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1 J i llIll EPA/600/9-87/004a February 1987

PROCEEDINGS: TENTH SYMPOSIUM ON FLUE GAS DESULFURIZATION Atlanta, Georgia, November 1986 Volume 1 Compiled by Barbara Emmel Radian Corporation P. 0. Box 13000 Research Triangle Park, North Carolina 27709

EPA Contract 68-02-3994, Work Assignment 75 EPRI Contract 982-40 Project Officers: Julian W. Jones Robert E. Moser U. S. Environm ental Protection Agency Air and Energy Engineering Research Laboratory Research Triangle Park, North Carolina 27711 Electric Power Research Institute 3412 Hillview Avenue Palo Alto, California 93404

AIR AND ENERGY ENGINEERING RESEARCH LABORATORY OFFICE OF RESEARCH AND DEVELOPMENT U.S. ENVIRONMENTAL PROTECTION AGENCY RESEARCH TRIANGLE PARK, NC 27711

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## ,2. 3. RECIPIENT'SACCESSION NO,

EPA/600/9-87/004a 

### Nl7 1666097B 4.TITI.EANOSUBTITLE I. IUP'OI'ITDATE Proceedings: Tenth Symposium on Flue Gas February 1987

Desulfurization, Atlanta, Georgia, November 1986; •.P'EAFOAMINGOI'IOANIZATIONCODE Volume 1 7.AUTMOPIIS) •.PERFORMINGORGANIZATIONREPORTNO. BarbaraB. Emmel, Compiler**~·**PEI'II"ORMINGOFIOANIZATION NAMEANDADDI'IES$ 10.PROGRAM EI.EMENTNO. Radian Corporation P.0. Box 13000 11.t;ONT.. A!;T/I;O..ANTNO. Research Triangle Park, North Carolina 27709 68-02-3994, Task 75 12.SPONSORINGAGENCY NAMEANDAOOAESS 13.TVI"EOF REPORTAND PERIODCOVERED EPA, Office ofResearchand**pevelopm~nt*** Proceedings; 11/17-21/86 14.SPONSORINGAGENCYCODE Air and Eneri.Y Erliineering Research**Labora~ory** EPA/600/13 Research Triangle Park, NC 277ll 15·suPPLEMENTARY NOTEs AEERL project officer is JulianW. Jones, Mail Drop 62, 919/541· 2489. {*)Cosponsored by EPRI, 3412 Hillview Ave., Palo Alto, CA 94304 under EPRI**l~on ract**  982..:40 EPRI nroiect nffi**f'~r·** RobertE. Moser. 16·Aas TRACTThe proceedings document the Tenth Symposium on Flue Gas Desulfurization {FGD), held in Atlanta, GA, November 17-21. 1986. The symposium. jointly sponsored by EPA and EPRI, had as its objective the exchange of technical information on FGD systems and processes applicable to utility and industrial boilers. Topies covered included: federal and state clean coal programs, the commercial status of FGD, acid deposition issues, FGD economics, industrial applications of FGD, and wet FGD additives (Volume 1); and wet FGDoperations and reliability, spray dryer FGD, dry FGD technologies, and FGD by-product disposal and utilization (Volume 2). The proceedings include 38 papers and summaries of 17 poster session presentations.**~7 .**  ICEV WOAOSAND POCUMENTANAL.VSIS ja. DESCAIPTOAS b .IPENTIFIEPIS/OP'EN ENDEDTEAMS c. CDSATI Field /Group Pollution Additives**~ollution** Control 13B llG Flue Gases Spray Drying**~tationary** Sources 21B 13H Desul.furization Byproducts**~**cid Deposition 07A,07D 14G Coal Disposal 21D Acidification Utilization 07B,07C Economics 18.O IS

T

AI8UTIONSTATEMENT 18.SECURITYCLASS (171URepol'f } 21.NO.OF I'AGES Release toPublic Unclassified lf lq 20.SECURITYCI.ASS (Thbptllf} 22.1"RICE Unclassified EPA l"orm 1220·1 (l·?a) i\ \

NOTICE This document has been reviewed in accordance with U.S. Environmental Protection Agency policy and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

iiABSTRACT The Tenth Symposium on Flue Gas Desulfurization was held in Atlanta, Georgia, November 17 through 21, 1986. This Symposium, jointly sponsored by EPRI and EPA, had as its objective the exchange of technical information 

