means of recovering copper that would otherwise escape from the 

smelter processes. 

The same grinding, flotation, and smelting processes that concentrate the copper p:'!Sl:nt 

in the ore also concentrate the arsenic, lead, mercury, and other Toxicity Characteristic metals 

present in the ore. These toxic metals are concentrated into the reverts along with the copper. 

Reverts are usually assayed for copper content but not for toxic metals, because the smelter does 

not consider reverts a waste. 

The large reverts, sometimes called .. cobble", are usually generated in or adjacent to the 

converter aisle. They typically contain over 50% copper. After any needed crushing and sizing, 

the majority of the large reverts are either fed directly into the furnace or are used in the 

converters as "cold-dope". The ongoing reactions in the converters are exothermic, and the cold 

metal pieces are used as "dope" to control the temperature inside the converters. 

These large reverts are required for the ongoing operation ofthe converters, and are 

stored, bought, or sold by smelters depending on need. The large reverts are often stored on the 

ground' 1 and were not being speculatively accumulated at the time of the inspections. 

In contrast, the fine reverts are normally reused by blending them into the smelter 

feedstock. The fine reverts have a market value and are routinely sold by Asarco, are usually 

stored on the ground, and were not being speculatively accumulated during our inspectjon. The 

fine reverts sampled during the investigation contained approximately 40% copper and exceeded 

the Toxicity Characteristics for lead and cadmium. Asarco considers fine reverts containing as 

little as 3% copper suitable for blending with the concentrate. 

Analysis and Interpretation: 

We have detennined that the large reverts are typically used by returning them directly 

into the ongoing smelting process. Essentially, they are pieces of copper being used as copper. 

Molten metal gpilled onto smelter floors is not a solid waste if it is picked up as practical and 

placed back into the smelting process (63 FR 28583}. We have determined that the large reverts 

or cobble. if not speculatively accumulated, are not solid wastes when used in this manner. 

The status ofthefine reverts appears to require a more detailed analysis. Materials arc 

not solid wastes when they are legirimarely recycled by being .. used or reused" as an ingredient 

in an industrial process to make a product, provided the materials are not being "reclaimed" (40 

CFR § 261.2(e)(l)(i)). Materials are ··used or reused" if they are " ... employed as an 

ingredient .. .in an industrial process to make a product ... " except where " ... distinct components 

11 40 CFR § 26L4(a}(l7} requires certain handling and storage practices for mineral 

processing secondary materials. 40 CFR § 26L2(c)(3), as codified, referenced these 

requirements for mineral processing secondary materials that are reclaimed. The "Battery" 

decision (Association ofBattery Recyclers, Inc. et al v. United States Environmental Protection 

Agency, {D.C. Cir. No. 98-1368), decided April 21, 2000) set aside the reference to 40 CFR § 

26 f .4{a)( 17) for characteristic-only byproducts and sludges (such as the fine reverts and acid 

plant blowdown) and that are not solid wastes when reclaimed. 

25 
• Asarco hasn't received post-constmer scrap copper in bulk in several years. 

• Copper-bearing reverts are measured in the monthly metal balance. An additional 400 

tons of"copper tools", such as the anode molds and the bumping block, are also 

inventoried. 

Revert Screening Area and Revert Handling RegyJatorv Issues: 

Issue# 1: 

Details: 

Analytical results show that " reverts" from copper smelting operdtions can be 

characteristically hazardous for lead and cadmium, and can contain 50% copper. 

If the revert material bas.mucb higher concentrations of copper and toxic metals 

than the ore, is re-introduction oftbe revert material into the smelter process 

legitimate? 

The copper ore typically contains approximately 0.3% to 0.6% copper. Analytical results 

show that the copper concentrate made from the ore is approx.imately 27% copper (Att. # 14), and 

exceeds the Toxicity Characteristics for lead (Att. #8). After smelting, the copper anodes 

contain approximately 99.4% copper. 

During the smelting process, copper smelter operators generate a variety of 

copper-bearing materials they call "reverts". For the purposes of this discussion, we are dividing 

reverts into two broad categories: 

"Large" reverts: Fairly large, dense and solid pieces of metal or primarily metallic 

material (including slag, matte, and blister copper) generated from the cooling of molten rrietal 

that bas escaped or been removed from the smelting or converting process. This category of 

reverts include metal that bas cooled on the inside of ladles (skulls), drips and spills from the 

handling of molten metal, and high-copper content material tbat has been skimmed from the 

surface of converters. 

