EPA-600/2-76-036e February 1976 Environmental Protection Technology Series DESIGN AND OPERATING PARAMETERS FOR EMISSION CONTROL STUDIES: Magma, San Manuel, Copper Smelter Industrial Environmental Research Laboratory Office of Research and Development U.S. Environmental Protection Agency Research Tiiangle Park, North Carolina 27711 ------- RESEARCH REPORTING SERIES Research reports of the Office of Research and Development. U.S. Environmental Protection Agency, have been grouped into five series. These five broad categories were established to facilitate 'urther development and application of environmental technology. Elimination ot traditional grouping was consciously planned to foster technology transfer and a maximum interface in related fields. The five series are: 1. Environmental Health Effects Research 2. Environmental Protection Technology 3. Ecological Research 4. Environmental Monitoring 5. Socioeconomic Environmental Studies This report has been assigned to the ENVIRONMENTAL PROTECTION TECHNOLOGY series. This series describes research performed to develop and demonstrate instrumentation, equipment, and methodology to repair or prevent environmental degradation from point and non-point sources of pollution. This work provides the new or improved technology required for the control and treatment of pollution sources to meet environmental quality standards. EPA REVIEW NOTICE This report has been reviewed by the U.S. Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policy of the Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use. This document is available to the public through the National Technical Informa- tion Service, Springfield, Virginia 22161. ------- EPA-600/2-76-036e February 1976 DESIGN AND OPERATING PARAMETERS FOR EMISSION CONTROL STUDIES: MAGMA, SAN MANUEL, COPPER SMELTER by I. J. Weisenberg and J. C. Serne Pacific Environmental Services, Inc. 1930 14th Street Santa Monica, California 90404 Contract No. 68-02-1405, Task 5 ROAP No. 21ADC-061 Program Element No. 1AB013 EPA Project Officer: R. D. Rovang Industrial Environmental Research Laboratory Office of Energy, Minerals, and Industry Research Triangle Park, NC 27711 Prepared for U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Research and Development Washington, DC 20460 ------- TABLE OF CONTENTS Page A. INTRODUCTION AND SUMMARY 1 B. PLANT LOCATION ACCESS AND OVERALL GENERAL ARRANGEMENT ... 1 C. PROCESS DESCRIPTION 4 D. EMITTING EQUIPMENT 7 a. Reverberatory Furnaces 7 b. Converters 7 c. Other Emitting Equipment 8 E. EXISTING CONTROL EQUIPMENT 8 F. GAS SYSTEM DUCTWORK 10 G. SULFUR BALANCE AND GAS COMPOSITION AT SYSTEM EXIT 10 H. GAS CHARACTERISTIC VARIATION 14 I. STACK DESCRIPTION 14 J. PRESENT TECHNIQUE FOR SOLID WASTE HANDLING 15 K. FOOTING AND STRUCTURAL REQUIREMENTS 15 L. EXISTING AND POTENTIALLY AVAILABLE UTILITIES 15 M. POTENTIAL NEW CONTROL EQUIPMENT PROBLEMS 15 REFERENCES 17 LIST OF FIGURES FIGURE 1. GENERAL AREA MAP 2 FIGURE 2. OVERALL PLANT AND GENERAL ARRANGEMENT (Located in Pocket Inside Back Cover) FIGURE 3. SAN MANUEL DIVISION SMELTER FLOW SHEET 5 FIGURE 4. PROCESS FLOW & SULFUR BALANCE SHEET 6 ------- A, INTRODUCTION AND SUMMARY The purpose of this report is to present background design data on the Magma Copper Company Smelter, San Manuel Division at San Manuel Arizona in sufficient detail to allow air pollution control system engineering studies to be conducted. These studies are primarily concerned with lean SCL streams that are currently not being captured. Physical layout of the plant and surrounding area along with existing smelter and control equipment is presented. Ductwork that would be considered for future system tie-in is defined. Emissions from operating equipment, gas flow rates, temperatures, sulfur balance and process flow sheet are included. Utilities, stack