EPA-600/2-77-023q
 February 1977
Environmental Protection Technology Series
                INDUSTRIAL!^
                   ENVIRONMENTAL USE:  Chapter 17.
                            The Gypsum  and Wallboard
                                                   Industry
                                   Industrial Environmental Research Laboratory
                                        Office of Research and Development
                                       U.S. Environmental Protection Agency
                                               Cincinnati, Ohio  45268

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                 RESEARCH REPORTING SERIES

 Researph 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.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                            EPA-600/2-77-023q
                                            February 1977
         INDUSTRIAL PROCESS PROFILES

            FOR ENVIRONMENTAL USE

                  CHAPTER 17
                      by

      P.  E.  Muelberg and B.  P.  Shepherd
                 Dow Chemical
            Freeport, Texas   77541

                Terry Parsons
              Radian Corporation
             Austin, Texas  78766
           Contract No.  68-02-1319
               Project Officer
               Alfred B.  Craig
   Metals and Inorganic Chemicals Branch
Industrial  Environmental  Research Laboratory
             Cincinnati,  Ohio  45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
     OFFICE OF RESEARCH AND DEVELOPMENT
    U.S.  ENVIRONMENTAL PROTECTION AGENCY
           CINCINNATI, OHIO  45268

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                                 DISCLAIMER
       This report has been reviewed by the Industrial Environmental Research
Laboratory - Cincinnati, U.S. Environmental Protection Agency, and approved
for .publication.  Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorsement
or recommendation for use.

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                        TABLE OF CONTENTS
                           CHAPTER 17
                                                            Page
INDUSTRY DESCRIPTION	1
    Raw Materials	2
    Products	2
    Companies 	  3
    Environmental Impact	4
    Bibliography	5

INDUSTRY ANALYSIS 	  6
    Process No.  1. Mining	9
    Process No.  2. Crushing/Grin ding	12
    Process No.  3. Pot Calcination	15
    Process No.  4. Rotary Calcination 	 18
    Process No.  5. Pulverizing	20
    Process No.  6. Packaging	23
    Process No.  7. Blending	25
    Process No.  8. Fabrication Plant	27
    Process No.  9. Calcination/Pulverizing	30

Appendix A - Raw Materials	33

Appendix B - Products	35

Appendix C - Companies and Products	37
                                in

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                          LIST OF FIGURES



                             CHAPTER 17





Table                                                     Page




 1       Product Tree	    7





 2       Gypsum Products from Gypsum Rock	    8
                               IV

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                         LIST OF TABLES
                           CHAPTER 17
Table                                                       Page
 A-l     List of Raw Materials	   32
 B-l     List of Products	   34
 C-l     Gypsum and Calcining Plants in the United
           States in 1973	   36
                               v

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                         ACKNOWLEDGEMENTS


This chapter of the Industrial Process Profiles for Environmental
Use was prepared for EPA by Dow Chemical, U.S.A., Texas Division,
under Contract No. 68-02-1329, Task 8.  The contributions of
P. E. Muehlberg and B. P. Shepherd in preparation of this catalog
entry are gratefully acknowledged.

Helpful review comments from Gilbert C.  Robinson were received
and incorporated into this chapter.

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               GYPSUM AND WALLBOARD INDUSTRY
INDUSTRY DESCRIPTION

The industry comprises operations which mine gypsum deposits
and process the mined gypsum rock into crushed or pulverized
uncalcined gypsum, pulverized calcined gypsum (various types
of wall plasters and specialty plasters), and a diversity of
prefabricated gypsum-core board products (wallboard, rock-
lath, sheathing, and formboard).   The latter end-product
category accounts for approximately three-quarters of the
total product tonnage and an even greater fraction of total
product value.

The relative simplicity of gypsum processing is evident from
the single flow diagram of Figure 2 (page 7).  All operation
except for differences in product mix are similar, employing
basically the same processes in fundamentally the same sequence.
Mining is by open-pit (quarrying) methods in three-quarters
of the operations.  Calcining is  conducted  in either pot-
kilns (usual) or in continuous rotary kilns.  The balance of
the operations chiefly involve size reduction and size
separations.  Most of the equipment, including that in pre-
fabricating plants, is standardized throughout the industry.

