EPA-600/2-76-281
October 1976
Environmental Protection Technology Series
                         DESULFURIZATION  OF  STEEL MILL
                                         SINTER  PLANT  GASES
                                        Industrial Environmental Research Laboratory
                                              Office of Research and Development
                                             U.S. Environmental Protection Agency
                                       Research Triangle Park, North Carolina 27711

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                  RESEARCH REPORTING  SERIES


Resear:h 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 further development  and application of environmental
technology.  Elimination of  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 re port 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 policies of the Agency, nor
does mention of trade names or commercial products constitute endorse-
ment or recommendation for use.
This document is available  to  the  public through the National
Technical Information Service,  Springfield,  Virginia  22161.

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                                   EPA-600/2-76-281

                                   October 1976
          DESULFURIZATION

            OF  STEEL  MILL

        SINTER  PLANT  GASES
                     by

     Gary D. Brown, Richard T.  Coleman,
  James  C. Dickerman, and Philip S. Lowell

             Radian Corporation
               P.O.  Box 9948
            Austin, Texas  78766
      Contract No. 68-02-1319, Task 58
            ROAPNo. 21AQR-005
        Program Element No. 1AB015
      EPA Task Officer:  Norman Plaks

 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

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                            ABSTRACT

           This report presents the results of a study to eval-
 uate the technical and economic feasibility of using limestone
 scrubbing technology to control sinter plant emissions.  Data
 from Soviet and Japanese sinter plants employing limestone
 scrubbing technology were used to develop a realistic design
 basis.   A conceptual process design was developed and used
 to prepare economic estimates.

           Results of the process design indicate that control
 of sinter plant emissions by limestone scrubbing is technically
 feasible.  Economic evaluations show that a retrofitted limestone
 scrubbing system will increase the cost of producing sinter by
 about $2.07 per metric ton of product sinter for a standard sin-
 ter plant operation.  For a sinter plant with a windbox:gas re-
 circulation system the cost increase would be about $1.59 per
 metric ton of product sinter.
                              111

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                       TABLE OF CONTENTS

                                                           Page

           ABSTRACT	   iii

           TABLE OF CONTENTS	    iv

           LIST OF TABLES	    vi

           LIST OF FIGURES	    ix

           CONVERSION FACTORS	     x

           GLOSSARY	    xi



 1.0       SUMMARY	    1



 2.0       INTRODUCTION	    3



 3.0       TECHNICAL DISCUSSION	    5

 3.1       Description of Steel Mill Sinter Plants	    5

 3.1.1     Process Description	    6

 3.1.2     Process Developments	    9

 3.1.3     Sinter Plant Emissions	   13

 3.2       Description of the Lime/Limestone Wet Scrubbing
           Process	   18

 3.2.1     Process Description	   20

 3.2.2     Design Considerations	   25

 3.2.3     Typical Operations Relating to Sinter Plants...   32

 3.3       Evaluation of USSR and Japanese Data	   33

 3.3.1     Summary of Soviet Data	   33

 3.3.2     Summary of Japanese Data	   35
                                iv

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 TABLE OF CONTENTS (cont.)                                  Page







 4. 0       DESIGN APPROACH	  37



 4.1       Des ign Bas is and As sumptions	  38



 4.1.1     Sinter Plant Design Basis	  39



 4.1.2     Limestone Scrubbing Design Basis	  44



 4. 2       Economic Basis	  55



 4.2.1     Capital Investment Costs	  55



 4.2.2     Annual Operating Costs	  58







 5.0       RESULTS	  60



 5.1       Process Designs	  60



 5 . 2       Limestone Scrubbing System Layout	  69



 5 . 3       Economic Evaluation	  74



 5.3.1     Total Capital Investment	  76



 5.3.2     Annual Operating Costs	  78







 6 .0       CONCLUSIONS AND RECOMMENDATIONS	  81



 6.1       Conclusions	  81



 6. 2       Recommendations	  82







 7 . 0       REFERENCES	  85







           APPENDIX A - COMMENTS ON THE SOVIET DATA	 A-l



           APPENDIX B - COMMENTS ON THE JAPANESE DATA	 B-l
                               v

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 TABLE OF CONTENTS (cont.)                                 Page
           APPENDIX C - DESCRIPTION OF RADIAN'S
                        PROCESS SIMULATION MODEL	 C-l
           APPENDIX D - PROCESS EQUIPMENT LIST AND COST
                        DATA	 D-l

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                         LIST OF TABLES
                                                           Page
 TABLE 3-1    SINTER-MIX COMPOSITION	    8

 TABLE 3-2    MATERIALS USED IN THE PRODUCTION OF SINTER
              AT STEEL PLANTS IN THE UNITED STATES	   12

 TABLE 3-3    COMPOSITION OF PARTICULATE EMISSIONS	   15

 TABLE 3-4    SIZE DISTRIBUTION OF PARTICULATE EMISSIONS...   16

 TABLE 3-5    TYPICAL CONCENTRATIONS OF GASEOUS EMISSIONS
              FROM STEEL MILL SINTER PLANTS	   17

 TABLE 3-6    SULFUR BALANCE FOR SINTER MACHINE OPERATION..   19

 TABLE 3-7    COMPARISON OF SCRUBBER TYPES FOR A LIMESTONE
              WET SCRUBBING SYSTEM	   28



 TABLE 4-1    SINTER PLANT DESIGN BASIS	   40

 TABLE 4-2    COMPOSITION OF PARTICULATES IN  SINTER PLANT
              FLUE GAS	   43

 TABLE 4-3    LIMESTONE COMPOSITION	   45

 TABLE 4-4    MAKEUP WATER COMPOSITION	   45

 TABLE 4-5    LIMESTONE SCRUBBING DESIGN PARAMETERS	   50

 TABLE 4-6    MASS  EMISSION RATES  FROM THE RADIAN  BASE  CASE
              STEEL MILL SINTER PLANT  AFTER LIMESTONE SCRUB-
             BING  OF THE WINDBOX EXHAUST GAS	   52

 TABLE 4-7    ITEMS USED TO ESTIMATE THE TOTAL CAPITAL  IN-
              VESTMENT REQUIRED FOR A  LIMESTONE SLURRY
              PROCESS	   57

 TABLE 4-8    BREAKDOWN OF ANNUAL  OPERATING COSTS  FOR A
              LIMESTONE SLURRY  PROCESS	   59

 TABLE 5-1    MATERIAL BALANCE  FOR A LIMESTONE SCRUBBING
              PROCESS ON A STANDARD SINTER PLANT	   63
                              VII

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 LIST OF TABLES (cont.)
                                             Page
 TABLE 5-2    MATERIAL BALANCE FOR A LIMESTONE SCRUBBING
              PROCESS ON A SINTER PLANT WITH WINDBOX
              RECYCLE	  64

 TABLE 5-3    DESCRIPTION AND DESIGN SPECIFICATIONS FOR
              MAJOR PROCESS EQUIPMENT	  65

 TABLE 5-4    OPERATING PARAMETERS FOR PROCESS DESIGNS	  68

 TABLE 5-5    SPACE REQUIREMENTS FOR A LIMESTONE SCRUBBING
              SYSTEM OH STEEL MILL SINTER PLANT APPLICATIONS 73
 TABLE 5-6



 TABLE 5-7


 TABLE 5-8
TOTAL CAPITAL INVESTMENT SUMMARY FOR STEEL
MILL SINTER PLANT FLUE GAS DESULFURIZATION
USING LIMESTONE SLURRY SCRUBBING	
LIMESTONE SLURRY PROCESS TOTAL ANNUAL OPERAT-
ING COSTS (STANDARD CASE).,	
LIMESTONE SLURRY PROCESS TOTAL ANNUAL OPERAT-
ING COSTS (RECYCLE CASE)	
77


79


80
                              VI11

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                        LIST OF FIGURES
                                                          Page
FIGURE 3-1   SCHEMATIC FLOW DIAGRAM FOR TYPICAL MODERN
             SINTER PLANT	   10

FIGURE 3-2   PROCESS FLOW DIAGRAM - LIME/LIMESTONE WET
             SCRUBBING 	   21



FIGURE 5-1   PROCESS FLOW DIAGRAM - LIMESTONE SCRUBBING
             PROCESS FOR STEEL MILL SINTER PLANT
             APPLICATION	   62

FIGURE 5-2   LAYOUT OF SCRUBBING SECTION OF A LIMESTONE
             SCRUBBING PROCESS FOR A STANDARD STEEL MILL
             SINTER PLANT OPERATION	   70

FIGURE 5-3   LAYOUT OF SCRUBBING SECTION OF A LIMESTONE
             SCRUBBING PROCESS FOR A RECYCLE STEEL MILL
             SINTER PLANT OPERATION	   71

FIGURE 5-4   LAYOUT OF FEED PREPARATION AND SLURRY PRO-
             CESSING SECTION OF A LIMESTONE SCRUBBING
             PROCESS FOR A STEEL MILL SINTER PLANT
             APPLICATION	:	   72
                              IX

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                       CONVERSION FACTORS

           The metric system is used in this report.  Following
 are jiome factors for conversion between metric and English
 systems:

           1 m (meter) ~ 3.281 feet
           1 m3 (cubic meter)  = 35.31.4 cubic feet
           1 mt (metric ton) = 1.1023 short tons
           1 kg (kilogram)  = 2.2046 pounds
           1 liter = 0.2642 gallon

 The capacity of FGD systems is expressed in Nm3/hr (normal cubic
 meters per hour)

           1 Nm3/hr = 0.589 SCFM

 L/G ratio (liquid/gas ratio)  is expressed in liters/Mm3

           1 liter/Nm3 = 7.481 gallons/1000 SCF
                                x

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                            GLOSSARY

           Carbide Sludge  -  Calcium oxide (CaO) and impurities
 formed as a byproduct of acetylene manufacture.

           Coke Breeze  -  coke fines that are generated during
 the crushing and sizing of the coke for blast furnace consump-
 tion and which are used as a fuel in the sinter  charge.

           Flue Gas -  sinter plant off-gas.

           Fluxing  -   any process in which materials (Fluxes)
 are added to the metal charge to aid in the removal of gases.
 oxides,  or other impurities.

           Fluxstone  -  limestone or dolomite.

           Fly Ash - particulates entrained in the  sinter  plant
 off-gas.
           Gangue  -  a waste rock or slag material remaining
 after most of the metal values have been removed.

           Relative Saturation  -  The relative saturation (RS)
 is  the product of the activities of the species  which react to
 produce the precipitating solid divided by the solubility
 product constant,  as  shown in the following equations for calcium
 sulfate.
           Ca  ' +  S04 +  2H20  £  CaSO,  -2H20
   RS   =   LaCa-H-  •  aso;  '  aH20(£)
For precipitation to occur, the relative saturation must be
greater than one, and the rate R positive  (see equation 2-4,
Appendix C) .  For dissolution to occur, the relative satura-
                              XI

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 tion must be less  than one,  and the rate R negative.   At
 equilibrium, the relative saturation is  equal to one,  and the
 rate is  zero.
           Slag  -  A residue that forms on the surface of
 molten metal during fluxing.

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 1.0       SUMMARY

           Desulfurization of sinter plant windbox gases by lime-
 stone scrubbing is commercially practiced in both the USSR and
 Japan; it is not currently practiced in the United States.  To
 determine the costs of applying this technology domestically,
 conceptual process designs were prepared for both standard sin-
 ter plant operations and operations employing a windbox gas re-
 circulation system.  Results of the conceptual designs were used
 to size process equipment.  An economic basis was selected and
 applied to the process designs to perform an evaluation of both
 capital and operating costs for each system.

           The services of two outside consultants were retained
 in order to help in obtaining the data and information that was
 necessary to perform this evaluation.  Mr. Richard Jablin, a
 consultant with over 35 years experience in steel mill engineer-
 ing and environmental control, provided much assistance and in-
 formation on steel mill sinter plant operations.   Mr. Jablin
 holds several patents in the area of steel making and has been
 employed by various steel companies since 1950.  He currently
 directs a consulting engineering firm, Richard Jablin and As-
 sociates, located in Winchester, Virginia.  Dr. Jumpei Ando,
 an international consultant and lecturer in the areas of SOX
 and NOX control, provided data and descriptions of several lime
 and limestone systems which are currently being used in Japan
 to remove S02 from sinter plant gases.  Dr.  Ando has held pre-
 vious positions with the Faculty of Engineering,  University of
 Tokyo and the Tennessee Valley Authority.   He is currently a
 Professor at Chuo University in the Faculty of Science and En-
 gineering.

           The process designs and cost estimates are based upon
 data obtained from the following sources:

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            1) information available from Radian
               files, Mr. Richard Jablin, and the
               open literature;

            2) information on Soviet technology
               obtained by the EPA as a result
               of a technology interchange agree-
               ment between the US and USSR;

            3) information on Japanese technology
               prepared for Radian by Dr. Jumpei
               Ando;

            4) cost data provided in a TVA report
               prepared by McGlamery, et al. (MC-147).

            The results of this evaluation indicate that the
 capital costs of a limestone scrubbing system, applied to a
 sinter plant having a capacity of 6312 mtpd of product, range
 from $8-10 million, depending upon whether or not the sinter
 plant: uses windbox gas recirculation.  For the same sinter plants
 the operating costs would be respectively, $1.59-2.07 per metric
 ton of product sinter.  The desulfurization system evaluated
 here uses a venturi prescrubber which would effectively remove
 parti.culates.  Optimisation of the technology could be accomp-
 lished by determining the effects of contaminants in the sinter
 plant: windbox gases on limestone scrubbing process chemistry
 and on corrosion in the prescrubber loop.
                               -2-

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 2.0       INTRODUCTION

           Sulfur dioxide  (S02)  emissions  from steel  mill
 sinter plants  are of  concern to the U.S.  Environmental  Pro-
 tection Agency.   Past experience of both  the  U.S.  electric
 power industry and of USSR and  Japanese steel manufacturers
 indicates  that limestone  slurry scrubbing is  a feasible tech-
 nique for  sinter plant emission control.   Under contract  to
 EPA,  Radian has  completed this  study to evaluate the applica-
 bility of  limestone slurry scrubbing to the sinter plant  emis-
 sion  control problem.

           The  objectives  of the study were twofold.   First,  the
 evaluation was performed  to determine the technical  feasibility
 of  applying limestone wet scrubbing technology to  control sinter
 plant emissions.   Potential process problems  and land require-
 ments for  solid  waste disposal  were identified.   Secondly, the
 study was  to provide  EPA  with process economics to aid  them  in
 determining the  economic  feasibility of applying limestone tech-
 nology to  sinter plants.

           To accomplish these objectives,  the following approach
 was taken.   First,  data on U.S.  sinter plant  operations were
 collected  and  reviewed.   Secondly,  data from  USSR and Japanese
 sources  were collected and evaluated to determine  the applica-
 bility of  foreign experience to domestic  applications.  From
 these evaluations,  a  design basis was formulated and used to
 develop  conceptual process designs  for limestone scrubbing
 systems  to control sinter plant emissions.  Both standard sinter
 plant operations and  windbox gas  recirculation operations were
 used  as  design cases.   Finally,  estimates were  made  of  process
 economics  for  both design cases.
                               -3-

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           The following sections of this report describe the
 evaluations performed as part of this study.   Section 3.0 is
 a technical discussion of sinter plant and limestone scrubbing
 operations.  A summary of the evaluations of Soviet and Japa-
 nese experiences with limestone scrubbing of sinter plant emis-
 sion.'; is also included.   Section 4.0 provides details of the
 design approach and basis.   Section 5.0 reports the study results
 and Section 6.0 presents conclusions and recommendations.
 Supporting details are included in the appendices.
                                -4-

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 3.0       TECHNICAL DISCUSSION

           In order to evaluate the applicability of limestone
 slurry scrubbing to steel mill sinter plants,  information on both
 the operations and emissions of U.S.  sinter plants was collected
 and reviewed.   Information on limestone slurry scrubbing opera-
 tions, obtained from previous Radian  reports and in-house
 files, was used as a basis for determining the process design
 considerations that would be important as related to sinter
 plant applications.  Data were also collected from Japanese
 and Russian sources on the operating  characteristics of lime-
 stone slurry scrubbing units which currently process steel mill
 sinter plant flue gases.
                                                    i

           Typical sinter  plant operations and emissions are
 described in Section 3.1.   A description of limestone slurry
 scrubbing is given in Section 3.2 and a summary of the data
 collected from both Soviet and Japanese limestone  scrubbing
 experiences is presented  in Section 3.3.

 3.1       Description of  Steel Mill Sinter Plants

           The  following sinter plant  description has  been  taken
 largely  from a report  prepared for  EPA by  National  Steel Corpora-
 tion  entitled  Sinter Plant Windbox  Gas  Recirculation  System
 Demonstration  (PE-179).

          The  function of  sintering, in the steel industry,
 is to convert  iron-bearing raw materials of a fine particle
 size into coarse agglomerates by partial fusion.  The sinter
 product has a porous cellular structure resembling clinker
 in physical appearance.  Its composition may be substantially
 different from that of the original iron-bearing fines.
                              -5-

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           Blast furnace sinter is categorized as acidic or basic,
 depending on the basicity ratio.   The basicity ratio is defined
 by the following equation:

      Basicity Ratio  -   Wt Percent CaO + Wt Percent MgO
                         Wt Percent Si02 + Wt Percent A1203

 Sinter with a basicity ratio of less than 1.0 is acid and
 that with a ratio greater than 1.0 is basic.  It has become
 common to refer to sinter with a basicity ratio of approximate-
 ly 1.0 as self-fluxing, while ratios in excess of 1.0 may be
 called burden-fluxing or superfluxed sinter.  Acid sinter of
 basicity less than 0.5 was the predominant product used as blast
 furnace feed until the early 1950's.  It was then realized that
 both economic and productive benefits to the blast furnace
 could be realized by incorporating in the sinter a part or all
 of the required furnace flux.   This was achieved by the addi-
 tion of limestone and/or dolomitic fines to the ore fines to
 be sintered.

 3.1.1     Process Description

           In the sintering process, a shallow bed of fine par-
 ticles is agglomerated by heat exchange and partial fusion of
 the quiescent mass.   Heat is generated by the combustion of a
 solid fuel contained within the bed of fines being agglomerated.
 The process is initiated by igniting the fuel at the top sur-
 face of the bed,  after which a thin, high temperature combustion
 zone is drawn downward through the bed by an induced draft.
 Within this zone, the surfaces of adjacent particles are at a
 fusf.on temperature and the gangue constituents form a semi-
 liquid slag.   The flow of volatiles and incoming air creates a
 frothy condition and freezes the trailing edge of the advancing
 fusion zone.   The product then consists of particles of ore
 bonded in a slag matrix of cellular structure.
                                -6-

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           In the ferrous industry, the material to be sintered
 consists essentially of a mixture of iron-bearing fines and a
 solid fuel.  The iron-bearing constituents are chiefly iron
 ore fines, recycled sinter fines and blast furnace flue dust,
 but may also include mill scale, and other steel mill waste
 products containing iron.  Coke breeze is the most common solid
 fuel, but other carbonaceous materials are used.  It has become
 common practice to add limestone or dolomitic fines to the
 sinter mix and this material may now be considered as an essen-
 tial constituent in a typical sinter mix.  Sinter-mix composi-
 tions for three different U.S. steel mill sinter plants are
 shown in Table 3-1 (VA-126).  This mixture of fine material is
 placed on the sinter strand in a shallow bed, seldom less than
 152 mm (6 inches) nor more than 508 mm (20 inches) in depth.
 In the ignition zone, the surface of the bed is heated to about
 1260 to 1371°C (2300-2500°F),  combustion of the fuel is initia-
 ted, and fusion of the fine particles at the surface begins.
 As air is drawn through the bed, the high temperature zone of
 combustion and fusion moves downward through the bed and pro-
 duces the bonded, cellular structure.

           Combustion of the solid fuel and propagation of the
 fusion zone through the bed is dependent on the air flow.  To
 assure an adequate air flow, the sinter mix is generally pre-
 conditioned to improve its permeability.   This can be accom-
 plished by eliminating excessively fine materials when economi-
 cally possible, but is normally achieved by the addition of
 coarse [12.7 mm by 3.2 mm (% inch by  V8  inch)]  sinter returns
 and by fluffing and/or micropelletizing the fine particles in a
 balling drum.

           The design and physical arrangement of sintering
 equipment and the flow pattern of raw materials and product
                                -7-

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                           TABLE 3-1
                    SINTER-MIX COMPOSITION
                       ( weight percent)
 Sinter-Mix Components
Plant 1
Plant 2
Plant 3
Iron Ore
Dry blast-furnance dust
Blast-furnance filter
 cake
Melt-shop slag
Rolling-mill scale
Basic-oxygen-furnance
 dust
Miscellaneous dust
Limestone or dolomite
Coke

          Total
 29.1
  1.3
 15.8

  6.5
 11.5
  3.5

  0.0
 28.2
  4.1

100.0
 82.0
  0.0

  0.0
 15.0
  3.0

100.0
 49.5
  5.6
  4.9

  0.0
  7.6
  0.0

  6.7
 20.8
  4.9

 100.0
 Source:  VA-126
                                -8-

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  differ considerably between various plants.   The choice of
  equipment and material flow is generally determined by the
  desired capacity,  space available,  capital costs, and prevailing
  technology.   However,  each plant can be divided into three
  distinct phases of operation,  namely, (1)  raw materials
  processing,  (2) sinter production and (3)  product processing.
  A schematic  flow diagram of a typical modern sinter plant is
  shown in Figure 3-1.

            This schematic flow diagram is typical of a modern
  sinter plant.   Many of the older plants lack certain features,
  such as hot  and/or cold screens, balling facilities, sinter
  breakers, coolers, and flexibility in materials handling.  Some
  of the newest plants have special process  control features to
  reduce the variation in the sinter product.   Examples of the
  new control  technology being applied to sinter plants are:
  (1) automatic raw material proportioning systems, and (2) com-
  puter control of the process.

           ^ A typical sinter plant strand normally operates
  at full load except for start-up.  The induced draft fan that
  pulls air through the sinter bed maintains a uniform suction
  pressure.  This results in a fairly uniform gas flow through
  the sinter bed.  The frequency of shutdown depends on the con-
  dition of the plant.  in a well  run  sinter plant  the operator
  would plan on running all week without an unscheduled shutdown.
  Scheduled shutdowns for a well run sinter plant are about one
  eight-hour shift every week (JA-136).

  3.1.2     Process  Developments

           Most  sinter plants are  operated  in a .similar manner,
  differing primarily  in the characteristics of the  raw materials
  which must be processed and the basicity ratio chosen for  the
  sinter product.  The general trend  in materials used for  sin-
                               -9-

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                     Figure 3-1 Schematic  flow diagram for typical  modern sinter plant

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 tering has been toward less  iron ore fines  and more iron-bear-
 ing waste materials  such as  mill scale,  ironmaking dusts  and
 slags.   Fluxstone additions  have increased  with the trend
 toward higher sinter basicities.   Table  3-2 shows  the  trend in
 sinter feed materials between 1960 and 1968.   The  increased use
 of mill scale,  cinder and slag,  other materials which  are pri-
 marily recyclable iron-bearing fines,  and fluxstone is  evident.
 The reduction in the use of  blast furnace flue dust and sludge
 is due to improved blast furnace burdens.

           A major factor influencing sinter plant  operation
 has been the trend toward higher sinter  basicities.  In 1962,
 only about 40 percent of the sinter produced had a basicity
 ratio in excess of 1.0.   At  the  present  time,  available data
 indicate that at least 85 percent of the sinter produced  in
 the United States and Canada has  a basicity in excess  of  1.0.
 Moreover,  at least six sinter plants regularly produce  sinter
 with a basicity ratio greater than 3.0 and  one plant in excess
 of 4.0.   Increasing  the sinter basicity  generally  reduces pro-
 duction capacity but increases the strength of the sinter
 product.   Improved sinter quality reduces the quantity  of fines
 to be recycled in the sinter plant and decreases the flue dust
 and sludge generated at the  blast furnace.   Higher basicity
 sometimes improves sinter strand operation  and reduces  the
 production and emission of fine  dusts.

           A new development  in sinter plant operations  is the
 practice of recirculating a  portion of the  windbox flue gas.
 Development work,  including  installation and operation  of a
 windbox recirculation system,  has been performed by the National
 Steel Corporation, Wierton Steel  Division,  and the Aliquippa
 Works of Jones and Laughlin  Steel Corporation.   The recirculating
 system at Wierton is designed with four  duct  valves which permit
 a  once-through operation of  recirculation rates ranging from 0-50
 percent.   A recirculation rate of 39 percent  was calculated
 to be the maximum recycle amount  because of the rapidly de-
 creasing oxygen content in the recirculated gas, and the  large

                              -11-

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                          TABLE 3-2

MATERIALS USED IN THE PRODUCTION OF SINTER AT STEEL PLANTS IN THE
UNITED  STATES
MATERIAL
Iron Ore
Flue Dust &
Sluc.ge
Scale
Cinder and Slag
Other
Flux£;tone
Fuel

1960
a) 35,900
b) 36,500
c) 74
5,200
5,300
11
980
1,000
2
49
50
.01
490
500
1
3,740
3,800
7
2,360
2,400
5
Year
1964
39,370
40,000
69
4,530
4,600
8
2,170
2,200
4
394
400
1
1,080
1,100
2
5,800
5,900
10
3,250
3,300
6

1968
33,170
33,700
64
3,050
3,100
6
3,150
3,200
6
394
400
1
1,770
1,800
3
7,480
7,600
15
2,660
2,700
5
a) Thousands of metric tons
b) Thousands of gross tons
c) Percentage of mix

Source:   PE-179
                                -12-

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CORPORATION


 rate of increase in fan horsepower with increasing recycle
 percentage.

           The windbox recirculation system offers the folloxvdng
 potential advantages as reported by Wierton (PE-179):

           (1)  reduction in quantity of gases to be
                cleaned,

           (2)  reduction in capital investment for gas
                cleaning equipment,

           (3)  reduction in total emissions to the atmosphere
                for a given dust concentration,

           (4)  reduction in hydrocarbon content of the
                exhaust gases,due to more complete combustion, and

           (5)  conservation of energy from recirculating
                hot gases.

           Because of  the potential advantages to be  gained
 from operating in a windbox recirculation mode, data from the
 Wierton Steel Division  operations have been used to  prepare  a
 conceptual design of  a  limestone  scrubbing system to treat
 S02 emissions.  Results of this conceptual design will be
 compared against a design of a  limestone system for  treating
 a sinter plant waste  stream without windbox recirculation.

 3.1.3      Sinter Plant Emissions

            Before discussing sinter plant emissions  it should
  be mentioned that every sinter plant is a special case.  They
  are all different, having different feed compositions, making
  it difficult to define a typical sinter plant.

                              -13-

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CORPORATION
            Emissions from sinter plants include particulates,
 condensable aliphatic hydrocarbons,  and gaseous components such
 as sulfur dioxide,  carbon monoxide,  and chlorides.   Table 3-3
 shows the particulate compositions for the three steel mill
 sinter plants whose sinter mix compositions were given in Table
 3-1.   The size distribution for particulates emitted from the
 main exhaust system of several sinter plants is given in Table
 3-4.

            Gaseous  emissions from sinter plants include
 significant amounts of carbon monoxide and sulfur oxides.
 Typical concentrations of gaseous emissions from steel mill
 sinter plants are given in Table 3-5.   Other gaseous components
 that are present in smaller amounts  include nitrogen oxides,
 chlorides,  and fluorides.

           Emissions from a sinter plant with windbox recircula-
 tion  vary from those of a  sinter plant without  recirculation.
 The major environmental effects of gas recirculation are an in-
 crease in the concentration of SC>2 in  the exhaust gas,  and a
 decrease in both hydrocarbon and particulate emissions.   In
 both  modes  of sinter plant operation,  the same  quantity of
 sulfur is oxidized  to produce S02.   Therefore,  although the
 concentration of SOz will  increase in  the recirculation case,
 the total quantity  of 862  emitted for  both cases will remain
 the same.   The advantage gained by using a gas  recirculation
 system is that the  total gas volume  to be processed  is  reduced
 thereby reducing the size  and capital  and operating  cost of
 required emission control equipment.

           Hydrocarbon emissions will be reduced as the  hydro-
 carbons in  the recycle stream will pass back through the flame
 zone  to be  combusted.   The particulate concentration should be
 the same for both cases,  although the  windbox recirculation case
 will  produce less total particulate  emissions.   The  stream com-
 positions used as a basis  for the limestone scrubbing design are
 presented and discussed in Section 4.1 - Design Basis  and
 Assumptions.

                              -14-

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                             TABLE 3-3
COMPOSITION OF P ARTICULATE

Particulate Component
Fe 0
CaO
MgO
K20
Si02
A1203
Na20
ZnO
MnO
Chlorides
Sulfates
Hydrocarbons
Other
Loss on Ignition
Total
(weight percent)
Plant 1
33.9
7.1
5.3
5.2
4.8
2.6
1.6
0.4
0.2
8.5
7.5
7.4
1.6
13.9
100.0
EMISSIONS

Plant 2
11.7
10.9
0.4
0.6
2.4
4.3
0.3
0.1
0.1
3.0
16.5
36.9
0.0
12.3
100.0
Source:   VA-126
                                                            Plant  3

                                                             28.0
                                                             15.0
                                                              2.0
                                                              8.1
                                                              4.6
                                                              2.5
                                                              0.0
                                                              0.0
                                                              0.0
                                                              8.8
                                                              2.1
                                                              0.0
                                                              0.0
                                                             28.9
                                                            100.0
                                -15-

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                              TABLE  3-4



           •  SIZE DISTRIBUTION OF PARTICULATE  EMISSIONS
Size gradin
Plant
A


B
C

D
K
g of dust from sinter plant main
Size, microns
295 211 152 104 76



84 71 54
95 90 79
96 88 73
75 64 53
96
89
63
78
37
58
52
40
88

51
65
25
33
38
29
76
exhaust
53 40

43
55
18
18
31
22
61
50
39
50
16
14
25
17
46
gases, %
30 20
41
34
44
14
8
21
13
35
33
26
33
10
6
13
8
25
undersize
10 5
19
14
17
6
2
5
3
13
7.5
5
7
2
--
--
--
6
Source:   BA-449
                                  -16-

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                       TABLE 3-5
   TYPICAL CONCENTRATIONS OF GASEOUS EMISSIONS FROM
               STEEL MILL SINTER PLANTS
       Component
            °2
            CO
            CO,
            H2°
            SO
Condensable Hydrocarbons
Mole Percent
    72.4
    14.5
     0.7
     6.3
     6.1
  25 - 1000*
   693**
 * ppm
   mg/NnT
Source:  PE-179
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          A sulfur balance for a sinter-machine operation is
 given  in Table 3-6.  The major sources of sulfur are the iron-
 bearing materials and the coke.  The fuel oil used for igniting
 the  sinter mix and the limestone used as a flux also contain
 some sulfur.  Sulfur is carried out of the system with the
 product sinter and as S02 in the combustion gases.  It was
 estimated that aobut 36 percent of the sulfur entering with the
 sinter feed left in the combustion gases (VA-003) .  It should
 be realized that the sulfur balance presented here was made
 for  a  specific case.  Sinter feeds with different compositions,
 basicity ratio, and using a different type of fuel for igniting
 the  sinter bed can have a sulfur balance that is much different.

 3. 2       Description of the Lime/Limestone Wet Scrubbing
          Process

          The lime/limestone flue gas desulfurization process
uses a slurry of calcium oxide or calcium carbonate to absorb
 S02  in a wet scrubber.   This process is commonly referred to
 as a "throwaway" process because the calcium sulfite and sul-
 fate formed in the system are disposed of as waste solids.   The
 overall reactions in the system are as follows.

For  lime systems:
            S02/ N + CaO,gx + %H20  +  CaS03 -%H20(s)      (3-1)
For limestone systems:
         S02 ^ ,  + CaC03,.  + %H20  •*  CaS03-%H20,s) + C02 , .
                                                          (3-2)
                             -18-

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 CORIPORAV9QN
                            TABLE 3-6
          SULFUR BALANCE FOR SINTER MACHINE OPERATION
Basis:  The production of one metric ton of sinter

                               Sulfur Content   Amount of Sulfur
   Material       Amount (kg)   (wt. percent)   	(kg)	
INPUT:
Iron-bearing         1,100          0.041             0.45
Material
Coke
Oil
Limestone
50
25
100
0.70
0.55
0.049
0.35
0.14
0.05
                                                      0.99


OUTPUT:


Sinter               1,000          0.055             0.55

Sinter Fines           144.5        0.055             0.03

Sulfur in                                             0.36
Combustion Gases                                      	

                                                      0.99
 Source:   VA-003
                                -19-

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CORPORATION

 Some oxygen will also be absorbed from the flue gas or
 surrounding atmosphere and will cause oxidation of absorbed
 S02 and formation of calcium sulfate.

 For limestone systems:
                 Ca   + S03 + %02 + 2H20  +  CaS04•2H20(g)

                                                          (3-3)
 The calcium sulfite and sulfate crystals are precipitated  in a
 hold tank and then sent to a solid/liquid separator where  the
 solids are removed.  The waste solids are generally disposed
 of by ponding or landfill.

 3.2.1     Process Description

           The basic design of a lime or limestone scrubbing
 system can be divided into the following process  areas:

           (1)  S02 Absorption,
           (2)  solid separation, and
           (3)  solids disposal.

Figure 3-2 shows a generalized process  flow diagram for the
lime/limestone slurry scrubbing processes.