dimensions, footing requirements and solid waste handling are defined. Avail- able area for new control equipment, gas characteristic variation and potential new control equipment installation problems are dis- cussed. The major uncontrolled source of SO- at this smelter are the three reverberatory furnaces with approximately 92,000 tons per year of SO- and 570 tons per year of particulate. There appears to be some additional space for new control equipment within the smelter area but not necessarily adjacent to the emitting equipment. B, PLANT LOCATION ACCESS AND OVERALL GENERAL ARRANGEMENT The Magma Copper Company Smelter is located to the northeast and adjacent to the town of San Manuel, Arizona. A portion of the USGS map showing land contours of the immediate area is presented in Figure 1. Design altitude for the plant is 3,200 feet with lati- tude 32° 37' and longitude 110° 37'. The overall plant and smelter general arrangement are shown in Figure 2. The primary particulate emission sources are the crushing and screening operations and the reverberatory furnaces and converters. The primary sources of sulfur dioxide are the -1- ------- IKW30* 540 1000 2000 3000 4000 5000 6000 7000 FEET ------- Figure 2 OVERALL PLANT AND GENERAL ARRANGEMENT (Located in Pocket Inside Back Cover) -3 - ------- reverberatory furnaces and converters. Ore source is from the local San Manuel Mine, an underground mine. Additional concentrate feed is obtained from outside sources. The Magma San Manuel smelter consists of three reverberatory furnaces with six converters. A seventh converter may be added at a later date if the need is indicated. The output from the converters is taken to the anode furnaces which supply the casting wheels for casting the anodes. Figure 3 is a smelter flow sheet schematic. (Ref. 1) The pollution control equipment consists of electrostatic pre- cipitators for cleaning the offgases from the reverberatory furnaces and additional electrostatic precipitators for cleaning the offgases from the converters. No S0_ control of the reverberatory furnace offgases is accomplished. A 2,400 ton per day single contact sulfuric acid plant collecting SO,, from the converter offgases was recently started up. In addition, a separate system has been established to neutralize the liquid effluent from the scrubber and other acid plant sources. Figure 2 showing the overall plant site indicates space for new control equipment could be found to the northwest of the smelter building. The area southeast of the smelter building could be used if an alternate area for emergency concentrate storage could be established. C, PROCESS DESCRIPTION The smelter flow sheet diagram is shown in Figure 4. The feed in the form of precipitates, concentrate, lime, flux,and flue dust is fed to one of the three reverberatory furnaces. Matte is produced in the reverberatory furnaces and is passed to one of the six converters which produce blister copper for further refining in the anode furnace. Copper from the anode furnace is then used to cast anodes. Gases from the reverberatory furnace pass through waste heat boilers, electrostatic precipitators and then out the stack. Gases from the converters pass -4- ------- mAsrriA San Manuel Division Smelter Flow Sheet SOLID FLOW SAN MANUEL CONCENTRATE OUTSIDE CONCENTRATE FLUX MOLTEN FLOW GAS FLOW __«»»^. LIQUID FLOW SILICA ROCK AND SULFIDE ORE CONCENTRATES AND LIMEROCK BINS 6 SAN MANUEL CONCENTRATE a 500 TONS 6 OUTSIDE CONCENTRATE 3 500 TONS 6 FLUX 3 375 TONS RECYCLED DUST PREHEATED AIR NATURAL GAS fcoNVERTER SLAG AIR REVERBERATORY FURNACES NO. 1: 32 FT. X 102 FT. INSIDE NO. 2: 31 FT. X 102 FT. INSIDE NO. 3: 36 FT. x 102 FT. INSIDE \ 2 WASTE HEAT BOILERS PER FURNACE ELECTROSTATIC PRECIPITATOR MATTE LADLE 300 CUBIC FEET 515 FT. STACK SLAG POT