Date: December 4, 2009

Subject: Site Visit – Doe Run Company Nonferrous Metals Sector Project EPA Contract No. EP-D-06-118; EPA Work Assignment No. 3-21 RTI Project No. 0210426.003.021

From: Michael N. Laney

To: Chuck French EPA/SPPD/OAQPS U.S. Environmental Protection Agency Research Triangle Park, NC 27711

1. Purpose

The purpose of the site visit was to gather in formation on The Doe Run Company’s primary lead smelting facility and operation in Herculaneum as well as their secondary l ead recycling facility and operation. In addition, information on th eir mining and milling operations and a new hydromettalurgical process was to be gathered.

2. Pre-Site Visit Meeting

Prior to the site visit to the Doe Run Co. mining, milling, primary and secondary lead facilities, a pre-site visit meeting was held in St. Louis. The following individuals attended this meeting and were present at each of the site visit locations:

Gwen Yoshimura, EPA Region 7 (Host agency) Mike Jay, EPA Region 7 Andy Chang, EPA Region 5 Gilberto Alvarez, EPA Region 5 Joe Winklemann, Missouri Department of Natural Resources Chuck French, U.S. EPA Sharon Nizich, U.S. EPA Rhonda Right, U.S. EPA Tom Rossendahl, U.S. EPA Mike Laney, RTI International

A representative of the host agency presented background information on past and current state implementation plan (SIP) activit ies related to the Doe Run Company’s primary lead smelter in Herculaneum. A brief overview of the planned hydrometallurgical primary lead process and Buick Recycling Center was given.Page 2 of 8

3. Doe Run Company, Herculaneum Smelti ng Division, Herculaneum, MO, October 19, 2009

At the Doe Run Herculaneum facility, representa tives of Doe Run provided an informational presentation as well as safety informati on. Following the presentation, EPA and Doe Run representatives walked through the smelting operation. Persons from the Doe Run Company in

attendance included the following individuals:

Aaron Miller, Environmenta l Management Coordinator Rusty Keller, Environmental Manager Gary Hughes, Plant Manager Also present, was Rob Kaleel of the Illinois EPA.

Background

The Doe Run Company at Herculan eum operates a primary lead smelter. Operation at the current location began in the 1890’s as the St. Joe Comp any. It is the only curr ently operating primary

lead smelter in the U.S. alt hough there are two facil ities in Canada and one in Mexico. Ore concentrate from Doe Run’s 6 lead mines is pro cessed at the Herculaneum primary lead facility. Until about 2003, Doe Run operated a second primar y lead smelter at Glover, MO. In 2003, the Glover primary lead smelting operations were su spended. The mineral galena (Missouri’s State mineral) is mined from the Vir burnum Trend, which is valued for the relatively small amounts of impurities, mostly trace amounts of copper, silver and zinc. The fac ility produces little or no pure lead as a final product; instead they produce lead alloys based on customer specifications. The alloyed lead is used in making lead-acid batter ies for automobiles, b ackup power supplies, cell towers components, machine counterweight s, computer linings , and crystal.

The Herculaneum facility is the only operating primary lead smelter in the U.S. and has a nameplate capacity of 250,000 ton/yr, although the State Implementation Plan (SIP) limits production to 113,000 tons/yr in 2009. This is to be increased to 130,000 tons/yr in 2010. Due to the new NAAQS for lead, which was lowered from 1.5 ug/m3 to 0.15 ug/m3, and SO2, the plant will cease lead metal production by about 2015. The plan is to replace the current pyrometallurgical process at Herculaneum with a hydrometallurgical process (Flubor process) at its facility in Glover, MO. They also sell l ead ore concentrate to China and will consider continuing this practice even after the Herculaneum fac ility ceases lead production.

Process Description

The facility is a primary lead sm elter. Lead concentrate, which contains approximately 75% lead by weight and a moisture content of 6-10% is carried by trucks from Doe Run’s mine/mills and delivered to the storage area at the Herculaneu m facility. The ore concentrate storage area is contained by a block wall several feet high to minimize wind disturbance of the pile, although

the size of the ore concentrate is like beach sa nd and the concentrate is heavy enough that it is not easily entrained. Fluxing materials (silica, limestone, mill scale) are stored in the same general area. The concentrate is tr ansferred to a car that moves by rail to the sinter building. The

rail car is moved inside the building and tipped into a hopper, and removed from the building.Page 3 of 8

Fluxing materials are similarly transferred to the sinter building. The concentrate and fluxing

material are crushed and mixed befo re entering the sinter machine.