The industry includes a total of 108 facilities (1973) in-
volving either mining plus mechanically processing crude
gypsum rock, or calcining and producing prefabricated
products.  Of this total, 36 facilities were integrated
mining-plus-fabricating operations.

The size of a single installation, gaged by the number of
employees, ranges from four persons in a small open-pit
mining operation to between 100 and 120 persons, in a large
facility combining an underground mine and a calcining-
fabrication plant.  Total employment during 1973 for the
entire industry was 3,200 persons.  In the same year about
19 million metric tons of gypsum products were produced from
12 million metric tons of domestically mined gypsum plus
7 million metric tons of imported gypsum rock.

Gypsum rock is mined in 22 states and is calcined and fabri-
cated in 32.  The relatively low unit value of crude gypsum
(approximately $4.50 per metric ton) economically limits its
rail transportation to relatively short, single-line hauls
and accounts for the importation of approximately 37% of the
crude rock consumed.  Imported rock was used to supply  32
calcining plants located near population centers in 15
states on all three seaboards.  In only five situations is

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 domestic gypsum rock transported by  rail  freight  from  the
 mine to a calcining plant.

 The industry has experienced  a  compounded,  annual A  1/2 per-
 cent growth rate during the decade ending with  the close of
 1973.   A compounded, annual 4 percent  growth  rate is pre-
 dicted to 1980.

 It is  believed that none of the operations  in the industry
 generate on-site power and that steam  is  generated on-site
 in package steam boilers.  Statistical information is
 entirely lacking.

 Raw Materials

 Bedded gypsum "rock" deposits form the usual  and  most  desir-
 able type of raw material for the industry  and  are usually
 the only type capable of economic exploitation.   These may
 be either near-surface deposits or lie at typical depths of
 50 to  400 meters.   This type  of deposit usually contains
 between 85 and 95  percent pure  gypsum.  Some  bedded  gypsum
 rock in Michigan contains about 99 percent  gypsum.

 Near-surface deposits of gypsite (gypsum  intermingled  with
 clay)  and selenite, containing  as little  as 70  percent
 gypsum, are of commercial value.

 About  three-quarters of the existing gypsum mines are open-pit
 operations.

 Usually,  it is not  economically possible  to beneficiate
 mined  gypsum ore except by screening.   Exceptions are  the
 gypsite deposits of Southern  California and the gypsum mined
 in Ottawa County,  Ohio, where heavy-media separation is used.

 Adverse environmental impact  situations arise from the
 "craters" and mounds of overburden resulting  from strip-
 mining methods and from the dust (non-toxic)  created during
 drying  and crushing the mined rock.   Quantifying  information
 is unavailable for  both types of problems.


The raw materials used in this industry are listed in Appendix A.

Products

The 19 million metric  tons of crude  gypsum consumed by the
industry during  1973 were processed  into  the  end-product
categories listed as  follows:

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Uncalcined products -

    Sold crushed for Portland cement retarder         20%
    Sold pulverized for agricultural use
      (land plaster)                                   1%

Calcined products -

    Prefabricated board products                      67%
    Wall plasters                                      ^%
    Plaster of paris, "soluble anhydrite,"
      dead-burned gypsum for specialty cements,
      paper fillers, paint pigment, and others

        Total

Prefabricated wallboard products are steadily replacing wall
plasters for interior wall construction.

A more complete list of products appears in Appendix B.

Companies

The 40 companies populating the industry are of two distinct
types:

    (1) Companies operating calcining-fabricating
        installations
    (2) Companies conducting only mining and grinding
        operations

The 13 companies comprising the first group, with two excep-
tions (Kaiser Gypsum Company and California Gypsum Company),
also mine a major fraction of their crude gypsum supply.
Collectively, they  operate 77 calcining-fabricating plants
and 41 mines.  Of these, 36 are integrated mine-plus-plant
facilities.  Nine of the companies are multi-industry
organizations with  operations in at least one other industry
producing end-products for use by the construction industries.

The second group includes 29 companies who sell sized, ground,
or crushed gypsum rock to the companies of the first group,
to the open market  for agricultural use, and to the cement
industry.  With exceptions, notably Universal Atlas Portland
Cement Company and  Southwestern Portland Cement Company,
these companies are all smaller than those of the first  type.
Their combined operations produce less than one-quarter  of
the total gypsum mined.