### regarding FGD systems and processes applicable to utility and industrial boilers. Topics covered during the Symposium included: Federal and State clean coal programs, commercial status of FGD, acid deposition issues, FGD economics, industrial applications of FGD, wet FGD additives, wet FGD operations and reliability, spray dryer FGDt dry FGD technologies, and FGD by-product disposal and utilization. The Symposium Proceedings, published in two volumes, include 38 papers and summaries of 17 poster session presentations.

iiiCONTENTS VOLUME 1 SESSION 1: CLEAN COAL PROGRAMS frank T. Princiotta, Chairman "The Federal Clean Coal Technology Demonstration Program," C. L. Miller . • . . . . . . . . . . . 1-1 "Ohio's Clean Coal Technology," D. A. Berger . 1-15 "Illinois Coal Development Program," J. Mead** SESSION 2: STATUS OF FGD Stuart M. Dalton, Chairman "Evolution of FGO Technology," A. Weir, Jr•••• 2-1 "Trends in Commercial Applications of FGO," H. T. Melia*, R. 

### s. McKibben, F. H. Jones, and J. L. Kelley • . • . . . 2-23 "Status of Acid Rain and S02 and NOx Abatement Technology in Japan," J. Ando* and C. B. Sedman . • . . • . • • . • 2-44 "Assessment of

## so2 ;Nox Emission Control Technology in Europe," W. Ellison* and C. B. Sedman . . • . • . . . . • . . . . . . . 2-66 SESSION 3A: FGO ECONOMICS: GENERAL Robert E. Moser, Chairman "Increasing the Clarity of Pollution Abatement Cost Estimates," J. A. Leggett, E . S. Rubin* and I. H. Torrens . . . . . . . 3-1 "Economic Evaluation of Twenty-Four FGO Systems," R. J. Keeth*,

. P. A. Ireland, and R . E. Moser ... · . . . • . . . . . . . . . 3-15 SESSION 38: FGD ECONOMICS: ACID DEPOSITION RETROFIT APPLICATIONS Julian W. Jones, Chairman "Plant Specific Retrofit Factors for Lime/Limestone FGD and Lime Spray Drying FGD," T. E. Emmel* and J. W. Jones . . . . . . . . . 3-35 "Evaluation of Flue Gas Desulfurization as an Acid Rain Control Strategy for Utility Coal-Fired Boilers in the State of Ohio," B. A. Laseke*, H. J. Johnson, and D. A. Berger . . . . . . 3-55 "The Tennessee State Acid Rain (STAR) Project," W. S. Bain 3-76 *Denotes Speaker **No written manuscript

v 

## PrecedingpageblankCONTENTS (Continued) SESSION4: ACID DEPOSITION ISSUES Michael A. Maxwell, Chairman "Status of the Acid Rain Debate," B. J. Mclean • . . . . . . . 4-1 "Status of the National Acid Precipitation Assessment Program," P. M. Irving . . . . . . . . . . . . . . . . . . . . . . . . . 4

-10 SESSION 5: INDUSTRIAL APPLICATIONS Michael A . Maxwell, Chairman "A Review of Proposed Industrial Boiler S0 2 NSPS: Engineering Analyses of FGO Technology," 0. A . Pahl, C. B. Sedman*, and E. F. Au1, 

### Jr. . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 SESSION 6: WET FGO: ADDITIVES Michael A. Maxwell, Chairman "Three Years of Organic Acid Use at San Miguel," R. Cmiel* and D

. Seeman . • . . . . . . . • • . . . . . . . . . . . . . . . . . 6--1 "Enhancement of Wet Limestone Flue Gas Oesulfurization by Organic Acid/Salt Additives," J. C. S. Chang* and T. G. Brna . . . . . . 6-10 "Comparison of the Effectiveness of FGD Additives for S02 Removal Enhancement and Additive Consumption," J. B. Jarvis*, D. R . Owens, and D. A . Stewart . . . . . . • . . . . . . . . . . . . . . . 6-25 "Thiosulfate Additives for Lime/Limestone Scrubbing," G. T. Rochelle*, Y. 