The function of the sinter machine is to roast the ore concentrate in order to drive off the sulfur. In the sintering machine, a thin la yer of sinter is layered over a sl otted belt that is several feet wide. The sinter is ignited us ing a gas flame from above while air is drawn down through the belt. As the belt advances, ore concentrate is pl aced on top of the burning sinter to a depth of approximately 9 inches. Air is blown from be low to help ignite the ore concentrates. Temperatures in the sinter machine are approxima tely 1300 F. This roastin g process is necessary

to remove the sulfur from the concentrate befo re it can be processed further. The nameplate capacity of the sinter machine is 100 tons/hr.

The sulfur is exhausted from the sinter machin e as SO2. The SO2 exhaust is first treated by an ESP before entering the acid plant where most of the SO2 is converted to sulfuric acid.

Sinter and coke are charged at th e top of one of two blast furnaces while air is blown in at the

bottom of the blast furnace. Molten lead exit s from the bottom of the blast furnace and is transferred to the drossing plant in pots using ove rhead cranes. Slag is also tapped from the blast furnace and is fed back to the sinter machine or placed in storage.

From the blast furnace, the lead bullion goes thro ugh drossing to remove copper. In drossing, the lead bullion is cooled gradually to allow the coppe r to separate from the lead which can then be skimmed off. The lead is approximately 97% pure at this point. The lead bullion is transferred to refining kettles for the removal of silver and zinc. Zinc is added for the removal of silver. Finally, the zinc is removed. The lead is refine d until it attains a lead concentration of 99.99%. At this stage, the lead is alloyed based on custom er specifications and cast into ingots. Some lead ingots go to the strip rolling mill and are rolled out into thin sh eets per customer specifications.

Environmental Controls

To control emissions of lead from the smelti ng operation, various enclosures, work practices, baghouses, electrostatic precipita tors and scrubbers are used. They have installed over 60 engineering controls in response to the states’ SIP for lead and in an effort to reduce their emissions down to 0.5 ug/m3. As a result of their efforts, they were able to meet the NAAQS lead standard of 1.5 ug/m3 most of the time.

Plant wide. Sprinklers are located throughout much of the plant facility and operate intermittently to keep roadways and other areas s ubject to vehicle traffic wet in order to suppress dust. Wetting operations are suspended when the outdoor temperature drops to 39 oF. A regenerative sweep, which uses a vacuum and HEPA system, is driv en around the facility roadways to remove surface dust and debris.

Concentrate Storage. A moisture content of at least 6% is maintained in the lead ore

concentrate. The concentrate is stored in a wa lled area to minimize wind effects. Delivery truck loads are covered with tarps and, before leaving, are washed to remove materials from the truck and tires. Materials are transferred from the hoppe r to the rail car through a sleeve that extends down to the railcar that helps slow down the ma terial and reduce dust emissions. Limits are alsoPage 4 of 8

placed on the number of times each day that certain activ ities in the storage area can occur as well as restricting the hour s of their occurrence.

Enclosures. The area in which the railcar is tipped a nd unloaded has been enclosed so that the tipping process takes place in an enclosed building. Doors have been placed on other buildings and required to be kept closed. Buildings enclosing the sinter machine, blast furnace and refining section are kept under negative pressure to keep the flow of ai r into the building.

Air Pollution Control Devices. Baghouses are used to control lead emissions from buildings and process equipment. The sinter machine is controlled by baghouse no. 3. The blast furnace top is controlled by baghouse no. 6; the front of the blast furnace is controlled by a separate baghouse (no. 5). In addition, the blast furnace is enclosed in a building and ventilated to a 300,000 acfm baghouse (no. 9), although the baghouse is designed to operate up to 500,000 acfm. The refinery process is enclosed in a building and ventilated to a 250,000 acfm baghouse (no.7). The kettle area is ventilat ed to a separate baghouse (no. 8). Exhaust gases from sintering are treated by an ESP before entering the acid plant where SO 2 is removed and recovered as

sulfuric acid.

Water Quality. All water runoff from the plant is sent to a thickener settling tank, filter press and PH adjustment before discharge.