Five  companies produced about 85 percent of the total  calcined
gypsum in 1972:

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    United States Gypsum Company
    National Gypsum Company
    Georgia-Pacific Corporation
    The Flintkote Company
    Kaiser Gypsum Company, Inc.

Slightly more than three-quarters  of the crude gypsum pro-
duced was mined by five companies  in 1972:

    United States Gypsum Company
    National Gypsum Company
    Georgia-Pacific Corporation
    The Flintkote Company
    The Celotex Company

Appendix C contains a  complete  list  of producing companies.

Environmental Impact

Fugitive emissions of  particulate  gypsum or calcium sulfate
from crushing and grinding equipment, calciners, and dryers
are inherent in the industry.   No  serious problems have
resulted when dust control equipment is adequate.  No quan-
tifying information is available.  Gypsum dust is non-toxic.

In addition to the temporary  overburden piles generated in
strip mining, mentioned above,  calcining plants may have
occasional, inadvertent solid wastes of "overburned"
material resulting from faulty  operation.  Disposal of this
material, anhydrite, is by landfill  methods or by beneficial
use in grading low-lying plant  areas.  The material is
entirely nontoxic.

Because process heat is supplied by fuel combustion,  sulfur oxides,
nitrogen oxides, particulates, and hydrocarbons may be present in
combustion gases, depending on the fuel burned and on the combustion
efficiency.

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Bibliography

Gypsum:  Housing Starts Drop May Lower Demand.  Rock
Products.  77.: 50-51, December 1974.

Havard, J. P.  Gypsum.  In:  Industrial Minerals and Rocks,
3rd Edition, Lovejoy, J. M. (ed.).  New York, Am. Soc. of
Min. Met. & Petr. Eng., I960.   p. 471-476.

Reed, A. H.  Gypsum.  In:  Minerals Yearbook, 1972, Schreck,
A. E. (ed.).  Washington, U. S. Dept. of the Interior, 1974.
1:597-604.

Reed, A. H.  Gypsum, Quarterly.  In:  Mineral Industry
Surveys.  Washington, U. S. Dept. of the Interior, July 23,
1974.   7 p-

Schroeder, J. H.  Gypsum.  In:   Mineral Pacts and Problems.
Washington, U. S. Dept. of the  Interior, 1970.  p. 1039-1048.

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 INDUSTRY ANALYSIS

 Mining of domestic  sources  of  gypsum  dates to  1792; the use
 of gypsum-derived plasters,  to 1835;  and commercial produc-
 tion of gypsum wallboard, to the  first decades  of the present
 century.   The  present-day technology  relating  to all three of
 these phases is in  general  use, with  minor variations, by all
 companies operating within  this highly competitive industry.
 Data derived from the  sources  listed  in the Bibliographies
 of the Process Descriptions  are generally valid for all
 installations.

 Availability of quantitative information on emissions has in
 most cases been inadequate  to  completely define the physical
 characteristics and quantities of process wastes, or even
 the factual existence  of an emission.  In these cases the
 possible occurrence of an emission  and its probable magnitude
 have been estimated from what  is  commonly known about similar
 or identical types  of  equipment operating on material having
 closely related properties.

 The chemical tree of Figure 1  attempts to give  diagrammati-
 cally a qualitative overview of the entire industry from a
 raw material-product standpoint.  A fairly wide diversity
 of end uses requires a disproportionately small fraction
 (2 percent) of total product tonnage  represented by dead-
 burned gypsum.

 The process flowsheet  of Figure 2 shows process blocks repre-
 senting the two most frequently used, alternative calcining
 methods in batchwise operated  pot kilns and continuous rotary
 kilns.   The infrequently used  method  of calcining the gypsum
 in hammermills  is not  shown.

 The single raw  material shown  on  the  flow diagram and labeled
 "gypsum deposit," includes  deposits of gypsite  and selenite
 as well as bedded gypsum, the  most important and desirable
 source.

 A  number  has been assigned  to  each of the process blocks,
 uniquely  identifying the process  with an appropriate title
 and with  a process  description.   Flag symbols  at the upper
 right-hand corner of the process  block are used to indicate
 the nature of  the waste streams,  if any, discharged from the
 process -  a circle  for atmospheric emissions,  a triangle for
 liquid wastes,   and  a rhombus for  solid wastes.  The flags do
not differentiate between inadvertent (fugitive) and designed
wastes.