"Fine" reverts: Cooled copper from smaller splashes and drips, along with copper bearing 

sands, mud, sweepings, drum and filter cake, CP-1 water sump solids, etc. generated during or 

subsequent to the smelting process. These reverts are finer in particle size than the often large 

and solid pieces of metallic copper discussed above. 

Unlike other Arizona primary copper smelters in their submittals to EPA, Asarco 

consistently used the term "reverts" to refer only to the same kind of materials we have defined 

as large reverts above (Att. # l 0). Asarco properly refers to the sump solids, dusts, filter 

material, etc. that we have defmed as .fine reverts by their proper source name. For example, 

sediments from the concrete sump at CP-1 are referred to as "concrete sump sediments" (Att. 

#29). lo the interest of brevity, we will consolidate these materials under the term ''fine reverts'' 

in tbis discussion. 

Because the initial concentration of copper in the ore is so low, materials that could be 

considered .. waste-like" in other industries (solids from the bottom of sumps, etc.) contain 

copper values several orders of magnitude higher than the ore. Asarco considers the 

24 
Outgoing Material: 

Bedding plant and furnace feed; cold dope to the converters and anode furnace; mill and 

concentrator feed; reverts and blister copper sales. 

Additional Process Information: (Supplements information in Attachment# l 0) 

• The reverts sorting area held approximately 300 tons of copper ladle and slag skulls. The 

skulls and converter aisle revens are dropped onto a 4" "grizzly'' screen to sort them by 

size. Skulls pieces larger than 2" are sent to the converters. Smaller material is sent to 

the .. Smitbco" crusher and hence to the bedding plant or for revert sales. 

• Asarco analyses of various revert material are included as Attachment #24. The Asarco 

analyses indicate: 

• The vent gas Cottrell dust displays the Toxicity Characteristics for cadmium at 127 ppm, 

and lead at 8.750 ppm; 

• The converter cyclone dust displays the Toxicity Characteristics for cadmium at 39.7 

ppm, and lead at 9.3 ppm; 

• The converter hood dust displays the Toxicity Characteristics for cadmium at 4.5 ppm, 

and lead at 12.9 ppm; 

• Reverts in the converter aisle dust display the Toxicity Characteristic for lead at 13.9 

ppm; 

• The converter hood dust displays the Toxicity Characteristics for cadmium at 4.5 ppm, 

and lead at 12.9 ppm; 

• The delumper reject dust displays the Toxicity Characteristics for cadmium at 16.1 ppm, 

and lead at 39.7 ppm; 

• The converter bood dust displays the Toxicity Characteristics for cadmium at 4.5 ppm, 

and lead at 12.9 ppm; 

• The baghouse bags display the Toxicity Characteristics for cadmium at 47 ppm, and lead 

· at 1 o. ppm; and, 

• The filter rock displays the Toxicity Characteristics for cadmium at 1.38 ppm, and lead 

at 63. 1 ppm. TCLP results for mercury were less than 0.002 ppm. 

• Asarco produces about 300 tons per day of combined reverts, of which approximately 

1 00 tons a day are used directly in the converters. 

• At the time of inspection, Asa.rco was purc~asing roughly 2,500 tons per month of blister 

copper (post-converter, but not yet fired in the anode furnace), and selling about 500 tons 

per month of revert fines. 

23 
·arsenic at 39 mg/L, cadmium at 5 mg/L, and lead at 8.9 mg/L. Total mercury is 79 

mglkg, but passes the TCLP for mercury at less than .02 mgiL (Att. #8). 

Asarco analysis· indicates the drum filter cake displays the Toxicity Characteristics ior 

cadmium at 49 ppm, and lead at 61. 1 ppm. TCLP results for mercury were Jess than 

0.002 ppm (Att. #2 1 ). 

• The drum filter cake, in addition to the approximately 40% lead, contains 2-4% copper. 

• Asarco generates about 700 tons/day (approxjmately 2,000 tons per month) of plate filter 

cake. 