REVERBERATORY SLAG TO DUMP MATTE ELECTROSTATIC PRECIPITATOR 380 CUBIC FEET SCRUBBER 2 STACKS 200 FEET BLISTER COPPER 3-13 FT. X 35 FT. 2-15 FT. x 35 FT. DUST TO REVERBERATOR IES NEUTRALIZATION PLANT FOR EXCESS ACID AIR REFORMED GAS REFINING VESSELS 2 - 13 FT. x 35 FT. 2 - 13 FT. x 30 FT. CASTING WHEELS 1 - 45 FT, DIAMETER, 28 MOLDS 1 - 34 FT. DIAMETER, 22 MOLDS SULFUR 1C ACID TO MARKET f— AIR REFORMED GAS TO SAN MANUEL REFINERY TO OUTSIDE REFINERY Figure 3 ------- Process Flow & Sulfur Balance Sheet Magma Copper Co./San Manuel Nov., 1975 3150 TPD Charge 30-32% S 950 TPD-S Pacific Environmental Services. Inc. /Reverb Off-Gas J 350,000-450,000 SCFM I 0.5-1.0% SO Reverb Slag to Dump 2431 TPD Flux - 616 TPD 4 IPD-S Cold Dope & Refinery Scrap 125 TPD (2 parallel S.C Scrubber Effluent 1200 TPD Sol'n 19.8 TPD-S Acid Plant Tall Gas 187,000 SCFM 0.11% SO- 13.1 TPD^S 7300 SCF7-! .032 Sc- 0.13 TPD-S ------- through water cooled hoods to electrostatic precipitators, then to scrubbing towers, mist precipitators and finally a Monsanto single contact acid plant. Temperatures, volume flows, and S09 percentages are shown on the flow sheet. D, EMITTING EQUIPMENT a. Reverberatory Furnaces The initial copper concentrate containing approximately 28% copper is fed to three natural gas or oil fired top charged reverberatory furnaces all 102 feet long by 32 feet, 34 feet and 36 feet wide respectively. The reverberatory furnaces have suspended roofs with sealing materials such as ceramic fiber, mud or asbestos packed along the joint. The roof is anchored with tie rods suspended from the ceiling. Magma normally operates three reverberatory furnaces at full capacity at all times. The reverberatory furnaces are fed from the top along the front 60% of the furnace side walls. Two air preheaters capable of operating on either No. 2 fuel oil or natural gas are used to preheat the air going to the reverberatory furnace burners. This allows an increase in the gas temperature and also combustion efficiency. It is necessary to have at least 60% fire to the reverberatory furnace to maintain temperature. A five year campaign is presently being conducted on the furnaces before reworking is required. The processes occurring within the reverberatory furnace are controlled by adjusting draft, fuel input, fuel air ratio, and feed scheduling. b. Converters The matte produced by the reverberatory furnace containing 32 to 35% copper is processed in three 13 foot by 35 foot and three 15 foot -7- ------- by 35 foot Peirce-Smith type converters. Converter slag is returned to the reverberatory furnace and blister copper is delivered to four anode holding furnaces. The 15 foot by 35 foot converters use an air supply varying from 30,000 to 45,000 SCFM. Scheduling of the converters to maintain a more or less constant flow of S0? to the acid plant is attempted. A single charge will remain in the converter for a period of about twelve hours. There are four or more slag blows of about 1% hours each and one finish blow. Oxygen has been used at a rate of up to 30 TPD at times in converter blowing air to increase the heat available allowing cold dope addition. c. Other Emitting Equipment Material handling in the feed preparation area during crushing and screening operations generates particulate. The anode/refining furnace generates small quantities of S0? and particulate. Leaks in ducts and at other pieces of equipment can release SO. and particulate. Ladles holding matte and slag will produce visible fugitive emissions. The acid plant will also produce S02 emissions. E, EXISTING CONTROL EQUIPMENT Gases from the three reverberatory furnaces, after passing through the waste heat boilers, are combined and enter an electro- static precipitator. Gases from the precipitator then pass directly to the 515 foot reverberatory furnace