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Raw Materials
  Industry
End-Products:

Gypsum ^~
Gypsite — *-
Selenite -»•—
Hiinrfllrined J 	 	 ^.
Gypsum J
^ (Calcined) ^
"~ I Gypsum J



_^n_' Anvinil tiipnl '_
<• Gypsum '
Prefabricated
•fc board
products
^ t Wall >
^ (plasters)
plaster )
(of par Is/
to ( "Soluble )
lanhydrlte'T"
^ (Dead-burned)
( gypsum /
•^ III «~J „! __4. 	 II






->~ Wall board
-^-Chipboard sandwiches
_^__ n,-,^!.- 1-,4-h
-^— Formboard
-^—Exterior sheathing
->-Roof decking
-*•— Pottery molds
-**- Ceramic molds
-**- Surgical casts
->— Specialty products
-^-Dessicants
~^~ Floor plasters
^ Hard plasters
L^- DessicanLs
~*~~ Hard plasters
->— Keene ' s cement
->- Paper fillers
                    FIGURE  I.   GYPSUM AND WALLBOARD  PRODUCT TREE

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Heat
                                                                      Alum Sol 'n-

                                                                          Heat _
                                                                                Calcination/
                                                                                Pulverizing  9




9

5









*^



•>-



raCKag ing
6

Additives •*— n
Rl pnrii nn

AriHitivfr" . .
Heat _
t "
Fabrication
Plant 8
? "^


_^J
M
9



9


                                                                                                   ^ | Cement
                                                                                                      t Retarder
                                FIGURE  2.   GYPSUM PRODUCTS FROM GYPSUM  ROCK

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GYPSUM AND WALLBOARD INDUSTRY                  PROCESS NO.  1


                            MINING

1.  Function

    The process recovers gypsum rock (CaSO»'2H20)  in a trans-
    portable size of up to 15-cm diameter lumps from bedded
    gypsum deposits.  Both open-pit and underground mining
    methods are used, depending upon the depth and thickness
    of the deposit and character of the overburden.  Open-pit
    mines predominate.

    The process may include the steps of coarse crushing and
    size separation.

    In open-pit operations, scrapers, draglines, front-end
    loaders, trucks, conveyor belts, and other types of
    earth-moving equipment are used to strip the overburden,
    with the addition of blasting equipment to recover the
    gypsum.  With underground operations, equipment types are
    similar to those used in underground bituminous coal
    mines.  Gyratory crushers are usual for size reduction.

2.  Input Materials

    Massive gypsum rock of the deposit constitutes the input
    material.  It usually contains particles of sand, clay,
    shale, or limestone.  These inclusions are limited to a
    low percentage in commercially valuable deposits, since
    any extensive beneficiation is economically unfeasible.

    In a small number of instances, the deposit is gypsite
    (gypsum or selenite crystals intermingled with clay).
    These deposits, when of commercial value, are usually
    worked by open-pit methods.

    The estimated quantity of massive rock mined per metric
    ton of gypsum present in wallboard product is  between 1.1
    and 1.2 metric tons.

    Some "gypsum" deposits are, in fact, anhydrite  (CaSOu).
    In these cases the material may still be crushed to small
    lumps (approximately 2 cm diameter) in Process  2 and sold
    to the cement industry for use as Portland cement retard-
    er or may be forwarded to Process 9 eventually  to become
    "Keene's cement"-type end products.  In these  cases the
    quantity mined is slightly greater than 1 metric ton per
    metric ton of respective end product.

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3.  Operating Parameters

    •Approximately three-quarters of active mines are open
     pit.
    •Seams 1 m thick are considered valuable if horizontal
     extent is sufficient O300 hectares) and if depth is
     reasonable (^50 m with rock overburden, or <5 m for
     unconsolidated overburden).  Most deposits are much
     thicker (5 to 30 meters).
    •Operations employing beneficiation (heavy-media) are
     rare .
    •Pines from primary crushing are usually sold to the
     Portland cement industry.

4.  Utilities
    Energy is usually supplied from fuel oil or gasoline for
    open-pit operations and may be either electrical or oil-
    supplied for shaft mines.  The energy consumption per
    metric ton of gypsum present in wallboard is grossly
    estimated to be:

    •Between 2 and 10 kWh, or,
    •Between 1 and 5 kg fuel oil.