           S02 Absorption

          Absorption of S02 takes place  in a wet  scrubber using
lime or limestone in a circulating  slurry.  Carbide sludge
(impure slaked lime) has also been  used  successfully at two
installations.  Particulates can be removed in the S02 absorber
or ahead of the absorber by an electrostatic precipitator or
particulate scrubber.  The selection of  a method  for removal of
particulates  is based on economics  and  operational reliability.
Removing particulates in the SOa absorber increases the solids

                              -20-

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                                                  REHEATER
                                                                   FAN
                                  S02 ABSORBER     r
                         FLUE GAS
                                                      ISTR,
                                 STEAM
                        •*- MAKE-UP WATER
LIME
 OR
LIME-_
STONE"
               SLURRY
                                                   I
                                 htl
       CRUSHING
         AND
       GRINDING
SLURRY
               EFFLUENT HOLD TANK
                                                       TO STACK
                                                      	>•
            FIGURE 3-2.  PROCESS FLOW DIAGRAM LIME/
                         LIMESTONE  WET  SCRUBBING
                                        SECOND STAGE
                                        SOLID-LIQUID
                                         SEPARATOR
                                            OR
                                       SETTLING POND
                                                                                           SOLID-LIQUID
                                                                                            SEPARATOR
                                                                                    I
                                                                                 SOLID  WASTE

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CORPORATION

 load in the S02 scrubbing system.  It is also believed that some
 components of the fly ash catalyze the oxidation of sulfite to
 sulffite which increases the potential for sulfate scaling.

           The absorption of S02 from the flue gases by a lime
 or limestone slurry constitutes a multiphase system involving
 gas, liquid,  and several solids.   The overall reaction of gas-
 eous SOj with the alkaline slurry yielding calcium sulfite and
 sulfate has been shown in Equations 3-1, 3-2, and 3-3.  The
 solid sulfite is only very slightly soluble in the scrubbing
 liquor and thus will precipitate to form an inert solid for
 disposal.  In the lime system some C02 may also be absorbed
 from the flue gas and will react in a similar fashion to form
 solid calcium carbonate.

           In most cases some oxygen will also be absorbed from
 the flue gas or surrounding atmosphere.  This leads to oxidation
 of absorbed S02 and precipitation of solid calcium sulfate as
 was shown in reaction 3-3.

           The extent of oxidation can vary considerably,
 normally ranging anywhere from almost zero to 40 percent in the
 electric utility industry.   In some systems treating dilute S02
 flue gas streams, sulfite oxidation rates as high as 90 percent
 have been observed.   In sintering operations, where the oxygen
 content of the flue gas is as high as 16 volume percent, sul-
 fite oxidation rates of 100 percent have been reported.  The
 actual mechanism for sulfite oxidation is not completely under-
 stood.   The rate appears to be a strong function of oxygen con-
 centration in the flue gas  and liquor pH.   It may also be in-
 creased by trace quantities of catalysts in fly ash entering
 the system.
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CORPORATION

           Various types of gas-liquid contactors can be used as
 the S02 absorber.  These differ in S02 removal efficiency as
 well as operating reliability.   Four general types of contactors
 are usually used for S02 removal:

           (1)  venturi scrubbers,
           (2)  spray towers (horizontal and vertical),
           (3)  grid towers, and
           (4)  mobile bed absorbers [such as marble bed
                and turbulent contact absorber (TCA)].

           The liquid to gas ratio  (L/G) generally ranges between
 4.7-14.7 liters/Nm3 (35-110 gal/1000 scf) depending upon the
 type of contactor.   Simple impingement devices are placed
 downstream from the absorber to remove mist entrained in the
 flue gas.

           The effluent hold tank receives the lime or limestone
 feed slurry and absorber effluent.  In addition, settling pond
 water and clarifier overflow can be sent to the hold tank.   The
 volume of the hold tank is sized to allow residence time for
 adequate calcium sulfite and sulfate precipitation.  Reaction
 time outside the scrubber is needed to allow the supersaturation
 caused by S02 sorption in the sorber to dissipate and to permit
 dissolution of absorbent.   Too  little residence time in the
 hold tank can cause calcium sulfite or sulfate scaling  in the
 system.

           The feed material for a  lime scrubbing process is
 usually produced by calcining limestone.   Feed for a limestone
 process generally comes directly from the quarry, and is then
 reduced in size by crushing and grinding.   The lime or  limestone
 is mixed with water to make a 25-60 percent solids slurry.
                               -23-

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CORPORATION

           Solids  Separation

           A continuous  stream of slurry of 10-15  percent  solids
 is  recycled to the absorber  from the  effluent  hold tank.   In
 addition,  a bleed stream is  taken off to be dewatered.  The
 dewat.ering step,  which  is  needed to minimize the  area needed
 for sludge disposal,  varies  depending on the application  and
 type of disposal.   The  waste sludge contains some unutilized
 lime or limestone.  This depends upon system design (additive)
 stoichiometry).   Generally,  more excess additive  is required in
 limestone  systems than  in  lime systems.

           For  systems with on-site pond disposal,  solids  may
 be  pumped  directly from the  effluent  hold tank to  the pond
 area.   Clean overflow liquor from the pond would  then be  re-
 turned  to  the  system.   Depending on the physical  properties
 of  the  solids  produced  in  the system,  a thickening device such
 as  a clarifier  can be used to increase the solids  content to a
 maximum of about  40 weight percent.   Additional dewatering to
 60-70 percent  solids  can sometimes be achieved by  vacuum
 filtration.

           Solids  Disposal

           Sludge  disposal  is one of the main disadvantages
 of  lime/limestone  FGD systems in comparison to regenerable  FGD
 processes.  The quantity of  sludge produced is large  in both
 weight  and volume,  and  requires  a large waste  pond or landfill
 area for disposal.

           On-site  disposal is usually performed by sending  the
 waste* solids to a  large pond.   Settling of the solids occurs
 and pond water  is  recycled back  to the process hold tank  for
 reus<;.   "Stabilization" methods  are currently  under development
                               -24-

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(CORPORATION
 to convert the sludge to structurally-stable, leach-resistant,
 landfill material.  These methods could be used when on-site
 disposal is not possible.  The stabilized material can then be
 trucked to an off-site area for landfill.

           At least four companies are developing sludge fixation
 processes.   A fixation process is currently employed to dispose
 of the sludge generated by a limestone wet scrubbing system
 installed on a 163 Mw unit at Commonwealth Edison's Will County
 Station.   The annual cost for sludge fixation is likely to be
 higher than the lime or limestone raw material cost.   Conversion
 of the sludge to a construction material is another disposal
 method under consideration.
 3.2.2     Design Considerations

           The flow rate and sulfur content of the sinter plant
 flue gas are the major parameters to be considered in the lime
 or limestone scrubbing system design.  The quantities of lime or
 limestone consumed and waste solids produced are roughly propor-
 tional to the amount of sulfur in the gas.  The tendency for
 scale formation in the system is also related to the amount of
 S02 removed from the gas.   Since all of the S02 removed must
 precipitate from solution before leaving the system, increased
 crystal seed must be provided in proportion to the amount of
 S02 removed.  The scrubber liquid to gas ratio would have to be
 increased for removal of high S02 concentrations and to avoid  •
 exceeding the scaling limits in the scrubber effluent liquor.
                                -25-

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CORPORATBON
           Gas-Liquid Contactors

           The different types of gas-liquid contactors can be
 separated into two categories; those having an open configura-
 tion and those having a closed (packed) configuration.  These
 gas-liquid contactors differ in their gas velocity, L/G ratio,
 gas-£iide pressure drop, and resistance to plugging.  These
 characteristics will be discussed for the different scrubber
 types.

           Depending on the scrubber type, SOz removal efficiency
 may be increased by:

           (1)  increasing the number of scrubber stages,
           (2)  increasing the contacting area per stage
                (usually increases gas-side pressure drop),
           (3)  increasing scrubber liquor to gas ratio,
                and
           (4)  increasing lime or limestone utilization.


 Some of these design measures not only affect S02 removal but
 also affect the scaling tendency of the system.

           The most frequently used contactors for S02 removal
 are :
           (1)  venturi scrubbers,
           (2)  spray towers (horizontal and vertical),
           (3)  grid towers,  and
           (4)  mobile bed absorbers (marble bed,  TCA
                packed column).
                                -26-

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CORPORATION

 The performance characteristics of each of these types of
 scrubbers are listed in Table 3-7.

           Any of these scrubbers could be applied for both gas
 absorption and particulate removal, however packed columns
 show a much greater tendency for solids plugging.  Resistance
 to plugging is an important parameter in scrubber selection.
 The open configuration of the spray tower gives it a lower gas-
 side pressure drop and makes it less susceptible to plugging
 when compared to the closed configuration of the marble bed and
 TCA scrubbers.

           The volume of flue gas to be treated normally
 determines the physical size of the scrubbing device.  The
 minimum and maximum velocities selected vary widely among the
 scrubber types but generally fall in a range of 1.5-7.6 ra/sec
 (5-25 ft/sec).   The highest gas velocities occur when using a
 venturi due to the small diameter of the venturi throat.   These
 high velocities,  however,  must be decreased before the gas enters
 the process mist eliminators.

           Absorber Operation

           The amount of slurry circulated is critical.  If the
 liquid to gas ratio is too low,  the slurry will absorb too much
 S02 per volume and critical supersaturation will occur.
 Crystallization will then take place in the scrubber rather than
 in the reaction tank.   The minimum L/G generally ranges between
 4.7-14.7 liters/Nm3 (35 and 110 gal/1000 scf),  depending on
 inlet SOz concentration,  type of scrubber,  and lime or limestone
 reactivity.   The lowest L/G's are used for venturi scrubbers
 and mobile bed absorbers such as marble beds.  High L/G's are
 common in spray columns while TCA's generally use mid-range
 values.   In general, L/G ratios are higher for limestone sys-
 tems than they are for lime systems due to limestone's lower
 reactivity.

                              -27-

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                                                          TABLE  3-7
oo
i
COMPARISON OF SCRUBBER TYPES FOR A LIMESTONE WET SCRUBBING SYSTEM
Scrubber Type
Parameter
SOj Removal Efficiency
Particulate Removal Efficiency
Typical L/G (gal/1000 scf)
for SOz Removal
Gas Side Pressure Drop (in H20)
for L/G Above
Gas Velocity (ft/sec)
Dissolution of Solids
Resistance to Solids Plugging
Marble Bed
Good
Good
40-70
8-12
3-8
Good
Fair
TCA
Good
Good
50-80
6-12
6-11
Fair
Good
Venturi
Fair
Excellent
20-50
8-20
125-300
Poor
Excellent
Grid Tower
Good
Good
50-100
1-7
6-11
Fair
Fair
Spray Tower
Good
Fair
70-110
1-3
5-25
Poor
Excellent

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CORPORATION
           Both calcium sulfite and calcium sulfate form scales.
 Calcium sulfate can form supersaturated solutions in the
 scrubber system.   The rate of scaling is sensitive to the super-
 saturation of calcium sulfate.  Test results from the TVA
 Shawnee test facility have shown that scrubber internals can
 be kept relatively free of scale if the sulfate (gypsum) satu-
 ration of the scrubber liquor is kept below about 135 percent
 (at 50°C).   If supersaturation is unchecked, calcium sulfate
 dihydrate starts  to crystallize on solid surfaces,  forming a
 scale.   The supersaturation can be controlled by seeding
 the liquid with calcium sulfate dihydrate crystals ,  xvhich pro-
 vide a large surface area on which the dissolved salts preferen-
 tially deposit.

           Evidence has also been encountered that coprecipita-
 tion of calcium sulfite and sulfate may occur.   This phenomenon
 may enable operation of the process in a mode where  calcium
 sulfate concentration will not reach its normal saturation level
 and thus will not  form sulfate scale.   Operation in  this mode
 seems to depend on the. level of oxidation occurring  in the system.

           Changes  in liquor pH can also cause scaling.   The
 solubility  of calcium sulfite decreases with increasing  pH.
 If the  pH is  allowed to fall below 5,  comparatively  soluble
 calcium bisulfite  is formed.   With a subsequent increase in
 pH value,  the bisulfite is converted to calcium sulfite  which,
 being less  soluble,  crystallizes out and forms  scale.

           The pH of a  freshly prepared  limestone slurry is
 usually between eight  and nine.   On contact with the  S02  in the
 flue gas the pH rapidly falls below seven, but below  pH six the
 decrease in pH is slow until  the  slurry  is  exhausted.  The effi-
 ciency  of S02 removal  is not  appreciably affected until the pH
 drops below  about 5.2.  The  effect  appears  to be independent

                                 -29-

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CORPORATION

 of the type of limestone.   Limestone scrubbers  usually operate
 with an inlet and outlet pH range between 5.2-6.4.   The scrub-
 ber pH can be changed by varying the limestone  feed.

           Mist Elimination

           Mist eliminator operation  has been a major trouble
 spot  in lime/limestone scrubbing.  All wet scrubbers introduce
 mist  droplets  into  the gas,  some  more than others.  The mist
 must  be collected and separated  to prevent corrosion and solid
 deposits on downstream equipment  and to avoid high energy con-
 sumption in evaporating  the  mist  in  the gas reheater.   Since
 the drops  are relatively large, usually 40 microns and  larger,
 they  can be removed effectively by simple impingement devices,
 such  as zig-zag baffles  (chevrons) or cyclonic demisters.
 Practically all designers have used  chevrons with the major
 exception  being Detroit  Edison, where a cyclonic vane-type
 eliminator was installed.

           Chevrons  have  had  trouble  with both inefficient
 mist  removal and  with plugging by soft deposits and scale.
 Almost  complete mist  elimination  by  chevrons has been achieved
 by mounting them  in a slanted or  vertical position instead of
 the usual  horizontal  position  so that the liquor  can drain off.
 This  prevents re-entrainment of  the  liquor in the gas.  Plug-
 ging  and scaling  of mist eliminators can be prevented by washing
 with  fresh water.   Intermittent washing with a high pressure
 soot-blower type  spray has  been  more successful than a  lower
 pressure continuous wash.   Wash  trays and wet electrostatic
 precipitators have  also  been used as part of the mist elimina-
 tion  system.  A wash  tray is placed  under a horizontal chevron
 to remove  solids  in the  entrained mist and to collect wash liquor
 flowing off the chevron.  Wet electrostatic precipitators remove
 both mist  and residual dust  in the flue gas.
                               -30-

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CORPORATION

           Sludge Dewatering

           The sludge dewatering step is used to concentrate the
 solids for ease of handling and disposal and to lower transpor-
 tation costs.  The clear liquor is usually recycled back to the
 process for reuse.  Sludge dewatering methods consist of clari-
 fication, bed drying, centrifugation,  vacuum filtration, and
 thermal drying.  In addition to these methods, interim ponding
 is sometimes used as a dewatering procedure.  The settling
 characteristics of the sludge determine the effectiveness of
 this technique.

           Clarifiers are presently used in S02 removal systems
 as a primary dewatering device when the solids content of the
 sludge is low.   Limestone scrubber sludges containing unreacted
 additive are reported to thicken well compared to lime sludges
 because of the coarse limestone present.  Limestone processes
 sometimes produce a turbid supernatant liquor.

           Because of the physical nature of sulfate crystals
 as opposed to sulfite,  dewatering is improved by a higher
 sulfate/sulfite ratio.   Therefore, good results (85-90 percent
 solids) have been reported for a sample obtained from the
 Chiyoda process,  which produces in a sludge with an extremely
 high sulfate to sulfite ratio.

           One engineering company currently markets  an S02/
 fly ash control process using a sludge dehydration operation
 after an alkali scrubbing system.   Clarifier underflow at 30
 percent solids  concentration is raised to  90-95 percent solids
 by passing the  slurry through a dehydrator co-current with the
 hot flue gases  (300°F).
                              -31-

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RADIAN
CORPORATOON
 3.2.3     Typical Operations Relating to  Sinter Plants

           Lime/limestone wet scrubbing should require no  new
 technical modifications for application to  steel mill sinter
 plants.   Sulfur  oxide levels in the  sinter  plant effluent gas
 (25-1000 ppm)  are in the same concentration range as  effluent
 gas from oil and coal-fired boilers   where  the majority of the
 FGD systems have been installed.   The oxygen content  of the
 gas (12-16 mole  percent)  is about  two to  three times  higher
 than that usually encountered from utility  boilers.   The  higher
 oxygen concentration in the effluent gas  should result  in a
 high rate of calcium sulfite oxidation.   This has proved  to be
 the case from Japanese experience   (see Appendix B) where 30-
 100 mole percent of the calcium sulfite was oxidized  to calcium
 sulfate  in the different FGD units.

           The significant amounts  of carbon monoxide  (about
 0.5-1.0  mole percent)  should have  no effect on the FGD  system
 because  of its relative stability.   The water content of  sinter
 plant gas generally ranges  between 5-10 mole percent.   The gas
 will evaporate large amounts of water from  the initial  liquid
 contacting device as is the case where FGD  scrubbing  is applied
 to utility boilers.

           The particulate concentrations  found in the gas are
 no higher than those commonly found  on coal-fired boilers.   High
 particulate removal efficiencies (over 95 percent) should be
 easily achieved  by a particulate prescrubber such as  a  venturi.
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           The  unburned  hydrocarbons  carried  by  the  effluent
 gases  are not  normally  encountered on  oil  or coal-fired  utility
 boilers.   A particulate scrubber will  remove some of  the hydro-
 carbons  but the  hydrocarbon  removal  efficiency  by wet scrubbing
 has  not  been conclusively  determined.  Most  of  the  hydrocarbons
 are  aliphatic  and  will  act as  an inert in  a  wet scrubbing system.
 The  addition of  windbox gas  recycle  systems  to  sinter plants  is
 expected to help control hydrocarbon emissions.  It has  been  es-
 timated  that the recycle system at Wierton will reduce the con-
 centration of  unburned  hydrocarbons  in the effluent gases by  50
 percent  (CU-055).

 3.3        Evaluation  of USSR and Japanese  Data

           Data concerning  FGD  systems  being  used to treat waste
 gases  from steel mill sinter plants  in Russia and Japan  xcere
 received and evaluated.  The Soviet  data for one limestone
 FGD  system and the Japanese  data for four  FGD systems were
 summarized and examined for  consistency with previous U.S. lime/
 limestone scrubbing experience.  Technical notes describing
 these  evaluations  in  detail, along with the  actual  Russian and
 Japanese data, are contained in Appendices A and B.
 3.3.1      Summary of Russian Data

           The Soviet data consisted of a description of the
 process  and  a discussion of operating parameters  for the  lime-
 stone  scrubbing  system  applied  to  the Magnitogorsk  sinter plant
 The  system removes  85 percent of the S02 and  50 weight percent
 of the particulates.  A computer simulation was performed by
 using  the  given  operating parameters and making several neces-
 sary assumptions to fill voids  where information  was lacking.
 Several  results  were found from the given  data and  the .computer
 simulation.
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           (1)  Oxidation was only 25 percent with a flue
                gas oxygen concentration of 15.9 percent.

           (2)  The SO 2 concentration in the flue gas was
                1600 ppm.   This is higher than the average
                concentration of 200 ppm believed to be found
                in U.S.  sinter plant operations (ST-368,  WO-092)

           (3)  The reported inlet and outlet particulate
                concentrations were 200 g/Nm3 and 100 g/Nm3
                                                           j
                respectively.  This is much higher than con-
                centrations normally found on coal-fired
                boilers (4.6-16 g/m3) or reported values
                for U.S. sinter plants (^ 1 g/Nm3).  It was
                concluded that the particulate concentrations
                were probably incorrect due to misplaced
                decimal points.  The actual values were
                probably 2 g/Nm3 and 1 g/Nm3 for the inlet
                and outlet flue gas particulate concentra-
                tions, respectively.

           (4)  The large particulate concentrations used in
                the process simulation model caused calcium
                sulfate to be subsaturated in the scrubbing
                system.  The Soviets reported that 10 weight
                percent of the calcium value of the sludge
                was calcium sulfate.

           (5)  It was not considered worthwhile to make
                further calculations on the assumed error
                listed in (3) above.
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 3.3.2     Summary of  Japanese  Data

           The Japanese  data consist  of  process•descriptions  and
 discussions  of operating  variables for  four  FGD processes
 applied to treating waste gases  from steel mill sinter  plants
 in Japan.   The processes  are:

           (1)   Kawasaki Steel, Mitsubishi Heavy Industries
                (MHI)  Process;

           (2)   Sumitomo Metal, Moretana Process;

           (3)   Kobe Steel Calcium Chloride  (Cal)  Process;

           (4)   Nippon Steel Slag (SSD)  Process.

 Two of  the processes, the MHI  and Moretana Processes, use a
 conventional  lime or  limestone absorbent.  The  Cal  Process
 uses a  lime  absorbent in  a 30  percent calcium chloride  solution.
 The SSD Process uses  a  40 weight percent CaO converter  slag  as
 an absorbent.   A  summary  table showing  all of the FGD processes
 that operate  on Japanese  steel mill  sinter plants is included
 in the  Japanese data  found in Appendix  B.

           Several important findings were obtained  from the
 Japanese data.

           (1)   The oxidation of  calcium sulfite to  sulfate
                in the scrubber was reported  to  be between
                50-100 percent  for the conventional  lime/
                limestone  absorbent processes.
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           (2)   The S02  concentration in the  flue  gas
                fluctuated between 800-1200 ppm every  20
                minutes.   High and stable S02  removal  was
                still  obtained under  these conditions.

           (3)   An inlet  HC1 concentration of 20-50 ppm in
                the flue  gas was  reported.  High chlorine
                concentrations in wet scrubbing systems can
                cause  corrosion.

           (4)   The oily  matter in the incoming flue gas
                necessitated the  use  of oil resistant  rubber
                linings  to prevent swelling.

           (5)   S02 removal efficiencies of over 90 percent
                were reported for inlet S02 flue gas con-
                centrations of 200-1200 ppm.

           (6)   Absorbent utilizations of 95  percent for
                lime and  80-85 percent for limestone were
                obtained.

           Results from the evaluation of Russian  and  Japanese
 data  were  used  to establish criteria for designing a  limestone
 scrubbing  system to treat waste  gas  from U.S.  sinter  plants.
 Section  4.0  describes, in detail,  the approach used to design
 the limestone scrubbing  system.
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 4.0       DESIGN APPROACH

           Computer simulations were used to prepare conceptual
 process designs of limestone scrubbing systems for sinter plant
 applications.  The Radian process model, a group of computer
 programs for simulating aqueous inorganic chemical processes,
 was used for these simulations.  The process model performs
 calculations based on (1) chemical reaction rate and equilibrium
 calculations, and (2) process and equipment data which define
 the process flow scheme and characterize each of the individual
 process units.   A thorough description of the Radian process
 model is provided in Appendix C.

           Several information sources were utilized during this
 program to develop design data for input to the limestone pro-
 cess model.  The open literature  was screened to assemble avail-
 able information.  Mr.  Richard Jablin was retained as a consul-
 tant and proved to be a valuable  source of information.   Data on
 a Russian sinter plant limestone  process was obtained as a
 result of an EPA sponsored US/USSR technology interchange agree-
 ment.  These data were evaluated  to determine how best to
 incorporate the Soviet operating  experience into a process
 design for U.S. sinter plants.  A report describing Japanese
 technology for  controlling sinter plant S02 emissions, prepared
 for Radian by Dr. Jumpei Ando,  also provided valuable information,

           Data  from the above sources were evaluated to
 determine realistic design parameters for use as input to the
 computer model.  A design basis for both a sinter plant and
 a limestone scrubbing system was  determined.  Section 4.1 des-
 cribes in detail the design bases chosen for these systems.
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           Results  of  the  conceptual  designs were  then used  to
 size process  equipment.   An  economic basis was  selected  and
 applied to the process  designs  to  perform an  evaluation  of  both
 capital investment and  annual operating  costs.  A detailed  de-
 scription of  the economic basis of this  design  is presented in
 Section 4.2.

 4.1       Design Basis  and Assumptions

           A conceptual  design basis  for  a limestone  scrubbing
 system to remove S09  from steel mill sinter plant waste  gases
 was developed from several sources.  These included:

           (1)  an  evaluation of U.S. steel mill sinter
                plant  operations and  typical emissions,

           (2)  a comprehensive  technical data base
                developed  by  Radian in the area  of
                lime/limestone wet  scrubbing technology,
                and

           (3)  an  evaluation of operating lime/limestone
                wet scrubbing systems in  the USSR  and
                Japan.

 Data describing both sinter  plant emissions  and limestone
 scrubbing operations were evaluated  to  establish  a realistic
 basiis for the conceptual design.  Sections  4.1.1  and 4.1.2
 discuss the sinter plant and limestone  scrubbing  design param-
 eter;; used as input to the computer  model.
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4.1.1     Sinter Plant Design Basis

          The sinter plant design basis was developed from an
EPA report describing the engineering and design of a sinter
machine windbox gas recirculation system (PE-179).   The No. 2
sinter machine of the Wierton Steel Division in Wierton, West
Virginia, was the subject of that report.  Two conceptual designs
were developed from the Wierton report, one for standard sinter
plant operation and one for a sinter plant with windbox gas re-
circulation.  The recirculation of windbox effluent gas has the
advantage of substantially reducing the volume of gas emitted
from the sinter plant, thus reducing the amount of gas to be
cleaned.  In addition, recirculating a portion of the windbox
effluent gas to the sinter strand allows unburned hydrocarbons
in the gas to be combusted in the second pass through the sinter
bed.  The concentration of particulates in the effluent gas
remains essentially unchanged but the amount of particulates
leaving the system is reduced due to the reduced gas volume.
These advantages make sinter machine windbox gas recirculation
an attractive method for meeting future emission regulations.
Therefore, a design of a scrubbing system for a plant with wind-
box gas recycle was performed in order to further identify the
advantage of a gas recirculation system over a standard sinter
plant operation.

            The design basis chosen for the two plants is given
in Table 4-1.   Both sinter machines produce 6312 mtpd (6958 tpd)
of sinter product.   Sinter production in the U.S. ranges from
1350 to 9100 mtpd (1,500 to 10,000 tpd) for individual sinter
strands (JA-136).   The parameters for Case 1 (standard operation)
are all taken from operating performance data for the Wierton
No. 2 sinter machine except for the sulfur dioxide  concentration
in the gas.   The actual S02 concentration in the gas from the
sinter machine was  less than 100 ppm.   Since this concentration
                              -39-

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                                 TABLE 4-1
      Parameter
Dry Gas   "
Total Gas
Gas Moisture Content
Gas Composition  (Dry)
S02 Concentration  (Dry)
Particulates (Dry)
Ccndensible  .   .
Hydrocarbons (.Dry;
Gas Temperature
SINTER PLANT DESIGN BASIS*
Case 1
(Standard Operation)
633,600 Nm3/hr
674,784 Nm3/hr
6.1 vol. 7o
Vol. %
N2 77.1
02 15.4
CO 0.8
COz 6.7
750 ppm
923 mg/Nm3
738 mg/Nm3
139'C (282'F)
Case 2
(39% Windbox Gas Recycle)
386,640 Nm3/hr
422,640 Nm3/hr
8.5 vol. %
Vol. %
73.3
13.3
1.4
11.9
1200 ppm
923 mg/Nm3
369 mg/Nm3
219'C (426*F)
  Based on 6312 mtpd sinter product.
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 was already low, it was decided to assume an increased SC>2 con-
 centration in the  gas  for  design  purposes.

            Data from a U.S.  sinter plant x^ith  an  S02  concentra-
 tion  of  approximately  900  ppm  (YO-042) were  checked to insure
 that  the concentrations of other  species in  the gas such  as N2,
 02, and  C02 would  not be significantly changed by assuming a
 higher SO2  concentration.  No  substantial change  in concentra-
 tion  of  the other  species  was  found.  Data from  Soviet,  Japanese,
 and other U.S.  steel mill  sinter  plants corroborated  this con-
 clusion.

           An S02  concentration of 750 ppm was chosen as  the
 design basis  for standard  plant operations.  Data from  Soviet
 and Japanese  sources indicated that  an S02 concentration  of 750
 ppm represented an average value  from processing  high sulfur
 sinter mixes.  Some sinter  plants  have  concentrations  that are
 at least that level (YO-042).

           The  design parameters  for the second case  (39 percent
 gas recycle on  a dry basis) were  taken from  the design of a gas
 recirculation system for the same Wierton No.  2 sinter strand.
 The concentration  of the unburned hydrocarbons was obtained from
 conversations with Wierton personnel (CU-055), and is a rough
 estimation.

           The  S02  concentration  for the second case was calcu-
 lated to be 1200 ppm (39 percent higher than for  the  standard
 sinter plant  case).  It was assumed that' the amount of S02 evolv-
 ed from the sinter strand would remain the same and that the S02
 in the recycled gas would pass back through the sinter strand
without further reaction.   Therefore, the total amount of S02
 evolved for both cases  would be equal,  although the S02  concen-
 tration of the gas  evolved from the plant with windbox gas re-
 circulation would be higher than for the standard operation case.

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           An average of the three particulate compositions
 presented in Table 3-3 was assumed for both cases.   It was felt
 that an average composition would be representative of the
 wide variations in sinter plant particulate emissions.  Emis-
 sion:; variations are caused by differences in sinter plant
 feed compositions.  The particulate composition assumed for
 this study is given in Table 4-2.

            The effect of varying particulate compositions on the
 operation and cost of a limestone scrubbing system should be in-
 significant.   The overall system change resulting from the CaO
 and MgO content of the particulate material will be small since
 limestone is  added to the pre-scrubber liquor loop to insure the
 desired S02 removal.   The equipment in the pre-scrubbing section
 of the system is all plastic-lined to prevent corrosion.  There-
 fore, differences in chloride content of the particulates will
 not affect the corrosion rate.

            Oxidation of calcium sulfite to calcium sulfate is be-
 lieved to be  increased by certain catalysts in the particulates
 entering the  system.   Iron oxides are believed to be oxidation
 catalysts.  The change of iron oxide content in the different
 particulate compositons could, therefore,  change the amount of
 oxidation in  the pre-scrubber and SOa absorber.   A system design-
 ed for low oxidation could experience scaling problems if high
 oxidation was actually encountered.   Also,  limestone sludge with
 a hig;h sulfate concentration dewaters more easily than a sludge
 with a low sulfate concentration.   This would affect the size
 of the clarifer.
                              -42-

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                            TABLE 4-2



           COMPOSITION OF PARTICULATES IN SINTER PLANT



                             FLUE GAS
          	Component                Weight Percent






          Fe203                             24.5



          CaO                               11.0



          MgO                                2. 6



          K20                                4.6



          Si02                               3.9



          A1203                              3.1



          Na20                               0.6



          ZnO                                0.2



          Chlorides                           6.8



          Sulfates                           8.7



          Hydrocarbons                       14.8



          Other         '                     0.7



          Loss on ignition                  18.4



                                           100.00
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            The condensible hydrocarbon concentration used is
 in the normal range for steel mill sinter plants.   The hydro-
 carbon concentration can vary to a large extent depending on the
 amount of hydrocarbons in the sinter feed.   No reported data was
 found on the percentage of the hydrocarbons which are condensible
 versus non-condensible.  The hydrocarbons in the sinter feed come
 primarily from oily turnings or from coke added as a fuel.
 4.1.2     Limestone Scrubbing Design Basis

           A limestone scrubbing system was selected instead of
 a lime scrubbing system for two reasons.

           (1)  Limestone systems are generally less
                expensive than lime systems, primarily
                because limestone is much cheaper than
                lime.  Furthermore, lime prices are ex-
                pected to escalate because of the cost
                of calcining limestone.

           (2)  Most steel plants typically use limestone
                in process operations and, as such, have
                a readily available supply.

           It was necessary to select both limestone and make-up
 water compositions in order to simulate the limestone scrubbing
 system.  The limestone composition presented in Table 4-3 was
 chosen based on previous pilot plant studies done by Radian.
 The make-up water composition listed in Table 4-4 was decided
 upon after conversations with Mr.  R. Jablin (JA-137).
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                            TABLE 4-3
                      LIMESTONE COMPOSITION
              Component                 Weight Percent
          CaC03                              97
          MgC03                               1
          Inert                               2
                            TABLE 4-4
                    MAKEUP WATER COMPOSITION

          	Parameter                 	mg/1

          Total Solids                      261
          Total Dissolved Solids            238
          Total Suspended Solids             23

          Alkalinity as CaCO.,                76
             SO^                    .         80
             Cl"                             29

             N03                              2
             HN3                              0.7
          pH                                  7.2
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           Process Equipment

           The following major equipment was included in the
 design to insure efficient FGD system operations.  The criteria
 used for selecting each of these items is discussed below.

           (1)  Prescrubber

                A venturi prescrubber was selected for sinter
                plant applications for three -reasons.

                (a)  Flue Gas Cooling and Saturation -  To
                    avoid evaporation of water from the
                    scrubber liquor and subsequent scale
                    formation at the inlet to the S02
                    absorber, the flue gas should be pre-
                    saturated.
                (b)  Chloride.Removal - The high chloride
                    concentrations in the flue gas would
                    cause corrosion problems in the S02
                    absorption system if not removed.

                (c)  Particulate Removal - An additional
                    benefit of using a venturi prescrub-
                    ber is removal of most of the parti-
                    culates entering the 862 scrubbing
                    system.

           (2)  Forced Draft Fan

                A fan is needed to overcome the pressure drop
 of the scrubbing system.  The existing waste gas fan is designed
 to handle sinter plant flue gas at high temperatures (up to
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                175°C) and with a significant particulate
                loading (^ 1 g/Nm3).   No problems should be
                incurred in installing an additional forced
                draft fan to operate under these conditions.
                Induced draft fans, which are installed
                after the FGD system reheater have suffered
                from corrosion due to scrubber mist carry-
                over in the stack gas.  Therefore, forced
                draft fans were selected for this design.

           (3)  Spray.Tower S02 Absorber

                A countercurrent vertical spray tower was
                chosen as the gas/liquid contacting device
                for S02 removal.  This type of contactor
                was chosen over other types of contactors
                mentioned in Section 3.2.  Spray towers have
                an open configuration'which reduces the
                possibility of scaling and solids plugging
                in the scrubber.