stack. Dust from the precipi- tator is combined with lime and is processed in a pug mill and returned to the reverberatory furnace feed. Gases from the converters enter water cooled hoods over each converter. The gases are then ducted together and enter a radiation/ conduction cooler which simply consists of a duct sized to provide -8- ------- 7,000 FPM gas velocity. Total gas flow from the converters t,o the acid plant varies from 154,000 to 200,000 SCFM. At this range of flow the gases are cooled from an inlet temperature of 1200 F down to 400°F to 500°F at the outlet of the cooler. They then pass into a precipitator which removes a major portion of the particulate matter. The converter gases then go to a 2,400 TPD sulfuric acid plant. The gases average 5.5% SO-. The Monsanto single contact acid plant was completed in January, 1975 and is currently in operation. It is designed to be converted to double contact. The gases are further cleaned, after going through the precipitator, by passing to one unpacked and one packed cooling tower that have weak acid flowing through to provide humidification and cooling. From the packed towers the gas, which will be at a maximum temperature of 140 F and will average 100 F, passes to six mist precipitators in a parallel series circuit. From the mist precipitators, the gas is passed to the dryer where the moisture is absorbed in concentrated acid. The gas is then passed through demisters and on into the S09 to SO converter which has four conventional stages with three inner stage heat exchangers that use incoming gas to cool the outgoing gas. One special feature of this plant is that there are two parallel trains starting downstream of the packed cooling tower and following through to the end of the acid plant. This design allows shut down of one side for maintenance while the other side continues to operate. In addition, each side has a preheater that is designed to "float" on line. The preheater controls the gas temperature into the first pass of the converter. If the concentration of SO.- in the gas stream is too low, for example, for autogenous operation, the burner will immediately and automatically turn up providing additional heat for efficient conversion. The burner is semi-automatic and will stop and start on the temperature signal from the converters. Carbate heat exchangers are used for cooling the weak acid. In addition, Teflon "spaghetti" coolers are used for cooling the strong -9- ------- product acid. An air cooled evaporation cooling tower is used to cool all process cooling water. Fiberglass reinforced plastic (FRP) is used for ductwork throughout to handle the wet S0_ laden gases up to the dryer. There are three main blowers for the process gas system with one being used as a standby unit. Each blower has a 6,000 horsepower motor and individual pressurized lubrication system. A neutralization plant is available to neutralize excess acid produced. This plant uses the concentrate tailings since they are basic and have a major portion of the material necessary to neutralize the acid. When total acid to be neutralized exceeds the quantity the basic mill tails can neutralize, lime rock slurry must be added. The neutralization system is used when the total amount of acid produced cannot be sold or exceeds storage capacity. Up to 800 TPD has been neutralized. F, GAS SYSTEM DUCTWORK Sufficient information was not obtained from the smelter to define ductwork. G. SULFUR BALANCE AND GAS COMPOSITION AT SYSTEM EXIT 1. Maximum Sulfur Balance Data Based on Enlarged Capacity Of 1,125,000 Tons of Concentrate Per Year Based on Data From Smelter (Reference 2) TPD Sulfur Input 954 Sulfur Emitted by Reverberatory Furnaces 259 Sulfur Emitted by Converters 660.9 Sulfur Removed in Slag 34.0 Sulfur Removed in Blister Copper .15 