5.  Waste Streams

    Atmospheric emissions of particulate gypsum and clay are
    surmised.  No quantitative information is available.
    The quantity of particulates is estimated to be less than
    5 kg per metric ton of gypsum present in wallboard.

    Excluding stripped overburden, solid wastes of clay,
    shale, limestone fragments, and low-grade gypsum are
    estimated to amount to between 0.05 and 0.15 metric ton
    per metric ton of gypsum present in wallboard.  Disposal
    is by local landfill.

    In open-pit operations, UD to approximately 2 metric tons
    of overburden (about 1 metric ton is usual) may be
    stripped per metric ton of gypsum present in wallboard.
    Disposal of these solids is also by local landfill.

6.  EPA Source Classification Code

        None established
                             10

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7.   References

    Cement, Lime and Plaster.  In:  Rogers'  Industrial
    Chemistry, Purnas, C. C. (ed.).  New York, Van Nostrand
    and Co., 1942..  p. 872-877.

    Hammond, W. A.  Calcium Compounds.  In:   Kirk-Othmer
    Encyclopedia of Chemical Technology, 2nd Edition,
    Standen, A. (ed.).  New York, Interscience Publishers,
    1964.  4_:20-23.

    Havard, J. P.  Gypsum.  In:  Industrial  Minerals  and
    Rocks, 3rd Edition, Gillson, J. L. (ed.).  New York,
    Am. Soc. of Min. Met. & Petr. Eng., I960.  p.  471-476.

    Reed, A. H.  Gypsum.  In:  Minerals Yearbook,  1971,
    Schreck, A. E. (ed.).  Washington, U. S. Dept. of the
    Interior, 1973.  £=569-576.

    Riegel, E. R.  Portland Cement, Lime and Gypsum Plaster.
    In:  Industrial Chemistry, 5th Edition.   New York,
    Reinhold Publishing Corp., p. 173-175.

    Schroeder, H. J.  Gypsum.  In:  Mineral  Pacts  and
    Problems.  Washington, U. S. Dept. of the Interior,
    1970.  p. 1039-1048.

    Taggart, A. P.  Gypsum.  In:  Handbook of Mineral
    Dressing.  New York, John Wiley & Sons,  Inc.,  1945.
    p. 3-40 to 3-42.
                             11

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GYPSUM AND WALLBOARD INDUSTRY                  PROCESS NO.  2


                       CRUSHING/GRINDING

1.  Function

    The process reduces the size of mined gypsum (CaSO,, • 2H20)
    rock from approximately 15 cm maximum diameter lumps  to
    a range required by the type of calcining equipment used.

    The steps of screening and drying are usually included
    in the process.

    Equipment may consist of:

    •Grizzlies for rough sizing.
    •Primary crushing equipment.  This may be a gyratory
     crusher, single-roll crusher, or hammer mill.
    •Vibrating screens for size classification.
    •Secondary crusher, usually of the roll type.
    •Grinding equipment.  This may be roller mills or
     Raymond mills.  Either type may be equipped to air-dry
     the product.
    •Rotary dryers may be used to dry the crushed product.

    Pine-grinding equipment is omitted if the operation
    uses rotary kilns for calcining in Process 3.

    The product of the process may be forwarded in any of
    five directions:

    •Directly to sales as an end product (agricultural
     gypsum, or "land plaster").
    •Directly to sales to the cement industry for use as  a
     retarder in Portland cement.
    •To Process 3, for calcination in pot kilns.
    •To Process 4, for calcination in rotary kilns.
    •To Process 9, for calcination in vertical, stack kilns.
     (The  quantity for this use is considerably less than for
     the first-named four.)

2.  Input  Materials

    Mined  gypsum rock, ranging in size from fines to lumps
    approximately 15 cm maximum diameter, is the input
    material.   Its estimated requirement is 1.03 to 1.07
    metric  tons per metric  ton of gypsum in wallboard.
                            12

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 3.   Operating Parameters

     •Product fineness is 95% minus  100 mesh for both  feed to
      pot kilns and for direct sale  as  agricultural  gypsum.
     •Particle size of product varies between 0.3 and  1.5  cm
      for feed to rotary kilns.
     •Particle size varies between 0.6  and 1.5 cm for  direct
      sale as retarder in Portland cement.
     •Lump size for feed to vertical kilns  (Process  9)  is
      typically 4 to 5 cm diameter.
     •A typical integrated crushing, grinding, and screening
      operation has a daily throughput  of  500 to 800 metric
      tons of gypsum.