           (4)  Ball Mill

                A wet ball mill was placed in the FGD system
                to grind large calcium sulfite and sulfate
                crystals contained in a bleed stream of waste
                sludge from the clarifier bottoms.  The ground
                crystals are recycled to the S02 absorber
                hold tank to insure that an adequate number
                of seed crystals are present to provide sites
                for calcium sulfite and sulfate precipita-
                tion.  The formation of large sulfite and
                sulfate crystals in the system can cause a
                shortage of sites for precipitation.   This can
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                result in the relative saturation of calcium
                sulfite and sulfate in the liquor to rise
                above critical supersaturation values.   The
                addition of seed crystal sites reduces  the
                chances of scaling.  Controlled seed crystal
                recirculation is a Radian proprietary concept,
           (5)  Demister
                A vertical chevron demister located in a
                horizontal duct will be placed downstream
                of the S02 absorber.  This type of demister
                has been shown to be effective in removing
                entrained mist without experiencing plugging
                problems.   A high pressure mixture of fresh
                water and clarifier overflow will be used
                to intermittently wash the demister.
           (6)   Reheater
                The reheater will be designed to  heat  the
                stack gas to 79.4°C (175°F)  for stack  gas
                buoyancy.  A low pressure steam heat ex-
                changer will be used to heat ambient air
                which will be blended with the stack gas
                stream to provide the necessary heat.   This
                type of design will prevent  fouling and
                corrosion problems experienced by reheaters
                placed in the stack gas duct.   Low pressure
                steam needed for the reheater is  available
                from steel mill operations.
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           Design Parameters

           Design parameters used for the conceptual design
 of the limestone scrubbing system are given in Table 4-5.
 The limestone scrubbing basis is the same for both sinter
 plant applications to permit accurate comparisons.

           Most  sinter  plants  in  the  U.S.  today use  a high
 basicity  sinter mix by adding limestone  or  dolomite to  the
 sinter feed.  The  addition  of the  alkali causes some of the
 sulfur in the sinter bed  to be fixed in  the sinter  as calcium
 sulfite and sulfate.   It  also produces a basic fly  ash  that
 contains  10-20  weight  percent CaO  plus MgO.   These basic species
 will  probably be soluble  to some extent  after removal from the
 gas stream in the  prescrubber.

           At  one Soviet sinter plant facility,  venturi  scrubbers
 were  used to  capture fly  ash  which contained 10-13 percent CaO.
 They  found that the CaO dissolved  in the water to neutralize
 the acids present.  The aqueous  medium leaving the  scrubbers
 was either weakly  alkaline  or neutral  (SU-094).  The venturi
 scrubbers removed  up to 98.5  percent of  the particulate and
 over  60 percent of the S02.  (SU-093) .

           The  venturi prescrubber system was designed to remove
 30 percent of the  S02  in  the  flue  gas.   This  was done because
 the presence of basic  fly ash components  would already cause some
 SO2 removal which  would have  to  be considered in the overall
 system design.   Also,  removing part  of the  S02 in the venturi
 prescrubber would  require less to be removed  in the absorption
 section and would  lower the absorption section equipment costs.
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                                   TABLE 4-5
                     LIMESTONE SCRUBBING DESIGN PARAMETERS
    Design Area
            Parameter
Venturi Pre-Scrubber
!30~ Countercurrent
Spray Scrubber
Total System
SO- Removal
Particulate Removal

SO- Removal
Particulate Removal
Calcium Sulfite Oxidation
Overall SO- Removal
Overall Particulate Removal
Overall Calcium Sulfite Oxidation
  Solids in Scrubbing Slurry
  Solids in Clarifier Underflow
  Solids in Disposal Pond
Design Specification
  fWeight-
        30
        98

        90.4
        70
        70*
        93.3
        99.4
        70*
        12
        40
        60
*Mole Percent
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           Previous operating experience  with  venturi  scrubbers.
 reported in the literature,  indicated that  a  particulate
 removal efficiency of 98 percent can be  easily obtained.
 Removal efficiencies of over 99 percent  are not uncommon with
 venturi scrubbers.  Therefore,  the venturi  prescrubber was
 designed to remove 98 percent of the incoming fly  ash.  Radian
 pilot plant experience indicated that an S02  spray scrubber  can
 remove about 70 percent of  the  remaining particulates  in the gas
 stream which had passed through an initial  particulate collection
 device.   The removal of 98  percent of the particulates in  the
 prescrubber and 70 percent  in the absorber  results in  an overall
 removal of  99.4 percent.  The Radian conceptual designs have
 particulate concentations of 844-867 mg/Nm3 at the inlet and 4.59-
 4.91  mg/Nm3  at  the outlet of the FGD System.   This degree  of
 particulate removal  seems reasonable when compared to  Japanese
 experience.   The Moretana Process  used at the  Kashima  Plant  achieved
 greater than 90 percent removal with the use  of two Moretana per-
 forated plate scrubbers.  The first  scrubber  is used to cool the
 gas and remove  particulates  while  the second  scrubber  is used as
 an S02  absorber.   The Radian design  achieves  a greater amount of
 particulate removal  because  the venturi  prescrubber is  capable of
 a much higher particulate removal  efficiency  than  the  perforated
 plate scrubber  used  at the  Kashima Plant.
           The conceptual design of the two  limestone  scrubbing
 systems was based on removing an equivalent percentage of  SO2
 from  both systems while reducing the SOa level in  the  stack
 gases below 100 ppm.  Equal S02 removal  rates were used for
 both  systems to achieve an  equal basis for  comparing  the capital
 investment  and  operating costs.   An  overall S02 removal efficiency
 of 93.3 percent was  chosen  for  both  systems.   This reduced the
 outlet S02  level to  44 ppm  for  the standard sinter plant case and
 67 ppm for  the  recycle case.  The  emission  rate for both particu-
 lates and S02 per unit of total strand feed is given in Table 4-6.
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                           TABLE 4-6
         MASS EMISSION RATES FROM THE RADIAN BASE CASE

       STEEL MILL SINTER PLANTS AFTER LIMESTONE SCRUBBING

                   OF THE WINDBOX EXHAUST GAS
 Basis: Mass emissions per unit of total strand feed including

        recycle fines and a hearth layer.


        Strand feed rate = 336 mtph  (370.4 tph)


                       Grams Pollutant        Pounds Pollutant
     Pollutant         Kilogram StrafuT Feed   'ion strand

 Partlculates
    (a) Standard Case          0.011                0.021
    (b) Recycle Case           0.006                0.013



 S02
    (a) Standard Case          0.27                 0.54
    (b) Recycle Case           0.41                 0.82
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These S02 removal efficiencies are consistent with the S02 removal
efficiencies experienced in Japan where greater than 90 percent
SOa removal was achieved from scrubbing sinter plant gases with
similar S02 concentrations.  (See Japanese data in Appendix B)

           Calcium sulfite and sulfate relative saturation
 levels in the scrubbing system are important parameters that
 affect the limestone system performance.   It has been shown
 by testing at TVA's Shawnee pilot plant that sulfate relative
 saturation levels should be kept below a maximum of 1.35 to
 prevent scaling (EN-310).   The maximum allowable relative
 saturation level for sulfite in lime/limestone systems is not
 as well defined.  Relative saturation levels as high as six
 have been reported in systems which operated without scaling
 problems.  It was decided to design the Radian scrubbing system
 to operate well below the maximum alloxvable saturation levels .
 Maximum sulfate and sulfite relative saturation levels of 1.16
 and 2.25 in the scrubber bottoms were chosen to insure scale-
 free operation.

           Data obtained from the open literature describing
 hydrocarbon removal from sinter plant operations is conflicting.
 Condensible hydrocarbon removal  efficiencies  are reported to
 vary from nil  to almost 70 percent  (ST-368,  BA-444).   The high
 removal efficiencies  were  obtained  when using a high energy
 scrubber.   From  the available  data,  one cannot ascertain the
 degree  of hydrocarbon removal  to  be expected from the venturi
 prescrubber included  as part  of  the limestone system design.
 The hydrocarbons included  in  the  particulate  composition were
 treated as  particulates and were  the only hydrocarbons  assumed
 to be removed  by the  scrubbing system.  All  hydrocarbons not
 collected in the scrubbers will  exit the  system with the stack
 gas from the absorber.
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          Limestone scrubbing systems noroially operate using
a limestone scrubbing  slurry of 10-15 weight percent  solids.  A
value of 12 weight percent solids was chosen for this design.
The bleed stream from  the SCL scrubbing  system, which removes
fly ash and calcium sulfite and sulfate, is normally  thickened
and sent to disposal.  A clarifier was chosen as the  thickening
device for this system.  The solids content of the clarifier
underflow can range anywhere from 20 to 40 weight percent.  An
underflow concentration of 40 weight percent solids was chosen
for this design because the solid waste  is made up primarily
of cai'-cium sulfate dihydrate crystals which settle more easily
than i:he calcium sulfite hemihydrate crystals.  Most scrubber
sludges contain more of the sulfite crystals than sulfate and
do not: settle as well.

          The amount of oxidation of calcium sulfite  to sulfate
has been reported to be anywhere from 25-100 percent from
Japanese and Soviet experience (see Appendix I and II).   A
value of 70 percent was chosen for the conceptual designs.

          The clarifier underflow  is transferred to a waste
disposal site where the sludge settles to  its final concentra-
tion.  The high rate  of sulfite oxidation  in this  system  pro-
duces a sludge whose  solids are composed predominantly of
calcium sulfate crystals  (about 65 percent of the  solids).
This relatively high  concentration of  sulfate crystals allows
the sludge to compact  to a final solids  concentration of  about.
50 weight percent.  Clear  supernatant liquor from the disposal
pcnd will be rccirculated to the system.
                               -54-

-------
CORPORATION
  4 . 2       Economic Basis

            An economic evaluation of a limestone slurry flue gas
  desulfurization process requires that both total capital invest-
  ment and annual operating costs be calculated.   The basis for
  the economic calculations performed for this study was the
  January, 1975,  report by McGlamery, et al. (MC-147) on detailed
  cost estimates  for advanced effluent desulfurization processes.
  A direct comparison of the limestone scrubbing  system design
  basis presented in Section 4.1 with the basis used by McGlamery
  allowed both equipment and operating cost estimates to be made.
  Cost estimates  for equipment not included in McGlamery's report
  were based on work done by PEDCo (PE-146).  The installed equip-
  ment cost vss based on retrofitting the limestone slurry process
  equipment to an existing sinter plant.


  4.2.1    Capital Investment Costs

            From  the  design basis presented in Section 4.1,  cal-
  culations were  made to estimate the equipment sizes required to
  prpcess flue gas  from the two  steel mill  sinter plant operating
  cases considered.   Once the equipment sizes  for both cases were
  determined,  size-cost scale factors presented by McGlamery,  et
  al.  (MC-147) were  used to obtain estimates of the delivered
  equipment costs.

            The criteria used to calculate  the total capital
  investment  required to install a limestone slurry flue gas
  desulfurizationjsystern on  an existing steel mill  sinter  plant
  Included the following.
                                -55-

-------
RJ1K9IIAN
CORPORATOON
           (1)   A cost index factor of 1.20375 (CH-278)
                was assumed in order to scale up the 1974
                equipment costs presented by McGlamery
                (MC-147)  to mid-1977 costs.   This factor
                was calculated from the Chemical Engineer-
                ing plant cost index based upon a September
                1975 factor of 1.0514 (obtained by divid-
                ing the September 1975 index by the Sep-
                tember 1974 index).   An annual inflation
                rate of 7 percent was chosen for the years
                of 1976 and 1977.

           (2)   Installation costs for retrofitting the
                limestone slurry process equipment to
                existing sinter plants were based on cost
                estimate  factors given by Wood (WO-078).

           (3)   The cost  of spray tower SOz  absorbers was
                based on  data reported by the Western Precipi-
                tation Division of Joy Manufacturing
                Company (JO-194).

           (4)   The cost  of the S02 absorber effluent
                clarifier was based on data presented
                by PEDCo  (PE-146).

           The  items used in calculating the total capital  in-
 vestment for the limestone slurry process include both  direct
 and indirect capital costs and are listed in Table 4-7.
                               -56-

-------
CORPORATION
                           TABLE  4-7

            ITEMS USED TO ESTIMATE THE TOTAL CAPITAL
       INVESTMENT REQUIRED FOR A LIMESTONE SLURRY PROCESS

 Direct Costs:

           Equipment  (Purchased)
           Piping
           Structural  Steel
           Concrete Foundations
           Insulation  and Painting
           Electrical
           Instruments
           Buildings and  Service
           Excavation, Site Preparation
           Auxiliaries
           Sludge Ponds  (installed)


 Fixed  Costs  (includes labor):

           Engineering Design  and Supervision
           Construction Field  Expense
           Contractor  Fees
           Contingency
                              -57-

-------
RADIAN
CORPORATION
4.2.2     Annual Operating; Costs

          Table 4-8 lists both the direct and fixed operating
costs which must be considered for an economic evaluation of a
limestone slurry process.  The estimates made for annual operat-
ing costs assumed a 1978 start-up of the limestone system.
Operating cO'St data taken from several sources served as a
basis for estimating 1978 costs (OT-043, MC-147, PE-146).
          The estimates presented here for both operating and
capital costs are much the  same as those which might be calcu-
lated  for comparable  size power plant flue gas desulfurization
units.  No spare equipment  for increased reliability has been
included.

          The results of the capital investment and annual
operating cost estimates for both sinter plant operating cases
are presented in Section 5.3.
                             -58-

-------
CORPORATION
                           TABLE  4-8

               BREAKDOWN OF ANNUAL OPERATING COSTS
                 FOR A LIMESTONE SLURRY PROCESS

 Direct Costs;

 Raw Materials
       Limestone

 Conversion Costs
       Operating Labor and Supervision
       Utilities
       Maintenance
       Analyses

 Fixed  Costs:

 Annual Capital Charges
   (Includes  depreciation,  taxes,  and insurance)

 Overhead
       Plant
       Adminis trat ive
                               -59-

-------
RADIAN
CORPORATION
5.0       RESULTS

          The results presented in this section reflect study
efforts in two major areas:

          (1)  Preparation of conceptual process
               designs for the two sinter plant
               limestone scrubbing systems, and

          (2)  preparation of cost estimates,
               including both capital and operating
               costs, for the two limestone scrubbing
               system process designs.

          Detailed discussions of the results of this study are
report.ed in  the following sections.  Section 5.1 presents a de-
scription of the conceptual process designs for the two limestone
scrubbing systems along with a detailed process flow diagram,
material balances, and design specifications of the process com-
ponents.  Section 5.2 presents a plot plan of a potential arrange-
ment for a limestone scrubbing system located in a sinter plant,
and Section  5.3 contains the results of the economic evaluations
of the two limestone scrubbing systems.

5.1       Process Designs

          Design parameters presented in Section 4.1 were used
as the; basis for preparing conceptual process designs for limestone
scrubbing systems to remove SOo from sinter sinter plant flue gas.
Process designs were developed for both standard sinter plant and
windbox gas  recirculation operations.
                               -60-

-------
CORPORATION


          A process flow diagram was prepared to depict the flow
of process streams through the various equipment.  Only one flow
diagram was prepared since the limestone scrubbing system will
employ the same types of equipment for both design cases.  Figure
5-1 is the flow diagram illustrating the process stream flows in
the limestone scrubbing system.

           Two scrubber modules in parallel were used to treat
the flue gas from the sinter plant while the limestone feed pre-
paration, slurry processing,  and calcium solids disposal sections
of the process use only one set of equipment.   Hoxvever,  for ease
of depiction the process flow diagram shows only one set of equip-
ment for the entire process.

          Material balances were prepared  for each design case
to determine  the process raw material requirements.   In addition,
material balance calculations were used to estimate  the sizes of
the various process equipment.  Tables 5-1 and 5-2 present the
results of the material balance calculations for the  two design
cases.  The tablcc present the total .nrocess flow rates for both
scrubbing modules.

          The design specifications  for the various process equip-
ment were determined from  the results of the material balance cal-
culations.  The function and operation of major equipment items
are described, and their design specifications given  in Table 5-3.

          Potential problem areas  in the FGD system  were investi-
gated.   It was found that  steel mill sinter plants normally operate
24 hours a day except  for  one eight-hour shift per week.  The FGD
system,  during this period, would  continue to circulate the scrub-
bing  slurry to prevent  settling of solids  and plugging of the lines
Another  potential problem  area is  the small amounts  of contaminants
contained in  the flue  gas.  Species  such as chlorides, fluorides,
                               -61-

-------
                                                                                           SPRAY
                                                                                           TOWER
                                                                                           SO, ABSORBERS
                                                                                            SO 2
                                                                                        ABSORBER
                                                                                        EFFLUENT
                                                                                       HOLD TANKS
HOPPERS. FEEDERS 6. CONVEYORS

                           ELEVATOR
                                                       MARK-UP	
-------
                               TABLE 5*1. MATERIAL BALANCE FOR A LIMESTONE SCRUBBING PROCESS ON A STANDARD SINTER  PLANT
T.TRKAH IIUTV.1KH *

HEMtHIi'TlUN
[o4<»l Stream flow ^*»'*
(g/5PC)
(« . f neJe /sec)
frr«p^*a|urr C°C)
eio
GAS l^i^SE
Gas PtiaST Flov^ Rale
(q-rviofe/S*e)
Cwm'/sec)
1 <<1/M9 ^ -,
Cc»n(>Oii(iao ( r»>olc Vt.,/
N2
0^
^•(-V,
*-*-'Z
M2O
SO2 (pP'^)
LIQUID Pimse •
Lulu 'd PliajP Flow BiW
(q/5C«.)
(o-f^Jc/5«)
frort.poilib" fmoJcjUy 'lO4i
SO3 =
MSO 3 ""
SO-l f
MCOj
H2C05 (o)
Co.*'
CO.HCO i *
Oi3O3(i)
Co SO^ < f )
AAq •'
AAq5O4 f«l
No*
Ci"
pH
CoSOi ftlal'V jtJura^'O^
O>5O^ O'lrji'vff S"''u*tl'(Or*
JiSX1!*^ 5tJ'di^uJ pp'*')
5c.l;d>Co.l~ foic
(^Q/ieel
(q.««>lr/W<)
C^,/M-»)
Corv\CV3lliOn C1"' ^o)
Cc.O
CoCO,
Co!)Oj '/I WyO
C«5O<- 7. UzO
Co 30-1
MqO
N<>2O
Nc.CI
Insrli
5per.iflt Gr^vi^y
O

t'r..'gr.ri.hber

?a^h~l i
eno
139
2BZ

a j' -a
167.44
2-13509

72 4
14 5
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2.239
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70.3
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sza
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3.15
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filll tOTKI

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2U7OOO
297OO













2304200
'27to20
0.435
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l\ZO
2157



11.83
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4.21
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4.51
29.4
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2.250
1.134
314fa
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313550
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21.02
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-------
TABLE 5-2. MATERIAL BALANCE FOR A LIMESTONE SCRUBBING PROCESS ON A SINTER PLANT WITH WINDBOX  RECYCLE
S1HKAM KUHilER -
DESCRIPTION
t
feWS^FI^SW.
{a-mcJv/Sff)
fernp. (°c)

Goi Pha^f Flow Pole
(<)/S«<)
Co-f>W*/Sct^

Nl
Ol
COl
HzO
SO jiff")
LIQUID PHftSE
Liq^iJ rv,o«. Flow fole
~.o»v»posil icnTmolaf ily • Id"'
S03-
HSO3"

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Mp CO aft)
Co **
Cc, MCOj •
CaSOJfo)
CaSOrfd)
AAq«
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lil -t
ci°-
pW
^iSOj SVlaliv* Sn^mlion
CaSO« fifelolive ^^urolion
->!3iolvcJ Solicfj (i^( ppm)
Sol.*!) 
(Xifl to
IS5Z3J
5242.
2i9
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IS5IS4
5241
117.4
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12.2
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-------
                                                                       TABLE 5.3
Ln
 I
                 Item
           1 .  Blower
                             No.

                              2
           2. Prescrubbcr     2
           3. Prescrubber     2
              Hold Tank
           4. Absorber
           5. Absorber Hold   2
           6. Dcmlstcr
           7. Reheater
           8. Clarlfier
DESCRIPTION AND DESIGN SPECIFICATIONS TOR MAJOR PROCESS EQUIPMENT


Description
The blower is a forced draft fan that is
installed prior to the FGD system. It Is
provided to overcome the FGD system pressure
drop.
The prescrubber is a venturi scrubber used
to:
i. Cool and saturate the gas.
2. Remove pnrticulates . hydrocarbons,
chlorides, S02 and other undersirable
emissions .
The prescrubber hold tank provides a loca-
tion for -limestone slurry addition to neu-
tral ixe and react with absorbed compounds.
Residence time is provided for calcium sul-
fite and sulfate precipitation.
The absorber is a countercurrent spray tower
that is designed to remove a high percentage
of the S02 and some of the remaining particu-
lates.
The absorber hold tank is an agitated Hank
that provides a location for limestone
addition to reach a constant slurry den-
sity. Residence time for sul f ite and
sulfate precipitation is provided.
The demister is a vertical chevron demister
installed in a horizontal duct after the
spray tower. The demister removes entrained
mist and solids in the stack gas.
The reheater is a low pressure steam heat
exchange that is placed outside of the
stack duct. Air is forced through the
Equipment

Parameter
Power rating
Gas flow rate
Pressure drop

Gas flow rate
Gas velocity




Volume




Gas flow rate
Gas velocity


Vo 1 ume
Liquid residence time



Gas flow rate



Power rating
Steam requirement
Surface area
Design Parameters
Standard
System
1530kw.,
1.41 .4m /s
609mniH20

141 .m3/s
38.1m/sec.




174.1. m"1




118.6m3/s
3. 05m/ sec.


531m3
7.2 minutes



118.5m3/s



4000 kw
1.83 !--S/sec
146.3m'

Recycle
System
Il45kw..
1.05.8m /s
609mmH20

I0r>.8m3/s
38. Im/sec.


"

199.4m3




78.4ni3/s
3. 05m/ sec.


708m3
12.8 minutes



78.3m3/s



2000 kw
0.92 kg/sec
73.4 my
exchange where it is heated and then
mixed in with the stack,, gas.  The stack
gas is reheated to 79.4 for bouyancy

The clarifier is a sol id-liquid separator
that concentrates the solid waste to 40
weight percent solids.  The clarifier over-
flow is low In suspended solids and is re-
cycled back to the process.
Feed slurry flow rate
                                                                                                               311  Liters/min.
                                              303  l.iters/min.
-------
                                                                          TABLE 5-3
                                               DESCRIPTION AND  DES1CN SPECIFICATIONS FOR MAJOK  PROCESS

                                                                          (Continued)
                                                                                                     Equipment Design Parameters
 I
CTv
                     Item
               9.  Ball  Mill
                                 No.
              10.  Prescrubber
                  Settling  Pond
              11.  Absorber
                  Settling  Pond
              12.  Limestone
                  Preparation
                  System
                Description
The ball mill is a continous wet ball mill
that grinds a small slip-stream of the solid
waste from the clarifier underflow.  The
outlet stream is sent back to the hold tank.
The ball mill grinds the solid particles to
provide additional surface area for calcium
sulfite and sulfate precipitation in the
hold tank.  The ball mill will generally
operate intermittently to control the quantity
and size of sulfite and sulfate crystals.

The prescrubber settling pond is a disposal
site for the participates, calcium sulfite
and sulfate sludge, and other component
captured In the prescrubber.  The waste
sludge settles to a concentration of fO weight
percent solids.  The pond is clay-lined and
designed for a 40 foot depth.

The absorber settling pond is a disposal
site for the particulatcs and calcium sul-
fite and sulfate sludge from the absorber.
The waste sludge settles to a concentrated
of 60 weight percent solids.  The pond is
clay-lined and designed for a 40 foot
depth.

The limestone preparation system crushes
and grinds the limestone from 0x4 cm
into 70 percent - 200 mesh.  The limestone
is slurried to a 60 weight percent solid
slurry before being sent to the process.
Parameter

Feed slurry flow rate
Volume
Solid waste feed rate
Acres (@ 40 fooC depth)
Volume
Solid waste feed rate
Acres (@ 40 foot depth)
                                                                                        Limestone  feed  rate
Standard
 System

18.9 I.iters/mtn.
403,050m
32 Liters/rain.
    8.2
566,600m-1
45 Liters/min.
   11.5
                          4l.4kg/mln.
Recycle
System

18.9 Liters/ruin.
348,200m
27.6 l.iters/min.
     7. I
554,700mJ
44 l.iters/roin.
   11.2
                    40.3kg/min.
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 and arsenic have been reported to be present in sinter plant flue
 gas (VA-126,  BA-449).   These species can cause corrosion problems
 if allowed to build-up in the scrubbing system.   These species  will,
 however,  be contained in the prescrubber loop where  they will build
 up to  some steady-state level.   All corrosion problems can then be
 handled in the prescrubber loop and not affect absorber operations.

          The  FGD system designed for sinter plant applications
includes an initial particulate collection system which is
separate from.the S02 absorption system.  The systems  are
separated to prevent potential oxidation catalysts,  chlorides,
and other corrosion causing agents from entering the S02 absorp-
tion system.

          Some important operating parameters for the  two systems
are given in Table 5^4.  The major differences in the parameters
for the standard and recycle cases are the liquid to gas ratio
(L/G) and the  liquid residence time in the hold tank.  The recycle
case has an L/G ratio that is 15.5 percent higher than for the
standard case  and the gas volume treated is about 35 percent less
on a wet basis, thus the absorbed pumping requirements for the
recycle case are about 25 percent less.   Although the hold tank
residence time is 78 percent higher for the recycle case, the
actual required hold tank volume is only 33 percent larger because
of the smaller liquid flow rate.  Another difference in the two
systems is an  increased steam reheat requirement of 100 percent
for the standard case due to both the increased volume of gas to
be heated and  the lower initial stack gas temperature.

          The  overall differences in stream flow rates and raw
material requirements for the standard and recycle cases are small.
This is due mainly to the fact that the same amount of S02 is being
removed by both FGD systems.   Major differences are evident, however,
in the sizes of the gas handling equipment.  These differences are
reflected in the capital investment costs of the systems which are
reported in Section 5.3.

                               -67-
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                                TABLE 5-4

                OPERATING PARAMETERS FOR PROCESS DESIGNS
           Parameter
Design Gas Velocity (m/sec.)

 Venturi Prescrubber
 Spray Tow<»r S02 Absorber

L/G (Liters/Nm3)

 Venturi Prescrubber
 Spray Tower $©2 Absorber

Design Pressure Drop (mm^O)

 Venturi Prescrubber
 Spray Tower $©2 Absorber
 Ducting and Demisters
 TOTAL

Liquid Residence Time (minutes)

 Prescrubber Effluent Hold Tank
 S02 Scrubber Effluent Hold Tank

Solid Residence Time (days)
 Prescrubber Effluent Hold Tank
 S02 Scrubber Effluent Hold Tank
Standard Operation
   38.1
    3.05
    4.7
   11.6(87.0)*
    7.6
    7.2
    1.1
    9.3
39% Recycle
38.1
 3.05
 4.7
13.4(100.1)*
                      254
                       76
                      279
                      609
12.0
12.8
 1.4
12.6
*gallons/MSCF
                                    -68-
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CORPORATION


 5.2       Limestone Scrubbing System Layout

           The conceptual process  designs  contained in Section
 5.1 were used to prepare layouts  of the limestone  scrubbing
 systems.   The layout,  which is divided into two  processing areas,
 was prepared to show the utilization of space for  the process.
 The first area is the scrubbing section between  the sinter plant.
 and the stack which includes the  scrubbers  and hold tanks.   This
 area is the most important  in relation to space  requirements in
 a retrofit situation because the  area between the  existing sin-
 ter plant and the stack is  usually  limited.   Figures 5-2  and
 5-3 show the layouts for the scrubbing sections  of a limestone
 scrubbing system applied to standard and  recycle steel mill
 sinter  plant operations.

           The second area is the  limestone  feed  preparation and
 slurry  processing section of the  system.  The layout for  this
 section,  shown in Figure 5-4,  is  the same for both sinter plant
 applications.   This is  because equal amounts  of  SOa  are removed
 in  both cases  and,  therefore,  about the same  amount  of limestone
 is  required and about  the same amount of  sludge  is produced.

           The  equipment sizes  were  estimated  from  the process
 design  data.   A report  by TVA was used as an  aid in  positioning
 some of the equipment  on the layout.

           The  total space requirements for  the two process  de-
 signs are shown in  Table 5-5.   The  recycle  operation requires
 more land area for  the  scrubbing  section  because of  the larger
 absorber  hold  tanks.   The hold tanks are  placed  beneath the
 scrubbers in both designs.   A length of 4.6m  (15 feet) was  chosen
 as  a reasonable spacing between equipment in  the scrubbing  section
                              -69-
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 PRESCRUBBER HOLD TANK
'DIA.=5.5M
                                                              SO2 ABSORBER HOLD TANK
                                                              DIA.= 8.0 M
                         /  VENTURI
                         (PRESCRUBBER

                         ». DIA. = 7.7M
                                                       37.3M-
FIGURE 5-2.   LAYOUT  OF SCRUBBING SECTION OF A LIMESTONE SCRUBBING PROCESS

                FOR A  STANDARD STEEL  MILL  SINTER  PLANT OPERATION
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                              PRESCHUBBER HOLD TANK
                              DIA.= 6.0M
               SO2 ABSORBER HOLD TANK
               DIA. = O.OM
                   /  VENTURI
                 / /PRESCRUBBER
SO2 ABSORBER
                                                                                     STACK

                                                                                     DIA.r BM
                   f  VENTURI
                   IPRESCRUBBER
                   v DIA. = 6.6M
SO2 ABSORBER

  DIA. =. 5.7M
                                                37.2M
FIGURE  5-3.  LAYOUT  OF  SCRUBBING SECTION OF  A LIMESTONE  SCRUBBING
      PROCESS FOR A  RECYCLE  STEEL MILL SINTER  PLANT OPERATION
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                   SLURRY FEED TANK
20M
o
o
                      (L_)
                       WET BALL MILL
  DEMISTEH WASH  PARTICLE
  HOLD TANK     RECIBCULATION
             SURGE TANK
      0 - D
      WET BALL MILL
                                    CRUSHER
                                    FEED BIN
                                                  CONVEYOR
                                             ELEVATOR NO. 1
                                        WEIQH DELT
                                   (  OYnATOnY CRUSHER
                                   ])ELEVATOR NO. 2
-1 r— -,
I ' i 1
_J L___J
PER HOPPER
/


CONVCYOn
R
1


Zl

ECEIVIN
^OPPER
                                                   LIMESTONE PILE
                                                     OIA. • 16M
     FIGURE 5-4.  LAYOUT OF FEED PREPARATION AND SLURRY PROCESSING SECTION OF A

        LIMESTONE SCRUBBING PROCESS FOR A STEEL MILL SINTER PLANT APPLICATION
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CORPORATION
                           TABLE 5-5.


       SPACE REQUIREMENTS FOR A LIMESTONE SCRUBBING SYSTEM

            ON STEEL MILL SINTER PLANT APPLICATIONS
       Processing Area
 Scrubbing
     length (r.)
     width (m)
     area (m2)
 Standard
Operation


    37.3
    20.6
   768
  Recycle
Oneration
     37.2
     22.6
    841
 Feed Preparation and
 Slurry Processing
     length (m)
     width (m)
     area (m2)
    66
    20
  1320
     66
     20
   1320
 Total Area
 (excluding waste disposal)(m2)    2088
                        (acres)       *0.52
                 2161
                    0.53
 Prescrubber Sludge Settling (m2) 33059
 Pond            "        (acres)     8.2
                28560
                    7.1
 Absorber Sludge Settling (m2)    46473
 Pond                  (acres)       11.5
                45497
                   11.2
 Total Area
 (including waste disposal)(m2)   81620
                        (acres)      20.2
                76218
                   18.8
                               -73-
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RADIAN
CORPORATION
           For the prescrubbers,  the  hold tanks  are  smaller  in
 diameter than the scrubbers  so  that  the  equipment spacing is
 measured from the outside  diameter of  the prescrubber.   For the
 absorbers,  the hold tanks  are larger in  diameter than  the scrub-
 bers  so that  the  equipment spacing is  measured  from the  outside
 diameter of the hold tanks.  Since the absorber hold tanks  for
 the recycle operation are  larger than  for the standard operation,
 the scrubbing area becomes larger.

           As  can  be seen,  most  of the  space  required is
 for disposal  of the fly  ash  and  calcium  solids.  The
 FGD process itself requires  only about 2270m2 (24,400  ft2).
 About,  42 percent  of this area or 950m2 (10,200  ft2)  is needed
 for the scrubbing section  between the  sinter plant  and the  stack.

           The most  significant difference in land requirements
 between the standard and recycle sinter  plant operations occurs
 in  the waste  disposal  area.  The recycle operation  requires
 5475 m2  (59000 ft2)  less for particulate and calcium solids
 waste-,  disposal.   This  difference is  mainly due  to the smaller
 prescrubber settling pond  because of the lower  particulate  load-
 ing for the recycle  case.
 5.3       Economic  Evaluation

           The results of the economic  evaluation performed  for
 this  study indicate that a reduction in  both capital investment
 and annual operating costs of a  limestone scrubbing system  can
 be  realized by employing windbox gas recirculation.  For the
 cases  considered  here, a 21.3 percent  and 23.2  percent reduction
 is  indicated  in capital  investment and annual operating  costs
 respectively.   The cost  of modifying the sinter plant  for wind-
 box recirculation was not  considered in  this evaluation.
                              -74-
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CQRPQRAiraON
          The reduced gas volume and quantity of particulates
to be removed were the major reasons for the lower required
capital investment cost for the recirculation case.  The 35 per-
cent reduction in gas volume did not reduce the plant cost pro-
portionately.  This is typical for small-scale units where the
initial fixed costs of the manufactured equipment represent a
larger portion of the total investment than do the costs for
larger equipment.

          Annual operating costs for the gas recirculation case
were lower because of both the reduced gas volume to be processed
and the lower capital investment required.  The reduced gas volume
required less electricity for handling and less steam usage for
reheating.  The reduction in these two direct costs also resulted
in a lower cost being assigned to plant overhead.  The reduced
capital investment resulted in both lower maintenance and annual
capital charges.


          The estimated total annual operating cost of the lime-
stone scrubbing  systems is $2.07 per metric ton of product sinter
for the standard operation case and $1.59 per metric ton of pro-
duct sinter for  the windbox recirculation case.  This results in
a price increase of about 2 percent or $5.00 per ton of product
steel when 80 percent of the blast furnace charge is sinter
(JA-145).