### J. Lee, R: N.**Ruiz~Alsop,** J. C. S. Chang, and T. G . Brna . . . . . . . . . . . . . . . . . . . . . . . . . 6-45 S

ESSION 7: POSTER SESSION "The Integrated Air Pollution Control System Design and CostEstimating Model {Version II)," P. J. Palmisano, B. A. Laseke, and N. Kaplan • • . . . . . • . . • . . . . . . . . . . . 7-1 "FGD Cost-Estimating Computer Model," R . J. Keeth, P. A . Ireland, K. S. VanWinkle, and R. E . Moser . • . . . • . . . . . . . 7-6 "Computer Programs for FGD Data Management and Operation," M. J. Hebets, C . A. Berry, R. W. Donaldson, M. T. Johnston, and 0. A. Stewart . . . . . . . . . . . . . . . . . . . . . . . 7-12

*Denotes Speaker

vi\



### CONTENTS (Continued) SESSION 7: POSTER SESSION (Continued) "Simulation of Spray Dryer Absorber for Removal of S02 

### from Flue Gases," H. H . Haibodi, T. l. Pearson, R. H. Counce, and W. T. Davis . . . . . . . • . . . • . . . . . . .. .. .. 7-17 

### "Interpretation of GADS Data," C. V . Weilert, D. B . Hammontree, and P. N. Oyer • . • . . • • • • . • • • • • . . . . . • . 7-22 

### "Leaning Brick Stack Liners,• H. S. Rosenberg, C. W . Kistler, E. R. Dille, and R. E. Moser . • • • . • • • • • • . • • . • 7-26 "100+ 

### MW Demonstration of Dry Sodium Injection Flue Gas Oesulfurization," D . W . Ablin, J. J. 

### Hammond, D. B. Watts, R. l. 

### Ostop, and R.G. Hooper • • . . • . . • . • • • . . . . . 

### 7-33 "Operating Experience of a Retrofitted Dry Scrubber at an Industrial Steam Plant," R. Baldwin, J. 

### Buschmann, and R. Goffredi • . • • . . • • . • • . . . . . . . . . • • . 7-38

"Planning Maintenance for Flue Gas Oesulfur1zat1on Systems," L

. N . Davidson, G. P . Miller, C . P. Wedig, and R. E . Moser 7

-45 

### "S02 /NOx Removal by Ca(OH)2," P. Chu and G. T. Rochelle • • • 7-50 

### "Combined 502

### /NOx Removal from Flue Gas by Electron Beam," D. J. 

### Helfritch • . ..•. • •• • . •.. • • . • •.• • "Removal of S02 

### and NOxfrom Stack Gases by Electron Beam Irradiation," D . 0. Ham and J. C. Person • ••.•••• "Description and Mechanism of limestone FGD Operating Problems Due to Aluminum/Fluoride Chemistry," 

### J. B. Jarvis, R. W. Farmer, 7-59 7-64 

### and D . A . Stewart • . • • • • • • • . • . . • • . • • . . • • . . 7

-70



### · "Enhancing Double-Alkali and Lime/Limestone Flue-GasOesulfurization Chemistries to Promote NOxRemoval," J. 

### B. l. Harkness, R. D. Doctor, and C . D. Livengood "A Review of Methods for Increasing Limestone Reagent Fineness 7

-75 

### for Flue Gas Desulfur1zation," R. K . Seward and K. A. Brame • •. 7-82 "FGO Materials Failure Causes,• P. F. Ellis, II, and R . E. Moser · 7-87 

### "Shawnee 10-HW 

### Spray Dryer/Electrostatic Precipitator Pilot Plant," R

. A . Runyan, 

### J. B . Barkley, 

### J. G . Patterson, Jr., L. 

### J. Henson, and S. F. Newton . • • . • • . • • • . • • • . • . . . • . . . . 7-92

viiCONTENTS VOLUME 2 SESSION SA: WET FGD: OPERATIONS AND RELIABILITY (PART 1) Charles E . Dene, Chairman "Advanced Computer Control System with On-Line FGD Process Simulator," K. Kondo*, N. Shinoda, S. Hagiwara, S. Kouno, Y. Watanabe, and Y. Nonogaki . . . . . . . . 8-1 "Materials of Construction Overview," G. H. Koch . . • . 8-19 "Design and Operation of a Wet Process Based Flue Gas Desulfurization System Without Reheat," J. E. Smigelski* and L. A. Maroti . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28 SESSION 88: WET FGD: OPERATIONS AND RELIABILITY (PART 2) Robert Glover, Chairman "Improvements in FGD System Reliability at Springfield IL City Water, Light, and Power's Dallman Station," 0. W. Hargrove, Jr.*, 0. P. DeKraker, E. Riordan, B . Buecker, D. Myers, and D . A. Stewart . . . . . . . . . . . . • • . . . . . 8