Sulfur Fixed Acid Plant 647.8 Slag and Solid Waste 34.0 681.8 Sulfur Fixed 71.5% -10- ------- 2. Sulfur Balance Data For August 1973 Throuph July 1974 Based On Average Production Of 750,000 Tons Concentrate Per Year (Reference 3) 32.07% sulfur in concentrate, average (660 TPD) Sulfur lost: In slag In blister copper In reverb gas In converter gas TPD 23.97 0.10 181.59 454.55 660.21 total % of Total Sulfur 3.630% 0.015% 27.505% 68.850% 100.000% total Sulfur lost in fugitive emissions: less than 2.5% of total sulfur, or less than 16.5 TPD Sulfur lost in acid plant sludge: not applicable Sulfur converted to H~SO,: not applicable Sulfur emitted from reverberatory furnaces: 181.59 TPD Sulfur emitted from roasters: not applicable Sulfur emitted from converters: 454.55 TPD 3. Reverberatory Flue Gas Analysis (Reference 4) so co N 0.7 - 1.0% 8.3% 69.71% 19.24% 10-15% 4. Converter Flue Gas Analysis During Slag Blow (Reference 4) so, »2 2 9-10% 82.27% 10.65% 5. Converter Flue Gas Analysis During Finish Blow (Reference 4) SO, N,, 13-14% 79.14% 10.43% -11- ------- 6. Range of Converter Gas Constituents Constituent Percent Range SO 5.0 to 14.0 SO .15 to .16 02 8.6 to 12.9 N2 78.75 to 82.27 HO 0 to 2.6 Traces of chlorine, fluorine, arsenic, antimony, bismuth s lenium, chromium, zinc, and lead with maximum dust loading of 0.5 grains per SCF. Trace Element Range Chlorides or Chlorine 10-30 ppm b.v. Fluorine or Fluorides 25-50 ppm b.v. 7. Gas Reformer Gas (Reference 4) Combustion Products - C0~, HO Process Gas - H , CO, CO , N Reformer gas is used to provide a reducing atmosphere for final refining in anode furnace. The anode furnace generates combustion products which go to the atmosphere with a negligible SO concentration and primarily CO- and HO. This is also true for the.air preheater. 8. Particulate Analysis Copper (as CuO) 10-15% b.w. Iron (mostly Fe (SO ) ) 10-20% b.w. Arsenic .04 - 0.6% b.w. Selenium .03 - 0.5% b.w. Tellurium .005 - .01% b.w. -12- ------- 9. Particulate Analysis (Reference 5) Compound Copper Iron Sulfur sio2 CaO A1203 Zn Pb Trace Elements Average % b,w, 18.3% 11.2% 12.13% . 4.9% 1.05% 0.39% 9.4% 2c *v • J /o L.T. 2% -13- ------- H, GAS CHARACTERISTIC VARIATION The S07 concentrations in the offgas from the reverberatory furnace will vary significantly depending upon the charge rate and the various sulfide materials contained in the charge. The normal or average charge rate into the furnace can vary as much as 4 to 1 over a period of time. This variation is a result of normal smelter operation and can be controlled only to a limited extent. S0_ concentration in the converter offgas also varies considerably because of the batch nature of the operation. Also, the variation in actual metallurgical operation between slag blows and copper blows will cause a variation in percent S0_. (See Section G). Between blows the converter may be rolled out for slag pouring or material charging. The attempt is always made to maintain at least two converters blowing gases into the system at any given time. Usually a converter will be provided with 18,000 to 20,000 SCFM to the tuyeres. An additional 100-120% of dilution air is generally estimated to be added to this gas flow resulting in a total gas flow from each con- verter in the range of 35,000 - 45,000 SCFM. Thus, the gas volume from the converter line to the control system acid plant and liquid SO- plant can vary over a wide range from maximum to zero. STACK DESCRIPTION Reverberatory Furnace Stack Height 515 feet Inside diameter 20.8 feet (top) Inside diameter 30 feet (base) Gas exit temperature 450 - 500° Fahrenheit Acid brick lined Draft at Base 2.6" w.c. -14- ------- Converter Stack Stack height 550 feet Inside diameter 20.0 feet (top) Exit temperature 4' Draft -2.5" W.C. Exit temperature 450 - 500° Fahrenheit Acid Plant