          The detailed results of both the capital investment
and annual operating cost estimates are presented in the follow-
ing section.
                              -75-
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RAPIAN
CORPORATION

5.3.1     Total Capital Investment

          A comparison of the total capital investment costs re-
quired for limestone slurry scrubbing of the two sinter plant
design cases considered is presented in Table 5-6.   The major
cost savings for Case B, the windbox recirculation system, are
in the particulate scrubbing, SOn scrubbing, gas reheating, and
gas handling areas.  Capital cost reductions of 19.9, 34.5, 27.4,
and 28.2 percent respectively occured in each of these areas be-
cause of both the reduced gas volume and quantity of particulates
processed in the recirculation case.  The lower values for in-
stallation and associated construction costs for the gas recircu-
lation case reflect the lower cost for the process equipment in
these four areas.

          The reduction of the quantity of particulates to be
scrubbed, due to gas recirculation, reduced the cost of particu-
late disposal by 13.3 percent.  Both modes of operation require
that the same quantity of S02 be removed from the gas stream.   Thus,
the cost of calcium solids removal is nearly identical in both cases

          As stated in  Section 5.3,  this  evaluation  indicates
that the total capital  investment required  for flue  gas desul-
furization can be  reduced by  21.3 percent if windbox gas  recir-
culation is employed  in the  sinter plant.   The capital costs
associated with  installing a  windbox gas  recirculation system
were not evaluated for  this  study.  However, these costs  are
discussed in the Wierton Report  (PE-179).  Additional work is
being done under this program and definitive costs will be deve-
loped.

          A detailed  breakdown of  the  equipment  costs  for each
of  the  limestone slurry  scrubbing areas  is  given in  Tables D-l
and D-2 of Appendix D.
                              -76-
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                                                        TABLE 5-6

                                 TOTAL CAPITAL INVESTMENT SUMMARY FOR STEEL MILL SINTER

                                 PLANT FLUE CAS DESULFURIZATION USING LIMESTONE SLURRY

                                                        SCRUBBING
                                                       Case A - Standard
                                                          Operation
                                                                  Case B - 397. Gas
                                                                   Rcclrculafl.on
Direct Costs:

   Process Equipment

      Materials Handling
      Feed Preparation
      Participate Scrubbing
      S02 Scrubbing
      Gas Reheating
      Gas Handling
      Solids Disposal
      Services
      Particle Rcclrculntion
         Subtotal.

   Equipment Installation
   Piping
   Structural  Steel
   Foundations
   Insulation  and painting
   Electrical
   Instruments
   BI, Building and Service*
   Excavation  and Fill Site
    Preparation
   Aux Lliaries
   Sludge Ponds (installed)
      Participate Disposal
      Calcium  Solids Disposal
         Subtotal Direct Costs

Indirect Costs:
   Engineering Design and
    Supervision
   Construction Field Expense
   Contractor Fees
   Contingency

      Subtotal Indirect Costs

      TOTAL CAPITAL INVESTMENT
5   32,850
    9/1,040
   673,170
 1,026,800
   210,470
   143,300
   178,200
   128,570
    31.950
                       $2,519,350

                          978,000
                          750,000
                          125,000
                        1,511,000
                           50,000
                          176,000
                          100,000
                          126,000

                          250,000
                           25,000

                          120,000
                          170.000
                        6,900,350
                          899,000
                          955,000
                          506,000
                        1.011.. OOP
                        3,371,000

                       10.271.350
 36,210
 97,230
539,190
672,600
152,900
102,860
191,800
128,570
 31.950
                    $1,953,310
                       762,000
                       586,000
                       100,000
                     1,172,000
                        40,000
                       137,000
                        78,000
                        98,000

                       195,000
                        20,000

                       104,000
                       166.000
                    $5,411,310
                       712,000
                       756,000
                       400,000
                       800.000
                    $2,668,000

                    $8.079.310
*Battery Limit
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RADIAN
CORPORATION
 5.3.2     Annual Operating Costs

           The estimated annual operating costs for both design
 case;; are summarized in Tables 5-7 and 5-8.   Both the operating
 costs and capital charges are included in these tables.  As can
 be seen from the values in these tables, the total operating
 cost for the limestone slurry scrubbing process can be expected
 to b<> reduced approximately 23.2 percent by windbox gas re-
 circulation.  This is due to the reduced utility requirements
 for gas handling and gas reheating and to the lower capital
 charges required when gas recirculation is used.

          This cost reduction would be affected  if capital  charges
and operating costs of  the windbox gas recirculation system were
included  in  the analysis.  However, these  costs  were not avail-
able  for  inclusion in this study.
                              -78-
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VO
 I
                                                                       TABLE  5-7
                                                               LIMESTONE SLURRY 1'ROCESS
                                                             TOTAL. ANNUAL OPERATING COSTS
                                                (Existing steel mill sinter plant - standard operation)
                                                    Annual Quantity
     Direct Costs
Delivered raw material
 Limestone
   Subtotal
Conversion costs
 Operating labor and supervision
 Utilities
  Steam
  Process water
  Electricity
 Maintenance
  Labor and material, .09 x 6,900,350
 Analyses
  Subtotal conversion costs
  Subtotal direct costs
     Indirect Costs
Average capital charges at 1.4.9%
 of total capital investment
Overhead
 Plant, 207. of conversion costs
 Administrative, 10% of operating labor
  Subtotal indirect costs
  Total annual operating cost
                                                        17. A M nitons
                                                      18,000 man-hr

                                                       89,500 M kg
                                                      290.000 M liters
                                                       23,270.000 UWh
                                                              Unit Cost. $
                                                                              6. 60/tnton
10,00/man-hr

 3.31/M kg
 0.029/M liter
 0.028/kWh
                                                                              2. 07/niton  product
                                                                                   sinter
                     Total Annual
                       Cost. $
  11/..600
  1 U , 600

  180,000

  296,000
    8,400
  651 ,600

  621,000
	29./i 00
1,786,400
1,901.000
                                                                                                    I ,530,400

                                                                                                      357,300
                                                                                                       18.000
                                                                                                    I. ,905,700
                                                                                                    3.806,700
                        Percent  of
                      Total  Annual
                     Operating  Cost
 3.0 \
 3.01

 4.73

 7.78
  .22
17.12

16.31
  .77
46.93
49.94
                                                9.39
                                               	._47
                                               50.06
                                              100.00
               Basis:
                 Remaining life of sinter plant, 30 yr.
                 Stack gas reheat to 79.4°C.
                 Sinter unit on-stream time, 7,000 hr/yr.
                 Midwest plant location, 1978 operating costs.
                 Total capital investment, $10,312,550; subtotal direct  investment, $6,898,550.
                 Sinter plant capacity of 631? nit pd
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                                                                        TAOLF, 5-8
                                                                LIMESTONE SLURRY PROCESS
                                                              TOTAL ANNUAL OPERATING COSTS
                                                  (Existing steel mill sinter plant - 39% gas recycle)
                                                     Annual Quantity
 I
00
o
     Direct Costs
Delivered raw material
 Limestone
   Subtotal
Conversion costs
 Operating labor and supervision
 Utilities
  Steam
  Process water
  Electricity
 Maintenance
  l.abor and material, .09 x 5,All,310
 Analyses
   Subtotal conversion costs
   Subtotal direct costs
                                                         17.0 M mtons
                                                       18,000 man-hr

                                                         44,900 M kg
                                                       267,200 M liters
                                                       16,800,000 kWh
                                                              Unit Cost.  $
                                                                               6.60/mton
10.00/man-hr

 3.31/M kg
 0.029 liters
 0.028/kWh
                     Total Annual
                       Cost. $
  112.200
  112,200

  180,000

  148,500
    7,800
  470,400

  487,000
   29.400
1.323.100
1,435.300
                       Percent of
                      Total Annual
                     Operating Cost
 3.84
 3.84

 6.16

 5.08
  .27
16.10

16.67
 1.01
45.23
49.12
                     Indirect Costs
                Average capital charges at 14.9%
                 of total capital Investment
                Overhead
                 Plant, 20% of conversion costs
                 Administrative, 10% of operating labor
                   Subtotal indirect costs
                   Total annual operating cost
                                                             1.59/tnton product
                                                                 sinter
                      1,204,000

                        264.600
                         18.000
                      1.486.600
                      2.921.900
                         41.21.

                          9.06
                           .62
                         50.88
                        100.00
                Basis:
                  Remaining life 06 sinter plant, 30 yr.
                  Stack gas reheat to 79.4°C.
                  Sinter unit on-stream time,  7,000 hr/yr.
                  Midwest plant location, 1978 operating costs.
                  Total capital investment,  $10,312,550;  subtotal  direct investment  $6,898,550.
                  Sinter plant capacity of 6312 mtpd.
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CORPORATION
 6.0       CONCLUSIONS AND RECOMMENDATIONS

           Conceptual process designs and cost estimates  were
 performed for limestone scrubbing systems to control sinter
 plant emissions.   The following conclusions  and recommendations
 are presented to  summarize the results of this effort.

 6.1       Conclusions

           1)  Lime/limestone scrubbing technology has
              been demonstrated in Japan and  the USSR
              to be an acceptable method for  removing
              SOa  from sinter plant effluent  gases.
              Based upon foreign experience and the
              conceptual process design performed for
              this study,  there is no apparent reason
              that lime/limestone scrubbing technology
              cannot be applied to controlling emissions
              from sinter plants in the United States.
              This study is,  therefore, an initial as-
              sessment of the economic impact of lime/
              limestone scrubbing on domestic iron and
              steel plants.

           2)  The  cost of sinter plant flue gas desul-
              furization was determined to be $2.07  per
              metric ton of product sinter for the stan-
              dard operation case and $1.59 per metric
              ton  of product sinter for the windbox  gas
              recirculation case.   This may increase the
              price of the steel product by about $5/ton.
              The  effect of this price increase on the
              profitability of steel production needs
              to be evaluated for each specific installation.
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RADiAN
CORPORATION
           3) Cost estimates indicate that windbox gas
              recirculation can reduce both capital in-
              vestment and annual operating cost re-
              quirements for sinter plant limestone
              scrubbing units by approximately 20 per-
              cent.  Estimates made during this study
              include only the costs associated with
              the limestone units and do not account
              for the additional cost of installing
              the windbox gas recirculation system.

           4) Nearly all existing sinter plants have
              some type of particulate control follow-
              ing the cyclones which are the primary
              particulate collection device.  The Radian
              conceptual design includes a venturi pre-
              scrubber to saturate and cool the hot sinter
              plant gas and to remove chlorides and parti-
              culates.   This design would be applicable
              to an existing plant when the presently
              used particulate collection device follow-
              ing the cyclones was removed.  To retrofit
              the SOz scrubbing system on a plant with
              an existing particulate scrubber, the pre-
              scrubber section would be excluded from the
              system design.  It is estimated that exclud-
              ing the pre-scrubber section of the design
              would decrease the overall cost by about
              20 percent.
 6.2       Recommendations
           1) The results presented in Section 5.0 indicate
              that limestone slurry scrubbing is a technically
                              -82-
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CORPORATION
              feasible method of flue gas desulfurization
              for steel mill sinter plants.   The results
              also indicate that a complete limestone
              system for a sinter plant as described in
              Section 3.0 would cost about 8-10 million
              dollars.   A recommendation of this study
              is that S02 removal in particulate scrubbers
              be investigated as an alternate S02 control
              technique for sinter plants.   The purpose
              of such a demonstration would be to provide
              an acceptable technique for meeting S02
              emission regulations while reducing the
              economic impact of flue gas desulfurization
              on sinter plant operation.

              Two S02 scrubbing mediums that are recom-
              mended for consideration in this evaluation
              are:  (1)  limestone slurry and (2) a sinter
              fly ash slurry mixture.

              Sinter fly ash usually contains between 10-15
              percent CaO and MgO,  two basic species capable
              of removing S02 in a wet scrubber.   The basic
              species come from the limestone or dolomite
              that  is mixed in with the sinter charge in
              order to produce a basic sinter.  The largest
              consituents of the fly ash are usually iron
              oxides.  Sinter fly ash entering the scrubber
              would be supplemented with fly ash removed in
              the initial particulate collection device as
              needed.

           2)  Theoretical,  laboratory,  and  pilot plant investi-
              gations should be conducted to determine the
                               -83-
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CORPORATION
              specific influences  of  sinter  plant  exit
              gas  components  on  process  operations,  and
              to obtain data  for process optimization.
              Of particular concern are  the  effects  on
              sulfite  oxidation  and the  potential  cor-
              rosion effects  in  the prescrubber  liquor
              loop.
                              -84-
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CORPORATION
 7.0        REFERENCES

 BA-444     Bayr, Robert B. and Richard J. Wachowiak,  "Elimination
            of Hydrocarbon Emissions from the Sinter Plant", TMS-
            AIME Ironmaking Proc. 31, 55-58  (1972).

 BA-449     Ball, D. F0, A. F. Bradley, and A. Grieve,  "Environ-
            mental Control in Iron Ore Sintering", Presented at
            the Minerals and the Environment Symposium, London,
            June 1974.

 BA-450     Ban, Thomas Eugene, "Sintering Process", U.S_. Patent
            3,849, 115  (November 1974).
       \
 BA-451     Ban, Thomas E., "Process for Conditioning  Sinter Draft
            for Electrostatic Precipitation of Particulate Material
            Therefrom", U.S. Patent 3,909, 189 (September 1975).

 BA-452     Ban, Thomas E., "An Improved Sintering Process to Over-
            come Environmental Problems in the Sinter  Plant", Pre-
            print No. 75-B-6, Presented at the AIME Annual Meeting,
            New York, February 1975.

 CH-278     "CE Plant Cost Index", Chem. Eng_r. 2_6 September 1975.

 CU-055     Current, G. P., "Private Communication", National
            Steel Corporation, Weirton Steel Div., Weirton, West
           Virginia, April 1976.

 EN-310     Environmental Protection Agency, Technology Transfer,
            Lime/limestone Wet-Scrubbing Test Results  at the EPA
           Alkali Scrubbing Test Facility, 2nd Progress Report.
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CORPORATION
 JA-136    Jablin, Richard, Private Communication, Richard
           Jab1in and Associates, Blue Bell, Pa., 15 April 1976.

 JA-137    Jablin, Richard, Private Communication, Richard Jablin
           and Associates, Blue Bell, Pa., 5 May 1976.

 JA-145    Jablin, Richard, Private Communication, Richard Jablin
           and Associates  Consulting Engineers,  25 August 1976.

 JO-194    Joy Manufacturing Company, Western Precipitation
           Div., Basic Handbook  of Air Pollution Control Equip-
           ment, Los Angeles,  1975.

 MA-544    Manning, G. E.  and  F. E. Rower,  "A Characterization
           of Air Pollutants from Sintering Plant Induced Draft
           Stacks", TMS-AIME Ironmaking Proc. 30, 452-460 (1971).

 MC-147    McGlamery, G.  G., et  al., Detailed Cost Estimates
           for Advanced Effluent Desulfurization Processes, Final
           Report, EPA-600/2-75-006, Muscle Shoals, Alabama,
           TVA, January 1975.

 MC-205    McGlamery, G.  G., et  al., "Flue Gas Desulfurization
           Economics", Presented at the 6th Flue Gas  Desulfuriza-
           tion Symposium, New Orleans, La., March 1976.

 OT-R-043  Ottmers, D. M., et  al., Evaluation of Advanced Re-
           generable Flue  Gas  Desulfurization Processes. Draft
           Report, Radian  Project No. 200-116, EPRI Contract
           No. RP 535-1, Austin, Tx., Radian Corporation, March
           1975.

 PE-146    PEDCo-Environmental Specialists, Inc., Flue Gas
           Desulfurization Process Cost Estimate, Preliminary
           Draft, Contract No. 68-01-3150, Task  2, Cincinnati,
           Ohio,  May 1975.

                               -86-
-------
CQRPQRAT8ON
 PE-179    Pengidore, D. A., Sinter Plant Windbox Gas Recircula-
           tion System Demonstration, Phase !_, Engineering and
           Design, EPA 600/2-75-014, Weirton, W. Va., Nat'1
           Steel Corp., August 1975.
 PE-193    Petrov, Yu A., et al., "Cleanup of Flue  Gases  at a
           Sintering Plant", Metallurgist 15  (7), 420  (1970).

 RO-219    Rowen, Harold E., "Protecting the Environment  During
           Agglomeration",  Presented at the Institute for Briquetting
           and Agglomeration, Hyannis, Massachusetts, August 1975.

 RO-256    Rowen, Harold E., "Agglomeration - an Environmental
           Tool", in Proc.  In s t. for Briquetting and Agglomera-
           tion, 13th Biennial Confernece, Colorado  Springs,
           Colorado, August 1973, pp. 13 ff.

 SC-328    Schmitt, R. J.,  "Corrosion Problems in a  Sinter Plant
           Exhaust Gas System", Corrosion II, 425t  - 29t  (1961).

 ST-368    Steiner, B. A.-,  "Pilot Plant Testing of  High-Energy
           Scrubbers for Sinter Plant Gas Cleaning", TMS-AIME
           Ironmaking Conf. Proc. 31., 59-69 (1972).

 ST-398    Steiner, Bruce,  Private Communication, Armco-Environ-
           mental, 27 April 1976.
 SU-092    Suitlas, John R., "Emission Characteristics and Pilot
           Plant Studies on a Sintering Plant Windbox Discharge",
           TMS-AIME Ironmaking Proc. 30., 461-68  (1971).

 SU-093    Suprunenko, R. S., et al., "Industrial Use of  Venturi
           Pipes for Wet Cleaning of Sinter Gas", Metallurgist
           12  (7), 358  (1967)..
                              -87-
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RADIAN
CORPORATION
 SU-094    Suprenko, R. S., et al., "Removal of Sulfur Dioxide
           from Sinter Gas", Metallurgist 1.4 (9), 542 (1969).

 SU-095    Suprenko, R. S., et al., "Wet Cleaning of Sintering
           Gas", Metallurgist 9 (10), 539-41 (1964).
 VA-003    Varga, John, Jr., et al., A Systems Analysis Study
           of. the Integrated Iron and Steel Industry, PB 184 577,
           May 1969.

 VA-126    Varga, John, Jr., Control of Reclamation (Sinter)
           Plant Emissions Using Electrostatic Precipitators,
           Final Report, EPA 600/2-76-002, Contract No. 68-02-
           1323, Task 32, Columbus, Ohio, Battelle-Columbus
           Labs., January 1976.

 WO-078    Woods, Donald R. , "Technique for the Estimation of
           Capital Costs for the Process Industry", Presented
           at the Symposium on Cost Estimation, Permian Basin
           Section of the AIchE, Odessa, Texas, April 1975.

 WO-092    Woodward, Kenneth, Private Communication, EPA Emission
           Standards and Engineering Div., Durham, N.C., 26 May
           1976.
 YO-042    York Research Corporation, Test Report of_ Sinter
           Plant Emissions at Bethlehem Steel Corp. , Bethlehem
           Plant, Bethlehem, Pennsy1vania, Final Report, 3
           volumes, Y-8479-18, Stamford, Connecticut, December
           1975.
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         APPENDIX A





COMMENTS ON THE SOVIET DATA
           A-l
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 CORPORATION
1.0       INTRODUCTION

          As a result of a technology interchange agreement between
the U.S. and the USSR which encourages cooperation between the two
countries in common areas of environmental concern, information
describing the operation of a full scale Soviet limestone wet
scrubbing facility was recently disclosed to the EPA.   Since the
scrubbing facility in question has been used to control S02 and
participate emissions from a USSR iron ore sintering unit,  it
was hoped that the Soviet data might provide a meaningful basis
for the application of lime/limestone wet scrubbing technology to
sintering operations in this country.  Unfortunately,  the Soviet
data was not of sufficient quality to be of any real use in this
area.

          The comments which are presented in this report are
based upon an engineering review of process data obtained from
two sources (KH-027,  LO-149).   The specific objectives of the
work which was performed as part of this assessment were:

          1)  to identify unique mechanical features of
              the Soviet sintering plant scrubbing
              process,

          2)  to determine normal operating ranges of
              important process variables, and

          3)  to identify potentially significant pro-
              cess problem areas.

The approach which was taken in order to accomplish these objec-
tives involved both:
                               A-2
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CORPORATION
          1)  a thorough analysis of the available
              information to identify key process
              features and performance characteristics,
              and

          2)  a computer simulation of the system
              to check the reasonableness and con-
              sistency of the Russian data.

          As a result of these activities, it was concluded that
the Soviet data were lacking substantially in the areas of both
completeness and accuracy.  For this reason it does not appear
that this information will lend any support to the limestone wet
scrubbing process development efforts which are currently underway
in this country.  Justification for Radian's position in this
regard is described in the next four sections of this report.

          In Section 2, a general conceptual description of the
Soviet scrubbing system and several important pieces of process
performance data are presented.  The data quality question is
discussed in Section 3.  Radian's approach to the development of
a computer simulation of the Soviet system is described in
Section 4.  Simulation results are discussed in Section 5.
                               A-3
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CORPORATION


2.0       DESCRIPTION OF SCRUBBING FACILITY

          The Magnitogorsk limestone scrubbing system consists
of 21 scrubbers separated into 3 scrubber banks.  Normally 16-17
scrubbers are operating with the remained down for cleaning.
Figure 2-1 shows the process flow diagram for one scrubber system.
Table 2-1 gives the operating parameters for one scrubber.  Scrub-
bert inlet and outlet flue gas compositions are presented in
Table 2-2.

          The gas is first sent to a spray scrubber through a
forced draft fan.  Slurry recirculated from the hold tank scrubs
the waste gases, removing 85 percent of the S02 and 50 wt percent
of the particulates .   The following equations give the overall
S02 absorption reactions:

                  CaC03 + S02 -> CaS03 + C02                 (2-1)

                  CaS03 + %02 -»• CaSCH                       (2-2)
Spent scrubbing liquor is processed in a cyclone filter.  The
underflow from the filter is sent to a sludge tank prior to dis-
posal.  The overflow; from the filter is sent to a hold tank
where fresh limestone slurry (prepared in a limestone slurry
tank) is added.  The sludge tank and limestone slurry tank are
common to 4-5 scrubbers.

          A unique feature of this system is the location of the
cyclone filter prior to the hold tank.  Most lime /lime stone
scrubbing systems utilize a clarifier or filter after the hold
tank to process a bleed stream from the recirculating slurry.
                               A-4
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INLET FAN
             XXX
              XXX
                        SPRAY SCRUBBER
                       HYDROSTATIC
                   SEAL FROM SCRUBBER
SCRUBBER FEED
CONSTANT HEAD
     TANK
                                            CYCLONE FILTER
                             FIGURE 2-1


                        PROCESS FLOW DIAGRAM
                    OF THE RUSSIAN MAGNITOGORSK
                     LIMESTONE SCRUBBING FACILITY
                                                            ~fc>-TO  STACK
                                                                                    V  1 '
                                                                              SLUDGE TANK
                                                                                                                      WATER  LIMESTONE
                                                                                                        Q
                                                                                                                        LIMESTONE
                                                                                                                      SLURRY TANK
                                                                                                         TO DISPOSAL
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CORPORATION
                       TABLE 2-1
OPERATING CONDITIONS FOR ONE SCRUBBER SYSTEM AT THE MAGNITOGORSK
                  SCRUBBING INSTALLATION
           Parameter
Gas Flow Rate
Liquid Flow
L/G
      Value
200,000 NmVhr
1,350,000 liters/hr
6.75 liters/Nm3
Gas Velocity
SO2 Removal Efficiency
Particulate Removal Efficiency
2.5 m/sec
85%
50%
Scrubber Inlet Slurry Density
Limestone Utilization
5 wt %
40%
Limestone Composition
87% CaC03
2% MgC03
Balance - Si02
Waste Sludge Calcium
  Distribution
60% CaC03
30% CaS03
10%
Hold Tank Volume
Hold Tank Residence Time
180 m3
8 minutes
                               A-6
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                                   TABLE 2-2
    THE AVERAGE CHEMICAL COMPOSITION OF WASTE GAS BEFORE AND AFTER PURIFICATION
                         MAGNITOGORSK SCRUBBING FACILITY
System
Location
Scrubber
Inlet
Scrubber
Outlet
Volume 70 (dry basis)*
CO 2
4.0
4.1
CO
0.6
0.6
02
17.0
17.0
N2
77.71
77.71
CHq
0.5
0.5
NOV
0.012
0.010
S03
0.011
none
S02
0.16
0.016
Dust
g/Nm3
200
100
Average Gas
Temperature (°C)
125
50
* Moisture content of gases (wet basis):   inlet - 7.1 volume percent
                                         outlet - 12.2 volume percent
-------
3.0       DATA QUALITY

          The data obtained for the Russian Magnitogorsk limestone
scrubbing system would have to be characterized as incomplete.
The primary areas where the data quality was questionable or
non-existent were:  1) inlet and outlet particulate loadings, and
2) make-up water composition.  A discussion of the problems asso-
ciated with the inlet and outlet particulate loading data is in-
cluded in Section 5.0 of this technical note.  In summary, it
appeared that the dust loading figures presented were two orders
of magnitude too high.

          The water make-up composition was not given in either of
the sources which were reviewed.   The composition of this stream
is important because it determines to a great extent the concen-
tration of the noncalcium dissolved salts in the system.  Both
the recirculating slurry and filter bottoms dissolved salt con-
centrations are affected by this parameter.

          The other data that was given in the literature appeared
to be reasonable for a limestone scrubbing system although some-
what incomplete.   It would have been very helpful in verifying
the results of the process simulation program to have had a total
solids and liquid composition of one of the streams in the scrub-
bing system.  The scrubber bottoms or hold tank slurry composition
would have been preferred.
                               A-8
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4.0       SYSTEM EVALUATION

          The computer simulation of the Soviet  scrubbing process
was attempted in order to calculate important stream flow rates
and compositions.  The following assumptions for the system were
made:

          •   The CO,  N2,  CEk,  and NOX species were
             assumed to be inert and to pass through
             the scrubber system.

             Vapor liquid equilibrium of C02 and H20 occurs.

             The particulates  collected in the
             scrubber were treated as insoluble
             inerts.

             The MgC03 and Si02  constituents of
             the limestone were  treated as inerts.

             The make-up  water dissolved salts
             composition  was taken to be 1000 ppm NaC&.

             The cyclone  filter  underflow was
             taken to be  10 wt percent solids.
             The feed stream to  the filter was
             5 wt percent solids.

             The cyclone  filter  was assumed to
             operate  at 75 wt  percent overflow
             and 25 wt percent underflow for the
             total stream.
                            A-9
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CORPORATION
          The computer model which was used to estimate steady-
state operating conditions for the  Soviet  limestone  scrubbing
process was developed by Radian to simulate aqueous inorganic
chemical processes.  In addition to simulating the reactions in
the system and the operation of each piece of equipment, a mat-
erial balance around the entire system was generated by the com-
puter.  A discussion of additional assumptions that are incorporated
in the computer model will be included in an appendix to the final
report for this task.  Since other subt.asks will utilize the pro-
cess simulation model, it was decided to present the discussion
of the model in an appendix to avoid repetition in other sections
of the final report.
                               A-10
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CORPORATBON


5.0       DISCUSSION OF RESULTS

          The pertinent results of the computer simulation are
shown in Table 5-1.  Two important results of the calculations
can be seen.  First, there is a high percentage of inerts
(84-88 wt percent) in the solids in the system streams.   Secondly,
calcium sulfate was predicted to be at sub-saturated levels in
all parts of the system.

          The high percentage of inerts which were computed to be
found in the process streams is explained by the high flue-gas
particulate loading data (pickup = 100 g/Nm3).  This particulate
loading is tremendously high as compared to other combustion
operations such as coal-fired utility boilers which generate flue
gases containing from 4.6-16 g/m3 of particulate matter  (prior to
any particulate control device).  Three possible reasons exist
for the large number of particulates.

          1)  Cyclones or other particulate control
              devices were either not used prior to
              the S02 scrubber or the particulate
              control equipment was not adequately
              maintained.

          2)  The dust loading could include con-
              densible and non-condensible hydro-
              carbons.   These hydrocarbons are
              usually contained in the sinter mix
              feed due to borings,  turnings, and
              other hydrocarbon laden materials
              from other parts of the steel mill.
                              A-ll
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i
i—1
N>
                                               TABLE 5-1
       System Location

       Hold Tank

       Scrubber Bottoms

       Waste Sludge

         Stream
RESULTS OF THE
Solids


CaC03
12,
8,
8.
.3
.9
.9
SCRUBBER SYSTEM SIMULATION PROGRAM
Composition (wt %)

CaSO
3
3
3



3-%H20 Inerts
.2
.3
.3
84.
87.
87.
5
8
8

Relative
Saturation

CaSOsro
6
0
1,
.39
.98
.0


CaS04 (K)
0.
0.
0.
68
81
79
Partial
Pressures (atm)

CO 2
(xlO~2)
8
7
11
.29
.97
.01

S02

(xlO-6) pH
0
10
0
.419
.57
.01.41
6.04
4.91
6.36
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          3)  The dust loading could be an incorrect
              figure.  Experience in U.S. sinter plants
              using well maintained cyclones show
              particulate loadings in the waste gases
              on the order of 1-2 g/Nm3.  The loading
              reported by the Soviets would  then be
              off by 2 orders of magnitude if  their
              operation is consistent with U.S.
              experience.  The fault in the data
              could then be attributed to misplaced
              decimal points.

It is concluded that this third possibility is the most reasonable
explanation for the apparent inaccuracy of the Soviet  data.
Further evidence that helps to support this conclusion is the sub-
saturation levels of the calcium sulfate in the computer simulation
of the system.  The sulfate saturation is low because of the high
percentage of inerts in the system.   The reported data shows that
there is 10 wt percent CaSOi, among the calcium species in the
waste sludge.   Calcium sulfate normally has to reach the saturation
level to precipitate and be present in the waste sludge.  The com-
puter simulation for the process, therefore, did not agree with
the reported behavior of calcium sulfate in the waste sludge.
More information on the composition of the process streams is
needed before the results of this process simulation case can be
used to draw reliable conclusions.

          If the inlet and outlet particulate loadings were reduced
by two orders of magnitude to 2.0 g/Nm3 and 1.0 g/Nm3,  respectively,
then the calcium sulfate saturation level in the waste sludge
would probably be reached and solid calcium sulfate would be
precipitated.   Further computer simulation using this assumption
was not performed.   Before further evaluation of the system is
performed,  it is recommended that more information be obtained from

                              A-13
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the USSR.  The data already supplied should first be verified
as to whether it is accurate.   Secondly,  more data on the operating
parameters of the system should be obtained so that the process
can be better characterized.
                               A-14
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CORPORATION
6.0       REFERENCES
              <*
KH-027    Kharkov, "Information on the development of a method of
          purifying agglomeration gases of sulfur dioxide".  Point
          AM-1-2 of Appendix 3, First Working Meeting of the
          Soviet-American Branch Group for Ferrous Metallurgy on
          Methods of Preventing Atmospheric (Air) Pollution,
          pp. 1-5.  Translated by E.  Fitzback, SCI IRAN, Santa
          Barbara, Ca.,  1975.

LO-149    Lowell, P.S.,  Trip Notes.  Gaseous Emissions Abatement
          Project Visit to the USSR,. 12-24, Oct., 1975.  EPA
          Contract No. 68-02-1319, Task 38.  Austin, Tx., Radian
          Corporation.
                                A-15
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                                                           TR 76-261
         INFORMATION ON THE DEVELOPMENT OF A METHOD OF PURIFYING
                  AGGLOMERATION GASES OF SULFUR DIOXIDE

  [Informatsiya o razrabotke sposoba ochistke aglomeratsionnydk gazov ot
                          serniystogo angidrida]

                                 Khar'kov
Point AM-.!.-?, of Apnprirb'x 3, First Working Meeting of the Soviet-American
 Branch Group for Ferrous Metallurgy on Methods of Preventing Atmospheric
                       (Air) Pollution, pp. 1-5.
                          Translated for EPA by
                 SCITRAN (SCIENTIFIC TRANSLATION SERVICE)
                        SANTA BARBARA, CALIFORNIA
                                   A-16
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            INFORMATION ON THE DEVELOPMENT OF A METHOD OF PURIFYING
                    AGGLOMERATION GASES OF SULFUR DIOXIDE

                                   Khar'kov

A Brief Description of the Technological Process for Trapping S00 from Agglo-
meration Gases.

     In order to purify agglomeration gases of sulfur dioxide in the Soviet
Union, a lime method has been widely used in fields of irrigated scrubbers,
as the most effective and economical method.  A line diagram of the device
is shown in Figure 1.  The flue gas extractor forces the agglomeration gases
into the scrubber, where they are irrigated with a lime suspension by means
of nozzles.  The process of absorption and neutralization of S0~ aay be given
in the form of a reaction:

                           CaC03  +  S02  -v CaS03  + C02
                           2CaS03 + 02  + ZCaSOi,

The purified gas is discharged into the  atmosphere  through the  smokestack. '
The constantly renewed lime suspension circulates  in a  closed system:   part
of the spent suspension is discharged into the slurry gutter and the required
amount of fresh suspension enters the circulation  collector.

Basic Technological Indices of the Industrial Device (for one system)
                                                             3
     Amount of run-through gas                      200,000  nm  /hr
     Flowrate of gas  in scrubber                    2.5  m/sec
                                                          3
     Amount of irrigation in  scrubber               1350 in /hr
     Degree of purification of gas of SO^           85%
     Coefficient of efficiency
     Lime                                           45%  - 50%
                                  A-17
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     Ifean intake concentration of SCL in the agglo-             .,
       raeration gases                                5-10 g/nm
BasicZquipmsnt of Sulfur Purification Devices

     The supply of agglomeration gas to the scrubber is carried out by the aid
                                                                3
of a flue gas extractor with a productivity rating of 200,000 nm /hr,
    head                         —    340 mm water column,
    power of electric motor      —    630 kw,
    rpm                          —    735 rpm,
along a gas duct made of sheet steel.   The gas duct is heat insulated  with slag
and coated with tin plate.  The scrubber is hollow with a conical bottom and
top; scrubber diameter - 6300 mm, scrubber height 24,000 mm.   The scrubber
walls are made of sheet steel and on the outside are heat insulated with slag
and coated with sheet tin. They are faced on the inside with a diabase and
acid resistant plate.  The top of the  scrubber is made of ordinary steel chemi-
cally protected with epoxide resin.  Within the scrubber are mounted 3 round
collectors vi t-h 2-n'nch involute nozzles.   The collectors are made of stainless
steel pipes 219 nun in diameter.  The lime suspension is fed into the collector
by a pump:
                                             3
     productivity                 —   1350 m /hr,
     with a head of               —   56 m water column,
     power of electric motor      —   500 kw, and
     rpra                          —   735 rpra.