-54 "Investigation of Mist Eliminator Reliability Problems at Utah Power 

### &Light's Hunter Station," G. Betenson*, 0. W. Hargrove, Jr., C. A. Brown, D. P. DeKraker, and D. A. Stewart . . . . . . . . . 8-66 SESSION 9A: SPRAY DRYER FGD Charles B. Sedman, Chairman "Limestone Spray Drying Absorption for S02 Control," E. S. Joens*, K . S. Felsvang, and R. Madhok ..... "Comparison of Dry Scrubbing Operation of Laramie River and Craig 9-1 Stations," J. B. Doyle*, B. J. Jankura, and R . C. Vetterick . . 9-22 "Dry Scrubber Operating Experience at the North Valmy Station," L. Smith*, L. Garrity, and R. Goffredi . . . . . . • . . . . . 9-31 "JoyjNiro Utility Spray Dryer FGD Operating Experience- An Update," J. R. Donnelly*, G. W. Tracy, M. T. Quach, K . S. Felsvang, R. L. Ericksen, and J. G. Eutizi . . . . . . • . . • . . . . . • 9-52

*Denotes Speaker

vi ii

### CONTENTS SESSION 98: DRY FGD TECHNOLOGIES Richard G . Rhudy, Chairman 

### "Status of Calcium-Based Dry Sorbent Injection S02 Control," R. Rhudy*, H. McElroy, and G . Offen ••..• • • • •••. . 9-68 "Pilot-Scale Studies of S02 

### Removal by the Addition of CalciumBased Sorbents Upstream of a Particulate Control Device," G. Blythe*, V . Bland, 

## c. Hartin, H . McElroy, and R . Rhudy •. .. 9-84 "Current Status of In-Duct Scrubbing Technology," K. R. Murphy*, E

. A. Samuel, and H. W. Pennline . • . . . • • • • • • • • 9

-106 

### "Development and Pilot Plant Evaluation of Silica-Enhanced Sorbents for Dry Flue Gas Desulfurization," W. Jozewicz*, C

. Jorgensen*, J. C . S. Chang, C . B . Sedman, and T. G. Brna . . • 9-123 

### "Dry/Semi-Dry Flue Gas Oesulfurization Using the lurg1 Circulating Fluid Bed Absorption," R. E . Graf* and J. D. Riley ••.•• . .. 9

-145 

### SESSION 10: FGD BY-PRODUCT DISPOSAL/UTILIZATION Dean H . Golden, Chairman "Engineering and Design Aspects: Disposal and By-Product Utilization of FGD Residues,• R . W . Goodwin • •••. . • "Effect of Wet lime FGO Operating Conditions on Improving**Pa~ticle** 

### Size and Dewatering of Sludge," L. B . Benson*, F . Baczek, 10-1 

### R

. H . Golightley, and J. A. Wilhelm . . • • • . • • • • • • • • . 10-20 "Design Considerations for FGD Solids Disposal/Utilization at a Power Plant with limited Space," J. A. Hengel*, R . G. Chapman, and D . W . Wilterdink . • • • . • . • . • • • • • . • • • • • 10-40 "Evaluation of Washing Alternatives for FGO Byproduct Gypsum Production," J. D. Colley*, S. H. Gray, D. A. Stewart, and 

### J. A . Wilhelm • • • • . • • • • • • • • • • . . • • • • • . • 10-57 

### "Design ofWaste Management Systems for Calcium Spray Dryer FGD Technology," A. P. Klimek*, A . G. Eklund, G . W. Dawson, and D

. H . Golden • •• • • • •..••**~** 

### . • • • • • • • • • • • • . 10-76 

### "Influence of Particulate Control on Waste Management: Integrated Environmental Control Pilot Plant Results," J. E. Cichanowicz, P. H . Maroney*, and S. A. Davidson . • • . • • • . • . . . 10-98 LIST OF ATTENDEES . 