• Asarco analysis indicates the plate filter cake displays the Toxicity Characteristics for 

cadmium at 56 ppm, and lead at 51.1 ppm. TCLP results for mercury were less than 

0.002 ppm (Att. #2~). 

• Asarco noted the plate filter cake contains zinc fume and fine zinc particulate, making the 

removal of water 9ifficult. The plate filter cake is solar dried on the filter plant's 

concrete pad. 

• Asarco analysis indkates spent plastic grid contacts in the ftlter plant press displays the 

Toxicity Characteristic for lead at 26 ppm. Asarco also generates used rubber linings at 

the fllter plant that displays the Toxicity Characteristics for lead. The spent plastic grids 

and rubber linings arc sent ofT-site as hazardous wastes (Att. #23). 

filter Plant Regulatory Issues: 

See the discussions in: Heap Leach; Gas Cleaning System and Sulfuric Acid Plant; 

Revert Screening Area and Reverts Handling. 

Revert Screening Area and Reverts Handling: 

Revert handling areas not already depicted and the Revert Screening Area are shown in 

photos 67-85. 

lncoming Material; 

Material considered "reverts''can include: Metallic reverts including solidified matte, 

blister cooper, and converter slag from minor splashes and spills; used refractory bricks; ladle 

skulls; solids from the CP-1 impoundment; plate filter cake; baghouse bags; delumper rejects; 

particulates from the flash furnace wet gas scrubbing system and Acid Plant blowdown; anode 

slag (to the converters); used refractory brick; 9-bin pump tails; the condensed fumes, dusts. and 

filter rock discussed in the Bedding Plant Area, Delumper, and Dryer section; and other 

miscellaneous copper-bearing materials. 

22 
above, the catalyst is used in the manufacturing of sulfuric acid. Therefore, the used catalyst is a 

manufacturing process waste. Because the used catalyst is a manufacturing process waste, it 

does not meet the vanadium pentoxide listing in 40 CFR § 261 .33. 10 The used catalyst is also not 

a listed process waste (the K 171 and K 172 listings apply only to the catalysts generated at 

petroleum refmeries). 

Thus, the used catalyst is being legitimately used or reused as an ingredient (silica) in the 

smelter feed, and is not a solid waste (40 CFR § 261.2(e)(l)). 

Filter Plant: 

lncomine Material: 

Particulates from the flash furnace wet gas scrubbing system;·blowdown from the Acid 

Plant Gas Cleaning system. 

Outgoing Material: - _ ., 

Plate ftlter cake to the bedding plant (30% copper); flash furnace scrubber blowdown 

returned to the scrubber system; drum filter cake (solids from the Cone settler) to 

Asarco's East Helena lead smelter; CSO acid to the heap leach. 

Note: Asarco's submittal discussed the cone settler overflow (CSO) in the Filter Plant 

section (Att. #10). For clarity purposes, we have discussed the CSO in the Gas Cleaning System 

and the Sulfuric Acid Plant section and in the Heap leach section. · 

Additional Process Information: (Supplements information in Attachment #10) 

• The filter plant and filter process is shown in photos 61-67. 

• Asarco generates about 100 tons/month of drum filter cake (photo 67). 

• EPA analysis indicates the drum filter cake displays the Toxicity Characteristics for 

impregnated beads. We believe this indicates the vanadium pentoxide-impregnated beads are 

considered unfit for use because the size of tbe silica beads falls below specifications, not 

because the vanadium pentoxide is consumed, contaminated, or no longer chemically effective 

as a catalyst. 

10 The comment in 40 CFR § 261.33 states &bat " ... The phrase 'commercial chemical 

product' ... does not refer to a material, such as a manufacturing process waste, that contains ally 

of the substances listed in paragraphs (e) or (f) [including P 120). Where a manufactun'ng 

process waste is deemed 10 be a hazardous waste because it contains a substance listed in 

paragraph (e) or (f), such waste will be listed in either§ 261.31 or§ 261.32 or will be identified 

as a hazardous waste by the characteristics setforth in Subpart C of this part." 