     The impeller of the pump is made  of a special alloy and the plate* is
corundized.  The pipes which supply the lime suspension are made of stainless
steel.  The operating lime suspension  is fed to a cyclone filter from the
scrubber via the hydraulic valve.  The characteristics of the cyclone  filter
are:  diameter - 2020 mm, height - 880 mm, width of the filter ( J^ ) aperture
- 10 Era.  (The remainder of this page is unreadable.)
* Translator's note:  due to poor quality of foreign text,  precise translation
of this term is not possible.
                                   A-18
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     The circulation collector is made of sheet steel and is faced on the in-
side with an acid resistant plate.  From the circulating collector, the suspension
proceeds through a pipe 500 mn in diameter to the intake pump.   The spent
suspension is drawn off through a rubberized slurry gutter into the slurry col-
lector.
     Diameter                   —     4,250 mm
     Height                     —     3,670 mm
                                           3
     Volume                     —     40 m .

     Transfer pumping of the spent suspension into the slurry removal system
                                                                    3
is carried out by means of pumps with a productivity rating of 600 m /hr,
     a head of 36 mm water column,
     electric motor power of 125 kw, and
     rpm - 985 rpm.

     Purified gas from the scrubber proceeds along a "pure" gas duct 4,000 nun
in diameter faced on the inside with an acid resistant plate and proceeds to
the smokestack, where it is discharged into the atmosphere.  The smokestack
110 meters high is made of sheet steel covered on the inside with epoxide
resin.   Compensators in the "pure" gas ducts are made of rubberized fabric.

The Physico-Chcmical Parameters of the Smoke-Gas Streams Before and After Puri-
fication.

     The quantitative and qualitative composition of the agglomeration plant
exhaust gases basically depends on the initial raw material and the conditions
of agglomeration.  Table 1 gives the average chemical composition of agglomer-
ation gases before and after purification.

     It is seen from the table that the agglomeration gases contain other com-
ponents in addition to sulfur dioxide, for example, sulfur trioxide, carbon
monoxide, and nitrous oxide.  Of the components of the agglomeration gases
listed in the table, sulfur dioxide and sulfur trioxide as well as dust are
primarily trapped.   All of the other components are not practically absorbed
by the lime suspension and are discharged into the atmosphere.
                                  A-19
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                                                    TABLE 1
	 	 	 	
Point of
removing
gas

Before
scrubber

After
scrubber

	
CO,
vol.

4.0

4.1


C0(
vol.

0,6

0,€

—- 	
* /.
vol .

17.0

17,0

••
'%*• ~'.fi
vol. vol.

77.71 0,5

'77.7I, 0.5


t/0f
vol.

0 0^i<^

oeoio

^ r ' r
• f \ i f~ r.. i "«s 7
^7 S^V, U'^S^
o Z i / . ^
/. if/1ffl
vol. vol. |
i !
i ;
| !
' i •' M 1 i H / -''i 9 r- iH
>^ ^ ^ i JU ^/ O 4 W ' X- ^ *-'
! i
none i !
Q»Gl& 100
, I

^ "5s" ,
^X 
O
-------
                                  Figure 1.

1- scrubber; 2- flue gas extractor; 3- dirty gas duct; A- collectors with noz-
zles; 5- circulation pump; 6- supply pipe; 7- hydraulic valve; 8- filter- 9-
circulation collector; 10- slurry gutter; 11- slurry collector; 12- slurrv
pump; 13- pure gas duct; 14- smokestack.
                               A-21
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         APPENDIX B






COMMENTS ON THE JAPANESE DATA
            B-l
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CORPORATION
 1.0       INTRODUCTION

          The  Environmental  Protection Agency  is  interested  in
 determining the  technical and  economic  feasibility  of  applying
 lime/limestone scrubbing technology  to  control S02  emissions
 from steel mill  sinter  plants.   Radian  Corporation  has  been
 contracted by the  EPA to investigate the  feasibility of using
 lime/limestone scrubbing for this  application.   Since  there has
 been no  work  in  this area performed  in  the  US, it was  decided
 to examine the operating experiences of lime/limestone  scrubbing
 units  treating gases from steel  mill sinter plants  in  other
 countries.

           As  part of a  first step in the  study,  data from
 Dr.  Jumpei Ando  was obtained describing the operation  of FGD
 scrubbing systems applied to Japanese  steel mill sinter plants
 (AN-1.39).  A copy of this information is  included at the end of
 this Appendix.   It was  hoped that the Japanese data might pro-
 vide meaningful information that would be helpful in the
 successful application of lime/limestone wet scrubbing systems
 to sinter operations in this country.   Although some important
 process  design information was lacking, the data provided infor-
 mation on the Japanese operating experience which should prove
 to be. of considerable value.

           The comments  presented in this  report  are based upon
 a review of process data  from Dr.  Ando's  report  and four
 additional sources (AN-138, AN-141,  PE-182, HI-149).   The
 objectives  of this assessment were-.

           (1)  to identify  unique mechanical  features  of
               Japanese sinter plant scrubbing processes.

           (2)  to summarize normal operating  ranges of
                important process variables,

                               B-2
-------
           (3)  to summarize Japanese operating experience,
               and

           (4)  to identify potentially significant process
               problem areas.

The approach taken to accomplish these objectives was to
examine data for four wet scrubbing processes treating flue
gas from Japanese steel mill sinter plants.  The four pro-
cesses investigated were:

           (1)  Mitsubishi Heavy Industries (MHI) Process
               installed at Kawasaki Steel plants  (Lime
               is used as the absorbent);

           (2)  Moretana Process installed at Sumitomo
               Metal plants (Limestone is used as the
               absorbent);

           (3)  Kobe Steel Calcium Chloride Process (Cal
               Process) (A lime absorbent is used in a
               30 percent calcium chloride solution);

           (4)  Nippon Steel Slag Process (SSD Process).
               (Converter slag containing 40 percent CaO
               is used as the absorbent).

          In Section 2.0, a summary of the operating parameters
and experience for each process is presented.  A discussion of
key process information is  contained in Section 3.0.
                             B-3
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CORPORATION


 2.0       PROCESS OPERATING EXPERIENCE

           A description,  including flow sheets,  of  the four
 processes investigated is contained in  Dr.  Ando's attached
 report.   It was  decided to summarize the operating  parameters
 and experience in tabular form in order to  be able  to  effectively
 determine important information.   Table 2-1 contains  a summary
 of the operating parameters for the MHI and Moretana  process.
 The summary of operating parameters for the Kobe Steel calcium
 chloride process is given in Table 2-2.   Insufficient  data were
 presented to prepare a summary table for the SSD process.

           It was hoped that enough information would be
 available for a  computer simulation of  the  MHI and  Moretana
 processes.   Although a substantial amount of information was
 obtained from the different sources,  key operating  parameters
 for the processes which are necessary for a computer  simulation
 were missing.

           The Radian process simulation model requires the
 identification of process input streams and important  operating
 variables.   Information which was lacking in order  to  simulate
 the two Japanese processes were:

           (1)   limestone composition for both processes,

           (2)  water make-up composition for both processes,

           (3)   fly ash composition for  both processes,

           (4)  the percent oxidation of calcium  sulfite in
               the scrubber for the Mizushima plant (MHI
               process),
                             B-4
-------
                                                TABLE 2-1

                          SYSTEM DESCRIPTION OF THE MHI AND MORETANA PROCESSES
                                           MHI Process
01
    	System Parameter	

    Absorbent

    Absorbent  Characteristics
Absorbent Utilization

Gas Treated
(1000 Nm-Vhr)
Type of Pre-Cooler

Pre-Cooler Dimensions
(meters)
Inlet Gas Temperature
CO

Outlet Gas Temperature
From Cooler (*C)
Pre-Cooler Inlet Gas
Composition (Vol. %)

   02

   CO

   co
    Inlet S02
    (ppm by Vol.)

    Outlet S02
    From Absorber
    (ppm by vol . )
                           General For All
                           Sintering Plants

                           CaO
                               95  -  99

                               120 - 900

                               Spray Tower
12 - 17


4-8
6-12

600 - 1,200
                     Mizushima Plant
                   (No. 4 Sinter Machine)

                   CaO

                   Lime has less than
                   1% MgO


                   95

                   350 - 850
                   Designed for 750
                   Spray Tower

                   14 x 8, 26 high


                   57


                   150
13.5



5-13

400 - 1,100

20 - 50
                              Moretana Process
                          	Kashima Plant	

                          CaC03

                          Limestone is less than  170
                          MgO and is ground to  pass
                          325 mesh

                          79 - 86

                          350 - 880
                          Designed for 880
                          Moretana Scrubber

                          6.5 Diameter, 24.5  high
                          (2 coolers used)
                                                                            150
14 - 15

1 - 1.5

6-8

4-10

200 - 450


3-15
-------
                                            TABLE  2-1 (Continued)
                                            MHI Process
to
i
         System  Parameter
     S02  Removal  (70)

     Inlet  Dust
     (g/Nm3)
     Outlet  Dust
     (g/NmJ)
     Dust  Removal
     Dust  Components
Inlet Cl
(ppm as HC ')

Inlet Oily Matter
(g/Nm3)

Type of S02 Absorber

Absorber Dimensions
(meters)o
(1000 NmJ/hr)
Gas Velocity
In Absorber  (m/sec)

Circulating Liquor
(m3/hr)
i ir
L/G
     Slurry  Cone,  (wt

     Inlet Liauor
     pH
                           Sintering Plants   (No. 4 Sinter Machine)

                           90 - 97            91 - 98
                           0.04 - 0.092
                            (ESP outlet)
Fe, Mn, Si, Pb, K,
Na, Ca, Mg, Al, Zn,
Cu, etc.

20 -50


0.057 g/Nm3
                                Spray  Tower
                   Spray Tower

                   14 x  6.5, 30 high
                                                   2.5
                           10 - 14
                           6.5 - 7.5
                   6.4 - 7.5
                                                   Kashima  Plant
>95

0.15 - 0.23


0.008 - 0.010

>,90

Ferric oxide
Moretana Scrubber
(perforated plate)

6.5 Diameter, 20.5 high
(2 absorbers used)


3-5

2,500
5-6
6 - 6.5
-------
                                         TABLE 2-1 (Continued)
                                          MH1 Process
   	System Parameter
   Oxidation In Scrubber
   (7o)
   Mist Eliminator Type

   Pressure  Drop
   (miT>H20)
   Reheat Temperature ("C)
   References
General For All
Sintering Plants
70 - 100
HI-149
   Mizushima Plant
(No. 4 Sinter Machine)
Considerable Extent
                   Cooler, Absorber, and
                   Mist Eliminator-120
140
AN-139
    Moretana Process
	Kashima Plant	

50

Vertical Chevrons In
Horizontal Duct

Cooler - 220-250
Absorber - 120-140
Eliminator - 20-25
Total System - 700-800
AN-138, AN-139, AN-141
td
i
-------
                                                TABLE  2-2
oo
System Parameter
Absorbent
Absorbent
Stoichiometry
Gas Treated
(1000 NnrVhr)
Inlet Gas Temperature
Cc)
Outlet Gas Temperature
Cc)
Inlet 02 Cone.
(Vol. 7o)
Inlet S02 Cone.
(ppm)
Outlet S02 Cone. From
Absorber (ppm)
S02 Removal (%)
Inlet Dust (g/Nm3)
Dust Removal (%)
SYSTEM DESCRIPTION OF THE KOBE STEEL
CALCIUM CHLORIDE PROCESS
General For
All Sinter Plants
Ca(OH)2 in a 30%
CaCl2 solution

50 - 375

70
Pilot Plant:
15 - 16
Pilot Plant:
200 - 400

>90
Most
V
Amagasaki Plant
Ca(OH)2 in a 30% CaCl2
solution
1.05
350
120
70
14 - 16
240 - 400
20
91 - 94
0.05 - 0.2
50
/,
Slurry Cone.
(wt 7o)
Type of Absorber
                        In Pre-Cooler
                                              Spray Tower
Spray Tower
-------
         _ System  Parameter

         Absorber  Capacity
          (1000  Nm3/hr)
         Absorber  L/G
          Slurry  Cone.  In Absorber
          (wt %)
          Absorber  Inlet Liquor pH
          Absorber  Outlet Liquor pH
          Oxidation in  Scrubber  (%)

          Pressure  Drop
          (mm H20)
                                        TABLE  2-2  (Continued)
   General For
All Sinter Plants
2

30


7
5.5
Pilot Plant - 30
     AmagasakiP1ant
175 (2 absorbers used)

3

30


6-8


750

Cooler, Absorber and
Mist Eliminator - 190
MD
         References
AN-139, PE-182
AN-138, AN-139
-------
CORPORATION
           (5)   the  scrubber  effluent  hold  tank  volume
                or residence  time  for  both  processes.

 The last  two  pieces of  information are most  important,  and
 are needed to adequately  characterize any  lime/limestone  wet
 scrubbing system.

           The operating experience of the  four  processes  is
 given in  Table 2-3.   In general,  the  availability of the
 Mizushima plant (MHI process)  and the two  plants  using  the
 Moretana  process was high.
                              B-10
-------
                                                                TAIil K 2-3

                                            OPERATINC  liXPIjlUKNCE 01'' 1.IHI5/1.7HESTONK SCKIIIili I Nli
                                               UNITS ON STKIil. Mil.I. S'lMTKK  PLANTS IN JAPAN
                                             Mill Process
    Pa ramcter
FCD System
      Oeneral For All
	Sintering  Plants

Absorbent=CaO

Gas Treated3        .,
 120,000-900,000 NMJ
                 hi:
 Mi.xushi.mil  Plant
(Si.iU-ei: Machine /M)

Absorbent=CaO

Cas Treateil=
 750,000 NM£
         hr
                                                                                Moretana  Process
Ahsorbent=CaCO.j

Cas Treated^

Kashiina Pl;mt=
 880,000 NM-*
         hr
Wakayama l'lant=
 370,000 NM3
         hr
                                                                                                         Kobo Steel
                                                                                                         Col Process
                                               Nippon Stoul
                                               SSIJ Process
Absorbont=Ca (Oil) v  Absorbent=Converter
 in a 30 percent    Slag
 Cul'.l... solution

Cas Treated=

Pilot P!aiit =
 50,000 NM2.
        lir
Aiuaj-'asaki Planl:=
 350,000 NM£
                                                                                                                        (ias  'l'reati;cl=Tol)at:a

                                                                                                                        Prototype Pl;iiiU =
                                                                                                                         200,000 NMJ
Start-Up Date
First plant completed
in L973
November,  1974
KM si lima PI ant-September
 1975
Wakayama  Pliint-May,
 1975
Pilot Plant-
 June to  Decem-
 ber, I 9 Ti
                                                                                                                        197-'.
Monthly
Avai.labi.l i.ty  (7.)
                           90 - 95+
                                                  Kashlma  -  100
                                                  Wakayama - 98
Opera t i nj^ Ex per Lei ire
J) The incoming j'iis
laden with oily matter
caused swelling of
rubber linings of a
pre-cooler on one
ins till'I at ion.  This
problem was solved
by using  oil resis-
tant rubber linings.
2) Using  the pll of
the reci.rculat ing
slurry as a control
factor, all of the
scrubbers are rnnn-
i ng with  exceI lent
stabi 1 i.ty.  The S09
concentration of
fh.ie g.'ises I'rom sin-
tering plants changes
Several minor  problems
occurred  in  the  first
three months result-
ing in about 907- sys-
tem avail ahll i ty :

I) Corrosion of  the
impeller  of  the
cooler circulation
pump.
2) Stop-up of  the
lime-slurry pump.

3) Breakage of a
firebrick  in the
furnace(reheater).
These problems were
solved and nearly
lOO"/. availability
Wakayama Plant:   Tiie FCD
system has been  in
smooth operation  except
for ;i defect  in  the plas-
tic lining in  a  cooler
which was found  at  the
beginning of  the  opera-
tion and was  repaired.
Kashiina Plant:   Slight
corrosion has  been  ob-
served in the  gas coolers
of the FCJI) system which
are constructed  with 316
stainless steel  anil
partially with a  high
Ni-Cr alloy.
                                                                                                      Pilot Plant:
                                                                                                      1) A soft de-
                                                                                                      posit formed on
                                                                                                      the wal1 of the
                                                                                                      absorber when
                                                                                                      the I./C ratio
                                                                                                      was smaller than
                                                                                                      I  but the de-
                                                                                                      posit could he
                                                                                                      washed off by
                                                                                                      using an L/C
                                                                                                      larger than 2.
                                                                                                      2) Corrosion has
                                                                                                      been the main pro-
                                                                                                      blem.  Stainless
                                                                                                      steoI, plastic,
                                                                                                      and rubber linings
                                                                                                      are used for  the
                                                                                                      mater ia I . Hecaiisc
                  There lias been  some
                  seal ing problem to
                  be solved lo ensure
                  a long-term con-
                  t i nuous opera L i on.
-------
                                                                    TABLE  2-3  (Continued)
                                                   Milt  1'rr.ccss
               Paramter
       SinterLng Plants    (Sinter Machine
                                                                                         Moretuma Process
          Operating Experience:
          (Continued)
 I
I—1
to
          References
from 800 -  1,200 ppm
every 20 minutes.  Kven
at this kind of: fluctua-
tion, the FGI) system
operated with high and
stable SO,  removal.

3) The sulflte oxida-
tion in the scrubber
reaches as  high as
1007..  Scaling was
prevented by:

  a) Addition of
  gypsum "seed"
  crystals  to pro-
  vide seed sites
  for calcium sul-
  fate crystal Iiza-
  t ion.
  b) liigh L/C. was
  used. A scrubber
  with a simple
  structure was used
  to maintain uniform
  chemical conditions
  of the scrubbing
  slurry and to keep
  all the internals
  wet and clean.
4) Combustible flue
gases from  steel mills
were burned to reheat
the scrubber gas.
was obtained in the
next three months.
                                 111-149
                                                           AN-139
                                                                                  AN-138,  AN-139
                                                                                  AN-141
   f\uuc: o ice I
   C'a I Process

die lower part
of tlie cooler,
where the hot
gas is intro-
duced was
corroded sever-
ly, the part
was replaced by
titanium, which
is durable.
                                                                    iii ppoii .^Lee i
                                                                    SSIJ Process
                                                   3)  Concentra-
                                                   tions of magnes-
                                                   ium and other Im-
                                                   purities increased
                                                   in  the absorber liquor
                                                   but caused no problem.
                                                   4)  The plant
                                                   operated without
                                                   scaling and waute-
                                                   w;iter problems.

                                                   AinJKflsak i  Plant:
                                                   'I'ho Tallowing pro-
                                                   hlems were en-
                                                   countered during
                                                   the two month test
                                                   run:'
                                                   I)  Unusual vibration
                                                   of  a centrifuge.
                                                   2)  Wearing of: a con-
                                                   trol valve.
                                                   3)  Scaling of a pll
                                                   mefer electrode.
                                                   4)  Breakage of rubber
                                                   lining in a reducer.
                                                   These problems were
                                                   solved and the plant
                                                   went into commercial
                                                   operation in April,
                                                   1976.

                                                   l'E-1.82, AN-139   AN-I 39
-------
CORPORATION

 3.0       DISCUSSION  OF  THE  SYSTEM DATA

           The  operating  parameters for the  two  lime/limestone
 processes  (MHI and Moretana  processes) are, of  course, more
 important  for  this study since  these  systems are very
 similar  to the type of FGD system considered in this project.
 But,  the information  obtained for the Cal and Slag processes
 should not be  neglected  since CaCOo and  CaO are the  absorbents
 in these systems  respectively.

           Several important  pieces of information were obtained
 from  the data  on  the  MHI and Moretana processes.

           (1)   An inlet  Cl concentration of 20-50 ppm in
                the flue  gas  was reported.   High chlorine
                concentrations in wet  scrubbing  systems can
                cause  corrosion.

           (2)   The oxidation in the scrubber was reported
                to be  between 70-100 percent.  Scaling was
                prevented by  recycling gypsum as seed crystals,
                using  a high  liquid to gas ratio (L/G), and
                by using  a scrubber with  a simple structure.

           (3)   The oily  matter in the incoming  gas
                necessitated  the use of oil  resistant rubber
                linings to prevent swelling.

           (4)   The S02 concentration  in  the flue gas
                fluctuated between 800-1200  ppm  every
                20 minutes.   High and  stable S02 removal
                was still obtained under  these conditions.
                              B-13
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CORPORATION


 These  four points need  to be considered when designing a  lime/
 limestone wet  scrubbing  system for a sinter plant facility.

          It was reported for the Kobe Steel calcium chloride
 process  that concentrations of magnesium and other impurities
 increased in the absorber liquor but caused no operating
 problems.  The magnesium and other impurities mentioned did not
 cause  a  problem in this  facility, but these species can affect
 process  chemistry and should be considered in any FGD system
 design.

          The  Nippon Steel slag process experienced complete
 oxidation of the lime absorbent to calcium sulfate.  It was
 reported that  the prototype plant encountered some scaling
 problem  that remains to  be solved to insure a long-term con-
 tinuous  operation.
                              B-14
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CORPORATION

 4.0       SUMMARY

           Lime/limestone  wet  scrubbing  has  been  successfully
 applied to steel  mill  sinter  operations in  Japan.   About  nine
 commercial lime/limestone scrubbing  installations  (excluding
 the Cal and SSD processes)  will  be operating  on  sinter  plants
 by  the  end of 1976.  Operating data  from existing  facilities
 have shown high system availabilities with  minor operating
 problems.   The S02  removal  efficiency has been consistently
 over 90 percent with very high lime  or  limestone utilizations,
                              B-15
-------
CORPORATION
 5.0       REFERENCES
 AN-138    Ando,  Jumped.,  "Status  of  Flue  Gas  Desulfurization  and
           Simultaneous  Removal of S02  and NOX  in Japan",
           Presented at  the  Flue  Gas Desulfurization  Symposium,
           New Orleans,  March  1976.

 AN-139    Ando,  Jumpei,  "Desulfurization of  Flue Gas from Iron-
           Ore Sintering Plants in Japan",  Tokoyo,  Chuo  Univer-
           sity,  May 1976.

 AN-141    Ando,  Jumpei,  Private  communications,  Chou University,
           29  May 1976.

 HI-149    Hirai,  M.,  et al.,  "MHI Flue Gas Desulfurization
           Systems Applied to  Several Emission  Sources",
           Presented at  the  6th Flue Gas  Desulfurization Sympo-
           sium,  New Orleans,  March  1976.

 PE-182    Pedco  Environmental, Inc., Untitled  Preliminary
           Draft,  regarding  recent developments in desulfuriza-
           tion technology in  Japan  up  to January 1975.
                             B-16
-------
  DESULFURIZATION OF FLUE GAS  FROM
     IRON-ORE SINTERING PLANTS
             IN JAPAN
            (May,  1976)
            Jumpei Ando






Faculty of Science and Engineering






         Chuo University






              Tokyo
               B-17
-------
                              CONTENTS


1.   INTRODUCTION
2.   MIZUSHIMA PLANT, KAWASAKI STEEL (MHI PROCESS)
3.   KASHIMA PLANT, SUMITOMO METAL (MORETANA PROCESS)
4.   KOBE STEEL CALCIUM CHLORIDE PROCESS (CAL PROCESS)
5.   NIPPON STEEL SLAG PROCESS (SSD PROCESS)
    ADDRESSES OF STEEL PRODUCERS AND PROCESS DEVELOPERS
                               REMARKS
     The metric system is used in this report.  Some of the conversion
figures between the metric and American systems are shown below:

                 1m (meter) =3.3 feet
                 lin  (cubic meter) = 35.3 cubic feet
                 It (metric ton) =1.1 short tons
                 1kg (kilogram) = 2.2 pounds
                 1 liter =0.26 gallon
                 Ikl (kiloliter) =6.29 barrels

     The capacity of flue gas desulfurization plants is expressed in
Nm"'/hr (normal cubic meters per hour),
            INm /hr = 0.59 standard cubic foot per minute
L/C-- ratio (liquid/gas ratio) is expressed in liters/Nm  .
            1 liter/Nm  = 7.4 gallons/1,000 standard cubic feet
For monetary conversion, the exchange rate of 1 dollar  = 300 yen is used,
                                B-18
-------
                          1.   INTRODUCTION

     In 1974 the Japanese steel industry produced 114 million tons
(metric tons) of crude steel  and spent $563 million for pollution
control, which was equivalent to 18.5% of the total investment made
by the industry in that year. Many desulfurization units have been
installed since 1971 to treat flue gas from iron-ore sintering plants,
the major source of SO- emission from the steel industry (Table 1).
As the absorbent, a lime slurry is used by Kawasaki Steel (MHI process),
a limestone slurry by Sumitomo Metal (Sumitomo-Fujikasui Moretana
process), a slurry of pulverized converter slag by Nippon Steel (SSD
process) and a calcium chloride solution dissolving lime by Kobe Steel
(Cal process).  All of those  plants by-produce gypsum.  On the other
hand, Nippon Kokan uses ammonia scrubbing to by-produce ammonium
sulfate or gypsum by reacting lime with the sulfate.
     By 1977, 22 FGD plants will be in operation with a total capacity
of treating 13,800,OOONm3/hr  (8,120,000scfm) flue gas, which is about
one-half the total gas from all sintering plants in Japan.
     Flue gas from sintering  plants is characterized by a high 02
concentration (12-16%), relatively low SO- concentration (200-1,OOOppm),
and a dust content rich in ferric oxide.  Oxidation of sulfite into
sulfate occurs in the scrubbers much more readily than with flue gas
from a boiler, because the oxidation is promoted by the high O^/SO™
ratio and also by the catalytic action of the ferric oxide.
     The present report will  describe mainly the lime and limestone
processes and the dimensions  and performance of the plants.
                                 B-19
-------
Table 1.
          S02  REMOVAL  INSTALLATIONS  FOR WASTE  GAS  FROM IRON-ORE SINTERING MACHINES
Steelmaker
Kawasaki Steel
n
n
"
ii
"
Sumitomo Metal
t;
D3 "
g
n
Kobe Steel
- "
ii
Nakayama Steel
Nippon Steel
"
Nippon Kokan
n
Plant site
Chiba
11
n
Mizushima
"
"
Kashima
Wakayama
Kokura
Amagasaki
Kobe
Kakogawa
Osaka
Tobata
Wakamatsu
Keihin
Fukuyama
Ogishima
Gas treated
(l.OOONm /hr) Process
120 M1-1I
320 "
650
750
900
750
880 Moretana
1,000 "
1,000
370
720
175 x 2 Cal
375 "
1,000 x 2 "
375
200 SSD
1,000 "
150 NKK
760
1,230 "
Absorbent
CaO
n
n
n
11
n
CaCO_
n
n
n
Ca (OH)
11
n
"
Slag
"
NH~, CaO
NH *
Year of completion
1973
1975
1976
1974
1975
1977
1975
1976
1977
1975
1976
1976
1976
1977
1976
1974
1976
1971
1976
1977
Gypsum (t/year)
3,600
13,200
26,500
27,600
32,400
27,600
32,400
40,500
40,500
14,400
26,500
12,600
12,600
72,000
13,500
7,200
32,400
7,200
12,000**
20,000**
*  Ammonia in coke oven gas
                                          **  Ammonium sulfate
-------
         2.  MIZUSHIMA PLANT, KAWASAKI STEEL (MHI PROCESS)

Layout of Sintering Machines and FGD Plants
     Kawasaki Steel installed FGD plants first at its Chiba works
using the lime-gypsum process developed by Mitsubishi Heavy Industries,
Satisfied with their operation, Kawasaki Steel introduced larger FGD
plants at its Mizushima Works, where four iron-ore sintering machines
with a unit capacity of 8,000-15,OOOtons/dayhad been installed.   The
FGD plants were erected in an iron ore storing yard adjacent to  the
sintering plants (Figure 1).  FGD plants for No.  3 and No.  4 sinter-
ing machines are in operation and a plant for No. 1 and No. 2 machines
is under construction.

No. 4 Sintering Machine
     Specifications of the No. 4 machine are shown in Table 2.   The
machine has 22 wind boxes.  The amount, temperature and composition
of gas from the wind boxes are shown in Figure 2.  The total amount of
                           3
the gas reaches l,100,OOONra /hr.  The S02~rich gas, about a half of
the total,  is selected by means of dampers as is  shown in Figure 3
and sent to the FGD plant.  The S02 concentration in the selected gas
ranges from 400 to l,100ppm while that in the rest of the gas ranges
from 40 to 90ppm.

       Table 2.  SPECIFICATIONS OF No. 4 SINTERING MACHINE
Equipment
Sintering machine
Main blower
Dust collector
Cooler
Type
Dwight-Lloyd
Induced fan
Electrostatic
precipitator
Lurgi
Specifications
Capacity 15,000t/day
2
Fire grate 410m
Capacity 21,000m /min x 2
Motor 7,800kW x 2
Capacity 21,000m /min x 2
Dust(Inlet 1'°8/Nm
(outlet 0.06g/Nm
2
Cooling area 550m
Cooling fan 15,000m /min x 2
                               B-2I
-------
Cd
i
ro
                                                        FGD plant under construction
                                                          for No.l and No.2 sintering machines
                                                          i"Fv-T--^< "^Li!
              Sintering machines
                (No.3 and No.
                          100m
A: Scrubber, etc.
B: Lime preparation
C; Dust treatment
D: Wastewater treatment
E; Control room
                                                         I Gas from No.l and No.2
                                                             sintering machines
                     Figure  1  Layout of FGD plants (Mizushima plant,  Kawasaki  Steel)
-------
0)  .S
B  \

r-i  "a
O  2
>  O
   O
to  o
rt
    80



    60



    40



    20



     0



1,000
0
O.
 

                                                3 'hO
                                                w ts
                                                07 B
                                                0) S
                                                fc -^
                                                a,
                                                B o
                                                
-------
Cd
i •

ro
                          Duct to FGD plant
                22-20
18


19
                                         T
                                          i
17 - 10
9,8
7-1
                          Duct to stack(without FGD)
                                              Fan
                                                             E.P.       Fan
                                                                    Stack
                               Figure  3  Gas  flow  from No.k sintering machine


                                          ( Figures show wind box numbers)
-------
FGD Plant for No.  4 Machine
     The plant uses the MHI process with one absorber and has a
capacity of treating 750,OOONm /hr flue gas (Figure 4).   The gas at
about 150°C containing 500-1,OOOppm S02 and about 13.5%  02  is first
cooled to 57°C in a cooler with water sprays and led into a plastic
grid packed absorber,  where it is treated with a lime slurry at pH
                                      o
6.4-7.5 at an L/G ratio of 7 liters/Nm  (about 50 gallons/1,OOOscf)
and has more than 90%  of S02 removed.  The treated gas passes through
a mist eliminator, is  heated to about 140°C by after-burning, and
sent to a stack.  A calcium sulfite slurry discharged from the
absorber is acidified  to pH 4  by adding sulfuric acid, led into an
oxidizer, and oxidized into gypsum by air bubbles generated by a
rotary atomizer.  The  gypsum slurry is sent to a thickener and then
centrifuged to less than 10% moisture.  The by-product gypsum is sold
as a retarder of cement setting.  The liquor from the centrifuge is
returned to the thickener; the thickener overflow is returned to the
absorber after lime is added.
     A portion of the  circulating liquor of the cooler is neutralized
with lime to recover low-grs.de gypsum.  The liquor from the centrifuge
is sent to a wastewater treatment system and reused.
     The specifications of the FGD unit are shown in Table 3.  As the
calcium sulfite is oxidized to a considerable extent in the absorber
due to the high concentration of oxygen in the gas, the gypsum is
recycled to the absorber as crystal seed in order to prevent scaling.
To ensure high operability of  the plant, spare units have been provided
for major pumps and the centrifuge.  Ah automatic system has been
installed to shut down and restart the plant with the sintering machine.
                                B-25
-------
                                             Mist eliminator
                                           -H2SO<,.   Oxidizer
                                                                         Centrifuge
    To . wastewater  treatra^ifC
                                Low-grade
                                 gypsum
Liquor tank
                       Gypsum
Figure ^.  Flowsheet of MHI lime-gypsum process ( one-absorber system)
-------
Table 3.  SPECIFICATIONS OF FGD UNIT FOR No.  4 SINTERING MACHINE
                 (Capacity 750,QOONm /hr)
       Cooler              14m x 8m,  26m high
       Absorber            14m >: 6.5in,  30m high
       Blower              750,OOONm3/hr, 2,400kW
                           Total pressure   380mmH20
       Mist eliminator     14m x 13m,  9.5m high
       Oxidizer            3.2m diameter,!5. 6m high
Performance
     The FGD plant for the No. 4 machine went into operation in
November 1974.  The performance is shown in Figure 5.   The gas volume
                                    o
fluctuated from 350,000 to 850,OOONm /hr and inlet SO, concentration
from 400 to l,100ppm.  The S02 removal efficiency was  91-98% and the
SO. concentration at scrubber outlet ranged from 20 to SOppm.
Availability (FGD operation hours per cent of total hours) was about
90% for the first three months because of several minor troubles such
as corrosion of the impeller of the cooler circulation pump, stop-up
of the lime-slurry pump, and breakage of a fire-brick  in the furnace.
Those problems were solved and nearly 100% availability was obtained
in the next three months.   The low availability in May 1975 (about
90%) was due to a shut-down of the sintering machine.
     On the average, the gas velocity in the scrubber  is about
2.5m/sec and the total pressure drop in the cooler, absorber and mist
eliminator is about ^OmmHoO.   Lime with less than 1% MgO has been
used.  The by-product gypsum contains about 7% moisture after being
centrifuged and has an average crystal size of about 40 microns.  The
requirements for the operation are shox
-------
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1 1 1 i l 1 1
Nov. Dec. .Jan. Feb. Mar. Apr. May
197^ 1975
Figure 5  Performance of FGD plant  for
          No.k sintering machine
               B-28
-------
slightly less than 1 mole lime to 1 mole inlet S0? has been vised to
obtain about 95% removal and thus the consumption of sulfuric acid
has been reduced.