# . 

# . ..

# . . .. • • • • • • • • 

# .. .

# . . A-1 *Denotes Speaker ixPREFACE The Tenth Symposium on Flue Gas Desulfurization was held in Atlanta, Georgia, November 17 through 21, 1986. This Symposium, jointly sponsored by EPRI and EPA, had as its objective the exchange of technical information regarding FGD systems and processes applicable to utility and industrial boilers. Thirty-nine papers and seventeen posters were presented by EPA and EPRI staff members, representatives of utility companies, equipment manufacturers, research and development companies and university researchers. Specific topics discussed in symposium presentations included Federal and State clean coal programs, the commercial status of FGO in the United States, Europe and Japan, FGO economics, acid deposition issues, industrial applications of FGD, wet FGD additives, wet FGD operations and reliability, spray dryer FGD, dry FGD technologies, and FGD by-product disposal and utilization. Participants in a poster session presented information on a variety of topics varying from computer applications to FGD chemistry to materials failure causes. The Proceedings of the Tenth Symposium have been compiled in two volumes. Volume 1 contains papers from the following sessions: Session 1: Opening Session/Clean Coal Programs Session 2: Status of FGD Sessions 3A/38: FGD Economics: General/ Acid Deposition Retrofit Applications Session 4: Acid Deposition Issues Session 5: Industrial Applications Session 6: Wet FGD: Additives Session 7: Poster Session Contained in Volume 2 are papers presented in these sessions: Session 8: Wet FGD: Operations and Reliability Sessions 9A/9B: Spray Dryer FGO/Dry FGD 

### Technologies Session 10: FGD By-Product Disposal/Utilization · The assistance of Janet Mangum, .Radian Corporation, in compiling these Proceedings is gratefully acknowledged.

XA Review of Methods for Increasing Limestone Reagent Fineness for Flue Gas Desulfurization by: Roland K. Seward and Kenneth A. Brame Kennedy Van Saun Corporation Danville, PA 17821 ABSTRACT Evolving technology in flue gas desulfurization (FGD) by wet limestone scrubbing has indicated that finer limestone slurry products might be needed to improve 

### so2 removal efficiencies. For new FGD installations this is not a problem because the engineer can design limestone slurry preparation facilities to meet his needs.**~owever,** at existing FGD facilities where there is a need for a finer limestone product, the problem becomes acute. This paper presents process/operating modifications which will maximize the fineness of the limestone slurry for an existing FGD unit. A review of limestone grinding system field data will illustrate the effects on limestone product size of . work index grindability, system feed rate, cyclone feed percent solids and other process variables. In addition, operating methods to maximize fineness will be presented. Effects of classification on system efficiency and limestone product size will be explained. STATEMENT OF PROBLEM Bench and commercial scale demonstrations have shown that limestone reagent fineness has a significant effect on limestone utilization. The results indicate that high utilization is achieved when the limestone size distribution is 80 to 90 percent passing 44 micron (325 mesh) (1, 2, 3, 4). This size is equivalent to 92 to 98 percent passing 74 micron (200 mesh). The majority of limestone grinding systems in operation were designed to produce limestone coarser than this optimum; however, in many of these systems fineness can be increased. EVALUATION METHOD The fineness obtained from a closed circuit ball mill system with cyclone classifiers can be limited by either specific energy defined as the energy required to reduce a unit weight of limestone from a given feed size to a given product size, expressed in kilowatt-hours per metric ton (KW-HR/MT), or separation obtainable by the cyclones. In order to determine a measure of a limestone grinding system's specific energy requirements, a bench scale ball mill test, called a Work Index Test, is performed on a given limestone. A survey of 300 limestone samples exhibited a range in work indexes from 4.2 to 13.3 KW-HR/ST with an average of 8.8 KW-HR/ST (5). The Work Index is used to calculate actual specific energy requirements of given limestones at various product finenesses. Since ball mills essentially draw constant power, mill capacity is found by dividing the mill power draw by the specific energy requirements of the stone for a given Work Index, feed and product size.

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## FIGURE 4 RECOVERY AT 74 MICRON (200 MESHl VERSUS RECIRCULATING RATIO 7-83Figure 1 shows a plot of specific energy versus percent passing 74 microns in the product. This Figure is based on 8, 10 and 12 Work Index limestones crushed to give a distributed feed of 19 mm (3/4") top size. This Figure also assumes properly sized cyclones have been selected for the circuit. Figure 1 can be used to estimate the highest obtainable system capacity if the cyclones are able to make the desired separation. An operator of a iimestone grinding system needs to be aware of the following conditions which effect speci fic energy requirements and thus produce a finer reagent: Decreasing system feed rate increases energy available for grinding• • Insure the mill is charged with the proper size grinding

balls and draws full power.