21 
saddles do not display any of the toxicity characteristics (A". #18). Asarco bas also determined 

that tbc catalyst fines are as effective a fluxing agent as the crushed silica from mines that is 

nonna11y used in the smelter feed, and that the catalyst fines are directly used as an ingredient 

(silica) in the smelter feed; thus, the undersized silica beads were never a solid waste. The imes 

contain approximately 7% vanadium pentoxide, about the same percentage as the new 

impregnated beads. Vanadium pentoxide is a commercial chemical product listed in 40 CFR § 

261.33 as acute hazardous waste number P 120 if and when discarded or intended to be 

discarded. 

Asarco reported the crushed, silica-containing quartz rock is routinely used in the smelter 

feed as a .. flux" to " ... combine with iron and alumina from the concentrate or matte and remo-v-e 

il as slag. "(see definition of flux, page 4, At1. # l 0). Asarco uses the vanadium pentoxide 

impregnated silica fines as a substitute for silica sand mined from quartz. The mined silica sand 

does not appear to be characteristic for toxic metals or contain detectable levels of vanadium 

pcntoxide. 

Rough calculations indicate that the vanadium pcntoxide in the silica is about 00.00025% 

of the total feedstock used by the smelter each year. The boiling point of vanadiUm is much 

higher tlian the working temperature of the copper smelting furnace, which indicates the 

vanadium in the spent catalyst fines will not vaporize and enter the furnace exhaust stack. 

Instead, the vanadium pentoxide will likely chemically reduce in the furnace to a vanadium 

metal, and would be removed (along with iron and alumina) in the Bevill-cxempt slag. 

Petroleum refmeries also use vanadium catalysts to convert S02 gas into S03 gas. The 

spent vanadium catalysts used for hydrorefming and bydrotreating in petroleum refining 

operations are K171 and K 172 listed hazardous wastes. Concerns about the toxicity of 

vanadium pentoxide was one reason the wastes were listed 7 The .. inert support media" for K 171 

and K 172 are exempted from the definition of hazardous waste (40 CFR § 261.3(c){2)(ii){E)). 

Analysis an~ Interpretations: 

Although the vanadium pentoxide is the sole active ingredient in the catalyst,

8 tt ts not 

.. spent" after use,9 and therefore does not meet the P 120 hazardous waste listing. As detailed 

The " ... self-beating pyrophoric properties and potential reactivity ... " of the sulfides in 

the refinery wastes were also a concern (60 FR 57783-85 and 63 FR 42168). This is not a 

concern at copper smelters. where the pyropboric reaction of the sulfur in the ore is used to heat 

the furnace. 

' The silica beads appear to act as a support media to increase the surface area 

exposing the catalyst impregnated in the beads to the S01 gas streams, not as an active ingredient 

in the conversion of sol gas to so) gas. 

' 40 CFR § 261.1(c)(l): "A 'spent material' is any material that has ~een used and 'OS a 

result of contamination can no longer serve the purpose for which it was produced without 

processing ... " According to facility submittals, when removed from the converting tower, the 

fines contain approxi~ately the same percentage (7%) of vanadium pentoxide as the new 

20 
• Chrome-containing corrosion inhibit<.rs are not used in the cooling towers. The make-up 

water is demineralized water. 

• Asarco's MSDS, analysis, and assays for the acid plant materials indicate: 

The ceramic saddles (photo 60) contain 37.2 ppm mercury (0.8 ppb TCLP) {Att. #18). 

The vanadium pentoxide fines contain 0.6 ppm mercury {<0.5 ppb TCLP) (Att. #18). 

The polypropylene plastic saddles from the cooling tower often display the toxicity 

characteristic for lead (Att. # 19). 

Mist eliminator filters fail TCLP for chromium, which is attributed to the stainless steel 

piping in tbe acid plant (An. #20). 

• Asarco generates approximately 40 tons of quartz rock and silica beads every two years. 

• Asarco generates about I 0 cubic yards per year of waste polypropylene plastic saddles. 

The plastic saddles are shipped off-site as a hazardous waste {Alt. #19). 

• Asarco generates about 40 cubic yards of mist eliminator filters once every 10 years. 

The mist eliminator filters are shipped off-site as a hazardous waste (Att. #20). 

• Asarco has a calcium sulfide surface impoundment wbich was used from 1973 through 

1992 to dispose of wastewater treabnent sludges from the acid plant. 40 CFR § 

261.4(bX7)(ii)(H) states that calcium sulfate wastewater treatment plant sludge from 

prj mary copper processing are not hazardous wastes, and thus the calcium sulfate surface 

impoundment was not evaluated during this investigation. 