      Table 4.   REQUIREMENTS OF FGD PLANT FOR No. 4 SINTERING MACHINE

Power (103kWhr)
Fuel* (106kcal)
Air** (103Nm3)
CaO (t)
H2S04 (t)
Water (10 3m3)
1974
Dec.
2,000
7,000
2,500
500
24
37
1975
Jan.
2,300
7,000
1,800
600
18
11
Feb.
2,100
6,300
1,900
460
19
24
Mar.
2,500
7,000
1,800
530
13
24
Apr.
2,600
10,000
1,900
470
8
29
Mav
2,100
2,900
2,300
360
7
19
!
     *  For reheating
** For oxidation
                                B-29
-------
        3.  KASHIMA PLANT, SUMITOMO METAL (MORETAMA PROCESS)

Moretana Process
     Sumitomo Metal is operating two plants and constructing three
more (Table 1), all using the Moretana process developed by Sumitomo
jointly with Fujikasui Engineering Co.  The process is characterized
by the use of the Moretana scrubber fitted with four perforated plates
made of stainless steel.  The holes range from 6 to 12mm in diameter
and the plate thickness from 6 to 20mm.  Both dimensions are varied
depending on the specific scrubbing conditions.  The free space in
the cross section ranges from 25 to 50%.  The bottom tray serves
mainly as a gas distributor and the upper three serve as absorbers.
The gas and liquid flows are so adjusted as to maintain a liquor head
of 10 to 15mm on each plate.  The gas velocity is higher than in
usual scrubbers.  The design gives extreme turbulence, producing foam
layers 400 to 500mm thick, and thus ensures a high SO^ and dust removal
ra'zio.  The mist eliminator is a set of vertical chevron sections
mounted in a horizontal duct after the scrubber.
     A flowsheet of the process is shown in Figure 6.  Gas from a
sintering machine is first treated with water in a Moretana scrubber
for cooling and to remove more than 90% of dust.  Removal of ferric
oxide dust is useful in reducing the oxidation in the absorber to
ease scale-free operation.  The gas is then treated with a limestone
slurry (or a mixed slurry of lime and limestone) 10-20% in excess of
stoichiometric amount in a second Moretana scrubber to remove more
them 95% of S02>  The limestone contains less than 1% MgO and is ground
to pass 325 mesh.  The calcium sulfite slurry discharged from the
scrubber is sent to a clarifier, and then to a pH adjusting tank where
the pH is adjusted to about 4.0 by adding a small amount of tLSO, .
                                B-30
-------
td
i
CO
       Sintering
        machine
                                                                                             After-
                                                                                             burner
                                                                    From  No.2  train
                                                        pH adjusting
                                                        tank
                                       H2SO
Oxidizer   Tank
                                Figure 6  Flowsheet of Moretana process
-------
Tae slurry is then sent to an oxidizer developed by Fujikasui to
convert calcium sulfite to gypsum.  The gypsum slurry is centrifuged,
and the filtrate is returned to the absorber.
     The discharge from the cooler is sent to a thickener.  The
overflow is returned to the cooler; the underflow is filtered.  The
filter cake is returned to the sintering machine and the filtrate is
sent to a wastewater treatment system.

Kashima Plant, Sumitomo Metal
                                                            3
     The Kashima plant with a capacity of treating S80,OOONm /hr gas
was started up in September 1975 and has since been in stable
operation.  All the gas from a sintering machine ranging in flow rate
                         3
from 350,000 to 880,OOONm /hr is treated.  The gas contains 200-450ppm
S02, 14-15% 02, 6-8% C02, 1-1.5% CO, 4-10% H20, and 0.15-0.23g/Nm3
dust at about 150°C.  The scrubbing units consist of two trains each
                                     o
with a capacity of treating 440,OOONm /hr gas.  The Moretana scrubber
works normally with a gas velocity between 3 and 5m/sec.  When the
gas flow rate is low one train only is used.  The size  of the equip-
ment and operation parameters are shown in Tables 5 and 6.

           Table 5.  SIZE OF EQUIPMENT
    Facility      Number
    Cooler           2
    Absorber         2
MLst eliminator      2
    Oxidizer         2
    Centrifuge       4
     Size (Specification)
6.5m (dia.) 24.5m (height)
6.5m (dia.) 20.5m (height)
6 x 6m, 2.4m (length)
2.8m (dia.) 5.4m (height)
550kg/hr each
                               B-32
-------
            Table 6.  OPERATION PARAMETERS
Cooler:
     Space velocity
     Circulated liquor
     Dust content
Absorber:
     Space velocity
     Circulated liquor
     pH of the liquor
     S0« content
Mist eliminator:
     Gas flow
     Washing liquor
Pressure drop:
     Cooler
     Absorber
     Eliminator
     Total
By-product gypsum;
     Moisture
     Crystal size
4.4 to 5.0mm/sec
      •3
5,000m /hr in two towers
0.15-0.23g/Nm3(inlet), 0.008-0.010g/Nm3(outlet)
4.4 to 5.0m/sec
      3
5,500m /hr in two towers
6 to 6.5
250-400ppm (inlet),  3-10ppm (outlet)

5.5-6.0m/sec
40m /hr in two units
220-250mmH20
120-140mmH20
20-25mmH20
700-800mmH20
6.0-9.5% (after centrifuge)
Larger than 50 microns
     Operating hours of the sintering and desulfurization plants are
listed in Table 7.  Operability of the desulfurization plant has been
maintained at 100%.
                               B-33
-------
          Table 7.   OPERATION OF KASHIMA PLANT
                                                1975                1976
                                    Sept.    Oct.   Nov.   Dec.   Jan.   Feb.   Mar.
      Operating hours
        Sintering plant              705     729    683   725    729    654    716
        Desulfurization plant       (501)*   729    683   725    729    654    716
        Availability of
         sintering plant
        Operability of
         desulfurization plant      (100)     100    100   100    100    100    100
               *  Started operation in September

     Performance of the No.  1 train is shown in Figure 7.   Inlet and
outlet SO™ concentrations have been 300-450 and 3-15pptn respectively.
The L/G ratio in the absorber is about 5 liters/Nm3 (36 gallons/1,OOOscf).
     Construction and operation costs for the Kashima plant are shown
in Table 8.

                Table 8.  COSTS FOR KASHIMA PLANT

       Plant cost ($1,000)                        15,000
       Running cost ($l,000/month)
          Power                                      121
          Fuel                                       121
          Limestone, chemicals                        47
          Other                                       38
       Fixed cost ($l,000/month)                     286
          Total                                      613
       Sintered product (t/month)                283,384
       Desulfurization cost ($/t)                      2.16
                                   B-34
-------
Cd
i
LO
en
           Sept. 10
     o
      B
        300 _
        200
     Q)
     tn
     2
     to

     S
          0
                                                   Oct. 1
                                                                                                             Oct.  25
                                   Cooler
                                         Absorber
                                    Mist  eliminator
500


ifOO


300


200




 30
     o
     05  20
         10

          0
     B
     a,
                                         Inlet
                                              Outlet
           Failure of
           S02 meter
-«—•—•—•—•—*    »—«—e—•—v—e—*-—•—»-
                                Figure 7  Operation data  of  No.l  train,  Kashima plant
-------
Wakayama Plant, Sumitomo Metal
                                                                   3
     An FGD plant at Wakayama with a capacity of treating 375,OOONm /hr
waste gas from a sintering machine started operation in May 1975 and
has since been in smooth operation except for a defect in the plastic
lining in a cooler which was found at the beginning of the operation
and was repaired.  Operability of the plant is 98% except for the
(scheduled shutdown of the sintering plant that normally occurs about
avery two months.  The mist eliminator is washed intermittently
(once in 30 minutes) with the circulating liquor and fresh water
alternately.  The pressure drop in the mist eliminator which is 30mm
H~0 at the beginning gradually increases while it is washed with the
circulating liquor.  When the pressure drop reaches 50mm, fresh water
±s used in place of the liquor until the pressure drop returns to 30mm.
'Che ratio of liquor to fresh water is about 80 to 20.
                             B-36
-------
      4.  KOBE STEEL CALCIUM CHLORIDE PROCESS (CAL PROCESS)

Process Description
     Kobe Steel has developed a new process using a 30% calcium
chloride solution dissolving lime as the absorbent.  A pilot plant
         2
(50,OOONm /hr) has been operated and two commercial plants (Table 1)
have just come on-stream to treat waste gas from iron ore sintering
plants.
     Calcium chloride solution dissolves 6-7 times as much lime as
does water.  High S0? recovery is attained at a low L/C of 3 liters/
  3
Nm .  The flowsheet is shown in Figure 8.
     Waste gas is first cooled in a cooler to which a calcium chloride
solution (about 5%, from a gypsum centrifuge) is fed to cool the gas
to about 70°C and to remove most of the dust.  The solution is con-
centrated here to about 30% and is sent to a scrubber system after
dust removal by filtration.  The gas is then led into an absorber in
which a calcium chloride solution (about 30%, at pH 7 dissolving lime)
is sprayed to remove more than 90% SO-.  The gas is then passed
through a mist eliminator and sent to a stack.  The liquor discharged
from the absorber at pH 5.5 containing calcium sulfite is sent through
a thickener to a centrifuge to separate most of the solution, which
is sent to a tank where calcium hydroxide is dissolved to raise the
pH to 7.  The calcium sulfite sludge from the centrifuge is repulped
with water and some sulfuric acid to produce a slurry at pH 4.  The
slurry is oxidized by air bubbles into gypsum, which is then centri-
fuged.  The liquor from the centrifuge containing about 5% calcium
chloride is returned to the cooler giving no wastewater at all.
     Since vapor pressure of the liquor is low, the temperature of
the gas after the scrubbing reaches 70°C as compared with the 55-60°C
for the usual wet process and thus less energy for reheating is required.
The mist eliminator is washed with the circulating liquor.  The
solubility of gypsum in the liquor is very low (nearly 1/100 of that
in water) and the evaporation of the liquor does not cause scaling.
                            B-37
-------
i

u>
oa
                   Cnnler
                                                                                                    After-

                                                                                                    burner
                                                            -,   .     Centrifuge
                                                           eliminator    _     °
                                               Figure 8  Flowsheet of Cal process
-------
     Continuous operation of the pilot plant for about 6 months showed
that a soft deposit formed on the wall of the absorber when the L/G
ratio was smaller than 1 but the deposit could be washed off by using
an L/G larger than 2.   A highly corrosion-resistant material is
required for the cooler; the lower part where the hot gas comes in
is made of titanium.

Amagasaki Plant
     The Amagasaki plant has two trains, each with a capacity of
treating 175,OOONm /hr flue gas at 120°C containing 240-400ppm SO-,
            3                                              "      ^
0.05-0.2g/Nm  dust and 14-16% 02>  The plant went into test operation
in February 1976.  The following problems were encountered during the
two months' test run:
          Unusual vibration of a centrifuge
          Wearing.of  a control valve
          Scaling of  pH meter electrode
          Breakage of  rubber lining in a reducer

     Those problems have been solved and the plant went into commercial
operation in April 1976.  The S02 removal efficiency ranges from
91-94%.  The dust removal efficiency runs to about 50%.  Gas velocity
in the absorber is 3m/sec.  Total pressure drop in the cooler,
absorber and mist eliminator is 190mmH«0.  The L/G ratio is 4.0 in
the cooler and 3.0 in the absorber.  More than 50% of calcium sulfite
is oxidized in the absorber.  The by-product gypsum has an average
crystal size of about  40 microns and contains about 8% moisture and 0.1%
chlorine after being  centrifuged.  The designed and actual require-
ments are listed in Table 9.
                             B-39
-------
  Table 9.  REQUIREMENTS AT AMAGASAKI PLANT

                          Designed value     Actual value
Power (kWhr/hr)                1,830            1,372
Water (t/hr)                       20                6.2
Steam (t/hr)                        2                1.8
Sulfuric acid (kg/hr)            106               50
Slaked lime (kg/hr)              328              150
Calcium chloride
  (35% solution, kg/hr)           60               50
                      B-40
-------
        5.  NIPPON STEEL SLAG PROCESS (SSD PROCESS)

     Nippon Steel has developed a process which uses converter slag
as the absorbent (Figure 9).   The slag contains about 40% CaO, 16%
SiO , 3% MgO, 3% Al 0 ,  and 35% FeO and Fe 0  and has no current uses.
Nippon Steel has operated a prototype plant with a capacity of treating
200,OOONm /hr waste gas  from a sintering plant since 1974.   A commercial
                  o
plant (l,000,OOONm /hr)  has just started operation.
     The process is similar to other lime/limestone-gypsum processes
except that it uses no oxidizer.  The gas is cooled and led into two
absorbers in series to remove 95% of SO,.,.  The slag is fed to the
second absorber to produce a calcium sulfite slurry which is led to
the first scrubber and entirely oxidized into gypsum in the scrubber
due to a low pH and the  presence of much iron compounds which act as
a catalyst.  The by-product gypsum contains about 40% impurities and
has been discarded.  The prototype plant has encountered some scaling
problem to be solved to  ensure a long-term continuous operation.  The
process may be useful for steel producers who normally have large
amounts of useless slag.
                          B-41
-------
                                   Absorber(l) Absorber(2)   [  1 Mist eliminator       Reheater
CO
i

-p-
r-o
Wastewater

     pit
                                                                                     Compressor
                                V
                        Gypsum /'K
                                     FIGURE 9 - FLOWSHEET OF SSD PROCESS
-------
         ADDRESSES OF STEEL PRODUCERS AND PROCESS DEVELOPERS
     The addresses of the steel producers and process developers
described in this report are listed below:
     Kawasaki Steel Co.
            1-12-1, Yurakucho,  Chiyoda-ku, Tokyo
     Sumitomo Metal Co.
            5-15, Kitahama,  Higashi-ku,  Osaka
     Kobe Steel Co.
            1-36-1, Wakihamacho,  Fukiai-ku,  Kobe
     Nippon Steel Corp.
            6-17-2, Ginza,  Chuo-ku, Tokyo
     Mitsubishi Heavy Industries  (MHI)
            2-5-1, Marunouchi,  Chiyoda-ku, Tokyo
     Fujikasui Engineering Co.
            1-4-3, Higashigotanda,  Shinagawa-ku, Tokyo
                       B-43
-------
RADIAN
CORPORATION
                          APPENDIX C



                 DESCRIPTION OF RADIAN'S PROCESS

                        SIMULATION MODEL
                            C-l
-------
RADIAN
CORPORATION
 1.0       INTRODUCTION

           Radian has developed a computerized process  simulation
 model, for lime/limestone wet scrubbing systems.   The program
 utilizes equipment modules to represent the wet  scrubbing system
 so that different process arrangements can be simulated.   The
 following discussion is a rather brief description of  Radian's
 process simulator as applied to limestone wet scrubbing systems.
                             C-2
-------
RADIAN
CORPORATION
 2.0       PROCESS DESCRIPTION

           A simplified flow diagram of the conceptual limestone
 scrubbing system is given in Figure 2-1.   In this  system the
 incoming flue gas is scrubbed with a limestone slurry in the
 spray tower.   The scrubber bottoms are combined with fresh lime-
 stone and recycled slurry from the clarifier in a  stirred hold
 tank where dissolution of limestone and precipitation of calcium
 sulfate and sulfite occur.   The major portion of the tank efflu-
 ent is returned to the scrubber.   The minor portion of the tank
 effluent is fed to the clarifier,  where some additional lime-
 stone dissolution and precipitation of calcium sulfate and
 sulfite may take place.   The clarifier underflow is solid waste
 which exits the process.

           The following sections describe the operation of
 various process components  in more detail.   Important design
 relationships are introduced which must be dealt with in some
 fashion in the process calculation scheme described in Section
 3.0.
 2.1       Scrubber

           The primary purpose of the spray tower is  to  provide
 interfacial area for transfer of SOa from the flue gas  to  the
 alkaline slurry.   Gas passing upward through the scrubber  is
 contacted with fine droplets  of slurry introduced at the top
 of the tower via spray nozzles.   SOa is absorbed by  these  drop-
 lets  as they fall through the tower.  Limestone  present in the
 slurry droplets may dissolve  and the absorbed SOa  may precipi-
 tate  as CaS03-%H20,  or if it  be oxidized,  as
                               C-3
-------
                             STACK GAS
o
I


FLUE
GAS >
LIMESTONI
MAKE-UP
WATER



4




\


i





A
A
\

„
i





/
/
\


' ^

C\
S


\ /
^ /
^


r \

/
^


\
\
^


r
/
/


^
^•


f

/
i







\

*


^\^J
SOLID
                                                                             WASTE


            FIGURE  2-1   FLOW DIAGRAM  OF SIMULATED  LIMESTONE  SCRUBBING  PROCESS
-------
CORPORATION
          A sophisticated  mathematical  treatment  of  a  spray  tower
 would probably  be  formulated  in  terms  of mass  transfer  rate to
 an  individual slurry  droplet  of  a  given size.  The  overall  mass
 transfer  performance  would  then  be calculated  by considering the
 number and size distribution  of  droplets in  the  total spray.  In
 the absence of  such a detailed description of  physical  phenomena
 in  the spray tower, its overall  performance  may  be  discussed using
 conventional mass  transfer  terminology derived for  packed-tower
 design.   The following discussion  is based upon  the performance of
 a spray tower and  should  not  be  used to describe other  types of gas-
 liquid contactors.

          The usual design problem  in application of an  absorber
 is  to select a  scrubber size  and liquid rate to  attain  a  specified
 absorption efficiency for a given  throughput of  gas.  The design
 relationship for these parameters  may  be written (normally  for a
 packed tower) as in Equation  2-1).

          K aV
          -£—   = N.T.U.                                   (2-1)
           nG
 Here,  K  (Ib mole/hr-ft2) is  the overall gas phase  mass transfer
 coefficient, a  (ft2/ft3)  the  interfacial area  per unit  volume of
 contactor,  nG (Ib mole/hr)  the gas flow rate,  and N.T.U.  the number
 of  overall gas  phase  mass transfer units.  The overall  packed
 height  of the tower is calculated  as follows:

          HT - (N.T.U)  (H.T.U)                             (2-2)

 Here, H.T.U. is  the height  of an overall gas phase  mass transfer
 unit.
                              C-5
-------
         N.T.U. may also be defined in terms of the amount of
absorption and the actual and equilibrium mole fractions of the
gas being absorbed (S02 in this case).
                     out
         N.T.U. = - f         dy

                     in                                   ^   '

When y is very small, as in S02 scrubbing where the S02 concen-
tration is in the ppm range, then the (1-y) term is approximately
equal to 1.
                   Y
                    out
         N
. T. U.  =  - f      dy
         •/       V —V~
For systems near atmospheric pressures and with small pressure
differentials, the N.T.U. m£y be expressed in terms of partial
pressures.

                      Pout    d

         N'T'U;"" L   p-p*

                 s   	^in  "  Pout ^      £n ll^l^in_      (2-5)
                    ^P~P  'in ~  ^P~P 'out    ^P~P  -'out

           Thus,  for a specified S02 removal,  the required
number  of  transfer  units depends on p*   which is  a function of
the  scrubber  liquor composition.  If  enough available alkalin-
ity  is  provided  in  the scrubber slurry,  p* will  remain  small
compared to p  and sorption  will proceed.  As  the available
alkalinity decreases, p* increases and N.T.U. grows large.
                              C-6
-------
RADIAN
CORPORATION
 Equation 2-1 shows that either Kg,  a,  or V must be increased
 to achieve such an increase in N.T.U.   A calculated N.T.U.  may
 be used, then as an index of difficulty of achieving specified
 sorption efficiency for a given set of operating conditions.
 Calculation of p* and N.T.U. is one of the primary objectives
 of the present analysis of scrubber performance.  The variables
 which enter into this calculation are the specified S02  removal,
 the amount and composition of scrubber liquor,  and the degree
 of limestone dissolution in the scrubber.  The  fraction of
 absorbed S02 which is oxidized also affects the equilibrium
 partial pressure and N.T.U.  A more complete design calculation
 would adjust scrubber design parameters such as gas velocity,
 height, diameter, to satisfy Equation 2-1.  The exact relation-
 ship of K a to these design variables is not yet known.   The results
          cS
 ot present calculations may be compared with previous pilot
 scale data, however,  to insure that calculated  values of N.T.U.
 and K aV are realistic.
      g
           Estimation of mass transfer requirements (N.T.U.)
 for the scrubber is one goal of an engineering  anslysis  based
 on process chemistry.  A second important aspect of scrubber
 performance is the level of supersaturation in  the scrubber
 liquor with respect to CaS03-%H20 and CaSOu-2H20.

           Slurry entering the scrubber will be  slightly
 supersaturated, with respect to the solid waste  components
 being precipitated in the hold tank.   These are CaSOn-2H20  and
 CaS03-%H20.  Previous laboratory and pilot scale investigations
 have shown that a major process problem, scaling,  is related
 to critical levels of supersaturation that should not be ex-
 ceeded for successful process operation.  Under normal opera-
 ting conditions,  the highest level of supersaturation in the
 process will be reached in the scrubber effluent.   Whether  or
                              C-7
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CORPORATION
 not the critical scaling point is reached will depend on the
 scrubber liquid-to-gas ratio,  the specified 862 removal, the
 composition of the inlet slurry and the degree of oxidation and
 limestone dissolution in the scrubber.   Calculated levels of
 scrubber effluent supersaturation reached under various oper-
 ating conditions can be compared with experimentally established
 limits to determine the susceptibility of the scrubber to
 scaling.   Since scaling is primarily a chemical problem and
 does not depend on assumptions regarding mechanical character-
 istics of the scrubber, this aspect of the present process
 analysis will be an important  contribution to any preliminary
 process design.  The utility of the simulation model as a design
 tool and as a method of predicting scaling conditions was demonstra-
 ted at a 3 MW limestone scrubbing pilot plant located at Pennsylvania
 Power and Light's Sunbury Station.   The simulation model was used
 to set process operating parameters.   To verify the model's accuracy,
 the system was operated at conditions in which the model predicted
 scaling to occur.   At those conditions  the system scaled.   The reli-
 ability of the model was shown .by the fact that the pilot plant
 operated throughout its life in an GQ.ggaled moae.

 2.2       Hold Tank

           The function of the process hold tank is to provide
 adequate reaction time in a well mixed environment for suffi-
 cient: dissolution of limestone and precipitation of calcium
 sulfate and sulfite to occur.   Since the hold tank is a well
 mixed vessel, the composition of the output stream will be
 essentially the same as the composition of the material in the
 tank.
                               C-8
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RADIAN
CORPORATION
           The performance of a hold tank may be calculated by
 simultaneous solution of the chemical reaction and mass transfer
 rate equations describing the phenomena taking place in the
 vessel.   Laboratory and pilot scale investigations have provided
 quantitative descriptions of precipitation and dissolution
 reactions important to a limestone scrubbing process.

           The rate expression which is used for the hold tank
 is given in Equation 2-4.

                   R  =  k A n V Ksp (RS - 1)              (2-6)

 Here,  R is the precipitation rate,  k is the rate constant,
 A is a proportionality constant,  n is the flow rate of the
 solid into the tank,  V is the hold tank volume, Kor. is the
                                                  »F
 solubility product constant,  and RS is the relative saturation.
 The relative saturation is the product of the activities of
 the species which react to produce the precipitating solid
 divided by the solubility product constant,  as shown in Equa-
 tions  2-5 and 2-6 for calcium sulfate.

               Ca44" + SOV + 2H20  t  CaSO,-2H20 4-          (2-7)
          RS   =   [aCa++  '  aSOV  '  aH20(o]/KsPCaSOl)-2H20     (2-8)

  For precipitation  to occur, the relative  saturation  is  greater
  than  one, and  the  rate R is positive.   For  dissolution  to occur
  the relative saturation is  less than  one  and the  Rate R is
  negative.  At  equilibrium,  the  relative, saturation  is equal  to
  one,  and the rate  is zero.
                                C-9
-------
          Several factors influence these solid-liquid mass
transfer rates.  One factor of major importance is the hold
tank volume.   If the volume is increased for a given relative
saturation and flow rate, the precipitation and dissolution
rates will increase.  If the volume is increased and the rates
are to remain  the same, the relative saturations must move
closer to one, indicating a closer approach to equilibrium.

          Another factor which will affect the rates is the
flow rate of the solid into the tank (i.e., slurry concentra-
tion) .  This flow rate controls the area on which precipitation
and dissolution may occur.  Increasing the area for a given
relative saturation will increase the rate.

          Variation of the proportionality constant A and the.
rate constant  k is known to occur with the particle size of
precipitating  or dissolving solids.   The exact functionality
of this change is unknown.  For purposes of investigating the
effect of such changes, the rate constant k can be changed in
process calculations.

          The principle criteria for hold tank design in
limestone scrubbing processes is that the hold tank effluent
supersaturation be low enough to prevent scaling conditions
from developing as the slurry is recycled through the scrubber.
A secondary requirement is that the  tank be large enough to
dissolve limestone for reasonable concentrations of limestone
in the slurry.   A larger hold tank will improve limestone
utilization.
                              C-10
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RAPIAN
CORPORATION
           The design and function of the hold tank interact
 with the scrubber operating parameters.  Up to a point, increas-
 ing the hold tank size will decrease the required scrubber
 liquor rate at least from the standpoint of supplying sufficient
 alkalinity and keeping the scrubber effluent supersaturation at
 a safe level.
 2.3       Clarifier

           The clarifier is intended primarily as a solid-liquid
 separation device; however, some additional solid-liquid mass
 transfer may take place here.   One reaction of possible signifi-
 cance that could occur in the clarifier is sulfite oxidation
 due to the large surface area available for transfer of oxygen
 from the atmosphere.  This oxidation could affect the levels
 of sulfite and sulfate supersaturation in the scrubbing system.

           The clarifier removes waste solids and some liquid
 from the process.  A major process variable associated with
 the clarifier is the amount of liquid leaving the process with
 the waste solids.  Soluble species such as chloride, sodium,
 and magnesium are introduced to the system as trace components
 in the flue gas, fly ash,  and limestone.   Since the liquid
 carried with waste solids is the only route by which soluble
 species can leave the system,  the concentration of these soluble
 salts in the process liquor will be inversely proportional to
 the liquor content of the waste solids.  These soluble species
 cause significant changes  in process chemistry through their
 interaction with ions that actually participate in .the absorp-
 tion, dissolution, and precipitation steps.
                              C-ll
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RADIAN
CORPORATION
 3.0       PROCESS MODEL

           This section describes  the computational scheme or
 model used to estimate steady-state operating conditions  for a
 limestone scrubbing process.

           The important physical  phenomena and process  rate
 steps introduced in Section 2 are formulated mathematically.
 Certain simplifying assumptions are made which lead to  practi-
 cal yet meaningful solutions  describing the performance of the
 process.

           The Radian process  model is a gorup of computer
 programs for simulating aqueous inorganic chemical processes.
 The foundation of the model is the ability to predict vapor-
 liquid-solid mass transfer rates  and chemical equilibrium for
 the CaO-MgO-NaaO-SOa-COa-SOa-NaOs-HCl-HaO system.   The  process
 model performs unit operation calculations and other engineer-
 ing manipulations based upon  (1)  rate and equilibrium calcula-
 tions and (2) process and equipment data which define the
 process flow scheme and characterize each of the individual
 process units.

           The programs which  make up the process model  may be
 grouped into five major subdivisions:   (1) rate and equilibrium
 calculation programs,  (2)  equipment subroutines which model
 each process unit and process input stream,  (3) an executive
 syst€m which interconnects the equipment subroutines to form
 an analog of the process flow diagram and controls the  sequence
 of computer operations,  (4)  convergence routines which  force
 convergence of the model iterative parameters,  and (5)  print
 routines  which print out stream and process  data.
                                C-12
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CORPORATION

 3.1       Process Model Flow Sheet

           The main flow scheme used in this  group of simulations
 is given in the symbology of the Radian process  model as
 Figure 3-1.   Subroutines FLUGS1,  ALKINP,  and WTRMKP simulate
 process inputs of flue gas,  limestone, and make-up water,
 respectively.  Subroutine SCRUBS models the  spray tower and
 RATHD1 simulates a stirred holding tank.   Subroutines DIVDER
 and DIVDR2 simulate stream splitters,  and FILTER models a
 clarifier-filter system.   Subroutine SYSTB1  is  an ancillary
 routine which performs material balance calculations around the
 entire system.

           Several assumptions have been incorporated into  this
 simulation system.

           (1)  The spray tower behaves as an adiabatic
                countercurrent contacting device  and the
                equilibrium partial pressure  of  SOa above
                the scrubber feed is negligible.

           (2)  The partial pressures of COz  and  HaO in
                the gas leaving the scrubber  are  in equi-
                librium with the scrubber liquid  at the
                scrubber temperature.

           (3)  No precipitation occurs in the scrubber.

           (4)  The temperature of the recirculating
                process liquor streams is fixed at the
                adiabatic saturation temperature  of the
                scrubber effluent  liquor.
                             C-13
-------
o

h-1
4>
       PLUGS 1
      FLUE  GAS
          2
        ALKINP
      LIMESTONE
          1
       WTRMKP
        WATER
       MAKE-UP
          3
                  SYSTB1
             OVERALL  SYSTEM
                 BALANCE
                     4
   SCRUBS
SPRAY TOWER
      7
> 	


v^.


i r
RATHD1
HOLD TANK
8
- XnS
                                 DIVDER
                                  TEE
                                   6
                                                                          FILTER
                                                                     CLARIFIER-FILTER
                                                                            5
DIVDR2
  TEE
   9
                         ORDER OF PROCESS CALCULATIONS: 1. 2. 3, 4, 5, 6.(7, 8, 9 ) *
                           FIGURE 3-1  CONCEPTUAL DESIGN  FLOW  PLAN
-------
RADIAN
CORPORATBON
           (5)   The temperature of the water make-up
                has no effect upon the circulating
                liquor temperature.

           (6)   Ionic reactions taking place in the  liquid
                phase are rapid and thus  are at equilibrium.

           (7)   The holding time of the clarifier (modeled
                by the FILTER subroutine)  is sufficiently
                long that solid-liquid equilibrium is  achieved.

           (8)   The hold tank closely approaches  an  idealized
                backmixed vessel.

           (9)   Neither chemical change nor phase separation
                occurs to a process  stream except in a
                process unit.

           The  two assumptions involving  the temperature  of the
 process  liquor streams should be good approximations.  Previous
 pilot unit work indicates that the scrubber effluent  liquor
 streams  closely approach the adiabatic saturation temperature.
 In simulation  cases previously conducted,  the  water make-up
 stream was on  the order of 0.5 percent of the  scrubber feed
 stream and thus would have a negligible  effect upon changing
 the process liquor temperature.   Heat loss to  the surroundings
 should be small in most instances.   Assumptions  one and  three
 are good approximations for a short-residence-time contactor
 with a high liquid-to-gas ratio such as  a spray  tower.   Assump-
 tion seven listed above is probably not  a good assumption in
 that it  does not reflect the true situation in a clarifier.
 This modeling  assumption may be justified from the  standpoint
 that solid-liquid equilibrium represents the maximum  chemical
 change that can occur across the clarifier. Thus,  the actual
                              C-15
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CORPORATION
 composition of the clarifier effluent streams will lie
 between the composition of the clarifier feed and the effluent
 composition as determined by solid-liquid equilibrium.  In
 general, this chemical change will be small.
 3.2       Equipment Subroutines

           This section gives a brief description of the major
 routines used in the process simulations.   The routines may be
 grouped into four sections:   (1) input routines (FLUGS1,  ALKINP,
 and WTRMKP),  (2) unit operation routines (SCRUB5,  RATHD1),
 (3) material balance routines (SYSTB1),  and (4) minor process
 unit routines (DIVDER, DIVDR2,  and FILTER).

           FLUGS1 - This routine simulates  a flue gas input
 stream with entrained fly ash.   It reads data cards for the
 temperature,  pressure, and flow rate of the gas stream and  the
 weight rate of the fly ash,  all in English  units ,  as well as
 the mole fraction composition of the gas and the weight frac-
 tion composition of the solid.   The calculations performed  are
 to  convert these data to program units and assign it to the
 specified output stream.

           ALKINP - This routine simulates  an alkali input
 stream,  which was limestone  for all cases  run.   It reads  data
 cards for the weight rate and weight fraction composition of
 the limestone.   The calculations performed are to  convert these
 data t:o program units and assign it to the specified output
 strean.
                               C-16
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RADIAN
CORPORATION
           WTRMKP -  This routine simulates  a water input stream.
 It reads data cards for the weight composition of the water
 stream and converts these data to molality in the specified
 output stream.   This routine does not assign the  flow rate of
 the output stream.

           SCRUB5 -  This routine simulates  a vapor-liquid
 contactor.  It is assumed that (1) the scrutber is adiabatic,
 (2) C02  and H20 are in vapor-liquid equilibrium,  and (3) no
 precipitation occurs.   The flue gas flow rate,  composition,
 and amount of S02 removal required is input to this routine
 as is the composition and flow rate of the scrubber slurry
 feed stream.   Since quantitative prediction of the amount of
 limestone that will dissolve in a spray tower is  not yet feasi-
 ble,  a fraction of  incoming limestone (and fly ash, if desired)
 is assumed to dissolve.   The type of contactor (co-current,
 countercurrent,  and back-mixed liquor)  may also be specified.
 The mass transfer coefficients reported here are  for counter-
 current  spray tower operation.

           The routine calculates the number of transfer units
 (and thus KgaV)  required to achieve the specified S02 removal
 using the specified feed rate  and composition.  The composition
 of the outlet slurry is also calculated.   As noted in Section
 2.0,  the supersaturation of this stream is of major interest.

           RATHDl -  This routine simulates  a well-mixed holding
 tank.  All input streams must  be completely known along with
 the tank volume and the rate constants for the solid-liquid
 mass  transfer of limestone,  CaS04-2H20,  and CaS03-%H20.   The
 output stream is calculated by simulataneous solution of rate,
 material balance, and equilibrium relationships.
                             C-17
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CORPORATION

           Hold tank performance can be modified by adjusting
 the tank volume,  the slurry solids  concentration,  or by chang-
 ing the precipitation and dissolution rate constants.