Reducing the size of the limestone feed to the system will reduce the specific energy requirements . Generally, grinding systems are designed for a 10-12 work index limestone; use of a lower work index limestone will decrease specific energy requirements. DATA If a system is not specific energy limited, it may be cyclone separation limited. Cyclone separation is a function of cyclone diameter, feed and associated overflow density, and feed size distribution. Each diameter cyclone has a limited fineness it will be able to produce. The fineness limit is also effected by the cyclone feed and overflow density. For a given feed size and density, smaller diameter cyclones are able to make a finer separation than larger cyclones. Figure 2 shows field data collected from 101 mm (4"), 152 mm (6") and 254 mm (10") cyclones, with similar feed size. If desired fineness is 98 percent minus 74 micron (200 mesh), 101 uun (4") or 152 mm (6") cyclones are required and must be operated below 35 percent solids cyclone overflow density. Figure 3 shows field data collected from 152 mm (6") cyclones. The percent minus 74 micron (200 mesh) in the cyclone overflow is a function of cyclone feed percent solids, and decreases rapidly beyond 58 percent solids . The cyclone overflow percent solids is also a function of cyclone feed percent solids . Fineness is maximized at less than 35 percent solids cyclone overflow (less than 54 percent solids cyclone feed) . This range also yields desirable recirculating ratios and recovery to overflow.

7

-84**Recirf~~at~ng** ratio is defined as the weight of limestone (dry weight) in the cyclone underflow divided by the weight of limestone (dry weight) in the cyclone overflow. The recirculating ratio is a measure of the amount of material returned to the mill by the classifier. Recovery to overflow is defined as the weight of dry material passing 74 micron (200 mesh) in the cyclone overflow divided by the weight of dry material passing 74 micron (200 mesh) available in the cyclone feed. (The cyclone feed has the same size distribution as the mill discharge.) Recovery is a measure of the amount of product size particles recovered by the cyclone. Figure 4 shows the relationship between recovery and recirculating ratio. Typical cyclone recovery range is .55 to .65. Low recoveries yield high recirculating ratios and inefficient grinding. In this condition, limestone that is already product size is returned to the mill and receives energy that could be better used on larger particles. Lowering the cyclone feed density will lower recirculating ratio and increase recovery. Low recirculating ratios (less than 1) and high recovery is an indication that the cyclone could accept a coarser feed size, specific energy requirements have been met, and the mill capacity could be increased. SOLUTION Fineness can be increased in many**syste~s** by simply maintaining the cyclone overflow density below 35 percent solids. If desired fineness is met and recovery is high but circulating ratio is low it may be possible to increase capacity and maintain fineness by increasing circulating ratio. To estimate the capabilities of an existing system, use Figure 1 to estimate the maximum obtainable mill capacity. Use Figure 2 to determine the limitations of cyclone classifiers. REFERENCES 1. Colley, J. D., Hargrove, 0. W. and Stewart, D. A., "Effect of Limestone Grinding Circuit on FGD Performance and Economics". Paper presented at the 8th Symp. on FGD. New Orleans, LA. 1983. 2. Colley, J. D., Glover, L. R., Donaldson, T. and Stewart, D., "Process Troubleshooting at a Utility Limestone FGD System". Paper presented at the 8th Symp. on FGD. New Orleans, LA. 1983 3. Stewart, D., Colley, J . D. , Hargrove, 

### o. W. and Jones, J. A., "Limestone Selection and Preparation for FGD"• . Paper presented at the 9th Symposium on FGD. Cincinnati, OH. 1985. 4. Chang, C. S. J. , Brna, G. T. and Kaplan, N., "Effects of Limestone Type and Grind on Dual Alkali System Performance". Paper presented at the 9th Symp. on FGD. Cincinnati, OH. 1985. 5. Gaughenbaugh, D. L. and Linn, R. J. , "Wet Limestone Grinding for Flue Gas Desulfurization". Paper presented at the 1986 SME-AIME Fall Meeting. St. Louis, MO., September 7-10, 1986.

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# FIGURE 1 SPEC[FICENERGY V ERSUS REAGENT FINENESS FOR t9M MX0 LIMESTONE FEED

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### MESH) VERS US CYCLONE OVERFLOW PERCENT SOLIDS 7-86