Gas Cleaning System and Sulfuric Acid Plant Regulatorv Issues: 

Issue #I : 

Issue #2: 

Details: 

See the discussion on the use of CSO weak acid in the Heap Leach section. 

Asarco uses spent silica impregnated with vanadium pentoxide as a substitute for 

mined silica. Is this practice legitimate? 

Vanadium pentoxide (V10s) is used as a catalyst in the acid plant's converting tower to 

convert so2 gas into sol gas. The vanadium pentoxide is impregnated into silica beads 

supported by a bed of quartz rock. After a period of time the physical size of the silica beads 

becomes small enough to inhibit the flow of gas through the catalyst bed. The undersized beads 

and pieces of beads ("fines'') are physically screen~ out of the catalyst bed. The coarse 

materials are reused in the converting tower. The used catalyst fines arc typically stored in large 

woven fiber containers called "supersacks", and were not being speculatively accumulated at the 

time of inspection. 

Asarco has determined that the spent catalyst fines, quartz rock bed, and the ceramic 

19 
• According to Asarco representatives, tbe historic slag contains about 0.6% copper, and 

the economical cutoff point is about 1.0%. 

Slag bas been successfully remiJied since the early 1990's. Asarco shut down tbe:.:-

electric furnace for slag cleaning in 1996. 

Slag from primary copper processing is not a hazardous waste ( 40 CFR § 

26l.4(b)(7)(ii)(A)). 

Slag Handling Resmlatory Issues: 

None. 

Gas Cleaning System and Sulfuric Acid Plant: 

Incoming Material: 

Flash furnace and converter off-gases; blowdown water; acid plant brick; quartz and 

plastic support media; vanadium pentoxide catalysts. 

Outgoing Material: 

Sulfuric acid; CSO and acid plant blowdown; silica beads (catalyst fines) to bedding 

plant; quartz. rock and ceramic saddles; used plastic saddles; used acid plant brick; dusts; filter 

cake. 

Additional Process Information: (Supplements information in Attachment #10) 

• Photos 56-60 show different aspects of the acid gas handling and particulate collection 

systems. 

• The acid plant bas been in operation since 1983. 

• The plant produces about J ,700 metric tons of sulfuric acid per day. About half of tbe 

acid is sold and half used for leaching. Asarco stated that they will often buy acid for 

leaching while selling their higher grade acid. 

• Dust exiting the Cottrell electrostatic precipitator contains about 200/o copper. 

• CSO acid bas a pH of 1.0 and fails the toxicity characteristics for arsenic, cadmium, lead, 

and selenium (Att. #8). The CSO acid also contains 4000 micrograms/L vanadium. 

Note: Sample AS13, described as "Tank #1" in the EPA analysis in Attachment #8, is 

distilled water that was used as a field blank. 

• The water shown in Figure 5 of Attachment #JO is fresh water. 

18 
Anode Barrel Furnace, Remelt Vessel. and Casting Wheel Regulatory Issues: 

None. 

Baghouses: 

Incoming Material: 

Converter fugitive gases and dusts from the secondary hood system; lime. 

Outgoing Material: 

Particulates to the pug mill, hence to the bedding plant; spent bags to the converters 

(about 7% copper); gases vented through the 1,000 foot stack. 

Additional Process Information: (Supplements information in Attachment # 1 0) 

• The baghouses contain approximately 11 ,000 polypropylene and Nomex bags. 

Baghouses Regulatory Jssues; 

See the Re,,ert Screening Area and Reverts Handling discussion. 

Slag Handling Areas: 

The slag handling area and processes are shown in photos 48-55. 

Incoming Material: 

Approximately 1200 tons/day of slag from the flash furnace; water. 

Outgoing Material: 

Frdctured slag less than l" in diameter to the rod mill feed; slag larger than 1" to the 

crusher; evaporated water. 

Additional Process lnfonnation: (Supplements infonnation in Attachment #I O) 

• The slag is poured about 1/4" to 'h" thick onto a 30 degree slope. 

• Areas of the Hayden Smelter, including the bricks and reverts handling area, are located 

on top of the "historical slag area". About 25 million tons of slag had been deposited 

since 1911. 

l7