4. Southeast Missouri Mining and Milling (SEMO) Division, West Fork, Missouri, October 20, 2009

At the Doe Run SEMO Division facility, repres entatives presented information on the mining and milling operations of the Doe Run Company. Following the presentation, EPA and Doe Run representatives visited the mine and mill site in West Fork. Persons from the Doe Run Company

in attendance included th e following individuals:

Bill Lane, VP Research and Technology Development Clifford Asbury, Environmental Manager Bob Roscoe, VP of Mining and General Manager Dennis Murphy, SEMO Safety and Environmental Manager Dave Ocun, Manager Technology Development Vanessa Eckhoff (?), Title? John _______, Engitec Technologies, Italy

Background

Current mining operations are condu cted in the Viburnum Trend a nd have been mined for about 50 years, with over 300 million tons total mined. The Viburnum Trend is 40 miles in length. Doe Run mining operations employ about 750 workers.

Ore from the mines are transferred to the milli ng operations where the ore is concentrated and readied for smelting. Recent production figures for the mines are as follows:Page 5 of 8

 Ore mined – 5 million tons/yr

 Lead concentrate produced – 280,000 tons/yr

 Zinc from concentration – 65,000 tons/yr

 Copper from concentrate – 20,000 tons/yr

Ores from SEMO are considered “clean” in that they only contai n lead, zinc, and copper unlike

ores from other locations that can contain cont aminants such as arsenic, bismuth, and antimony. Because they do not contain these other meta ls, Doe Run ore concentrate are in demand worldwide. Approximately 70% of the ore con centrate goes to Doe Run’s primary smelter at Herculaneum. The rest goes to the SEMO port, wh ich is a state-of-the-art facility for handling concentrate, especially lead concentrate. The copper concentrate goes to a copper smelter in

Canada.

Doe Run is carrying out remediation operations at their former mining and milling operations

that were located in the old lead belt. Chat and tailings piles at those lo cations contain less than

0.1% lead.

Doe Run supplies about 70% of the lead ore conc entrate consumed in the United States. The Red Dog zinc mine in Alaska produces lead as a bypr oduct of their zinc process. A silver mine in Idaho also produces a lead ore concentrate.

Process Description

All of the mining operations are underground. Th e ore bodies range in thickness from a few

inches to 120 feet. The host rock is a dolomitic li mestone and is very stable for their underground mining room and pillar operations. Useful ore is a bout 4 -10% of the rock mined; the rest is dolomite. Mine depths range from 500 to 1,200 feet below grade with the total length of tunnels

in current mines of 20 – 30 miles. In the mini ng operations, rock is broken by blasting. Initial primary crushing operations are typically underg round and reduce the rock size from about 24 inches down to 6 inches. At some mines, primary crushing is done after the rock is hauled to the

surface.

In milling, the rock is subjected to secondary an d tertiary grinding to reduce the size of the material to allow the physical se paration of the lead (galena), zi nc (spharite) and copper ores.

The fine ores are then transfe rred to the flotation circuit.

In the flotation circuit, concen trates of lead, zinc and copper are produced. The flotation circuit recovers about 95% of the lead, 75% of the zi nc, and 50% of the coppe r. Additional grinding (secondary grinding) takes place in a Rod Mill then a Ball Mill be fore the ore is subjected to flotation. In flotation, chemical additives cause the lead and copper to adhere to bubbles generated in the slurry tanks, which then rise to the surface; zinc and dolomite sink and are moved to another process. The zinc and dol omite go through another flotation process to separate out the zinc; the taili ngs go to tailings storage. Each product goes to thickening tanks

where the metals sinks and is then vacuumed filtered to reduce the moisture content down to

6 – 10%. The ores are loaded into trucks for transport.Page 6 of 8

A brief stop was made at the Br ushy Creek Mine and Mill. The mi ne head and mill building was visible. Due to the time required to coordinate a trip down into the mine and to visit the mill, no

mine or mill tour was conducted.

5. Flubor Demonstration Project, West Fork, Missouri, October 20, 2009

Background

The Doe Run Company sees lead as continuing to be a vital material for the U.S. and the world.

Besides the current lead-acid batte ries used in automobiles, Doe Run sees energy storage systems in hybrid vehicles and renewable energy source s (e.g., wind power) as well as emergency backup storage systems, to continue to be vital to na tional interest and secu rity. Seeking a cleaner method of producing lead, the Doe Run Company built a demonstration pr oject to test the feasibility of a hydrometallurgical process for producing lead metal. The process, called the Flubor, process, was developed by Engitec Technol ogy in Italy. Fluboric acid is used to dissolve

the lead sulfide ore concentrate that allows the separation and c oncentration of lead. The process is patented and proprietary and has yet to be used in the full scale pr oduction of lead. Doe Run representatives see this hydro-process as the future of lead production where the process operation is wet, low temperature and characterized by low volatility in contrast to current pyrotechniques which use high temperatures and re sult in the volatilization of lead. The Flubor process would virtually eliminate lead emissi ons, would have a smaller carbon footprint and would be a sustainable technology. There are currently no Flubor processes being used in metals production. According to the Doe Run representa tives, the process would be fully contained, emit no sulfur, reduce lead emissions by 99.67%, re quire no heat, and produce no process waste. During the visit to the Flubor demonstrati on project, the proce ss was not operating.