           SYSTB1  -  This  routine performs  a mass and energy
 balance about the process based on  complete knowledge of the
 flue gas and  limestone streams, the composition of the make-up
 water stream, and the following system parameters:   (1)  the
 fraction of the SOa  in the flue gas which is absorbed,  (2)  the
 fraction of the absorbed SOz  which  is oxidized to  SOs,  (3)  the
 pressure drop across the scrubber,  (4)  the particulate removal
 efficiency of the scrubber,  and (5) the desired filter bottoms
 pH.   Additional information is  taken from other routines as
 need be.

           Based on  total removal of SOa and HG1,  the specified
 fractional removal  of SOz,  and  a guess at the loss of COz,
 the  non-aqueous portion  of the  scrubber exit gas  is calculated.
 An adiabatic  heat and material  balance is then performed to
 find the water in the scrubber  exit gas,  assuming  that the
 liquid circulating  through the  scrubber and the exit gas are
 at the adiabatic  saturation temperature.

           Based on  (1)  the weight fraction solids  in the filter
 bottoms; (2)  complete information for the flue gas,  scrubber
 exit gas,  and limestone•streams;  and (3)  the composition of the
 make-up water streams,  the filter bottoms flow rate and compo-
 sition,  and the make-up  water flow  rate can be calculated.

           DIVDER  -  This  routine simulates a stream splitter.
 Based on the  flow rate for the  first output stream and com-
 plete information about  the second  output stream,  complete
 information for the  input stream and the  first output  stream
 are  calculated.
                              C-18
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CORPORATION

           DIVDR2 - This  routine also simulates a stream splitter,
 The difference from DIVDER is  that in DIVDR2 the feed stream is
 completely known and the flow  rate of the first output stream
 is known.   Based on these data,  complete information for both
 output streams is calculated.

           FILTER - This  routine models a solid-liquid separator.
 Input data are the weight fraction solids in the feed and
 bottoms streams and the  separation efficiency, i.e.,  the frac-
 tion of the feed solids  which  are transferred to the bottoms.
 3.3       Calculation Sequence

           In the execution of a simulation computer run,  the
 executive system makes three passes  through each of the equip-
 ment subroutines which is  used in the simulation.   In the first
 pass the  data cards  are read,  the input  data are printed,  and
 any necessary initialization (such as assigning the weight
 fraction  solids  in the filter bottoms in the FILTER routine)
 is  performed.  In the second pass the simulation calculations
 are performed as follows.

           (1)  The input routines FLUGS1,  ALKINP,  and
               WTRMKP are  called.  These routines  perform
               all of their operations on the first pass
               and do not  play an active part on the second
               pass.

           (2)  Subroutine  SYSTB1  calculates the scrubber
               exit  gas and the filter bottoms stream.

           (3)  Subroutine  FILTER calculates the filter
               feed  and filter overhead.
                             C-19
-------
CORPOSLATBON

           (4)   Subroutine  DIVDER calculates  a first
                guess  at  the scrubber  slurry  feed stream
                and the hold tank effluent  as having
                equilibrium compositions.

           (5)   Subroutine  SCRUBS calculates  the  scrubber
                bottoms stream.

           (6)   Subroutine  RATHD1 calculates  the  tank
                effluent  based on rate calculations.

           (7)   Subroutine  DIVDR2 recalculates the scrubber
                feed and  filter feed streams  based on the
                hold tank effluent.

           (8)   Steps  5,  6,  and 7 (subroutines SCRUBS,
                RATHD1, and DIVDR2)  are iterated  until the
                compositions and flow  rates of the streams
                involved  approach their steady-state  values.

           This  completes the second pass.  At this point,  the
 executive system prints  complete stream data for all process
 streams.   After the stream print,  a final  pass is made through
 the equipment  subroutines,  and any ancillary output  which  was
 not printed in  the. stream  print,  such as KeaV and N.T.U. in
                                           O
 the scrubber is printed.
                              C-20
-------
R&D1AN
CORPORATION
 4.0       PROCESS SIMULATION CASE

           The following pages represent  a typical  process
 simulation of a limestone wet scrubbing  system.  The  computer
 output 'for the conceptual design of the  limestone  scrubbing
 system on the sinter plant with 39  percent windbox gas  recycle
 was chosen.   The stream values shown were those  used  to prepare
 the material balance which was presented in Section 5.1 of this
 report.  The flow plan used for the simulation case was pre-
 viously given in Figure 3-1 of this Appendix.
                              C-21
-------
RADIAN
CORPORATION
  22
           ! 1 121:57.151
                                INPUT SPECIES (-JI.ES)
                                                    TEHPEHATUSi
                                                               57,473 OES, C,
          PH i
H20 e
CAO »
VA20 •

COMPONENT
M2Q
H2C03
HC03-
HN03
M2503
HSfU-
XS04-
CA«t
CAOH*
CA"Ct'3»
CAC03
CA-JG3*
CASU3
CAS04
MOOh*
.1GHC03*
"or.03
1GS04
Minn
MAC03-
NAN03
•US04-
OH-.
CL-
C03--
>J03-
S03»
COMPONENT
CA(OH)3(S)
CACU3CS)
CAS03(S)
MCC03CS)
PSfiZ i 3.^47,11-
Prl"0i « 1.76722

1 I b 7 1 .•> ,1 » J 3
i , 5 2 s m « .1 a
AOUEO'JS SOLUTION EO
."OUAUITY
5,412-07
1 ,338-WJ
1,849-^3
1 .323-12
2!<:5S-fl4
1,154-^2
3,323-fS
2,173-iU
2.711-^5
j!l49-34
7.',1S5-H3
6, 153-1*4
3.S83-.1"
21413-fl?
7.178-11
2,193-OS
4.335-.18
s:;;j:s;
2.216-37
3.S97-il5
J.B93-U2
1CLALITY ACT
21224-2!
i. 152-01
8 ',1',!! i
*,M*
ft ATI,
-17 4T»,,
10LECUIA3 'H»T£R i 1
6.3397 IONIC STSEv&Ti > 4.97
HCL 4.29699*d!)
C02 2,it23J««2
w;n3 a.^.i^^tt
N205 3,a7535-.a2
SQ2 3,81311*32
533 9,1359S*ii2
UIlIoSIA
ACTIVITY ACTIVITY COEFFICIENT
4.574-B7 B.451-B1
9,994-.'!
1 , 3 i ^ • 8 3 1 , ^ ii 9 • il 3
t!?'J3-24 8,11)9.^1
5,103-?.3 4,4J4-,11
2.SJ5.03 B,HS-?.l
2,735-26 1 ,tV9*Q?, '
3,i/s-«4 i,?ee»?^
7, 1 16-«3 1 , ?rffl»ijiJ
2.355-.14 4,536-'^l
2,^i4-37 1,7'JO'fH
5 , b3 t -Pi 1 ,?09 !,l&?-il4

,71?t.l»il3 t « » 1 1 , 7 9 M t ;i H
                                  C-22
-------
J
2
3
4
S
6
7
0
9
AL«INP
FL'JGSl
MTRMXP
STST31
FILTER
OIVOER
SCRUBS
RATH01
OIVOR2



2
7
9
2
1
»
CORPORATION


            SINTER PLANT  ( 3ux RZCYCLE  J  LIMESTONE  SCRUBBING SYSTEH

                          PROCESS DESCRIPTION

  EOUI", NO,     EQUIP, NAME     INP'JT  STREAMS          OUTPUT STREAMS

                                                        1
                                                        2
                                                        3
                                          1              4   S
                                                       10   9
                                                        6   7
                                                        4   8
                                         IB   3          9
                                                        6   7


                     QROER OF PROCESS CALCULATIONS

           1,2,3,4,3,6(7,5,9).

           RtCiCLE. LOOP FROM   7  TO    9                                '



  SYSTEM AMO EJUIP«ENT PARAMETERS

      SYSTJl,  C.OU1PMENT NUMfitR  4
           Su? 4-)SURdED i   Sf>,43 X       NO  ABSORBED  •     ,30 X
           S'T2 OXIOtZEO •   ' P. 03 X       NQ2 ABSORBED  •     ,00 X
           Ll^E 50L1CS MYOR/HNG IN SYSTEM*  CAO  «   130.39  X   M50 •  106,00 X
           PKCSSuRE DROP CONSTANTS*  GAM-itl *   a,038      GAH14 2 >  9,003     GAM«» 3 •  a.;
           PARTICIPATE REMOVAL CONSTANTS*  BETA  l •   l,204*0<)  BETA 2 »  a,a»0     BETA  3  »
           I"ITI»L  VALUE OF  XA(C3?) «   9,*W9
           SOLIO itSTE PH LIMITED TO  6,80 i 0,S

      FILTE*,  ETUIPWENT NUMBER  5
           FEEO i«T  FR SOLIDS «  12,32 X   UNDERFLOW »T  FR SOL13S »  48,33 X
           SEPARATION EFFICIENCY « IJ0.00 X


                          S  rLO" "  i
      SCSUJS,  iS
           •)»C*MIx£r) O^ESATnx      PRECIPITATION NOT  ALLO«EO
           Ll*E  SOLIDS HYOHAU'iG IN SCRUBBF.H*  CAO  >  iad,i»M  X    .MGO « 188,38 X
           FRACTIONS OF  SOLIOS AvUL'S'.E fJR REACTION*
                           CACUHJ2   *G(OH)2    CAC03      flGC.Ii      MGS04     NA20      I.ACL      LIMESTONE
                SLURRY*        .33 X     ,?) X
                FLUE GAS*  loa.aa x  u^.??« x     ,90  x      ,?)8tf    WT x             HGS03   0,0000    »r x
          T,n     K,P^M«I    WT x             CAS04   K,0e0M    -aiua     n,?<<)«ai MRLE x      NACL      6,8i«a    MT x
          so3     3,ai>cM    MOLE x      INERT    7a,3na    WT x
          Ni       8,37j*i»
-------
22
 STREAM
 T n T 4 I   0
2
,16500+06
5/80.2
330,38
1 ,0003
r -.11635+09
, 12004^02
12,644
,16499+06
5780,2
, 15666+06
,12956+06
-,11634+09
1,0532
4,0230
641 ,60
,00000
,010080
635.82
,00000
3510,3
,0)0000
96H,41
,00000
,69600-01
11,100
,00000
,00000
1 1 ,000
,00000
60,730
,00000
17,100
,00000
3 4
1114,6 ,16489+06
61,857 b779,5
204.27 330,24
,00000 1,0003
*•, 42386+07 ^,11647+09
,00000 ,36015*03
,W?l000 3,7930
,035500 ,16489 + 06
,00000 5779,5
,030110 ,15657 + 06
, 000HM ,12954+06
S0?.0t30 !•>, 11647 + 09
,030190 1,0532
,0f)0W0 ,38621
,00P)W0 645,23
,00000 ,00000
,0MB M0 ,00000
,03000 634,55
,0H0^0 ,00000
,«»0o0 3510,3
,0fl0tfW ,000120
, R 0 0 !rt fl 989,03
,000*10 ,00000
,0fl«tfM ,66824*02
, (?) j* 0 ^ 0 11,164
,00000 ,00(900
, PI tj 0 rl U ,00000
,00000 10,97U
, PJaavH* ,00000
,wn0aa 00,737
,0rt0W0 ,00000
,00000 17,113
.000100 ,00000
5
1675,0
60,278
330,24
,00000
ef56096+0;
40,000
,00000
,00000
,00000
,00000
,00000
,010000
,00000
,00000
,00000
,00000
,00000
( 00000
»0ft0f10
,00000
,00000
,00000
,000100
,00000
,00000
,00000
,00000
.000M0
,00000
,00000
,00000
, 00HC19
,00000
6
,18458+07
96469,
330.24
,00000
r *, 70715+10
11.981
.00000
.00000
,00000
,00000
,00000
t 0(3000
, 0002)0
,6100*0
.00000
.00000
,00000
,00000
.00900
.PS000R
,000V)0
, 00000
,00300
,00000
,00000
,00000
,00003
.00000
,00000
,00000
,00000
,00000
,0t)0H0
n
0
n
5
0
g

0M
z





























-------
 22 JI.IN 76    11:25:00,037
  STREAM NUMBER
  SLURRY STREAM
     FLOW MATE (G/SEC)
               (G-MOLE/SEC)
               (L/SEC AT T)
     ENTHALPY  (CAL/SEC)
     BULK r>hNSlTY(G/ML AT T)
     KEY COMP RATE(GMQL£S/SEC)
       SO?
       C02
       SO 3
       M205
'       CAO
       MGU
       MA2f)
       HCl-
    '  H20
  LIQUID PHASE
     FLOW RATE (G/SEC)
               (G-MOLfcS/SEC)
     EN1HALHY  (CAL/SEC)
n   DENSITY    (G/ML AT T)
r!o   KEY HUMP RATE(G-MOLEtt/SEC)
01     502
       CAM
       MGlJ
       H20
     KEY  COMP
       SM2
       dig
       503
                  ,80
CONC(G-(10LP.S/KG  H20)
                  - wid
       CAM

       viA2(
       HCI.
                                SINTER PLANT  ( 39%  RECYCLE  )  LIMESTONE SCRUBBING  SYSTEM
                                 23496
88
o
     PH
, 00000
, 00000
,04000
,00000
,00000
. 0000(3
,00000
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,00000
,00000
, 00000
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.00000
. 00000
, 0000PI
, 00000
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,00000
,00000
.00000
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,00000
.00000
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,00000
,00000
20)
e. w /
.00000
,00000
.00000
,00000
,ni)00w
,00000
,00000
, 001100
,0^000
.00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
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,00000
,00000
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,00000
,00000
,00000
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,00000
,00000
,00000
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,00000
,00000
,00000
,00000
,00000
,00000
1114,6
61,857
-,42306+07
,99626
,00000
,141 98-02
,92754-03
, 1 h0fe)6-04
,20086-02
, 0001^0
,00000
,90063-03
61,852
,00000
, 1 2742-02
,83239-03
, 1 bl bS-04
.1B026-02
,00030
,03000
.83824-03
7,1250
,00000
, 00000
, 00000
, 00000
,03000
.00000
,00000
,00000
,00000
,00000
,00000
.00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000 .,'.-
,00000 '
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,0000(1
,00000
1675.0
60,276
1,0163
», 56096 + 07
1645,0
1,0910
,79089
2,5476
,18004-04
4,4264
,89429-03
,94094-03
.25140-02
61.239
1(505.0
55,676
-,37754*07
,98742
.43480-03
,35443-02
,17082-01
,18004-04
.17995-01
,89429-03
,94094-03
.25140-02
55,633
,43382-03
,35363-02
,17043-01
, 17963-04
,17954-01
,89228-03
,93882-03
,25083-02
6,3878
,19458*07
96469,
1734.2
",70715*10
1122,0
380.61
260.42
910,97
,30669-01
1567,0
1,5244
1.6036
4,2846
96738,
,17127+07
94867,
",64334+10
.98759
1.0353
5,8335
31.201
,30669i01
32.848
1,5244
1.6036
4,2846
94789,
,60628-03
,34161-02
.18271-01
,17959-04
,19235-01
.89269-03
,939^7-03
.25090-02
6,3397
-------
22  JUN  7b    11:25:00.283
 STREAM NUNBtK
 UI nil ID PHASE(CONT)
     LliJe  Hiiij wATt  (Kb/Ski:)
               (LITtKS/SEC)
i
10
     C(HC
       H*
       nn-
       HSU3-
       S043
M03-
HSH4-
M2S03CL)
CA + t
CALHU
CAb(MCL)

CAHC03+
CAb04(L)
CAN03+
Mf,+ +
      MA f
      MAUHCU
      N A L !3 3 -
      CL-
            (G-HOLFS/KG  H20)
                                , 04)^00
                                ,00000
                                ,00000
                                ,00000
                          ,00000
                          ,00000
                          ,00000
                                ,00000
                                ,00000
        SOLIDS
                                .30000
SINTER
2
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,(10000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,0(0000
,00000
,00000
,00000
,000(50
, 00000
, 0 0 0 0 0
,00000
,130000
,00000
,00000
,00000
,00000
.00000
.00PI00
,«000H
PLANT ( 39% RECYCLE ) LI
3
1,1143
1,1163
,80772-07
, 1 0804s06
,00000
,00000
,71 125-03
,10734-02
,7H269»!06
,32247-04
, 356/3*06
900WH0
, 1 76t48i»03
,16574*02
• *5«Jt'O3^Wti
• W tl u) kl 0
, 1 55 4 Id 3 *• 0 5
,22899-04
,121 14-03
97H 453-07
, M U 0 Id H
, 0 H 51 W 0
,MldPi^M
* {/» ty 0 ^ W
• 0 id 0 W W
, 0 51 0 0 0
,080^0
,0ir)0tf 0
, 0 M 0 y 0
,0a0Hw
,0H0fe30
, 0 a a H 0
,80824-03
.5/OX4-M2
26ifl,76
4
,00000
,00000
,00000
,00000
,00000
,00000
,»0000
,00000
,00000
,t* 1)000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
, 00000
,00000
,00000
,00000
,00000
,00000
,00000
, P! Id 0 tJ 0
, 00000
,00000
,00000
, 00P100
,00000
, 00000
,00000
,00000
,00000
MESTONE SCRUBBING SYSTEM
5
1,0023
1,0150
,48348-06
,24654«0b
0 167B3*-03
,29358*04
,10245«01
,19976-02
,643H6«ft6
,35039-04
,54464-06
,S0658«-08
,13000-02
,110513-01
,35488-07
,23144-03
.31530-05
,22576-03
,64898-02
,871 59-06
,62131 -03
t 40824-07
« 5 1892-05
,63275-05
,25912-03
t 299 18-06
g 1 8265-02
,80559- 1 \fl
,52560-07
,23909-05
,48706-04
, 1 6207-07
,25083-02
,472M8-0i
2757,3
6
1707,7
1729,1
,54125-06
,22158-06
,24560-03
,38968-04
.10901-01
,18469-02
,54013-06
, 34997*04
,63723-06
,13135-07
,13379-02
,11644-01
,33246-07
,31487-03
,,27108-05
,21776-03
,70547-02
,90536-06
,61581-03
,35879-07
B66232-05
,57258-05
,26425-03
,24131=06
.18251-02
,71775-lfe)
,43355-07
,21933-05
,50796-04
,16011-07
,25090-02
,49771-01
2932.2
ft
a
i
-4
B
































-------
' 22 Jl.lN 7o 1 i: 25 1043,542
STREAM NUMBER
SOLIH PHA5F.
Fl.OM RATE (G/SEC)
(G-MUUE/SF-C)
ENTHALPY (CAL/SEC) «
SPECIFIC GRAVITY
KF.Y CMMP RATE(GMULESXSEC)
SO 2
C02
S(U
N-2D5
CAO
MGO
SA20
HCl
H2U
COMP RATE CG MOLES/SEC:
0 CAD
r!j CA(QH)2
-J CACfM
CA503
CASOii* 1 /2H20
CAsr»4
CAS04*2H20
Mfid
*if.C(U*bH20
1(il>rM
MGSO-.J*3H2n
1fiSQ.5*bH20
M G S ft ^
MGCl 2
NA«?f)
MAC I..
INhWTS
L I. iiFS fONE
XLS
SINTER PLANT ( 39%
1

456,17
4.6014
F,13145+0;
2,7271

,00000
4,4208
, 00000
,00000
4,4208
,00000
,00000
, 00000
, 00000
I
,00000
,00000
4,4208
,00000
,00000
,00000
,00000
,00000
„ 00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,18054
,02)000
,000(10
2

1.9807
,27294*- 01
' *5fl93,4
3,1515

,00000
,00000
,12657-02
,00000
,51508-02
,12772p02
,13439-02
,23044-02
,00000

,38851-02
,00000
,00000
,00000
,00000
,12657-02
,00000
,12772-02
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,19174-03
,23044-02
,18370.»01
,00000
,00000
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,00000
,00000
,00000
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,00000
,00000
,00000
.00000
,00000
,00000
,00000
,00000
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,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,000110
,00000
,007100
,0?t0H0
,000fci0
,00000
,00000
,00000
,000fr'0
,00000
,0JI0(40
.0*19 019
RECYCLE ) LIMESTONE SCRUBBING SYSTEM S3
4

.59386
(81833«02
-1767,0
3,1515

,00000
,00000
,37949*03
,00000
,15443*02
,38294»03
,40294-03
,69091»03
,00000

,116481-02
,000140
,00000
,00000
,00000
,37949-03
,00000
,38294»03
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,57487-04
,69091*03
,55077-02
,00000
,00000
5

670,02
4,6019
«, 18342+07
2,4226

1,0906
,78734
2,5305
,00000
4,4084
,00000
,00000
,00000
5,6063

,00000
,00000
,78734
,00000
1,0906
,00000
2,5305
,00000
,00000
,00000
,00000
,00000
,00(100
,00000
,00000
,00000
,00000
,00000
.00000
,19340
,00000
,00000
6 99]£l
^H KKB
,23312 + 06 S™
1601.5 gg
••,63816 + 09 ^2
2.4228 5

379,78
274,59
879.77
,00000
1534.1
,00000
,00000
,00000
1949,4

,00000
,00000
274.39
,00000
379.78
,10091-02
879,77
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
.00000
,00000
,00000
67,390
,00000
,00000
-------
o
co
 22 JUN 7t>     11 :25J00,775
  STREAM NUr^RER
  ELEMEMTSO;- ATOMS /SEC
  TOTAL STRtAM

       C
       N

       MA

       S
       Cl.
       CA
  GAS PHASE
       H
       C
                                            SINTER
                                             2
     S
     CL
LIQUID PHASE
     H
     C
     M
     rj
     MA
     if.
     s
     CL
     CA
SOLID PHASE
     H
     C
     sj
     0
     MA

     S
     CL
     CA
                              ,0i4000
                              4,4208
                              ,00000
                              13,262
                              ,00000
                              .021000
                              4,4208

                              ,00000
                                ,00080
                                13.262
1976,8
641,60
702W.7
3551,3
 A *•<•«•* ft
4,b)243
,23044-02
,51508-02

1976,8
641,60
7020,7
3551,3
4.K230
                                             00000
                                            ,12657-02
                                            ,23044-02
                                            ,51508-02
kNT ( 39X RECYCLE ) LIMESTONE SCRUBBING SYSTEM g
3

123.70
,1^1 98-02
,36012*04
61,859
,000110
,04100?!
,92754*03
,900(13*03
,20086o02
,08000
,00000
, 0&H00
,00000
,02)000
,00000
123,70
,14198*02
,36012*04
61,859
,000100
, 0 0 K) 0 0
,92754-03
, 90063*03
,20086-632
,03000
, P1W00PI
,03000
,'00000
, 0#H00
,00000
,08^00
,0^000
,030190
4

1978,1
645,23
7020,7
3549,4
, 80588*03
*^ & r^ (\ A — n *t
u OOC?'*T"iOv
,3B659
,69091-03
,15443*02
1978,1
645,23
7020,7
3549,4
.38621
,00000
.00002
,00000
,00000
,0tf{-)00
,00000
,00000
,140300
.00000
,00000
,69091*03
, 00&I00
, 0 05500
,34687*02
,80588-03
,38294«f03
,3/949-03
,69091-03
,15443-02
5

122.48
,79089
,36006-04
77.074
,18819-32
,89429-03
3,6386
,25140-02
4,4264
,80000
,00000
,00(400
,00009
,H0(300
,00000
111,27
,35443-02
,36008-04
55,712
,18819-02
,89429-W3
,17517-01
.25140-W2
,17995*01
11,213
,78734
,00000
21.362
,0140110
,0(4000
3,6211
,00000
4,4(584
6

,19348*06
28k). 42
,61337-»01
.10236+06
3,2073
1,5244
1291.8
4.2846
1567,0
.00000
, 00000
,00000
.000V30
.00000
,00000
,18958*06
5,6335
,61337-01
94932.
3, 2 '37 3
1,5244
32,236
4,2846
32,848
3898,9
274.59
,00000
7431,6
, 00000
.0(9000
1259,5
.0(4000
1534,1
a
S
S
2
5






























-------
22 JIJN 7t>    ii:25:wi
 STREAM NUMBER
 TOTAL STRtAH
    FLJ* RATE (G/SEC)
              (G-MOLE/SEC)
    TEMPERATURE (DEG, K3
    PHESbUKE  (ATM)
    ENTHALPY  (CAL/SEC)
    SOUIliS    (WT X)
              (MG/CU M)
                                            SINTER PLANT ( 39X RECYCLE ) LIMESTONE  SCRUBBING SYSTEM
                              5614,1
                              278.33
                              330.24
                              11,981
GAS
   FLO*


n
i
K>
O









UENSI TY
COMP
SDii
CO*
NO
MO 2
02
sn«j
N2
HCL
H2H
CM 4
COMP
502
     NfJ
              (G/SEC)
              (G-MOLE/SEC)
              (L/SEC AT T)
              (L/StC, STP1
              (CAL/SEC)
              (G/L AT T)
              (G-MOLES/SEC}
             (MOLE X)
                              ,30000
    8

 ,19460+07
 96469,
 330,24
",70717+10
 11,976
 ,00000

 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000

 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000

 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,03000
 ,00000
 ,00000
     CH4
 ,19514+07
 96747,
 330,24
 ,00000
-,70919+10
 11,981
 ,00000

 ,00000
 ,000k10
 ,00000
                                                      ,00000
                                                      ,0210140
                                                      ,00000
                                                      ,00000
                                           .00000
   10

 3908,4
 216,52
 330,24
 ,0i<9000
-,14682+08
 ,00000
 ,00000

 ,00000
 ,00000
 ,00000
 ,00000
 .00000
 ,00(900

 ,00000
 ,00000
 ,00000
 ,019000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000

 .00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
 ,00000
                                                                  ,00000
-------
22 ,JUN 7t>    11:25102.
 STREAM NUMBER
 SLURHY STKEAM
    FLCH NATE  (G/SEC)
               (G-MULE/SEC)
               (L/SEC  AT  T)
    ENTHALPY   (CAL/SEC)
    BULK UtNSITY(G/ML  AT  T)
    KEY COMP RATECGMOUES/SEC)
      SO 2
      CO 2
      5)03
                                              SINTER PLANT  (  39X RECYCLE 3 LIMESTONE SCRUBBING  SYSTEM
                                               8910
       CAU
       MfiCI
       HCL
r>
i
oo
o
  LIQUID PHASE
     FLOW RATE

     ENTHALPY
     DENSITY
     KEY COHP I
       502
       cap
       s o .i
              CG/SEC)
              (G-MOLES/SEC)
              (CAL/SEC)
              (G/ML  AT  T)
      CM)
      m;u
       HCL
     KEY COMP
       S02
       C02
             CONIC (G-MOLKS/KG
       CAii
       MGM
       MAir1:)
       HCL
     PH
5614,1
278.33
5,0040
",20403+08
1121,9
j
1.0987
, 80908
2.6283
,88485-04
4,5211
, 43983-02
, 46268-02
,12362-01
279,11
4941,5
273.71
*, 18562+08
,98759
O
,29871-02
,16831*01
,90021-01
,88485-04
,94773-^01
,43983-02
,46268-02
,12362-Wl
273.49
H2D)
,6W628«03
,34161-02
,18271-01
,1/959-04
,19235-01
.89269-03
,93937-03
, 25090^02
6,3397
,19460+07
96469,
1734,2
-.70717+10
1122,1
381,91
276.80
913,53
, 30670W01
1567.0
1.5253
1 ,6047
4,2863
96739,
,17129+07
94869,
' -,64338+10
,98772

2.0751
4S2923
33,013
,30670-01
34,156
1,5253
1.6047
4,2863
94788,

,12152-02
,25136-02
,19332-01
.17960-04
,20001-01
,89322-03
,93969-03
.251«0-02
5,8535
,19514+07
96747,
1739,2
-,70919+10
1122, 0
381,91
281,23
913,60
,30757-01
1571,5
1,5288
1,6083
4,2970
97017,
,17176+07
95141,
•p, 64519 + 10
,98759

1,0383
5,8504
31,291
.3M757-01
32,943
1,5208
1,6083
4,29/0
95/162.

,60628-03
,34161-02
,18271-01
, 1 7959-04
,19235-01
,89269-03
, 939M7*03
,25390-02
6.3397
,00000
,00000
,00000
,00000
,00000
,000li90
,00000
,00000
,00000
,00200
,010000
,000(30
,00000
.00000
39M8.4
216,52
-,14682+08
,98742

, 1 6909-02
,13783-01
,66430*01
,70015-04
,69980-01
,34778-02
,36592*02
,97767*02
216,35

,43382-03
,35363-02
,17043-01
,17963-04
,17954-01
, 89228*03
,93882-03
,25083-02
6,3878
                                                                                                          I®
                                                                                                          z
-------
22 JUN 76    11 t25}02,25iO
 STREAM NUMBER
 LIQUID PHASE(CONT)
    LUil. H20 RATE  (KG/SEC)
               (LITERS/SEC)
                  (G-MOUE3/KG
                                              SINTER PLANT ( 39X RECYCLE ) LIMESTONE  SCRUBBING SYSTEM
                                               8910
o
i
LO
      H*
      DH-
      HSH3-
      5043
      HC03-*
      C03 =
      N03-
      HS04-
      H2C03(1.)
      CA + +
      CAOH +
      CAHCD3+
      CAS04fU)
      C A N il 3 •»•
      M G + *
      MGOH*
      .1GSM3(U)
      SGHCU3+
      MGbi.i4CL)
      MRC03fU)
      N)A +
      NAMHtU
      N A C 0 3 -
      NAMC(I.ICL)
      N A S 0 4 -
       CL-
     IONIC STRENGTH
     DISSUUVEI) SOLIDS
                      (WPPM)
 4,9270
 4.9889
H20)
 ,54125-06
 ,22158-06
 ,24580-03
 ,38968-04
 ,10901-01
 ,18489-02
 ,54013-06
 ,34997-04
 ,63723-06
 ,13135-07
 ,13379-02
 ,11644-01
 ,33246-07
 ,31487-03
 ,27108-05
 ,21776-03
 ,70547-02
 ,90536-0b
 ,61581-03
 ,35879-07
 ,66232-05
 ,57258-05
 .26425-03
 ,24131-06
 ,18251-02
 ,71775-10
 ,43355-07
 ,21933-05
 ,.50796-04
 ,1601 1-07
 ,25H9v)-02
 ,49771-01
 2932,2
1707.7
1728,9
,16604-05
,72498-07
,81661-03
,42577-04
,11485-01
,75341-03
,72386-07
,34979-04
,20372-05
,13332-06
,16656-02
,12039-01
,11143-07
,34879-03
,36832-06
,90888-04
,75211-02
,92566-06
,61251-03
,11581-07
,70655-05
.23014-05
,27130-03
,31575-07
,18256-02
,23376-10
,57547-08
,H8954-06
,52905-04
,15907-07
,25100-02
,51404-01
3058,8
1712,6
1734,1
, 54123-06
,22158-06
,24580-03
,38968-04
,10901-01
,18489-02
,54013-06
,34997-04
,63723-06
,13135-07
,13379-02
,11844-01
,33246-07
,31487-03
,27108-05
,21776-03
,70547-02
,90536-06
,61581-03
,35879-07
,66232-05
,57258-05
,26425-03
,24131*06
,lb2bl-02
,71775-10
,43355-07
,219.53-MS
,50796-04
,16011-07
,25090-02
,49771-01
2932,2
3,8977
3.9473
,48348-06
,24654-06
.16783-03
,29356-04
,10245-01
,19976-02
,64386-06
,35039-04
,54464-06
,80658-08
,13000-02
,110143-01
,35488-07
,23144-03
,31530-05
,22576-03
,64898-02
,87159-06
,62131-03
,40824-07
,51892-05
,63275*05
,25912-03
.29918-06
,18265-02
,80559-1 0
,52560-07
,23909-05
,48706-04
,16207-07
.25083-02
.47208-01
2737,3
-------
22 JUN 7b 11125102,475
STREAM NUMBER
SOLID PHASE
FLOW RATE (G/SED
(G^MOLE/SEC)
ENTHALPY (CAL/SEC)
SPECIFIC GWAVITY
KEY COUP KATE(GMOLES/SEC)
so a
COi?
SO 3
M2U5
CAO
MGU
MA20
HCU
H20
_ COUP RATE (G MOLES/SEC)
i CAO
£ CACOH12
CACfM
CASOJ
CASOJ*1/2H20
CAS04
CAS04*2H20
MGU
NG COtO 2
MGCQA
•1GUfM*3H20
MGC()3*bH20
MGSCM
MCii>03*.JH20
fl(;SOii*6H2n
MGS04
MGCL2
MA 20
NACL
IMERT5
LINES TUNE
XLS

7

072,60
4.6207
,18412+07
2,4228

1,4)957
.79225
2,5383
,00000
4,4263
,000^0
,00000
,00000
5,6245

,00000
,00000
,79225
,03000
1,0957
,29114-05
2,5383
,00000
,00000
,0(4000
, 300U0
,045000
,fl00U0
,v}W0fc)0
a 0 tl ' W W
• "i ^1 V) fe) B
,<5y000
,021000
,Mr10^H
,19443
,00000
.MM 00
SINTER PL
8

,23305+06
1600,3
-,63794+09
2,4225

379,83
272.50
080,52
,00000
1532,9
,00000
,00000
,00000
1951,0

,00000
,00000
272,50
,00000
379.83
,10120*02
880,52
,000a0 '
,0ti0fc)0
,00000
,000^0
,00000
,00040
,00000
,0.0000
,00000
.00000
,00000
,0001*0
67,403
,000190
,000140
ANT ( 39X RECYCLE )
9

,23379+06
1606.1
v, 647)00 + 09
2,4228

380,87
275,38
882,31
,00000
1538,6
,00000
, 03000
,00000
1955,1

,00000
,02000
275,38
, 030ldft
38(3,87
,iui2a*a2
882,31
,0001-10
,00000
,0210(40
,001500
,00000
,00000
,00003
,000k}ft
.000U0
,00000
,00000
,00000
67,5d4
, W0W00
,003^0
10

,00000
,00000
,00000
,00000

,00000
,00000
,00000
,00000
,00000
, PI0000
,00000
, 00000
,00000

,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00900
,00000
,110000
,00000
,0000(9
,00000
,00000
,00000
,00000
,00000
,00000
,00000
LIMESTONE SCRUBBING SYSTEM
                           HI
                           o1
                           z
-------
22 JUN 76    11I25J02.665
 STREAM NUMHb^
 ELEMENT su;-ATOMS/SEC
 TOTAL STKEAM
      H
      C
      M
      0

      MG
      S
      CL
      CA
 GAS PHASE
      H
      C
SINTER PLANT ( 39X RECYCLE )  LIMESTONE SCRUBBING SYSTEM
 8           9          10
                                                                                                      n
                                                                                                      o
                                                                                                      3D
o
w
      0
      S
      CL
 LIQUID PHASE
      H
      C
      N
      0
      NA
      MG
      S
      CL
      CA
 SOLID PHASE
      H
      C
      N
      0
      MA
      MG
      S
      CL
      CA
558.23
,80908
,17697-03
295,34
,92536-02
,43983-02
3,7271
,12362-01
4.5211
,00000
,05*000
,00000
.021000
,00000
,00000
546,98
,16831-01
.17697-03
273,90
,92536-02
.43983-02
.93008-01
,12362-01
.94773-01
11.249
.79225
,00000
21,442
,80000
.40000
3.6341
.H3PI30
4,4263
.19348+06
276,80
,61341-01
,10237+06
3,2093
1,5253
1295,4
4,2863
1567,0
,00000
,00000
.000019
,00000
,00000
,90000
,18958+06
4,2923
,61 341-01
94937,
3.2093
1.5253
35,088
4,2863
34,156
3901,9
272,50
,00000
7430,0
,00000
,00000
1260,4
,00030
1532,9
,19404+06
281,23
,61514-01
,10266+06
3,2165
1.5288
1295,5
4.2970
1571,5
,00000
,00000
,00000
,00000
,00000
,00000
,19313+06
5,8504
,61514^01
95206.
3,2165
1,5288
32,329
4,2970
32,943
3910,1
275,38
,00000
7453,0
,00000
.00000
1263.2
,00000
1538,6
432,71
,13783*01
,14003*03
216.66
,73184-02
,34778-02
,68120-01
,97767-02
, 69980-01
,00000
.00000
,00000
,00000
,00000
,00000
432,71
,13783-01
,14003*03
216,66
,74184-02
,34778«02
,68120*01
,97767*02
,69980*01
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
,00000
-------
 22 JUN 76    11:24:59,710                    SINTER  PLANT ( 39% RECYCLE  ) LIMESTONE SCRUBBING SYSTEM   0
                                                                                                         39
   5CRIBI5, rJRUIPMENT NUMBER  7                                                                           §
        L/G = 8,15413^01 KAL/100a  ACF                                                                    |
        PhESSUHE DROP »    ,fe)0 PSI                                                                        §
        P*RTICULATE REMOVAL  s   70.02  X                                                                   |
        KGAV(S02) s  l(M7ti62 + 05  LBMOLE/HR  ATM                                                           1
        MTUCS02) *  2,347

   5TOICHIOMETRY s 1M9*9 HOLE X  LIMESTONE  PER S02
o
i
OJ
-------
RADIAN
CORPORATION
                          APPENDIX D



                           COST  DATA
                              D-l
-------
CORPORATION
 1.0
EQUIPMENT LIST
           The items listed in Tables D-l and D-2 are the equip-
 ment required to process the flue gas from the two sinter plant
 cases considered in this study.  The equipment arrangement was
 shown, in Figure 5-1.  The limestone process was divided into
 ten areas to allow comparisons of the two cases to be made
 easily.