Stacks (2) Height 250 feet Diameter 10 feet Draft (forced) +10.0" W.C. Steel J, PRESENT TECHNIQUE FOR SOLID WASTE HANDLING Slag from the reverberatory furnaces is taken by ladle car to the dump. Dust from the reverberatory furnace gas precipitator is treated in a pug mill and then recycled through the bedding plant and added to furnace feed. Dust from the converter gas precipitator is taken by truck to the bedding plant for recycle to the furnace. K, FOOTING AND STRUCTURAL REQUIREMENTS Seismic zone 2 and wind load 20 PSF are used for design. Ambient temperature range is 110 F to -20 F. L, EXISTING AND POTENTIALLY AVAILABLE UTILITIES Water is supplied from wells. It can be expected that future supplies of fuel gas in this area will be limited. Plans for handling and burning coal are currently being formulated. Electricity should be sufficiently abundant for most control requirements with the possible exception of use of an electric furnace to replace the reverberatory furnace. -15- ------- M. POTENTIAL NEW CONTROL EQUIPMENT PROBLEMS The variation of emissions could limit control system effectiveness. It appears that the area adjacent to the smelter is sufficient to allow installation of new control systems. -16- ------- REFERENCES 1. Magma Copper Company 2. Magma Copper Company - San Manuel Smelter - Smelter Flow Sheet 3. Letter to Mr. P.M. Covington, EPA from Mr. W.L. Parks, Magma Copper Co. dated September 11, 1974 4. Smelter material balance 4th Qtr. 1971 5. Letter from T.E. Hearon, Magma to I.J. Weisenberg PES, October 8, 1975. -17- ------- TECHNICAL REPORT DATA (Please read Instructions on the reverse before completing) 1. REPORT NO. EPA-600/2-76-036e 2. 3. RECIPIENT'S ACCESSION>NO. 4. TITLE AND SUBTITLE Design and Operating Parameters for Emission Control Studies: Magma, San Manuel, Copper Smelter 5. REPORT DATE February 1976 6. PERFORMING ORGANIZATION CODE 7. AUTHOR(S) B. PERFORMING ORGANIZATION REPORT NO. I.J. Weisenberg and J. C. Seme 9. PERFORMING ORGANIZATION NAME AND ADDRESS Pacific Environmental Services, Inc. 1930 14th Street Santa Monica, CA 90404 10. PROGRAM ELEMENT NO. 1AB013; ROAP 21ADC-061 11. CONTRACT/GRANT NO. 68-02-1405, TaskS 12. SPONSORING AGENCY NAME AND ADDRESS EPA, Office of Research and Development Industrial Environmental Research Laboratory Research Triangle Park, NC 27711 13. TYPE OF REPORT AND PERIOD COVERED Task Final; 4-10/75 14. SPONSORING AGENCY CODE EPA-ORD 16. SUPPLEMENTARY NOTES EPA Task Officer for this report is R.Rovang, 919/549-8411, Ext 2557. i6. ABSTRACT rep01^ gives background design data for a specific copper smelter. The data is sufficiently detailed to allow air pollution control system engineering studies to be conducted. , These -studies will be concerned primarily with lean SO2 streams that currently are not being captured. Physical layout of the smelter and the surrounding area is presented, along with existing control equipment. Ductwork that would be considered for future system tie-in is defined. Emissions from operating equipment, gas flow rates, temperatures, sulfur balance, and a process flow sheet are included. Utilities , stack dimensions , footing requirements , and solid waste handling are defined. Available area for new control equipment, gas characteristic variation, and potential new control equipment installation problems are discussed. 17. KEY WORDS AND DOCUMENT ANALYSIS DESCRIPTORS b.lDENTIFIERS/OPEN ENDED TERMS c. COSATI Field/Group Air Pollution Copper Smelters Design Sulfur Dioxide Utilities Air Pollution Control Stationary Sources Emission Control Operating Data Solid Waste Handling Wastes 13B 07B 11F 18. DISTRIBUTION STATEMENT Unlimited 19. SECURITY CLASS (This Report) Unclassified 21. NO. OF PAGES 20 20. SECURITY CLASS (This page) Unclassified 22. PRICE EPA Form 2220-1 (9-73) 18 ------- |