The Doe Run Company is currently in the proc ess of conducting feasibility and engineering studies in order to acquire funding to construct a full scale Flubor process. The plan is to build the operation in Glover, Missouri, at the site of a primary smelter that is currently not running. Plans are to construct the proce ss in two phases with phase one to start operation in 2012. Each phase will be capable of processing about 78,000 t ons/yr of ore, with a lead metal output of about 60,000 tons/yr.

Process Description

The general steps in the Flubor process are leaching, filtering or residue removal, and electrowinning. Lead concen trate is dissolved in a water flubor ic acid solution. This dissolves the

lead and oxidizes the sulfur. The solution is filte red to remove the sulfur and zinc components. After filtering, the solution goes to the electrowinning unit where an electric current is passed through the solution causing the l ead to migrate to and coat the cathode. The solution is regenerated in the electrowinning process and returned to the l eaching reactor to dissolve other

lead concentrate. A thin lead sh eet is used as the cathode materi al. Using lead as the cathode, the

entire cathode with the accumulatio n of lead can then be remelted later. The current plan is to remelt the cathode at the Herculaneum smelter, a dd in the customer specific alloys and cast the finished ingots.Page 7 of 8

6. Resource Recycling Division (also known as the Buick Resource Recycling Division), Boss, Missouri, October 20, 2009

At the Doe Run Resource Recycling Division, repr esentatives of the facility provided an informational presentation on th eir recycling operations. Follow ing the presentation, EPA and Doe Run representatives toured the recycling operation. Persons from the Resource Recycling

Division in attendance included the following individuals and others:

Steve Arnold, General Manager James Lanzafame, Environmental and Health Manager Barbara Sheppard, Human Resources and Community Relations Matt Wool, Doe Run, Council

Background

The facility currently has 290 employees. The facility was or iginally a primary smelter but was converted in 1991 to its current operation. They process 14 million batteries/yr, 80% of which are batteries used for startup, lighting, and ignition (SLI); 20 % are large batteries used in missiles, locomotives, and backup supply. It also receives lead paint from abrasive blasting, dental x-ray plates, and used cathode ray tube glass. Approxima tely 160,000 tons of lead are recycled annually. This facility is a classified as a hazardous waste facility. A laboratory is onsite when it is necessary to analyze inco ming shipments for safety reasons.

Process Description

Incoming SLI batteries are dumped into a bunker area where the batter ies are broken up and

shredded to liberate the weak sulfuric acid and re move any remaining charge. The acid is used later in the process. Some batteries are delivered to the facility in steel drums. These drums are

shredded and added to the blast furnace. The shre dded batteries are moved on a vibrating feeder that feeds a conveyor belt into a hammer mill, whic h reduces the batteries into small pieces. The lead and other metal pieces are fed to a reverber atory furnace producing lead and slag (which is lead-antimony). This is further treated in a blas t furnace to produce lead and slag. The lead is transferred to the dross plant, then to refi ning, alloying and casting. Slag from drossing and refining goes to an onsite repository which is permitted as a hazardous waste landfill even though the slag is not a hazardous waste.

Plastic from the process is coll ected and goes to a recycler. The lead sulfur battery paste is

treated with a sodium carbonate to form a lead oxide and sodium sulfate. This is processed into a food grade sodium sulfate and used as filler in powdered soap. Other U.S. secondary lead

smelters do not make the sodium sulfate.

Environmental Controls

Controls at the facility incl ude a recently added baghouse on the refining building, which was added at a cost of $1.4 million. A sweat furnac e and blast furnace are controlled by baghouses. The steel drum shredder is controlled using baghouses. A lead oxide pug mill used for antimony and tin removal are controlled by a baghouse and HEPA filter. They also operate a 425,000 acfmPage 8 of 8

main process baghouse. They have added en closures, high speed automatic doors, and sweeper/vacuum trucks as part of their work practices to reduce fug itive emissions. In 2011 a new 160 acfm baghouse is planned for the blast furnace, dross crane building. They also have a startup, shutdown, and malfunction plan in place.