           The size cost scale factors listed in Tables D-l
 and D-2 were used to obtain order-of-magnitude cost estimates
 for the process equipment.   Capital investment costs for com-
 plete plants can be correlated to within + 30% with these fac-
 tors using some plant parameter as a  basis for equipment sizing,
 The correlation used in this study was of the form:
Capital
Cost
                  'Capital cost ~
                  for reference
                      size
                      x
size parameter
reference size
parameter
                                              x I
      where:  I = inflation index factor
              n = size-cost scale factor

 This technique allows a reasonably accurate estimate of plant
 cost to be made from data on different size plants without
 obtaining price quotations from equipment vendors.

      The inflation indices used for cost estimates of this sort
 introduce some error into the estimate, but this is unavoid-
 able.   Several publications, most notably Marshall and Stevens,
 Chemical Engineering Magazine,  and Nelson Refinery Construction
                               D-2
-------
RADIAN
CORPORATION
 and Equipment Inflation Indices, list inflation indices based
 on a year in the late 1950's (e.g., 1957 = 100.).   Using these
 indices, costs of equipment can be scaled up to the present
 with reasonable accuracy.   However, projecting costs into the
 future  (1977 in this case) introduces a possible error.  Nor-
 mally,  some inflation rate in the 7-9 percent per year range
 is used to estimate future equipment prices.  The inflation
 rate assumed can be based on past performance as indicated by
 the published inflation indices but projecting past inflation
 rates into the future can introduce error.

           The Chemical Engineering plant cost index was used for
 this study.   The 1974 costs were scaled up to 1975 costs using
 indices from this index.   To project costs from 1975 to 1977
 a yearly inflation rate of 7 percent was used based upon inflation
 rates of previous years.   The high inflation rates experienced since
 1973 were considered abnormally high so they were not used.
                              D-3
-------
                                            TABLE D-l
CASE 1: STANDARD OPERATION
WORK SHEET FOR PROCESS EQ'JIP>ENT COSTS
AREA 1 - MATERIALS HANDLING




1.

2 _


3.


4.


5 .
6.


7.



S.
9.
10.
11.
12.


13.


11.



I cam
Unloading
hopper i!o. 1
Line scone
feeder iio. 1
(vibrat:,ng)
Convevoi..'
(belt) !!o. 1


Convevoi.'
(belt) iio. 2


Hoppers
under p:.Le
Limestone
feeder iio. 2
(vibrating)
Conveyo::
(belt) !!o. 3


Tunnel
surap puitp
Elevator.'
No . 1
Bin
Car shaker
Dust
collecting
system :.'o. 1

Dust
collecting
system iio. 2

Bag filrer
system



Xo. DescriDtion
1 Capacity ,31m , carbon
steel
1 5.8 kg/s


1 5.3 kg/s


1 5.3 kg/s


3 Capacity 0.21m3, car-
bon steel
3 2.8 kg/s


1 2.3 kg/s



2 3.2 x 10~4m3/s, carbon
steel, neoprene lining,
186.5 watt motor
1 2.8 kg/s
1 Capacity 15.6m3, car-
bon steel
1 Railroad trackside
vibrator
1 0.12 n3/s inertial
separator, cyclone,
hoppers, fan", and
drive
1 0.33 ra3/s inertial
separator, cyclone,
hoppers, fan, and
drive
1 0.87 n /s, automatic
fabric dust collectors.

Size-Cost
Scale
Factor
0.68

0.58


0.81
0.65

0.81
0.65

0.68
0.58


0.65

0.81



Factor
Source
Chen. Engr. 3-24-69
Guchrie
Chem. Engr. 3-24-69
Guthrie

Fund, of Cost Enzr.
1964
Chem. Engr. 3-24-69
Guthrie
Fund, of Cost Engr.
1964
Chem. Engr. 3-24-69
Guthrie
Chem. Engr. 3-24-69
Guthrie
Chem. Engr. 3-24-69
Guthrie

Chem. Engr. 3-24-69
Guthrie
Fund, of Cost Engr.
1964
Depends on gpra and head re- .
quirements resulting in
changes of motor and impeller
size
0.83
0.68
	
0.80


0.80


0.68
Chem. Ensr. 3-24-69
Chem. Engr. 3-2^-69
	
Chesn. Engr. 3-24-69
Guthrie


Chem. Engr. 3-24-69


Chem. Engr. 3-24-69
Base
Cost
Each
(1977)
560

1,100


580


2,750


470
570


4,240



720
2,560
4,280
7,950
590


1,100


2,580

Total
Mid-1977
Cost
560

1,100


580


2,750


1,410
1,710


4,240



1,440
2,560
4,280
7,950
590


1,100


2,580
                     bag  support, shaker sys-
                     tem,  isolation damper,
                     motor, drive, dust hopper,
                     fan  and motor
SUBTOTAL
                                          D-4
-------
                                      TABLE D-I  (Continued)



AREA 2 - FE
ED PREPARATION
Size-Cost
Scale

i

2 .

3.

4.

5 .



6.


7 .



3.



9.


10.
11.

I cera
Bin discharge
feeder
Weigh feeder

Gyratory
crusher
Elevator
No. 2
Wet ball
r.ill


Slurry feed
tank
Lining
Agitator,
slurry
feed
tank
Pumps, slurry
feed rank


Dust
collecting
system
Hoist
Bag filter
system
N'o.
1

1

1

1

1

1

1

1
!



7



1


1
1

Description
0.8 kg/s, 'carbon
steel
0.8 kg/s, carbon
steel
0.8 kg/s

0.8 kg/s

7.4 kg/s

78330 W motor

Capacity 20. 8m ,
carbon steel
6.35 x 10" m neoprene
1492 W, neoprene coated



6.9 x 10~4m3/s,
carbon steel, neoprene
lined

0.42 m3/s, inertial
separator, cyclone,
hoppers, fan and drive
1800 kg electric
0.87 m /s, automatic
fabric dust collectors,
Factor
0.58

0.65

1.20

0.65

0.65

1.07

0.68

	
0.50

0.46

Depends
Factor
Base
Cost
Each
Source (
Chem. Engr.
Guthrie
Chem. Engr.
Guthrie
Chem. Engr.
Guthrie
Chem. Engr.
Guthrie
Chen. Engr.
Guthrie
3-24-69

3-24-69

3-24-69

3-24-69

3-24-69

Fund, of Cost Ener.
1964
Chem. Engr.
Guthrie
	
Chem. Engr.
Guthrie

3-24-69


3-24-69



3

2

1

50

3

5

4
3

1977)
320

,900

,450

,140

,550

,600

,450

,820
,020

Total
Mid- 1977
Cost


3

2

1

50

3

5

4
3

320

,900

,450

,140

,550

,600

,450

,820
,020

Fund, of Cost Engr.
1964
on gpra and h
quirements resulting
changes
size
0.80


0.81
0.68

of motor and

Chem. Ener.
Guthrie

Popper, H.
Chem. Engr.


ead re-
in
impeller

3-24-69



3-24-69


1



1


10
2


,990



,340


,890
,580


3



1


10
2


,980



,340


,890
,580

                     bag support,  shaker sys-
                     tem,  isolation damper,
                     motor,  drive,  dust hopper,
                     fan and motor
SUBTOTAL
                                              D-5
-------
                                    TABLE D-I (Continued)
AREA 3 - PARTICULATE SCRUBBING

1.


2.



3.



4

5.

6 .

7.



Item
Tank ,
particulate
scrubber,
effluent
hold
Lining
Agitator,
effluent
hold ca'.ilc

Pumps ,
recyc le
slurry

Venturi
scrubber
Venturi
sump
Soot
blowers
Bleed
pump


Size-Cost
Scale Factor
Mo. Description Factor Source
2 Capacity 174. 1 a ,
carbon steel

2 6.35 x 10 m neoprene
2 7460 W, neoprene
coated


3 .4 m /s, carbon
steel, neoprene lined


2 93.7 m /s, carbon steel,
neoprene lined
2 Carbon steel, neoprene
lining
10 	

3 1.9 x 10"3 tn3/s, carbon
steel, neoprene lined


0.68 Chem. Engr. 3-24-69
Guthrie

	 	
0.26 Fund, of Cost Engr.
1964
0.50 Chem. Engr. 3-24-69
Guthrie
Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
size
0.60 Universal Oil
Products
0.63 Cheta. Engr. 3-24-69
Guthrie
1.00 TVA

Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
size
Base
Cost
Each
(1977)
29,150

21,460
5,770



20,950



160,250

51,430

4,820

2,000



Total
Mid-1977
Cost
58,300

42,920
11,450



62,350



320,500

122,860

48,200

6,000



SUBTOTAL
                                        D-6
-------
                                      TABLE D-l (Continued)

AREA 4 -
S02 SCRU33I.NG
Size-Cose
Scale Factor
I eera
1. Spray cower
scrubber
2 . Spray tower
sump
3. Tank
absorber
ef f luenc
hold
Lining
4. Asitator,
S02
absorber
hold tank
5. P-or.ps, S02
absorber
recycle
slurry
6 . Pur.p s ,
makeup
water

7. Sooc
blowers
S. Derrdster

9 , PUI7.D ,
bleed


10. Tank
Denis Cer
Wash
11. Pump,
Demister
Wash

SraiOTAL
No. DescriDtion Factor Source
2 Gas flow 93.7 m3/s,
carbon steel, neoprene
2 Carbon steel, neoprene
lined
2 Capacity 530.9 m3, car-
bon steel, field erected


2 6.35 x 10 m neoprene
2 22380 W, neoprene
coated


5 .62 m /s, carbon steel,
neoprene lined


2 1.1 x 10"3 m3/s, carbon
steel, neoprene lined


10

2 Carbon steel, neoprene
lined
4 6.7 x 10"" m /s, carbon
steel, neoprene lined


2 Capacity 1.89m , carbon
steel, neoprene lined
4 1.3 x 10 m /s, carbon
steel, neoprene lined



	 Western Precipitation
Div. Joy Mfr. Co.a
0.68 Chem. Engr. 3-24-69
Guthrie
0.68 Chem. Engr. 3-24-69
Guthrie


...
0.50 Chem. Engr. 3-24-69
Guthrie


Depends on gpn and head re-
quirements resulting in
changes of motor and impeller
size
Depends on gpm and head re-
quirements resulting in
changes of motor and imoeller
size
1.00 TVA




Depends on gpm and head re-
quirements resulting in
changes of ir.otor and impeller
size
0.68 Chem. Engr. 3-24-69
Guthrie
Depends on gpm and head re-
quirements resulting in
chanaes of motor and impeller
size"


Base
Cost Total
Each Mid-1977
(1977) Cost
232,000 464,000

60,460 120,920

37,680 75,360



32,250 64,500
12,360 24,720



32,620 163,100



1,500 3,000



4,820 48,200

23,200 46,200

2,000 3,000



1,400 2,800

1,500 6,000



1,026,300
Indicateds source of spray tower  cost
                                             D-7
-------
                                         TABLE D-l (Continued)

1.
2.
Item
Steam
reheaneT
Sooc
blowers
No.
2
10
AREA 5 - REHEAT
Size-Cost
Scale
Description Factor
4.0 x 106 K racing 0.30
146.3 m2 surface area
1.00
Factor
Source
Chem. Engr. 3-24-69
Guthrie
TVA
   SUBTOTA1
                                                                                    Base
                                                                                    Cost     Total
                                                                                    Each    Mid-1977
                                                                                    (1977)     Cost
                                                                                   81,130   162,270


                                                                                    4,820    48,200


                                                                                            210,470
                                        AREA 6 - GAS HANDLING
1. Fan
                        1.53 x 10  W motor drive  0.68
                                    Chem. Engr. 3-24-69    71,650    143,300
                                    Guthrie
                                       AREA 7 - SOLIDS DISPOSAL



1.
2.



Item



Clarifer:
Pumos,
feed
pond



No.
1
2




5.5
1.3
bon


Description
x 10~3 m3/s
x 10"3 m3/s, car-
steel, neoprene
Size-Cost
Scale
Factor
...
Depends
Base
Cost


PEDCO
on gpm
Factor
Source
(PE-146)
and head re-
quirements resulting in
Each
tl 9
161,
1,

77)
000
500

Total
Mid-1977
Cost
161,000
3,000

                        lined
3. Pump, cT.arifer  2
   water rocvcle
4. Pumps, yiarticu- 2
   late pond water
   recycle
5. Pumps, S02
   pond wacer
   recycle
   SUBTOTAL
                               ,-3
4.1 x 10 J m3/s, car-
bon steel, neoprer.e
lined
3.2 x 10"3 3i3/s, carbon
steel, -eoprene lined
5.8 x 10"  m /s, carbon
steel, neoprene lined
changes of motor and impeller
size

Depends on gprn and head re-      3,500
quirenents resulting in
changes of motor and impeller
Depends on gpm and head re-      2,500
quirements resulting in
changes of motor and impeller
size

Depends on gpm and head re-      1,100
quirements resulting in
changes of motor and impeller
size
7,000
5,000
2,200
                                                                                             178,200
                                                D-8
-------
                                         TABLE D-l (Continued)

                                          AREA 8 - UTILITIES

                          Note:  There is no process equipment in :his area.
                                           AREA 9 - SERVICES
     leer.
1. Payloader

2. Plane
   vehicles

3. Maine. &
   instrument
   shop-
   equipraenc

i. Service
   building-
   equipmenc

5. Stores-
   equipmenc
   SUBTOTAL
                  N'O.
      Descripcion
                                                Size-Cose
                                                 Scale
                                                 Faccor
                                            Faccor
                                            Source
                                 Base
                                 Cose     Tocal
                                 Each    Mid-1977
                                (1977)
	     Cose

29,350     29,850

           12,050


31,780     31,780
                                                           42,130     i2,130



                                                           12,760     12,760



                                                                     128,5/0
                                   AREA 10 - PARTICLE RECIRCULATIOS
Item
1. Wee ball
mill
No.
1
Descrioeion
3.2 x 10"4 m3/s
Size-Cose
Scale
Faccor
.65
Factor
Source
McGlanery
2.  Pump,
   particle
   recirculacion
3. Tank,
   particle
   recirculaeion
   surge
3.2 x 10*6 m3/s,
molded polypropylene
Capacity l.lm , carbon
steel, neoprene lined
Depends on gpm and head re-
quirements resulting in
changes of mocor and irr.peller
sizes
.68
         Me Glemery
                                                                                    Base
                                                                                    Cose     Tocal
                                                                                    Each    Mid-1977
                                                                                   (1977)     Cose

                                                                                   29,950    29,950
   500
 1,000
1,000
1,000
   SUBTOTAL
                                                                                             31,950
                                                D-9
-------
                                            TABLE D-2
CASE 2: 397, SINTER GAS RECYCLE
WORK SHEET FOR PROCESS EQUIPMENT COSTS




1.

i


3.


4 .


5 .

6.


7.


3.
9.
10.
11.
12.
13.

14.



Item
Unloading
hopper Mo. 1
Limescoae
feeder Mo . 1
(vi.braci.ng)
Conveyor
(belt) No. 1


Conveyor
(belt) N'o. 2


Hoppers
under pile
Limestone
feeder Mo. 2
(vibrating)
Convevor
(belt) N'o. 3


Tunnel
sump pusp
Elevator
No. 1
3in
Car shaker
Dust
collecting
system No. 1
Dusc
collecting
system N'o. 2
Bag filter
system
AREA 1 -


No. Descriotion
1 Capacity .34 m3,
carbon sceel
1 6.3 kg/s


1 6.3 kg/s


1 6.3 kg/s


3 Capacity 0.23 m3,
carbon steel
3 3.0 kg/s


1 3.0 kg/s


2 3.2 x 10'4 m3/s,
carbon steel, neoprene
lining, 186.5 watt
motor
1 3.0 kg/s
1 Capacity 17 m", carbon
steel
1 Railroad crackside
vibrator
1 0.12 m3/s, inertial
separators, cyclone,
hoppers, fan, and drive
1 0,35 m3/s, inertial
separators, cyclone,
hoppers, fan, 'and drive
1 0.94 m /s, automatic
fabric dust collectors.
MATERIALS
Size-Cost
Scale
Factor
0.68

0.58


O.S1
0.65

0.81
0.65

0.68

0.58


0.65
0.81

HANDLING

Factor
Source
Cham. Engr. 3-24-69
Guthrie
Chem. Engr. 3-24-69
Guthrie

Fund, of Cose Engr.
1964
Chem. Engr. 3-24-69
Guchrie
Fund, of Cost Engr.
1964
Chem. Engr. 3-24-69
Guthrie
Chem. Engr. 3-24-69
Guthrie
Chen. Engr. 3-24-69


Chem. Engr. 3-24-69
Guthrie
Fund, of Cost Engr,
1964
Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
sizes
0.33
0.68
..i.
0.80
0.80

0.63
Chem. Engr. 3-24-69
Chem. Engr. 3-24-69
	
Chem. Engr. 3-24-69
Guthrie
Chem. Engr. 3-24-69

Chem. Engr. 3-24-69

Base
Cost
Each
(1977)
600

1,160


620


2,940


490

600


4,490


720
2,760
5,470
6,600
590
1,160

2,730

Total
Mid-1977
Cose
600

1,160


620


2,940


1,470

1,300


13,470


1,440
2,760
5,470
6,600
590
1,160

2,730
                    bag support, shaker sys-
                    tem, isolation damper',
                    motor, drive, dust hoppe:
                    fan and motor
SUBTOTAL
                                                                                         36,210
                                          D-10
-------
                                      TABLE D-2 (Continued)
AREA 2 - FEED PREPARATION
Size-Cost
Scale
Item
1. Bin discharge
feeder
2. Weigh feeder

3. Gyratory
crusher
4. Elevator
.No. 2
5. Wet bail
nill


6. Slurry feed
tank
Lining
7. Agitator,
slurrv
feed
tank
8. Pumps, slurry
feed tank


9. Dust
collecting
system

10. Hoist
11. Bag filter
system
NO.
1

1

1

1

1

1

1

1
1



2



1


1
1

Descriotion
0.8 kg/s, carbon steel

0.8 kg/s, carbon steel

0.8 kg/s

0.8 kg/s

7.9 kg/s

85790 W motor

Capacity 20.9 ai ,
carbon "steel
6.35 x 10 in neoprene
1492 W, neoprene
coated


7.6 x 10" m /s, carbon
steel, neoprene lined


0.47 m /s, inertial
separator, cyclone,
hoppers, fan, and
drive
1800 kg electric
0.94 ni /s, automatic
fabric dust collectors,
Factor
0.58

0.65

1.20

0.65

0.65

1.07

0.68

	
0.50

0.46

Depends
Factor
Source
Chem. Engr.
Guthrie
Chem. Engr.
Guthrie
Chem. Engr.
Guthrie
Chem. Engr.
Guchrie
Chem. insr.
Guthrie
3-24-69

3-24-69

3-24-69

3-24-69

3-24-69

Fund, of Cost Engr.
1964
Chem. Er.gr.
Guthrie
	
Chem. Engr.
Guthrie

3-24-69


3-24-69

Base
Cost
Each
(1977)


3,

2,

I,

52,

3,

5,

4,
3,

320

900

450

140

870

970

570

930
020

Total
Mid-1977
Cost


3

2

1

52

3

5

4
3

320

,900

,450

,140

,370

,970

,570

,930
,020

Fund, of Cost Engr.
1964

on gpm and head re-
quirements resulting
changes
size
0.80


0.81
0.68

of motor and

Chem. Engr.
Guthrie


Popper, H.
Chem. Engr.

in
impeller

3-24-69



3-24-69


1.



I,


10,
2,


990



460


890
730


3



1


10
2


,980



,460


,890
,730

                     bag support, shaker sys-
                     tem, isolation damper,
                     motor, drive, dust" hopper,
                     fan and motor
SUBTOTAL
                                                                                           97,230
                                           D-ll
-------
                                    TABLE D-2 (Cor.tinued)
                                AREA 3 - PARTICULATE SCRUBS ISC
Base
Size-Cost Cose
Scale Factor Each

1.


2.

3.
4.
5 .
6.
7.
Item No.
Tank 2
particulars
scrubber,
effluent.
hold
Lining 2
Agitator, 2
effluent.
hold tar.k
Pump s , 3
recycle
slurry
Vencuri 2
scrubber'
VB.nturi 2
sump
Soot blowers 10
Bleed pimp 3
Description . Factor Source (1977)
Capacity 199.4 m3,
carbon steel

6.35 x 10 m neoprane
7450 W, neoprene
coated

.26 m /s, carbon
steel, neoprene
lined
53.7 m /s, carbon steel,
neoprene lined
Carbon steel, neoprene
lining

1.6 x 10 m /s, carbon
steel, neoprene lined
0.68 Chen. Engr. 3-24-69 31,970
Guthrie

	 23,540
0.26 Fund, or Cost Engr. 5,770
1964
0.50 Chem. Engr. 3-24-69
Guthrie
Depends on gpm and head re- 17,450
quiretnenta resulting in
changes of motor and impeller
size
0.60 Universal Oil 121,040
Products
0.68 Cheni. Engr. 3-24-69 44,000
Guthrie
1.00 TVA 4,820
Depends on gpm and head re- 2,000
quirements resulting in
changes of motor and impeller
size
Total
Mid-1977
Cost
63,940

27,080
11,450

52,350
242,080
88,000
48,200
6,000
SUBTOTAL
                                           D-12
-------
                                     TABLE  D-2  (Continued)
AREA 4 - SOi SCRUBBING
Size-Cost
Scale Factor

1.
2.

3.




/.


5 .



6.



7.

3.

a _



10.


11.




Item
Spray cower
scrubber
Spray tower
sump
Tank,
absorber
effluent
hold
Lining
Agitator, S07
absorber
hold tank
Pumps, S02
absorber
recycle

Pump s ,
makeup
water

Soot
blowers
Demister

Pump, bleed



Tank,
demister
wash
PlLT.p ,
deir.ister
wash

SUBTOTAL
No.
2
2

2



2
2


3



2



10

2

4



2


4




Description Factor Source
Gas Flow 117.4 m3/s,
carbon steel, neoprene
Carbon steel, neoprene
lined
Capacity 707.9 m ,
carbon steel, field
erected

6.35 x 10 m neoprene
29840 W, neoprene
coated

.46 m /5, carbon steel,
neoprene lined


1.2 x 10 m /s, carbon
steel, neoprene lined




Carbon steel, neoprene
lined
6.7 x 10 "* n /s, carbon
steel, neoprene lined


Capacity 1.89 m , carbon
steel, neoprene lined

1.3 x 10 m /s, carbon
steel, neoprene lined



Wester Precipitator
Div., Joy Mfg. Co.a
0.68 Chem. Engr. 3-24-69
Guthrie
0.68 Chem. Engr. 3-24-69
Guthrie


	
0.50 Chem. Engr. 3-24-69
Guthrie

Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
size
Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
size
1 . 00 TVA

	 	

Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
size
0.68 Chem. Engr. 3-24-69
Guthrie

Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
size

Base
Cost Total
Each Mid-1977
(1977) Cost
145,260 290,520
44,000 88,000

45,820 91,640



39,220 78,440
13,250


27,000 27,000



1,500 3,000



4,820 48,200

14,500 29,000

2,000 8,000



1,400 2,800


1,500 6,000



672,600
Indicates source of spray  tower cost
                                           D-13
-------
                                         TABLE D-2  (Continued)

                                            AREA 5  -  REHEAT
     Icera


     Item
1. Steam
   reheater

2. Sooc

   SUBTOTAL
No.

 2


10
      Description
                              Size-Cost
                               Scale
                               Factor
                                           ractor
                                           Source
                                 Base
                                 Cost     Total
                                 Each    Mid-1977
                                 (1977)     Cost
2.0 x 10° W rating
73.4 m<-     Jin-far
73.4
            surface area
0.80     Chem. Engr. 3-24-69    52,350    104,700
                           1.00
                                    TVA
                                 4,820     48,200

                                          132,900'
                                         AREA 6 - GAS HANDLING
Item
1. Fan
Base
Size-Cost Cost Total
Scale Factor Each Mid-1977
No. Descriotion Factor Source (1977) Cost
2 1.14 x 106 W drive 0.68 Chem. Ener. 3-24-69 51,430 102,860
                                                            Guthrie
                                       AREA 7 - SOLIDS DISPOSAL
1. Clarifier

2. Puir.ps, pond
   feed
3. Pump, clarlfier 2
   water recycle
4.  Pump s,
   particuJace
   pond wat-er
   recycle

5.  Pumps, H02
   pond wat;er
   recycle
      5.8 x 103 m3/s

      1.4 x 10~3 m3/s, car-
      bon steel, neoprene lined
      4.4 x 10   m /s, carbon
      steel,  neoprene lined
      3.7 x 10"3 m3/s,
      carbon sceel,  necprene
      lined
      5.8 x 10   m'Vs, carbon
      steel,  neoprene lined
                           0.68
         PEDCO (PE-146)
                           Depends on gpn and head re-
                           quirements resulting in
                           changes of niocor and impeller
                           size

                           Depends on gpn; and head re-
                           quirements resulting in
                           changes of motor and impeller
                           size

                           Depends on gpm and head re-
                           quiremencs resulting in
                           changes of motor and impeller
                           size
171,600

  1,500




  3,500




  4,000




  1,100
171,600

  3,000




  7,000




  3,000




  2,200
   SUBTOTAL
                                                 D-U
-------
                                         TABLE D-2 (Continued)
                                          AREA S - UTILITIES

                          Note:  There is no process equipment in this area.


                                          AREA 9 - SERVICES
     Item
1. Payloader

2. Plant
   vehicles

3. Maine. &
   instrument
   shop-
   equipment

i. Service
   building-
   equipment

5. Stores-
   equipment
   SUBTOTAL
                  No.
                              Description
                                                Size-Cost
                                                 Scale
                                                 Factor
                                            Factor
                                            Source
                                Base
                                Cost     Total
                                Each    Mid-1977
                               C1977)     Cost

                               29,850    29,850

                                	     12,050


                               31,780    31,780
                                                           42,130    42,130



                                                           12,760    12,760



                                                                    128,370
                                   AREA 10 - PARTICLE RECIRCULATION



1.



Item
Wet ball
mill
Size-Cost
Scale
No. Description Factor
1 3.2 x 10~4 m3/s .65


Factor
Source
McGlamery

2.  Pump,
   particle
   recirculation
3.  Tank,
   particle
   recirculation
   surge


   SUBTOTAL
3.2 x 10~4 m3/s,
molded polypropylene
Capacity 1.1 o ,  carbon
steel, heoprene lined
                                                                                    Base
                                                                                    Cost      Total
                                                                                    Each     Mid-1977
                                                                                   (1977)      Cost

                                                                                   29,950     29,950
Depends on gpm and head re-
quirements resulting in
changes of motor and impeller
size
                                                    .68
        McGlamery
  500
1,000
1,000
1,000
                                                                                             31,950
                                                   D-15
-------
RADIAN
CORPORATION
 2.0
COST FOR SLUDGE PONDS
           The cost  for  the  sludge  ponds was not  included in the
 previous section because  they were not considered  to be equip-
 ment items.   The cost of  the ponds, unlike the equipment items,
 includes installation,  and  the  cost for pumps and  piping to and
 from the pond (~1 mile) are included.  The ponds are clay-lined,
 and they are sized  for  a  30-year operation at 7000 hr/yr operat-
 ing time.   A midwestern plant location is assumed.  The total
 cost is  expected to vary  for each  specific plant location due
 to differing land costs.  Table D-3 contains the cost informa-
 tion for the sludge ponds.
                            TABLE D-3
    Item
Prescrubber settling
pond, Standard System
                   COST DATA FOR SLUDGE PONDS
              Area @ 40 foot     Source
                 Depth (acres)   	
                  8. 2              TVA
       Total Cost
        Mid-1977
        Dollars
         120,000
Absorber settling
pond, Standard System

Prescrubber settling
pond, Recycle System
                 11.5
                  7.1
TVA
TVA
170,000
104,000
Absorber settling
pond, Recycle System
                 11.2
TVA
166,000
                              D-16
-------
                                TECHNICAL REPORT DATA
                          (Please read limnictions on the reverse before completing)
1. REPORT NO.
 EPA-600/2-76-281
                                                       3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Desulfurization of Steel Mill Sinter Plant Gases
                             5. REPORT DATE
                             October 1976
                                                       6. PERFORMING ORGANIZATION CODE
7.AUTHOR(S)Gary D  Brown>  Richard T. Coleman, James
 C.  Dickerman, and Philip S. Lowell
                                                       8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
                                                       10. PROGRAM ELEMENT NO.
 Radian Corporation
 P.O. Box 9948
 Austin, Texas  78766
                             1AB015; ROAP 21AQR-005
                             11. CONTRACT/GRANT NO.
                             68-02-1319, Task 58
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; 3-9/76	
                             14. SPONSORING AGENCY CODE
                              EPA-ORD
15. SUPPLEMENTARY NOTES IERL_RTp task officer for this report is Norman Plaks,  919/549-
8411 Ext 2557, Mail Drop 62.
is. ABSTRACT
              rep0r|- gives results of an evaluation of the technical and economic
 feasibility of using limestone scrubbing technology to control sinter plant emissions.
 Data from Soviet and Japanese sinter plants employing limestone scrubbing technol-
 ogy were used to develop a realistic design basis. A conceptual process  design was
 developed and used to prepare economic estimates.  Results of the process .design
 indicate that control of sinter plant emissions by limestone scrubbing is  technically
 feasible.  Economic evaluations show that limestone scrubbing will increase the cost
 of producing sinter by about $1. 82 per metric ton of product sinter for a  standard
 sinter plant operation. For a sinter plant with a windbox gas recirculation system,
 the cost increase would be about $1. 44 per metric ton of product sinter.
17.
                             KEY WORDS AND DOCUMENT ANALYSIS
                DESCRIPTORS
                                          b.IDENTIFIERS/OPEN ENDED TERMS
                                         c.  COSATI Field/Group
Air Pollution
Sintering Furnaces
Iron and Steel Industry
Sulfur Oxides
Dust
Cost Analysis
Desulfurization
Scrubbers
Calcium Oxides
Limestone
Air Pollution Control
Stationary Sources
Windbox
Gas Recirculation
Particulate
Lime/Limestone Scrub-
 bing
13B
13A
11F
07B
11G
14A
07A
08G
13. DISTRIBUTION STATEMENT

 Unlimited
                 19. SECURITY CLASS (This Report)
                 Unclassified
                         21. NO. OF PAGES
                              215
                 20. SECURITY CLASS (Thispage)
                 Unclassified
                                          22. PRICE
EPA Form 2220-1 (9-73)
                                       D-17
-------