 4.   Utilities

     Consumption of electrical energy per metric ton of
     gypsum in wallboard:

     •Between 0.8 and 1.5 kWh for  crushing  to 1-cm lumps.
     •Between 10 and 15 kWh for  crushing and grinding to 95%
      minus 100 mesh.
     •In operations where a rotary dryer is  used for removing
      free water, the  electrical energy consumption will be
      increased by 3 to 5 kWh.

     Fuel consumption  for removing free water (estimated at
     5% of gypsum weight)  is estimated between 50x103 and
     100x103 kcal per  metric ton of  gypsum  in wallboard.

 5.   Waste Streams

     Fugitive emissions of gypsum  dust to the  atmosphere re-
     sult from all types  of crushing and grinding  equipment,
     as  well as  from the  rotary  dryer.  No  quantitative in-
     formation is available.   The  total amount  of  particulates
     is  estimated to be less  than  5  kg of minus  100-mesh
     gypsum per metric ton of gypsum in wallboard, with dust
     collection equipment  operative.

     Solid wastes are  discharged from grizzlies  and vibrating
     screens.   These consist  of  sand, clay,  limestone, and
     gypsum particles.   Their total  weight  is  estimated be-
     tween 30  and 50 kg per metric ton of gypsum in wallboard.

     Fuel  combustion may result  in emissions  of  sulfur oxides,
    nitrogen  oxides,  particulates and hydrocarbons,  depending
     on  fuel burned and combustion efficiency.

6.  EPA Source Classification Code

    3-05-015-01  Raw Material Dryer
    3-05-015-02  Primary Grinder
                           13

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References

Cement, Lime and Plaster.  In:  Rogers' Industrial
Chemistry. Furnas, C. C. (ed»).  New York, Van Nostrand
& Co., 1942.  p. 872-877.

Hammond, W. A.  Calcium Compounds.  In:  Kirk-Othmer
Encyclopedia of Chemical Technology, 2nd Edition,
Standen, A. (ed.).  New York, Interscience Publishers,
1964.  4_:20-23.

Havighorst, C. R.  A Quick Look at Gypsum Manufacture.
Chem. Eng.  ;72:52-54, January 4, 1965.

Reed, A. H.  Gypsum.  In:  Minerals Yearbook, 1971,
Schreck, A. E. (ed.).  Washington, U. S. Dept. of the
Interior, 1973.  I_:569-576.

Riegel, E. R.  Portland Cement, Lime and Gypsum Plaster.
In:  Industrial Chemistry, 5th Edition.  New York,
Reinhold Publishing Corp., p. 173-175.

Schroeder, H. J.  Gypsum.  In:  Mineral Pacts and
Problems.  Washington, U. S. Dept. of the Interior, 1970.
p. 1039-1048.

Shreve, R. N.  Gypsum.  In:  Chemical Process Industries,
3rd Edition.  New York, McGraw-Hill, Inc., 1966.  p. 180-
182.

Taggart, A. F.  Gypsum.  In:  Handbook of Mineral Dress-
ing.   New York, John Wiley & Sons, Inc., 1945.  p. 3-40
to 3-42.
                        14

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GYPSUM AND WALLBOARD INDUSTRY'                  PROCESS NO.  3


                        POT CALCINATION

1.  Function

    The process removes combined water from ground gypsum
    rock (CaSOi,'2H20) by calcination in a kiln of specialized
    design (gypsum pot-kiln).

    The kiln feed is received from Process 2.   Almost all of
    the product tonnage is calcium sulfate hemihydrate
    (CaSOn "|H20).   It is forwarded to Process  5 for pulveriza-
    tion.  In a small fraction of the cases, the product is
    "second-settle" stucco, or anhydrite (CaSOi,) and may have
    end uses similar to those of the Keene's cement end
    product of Process 9.

    The step of mixing calcium chloride liquor (CaCl2) is
    included in the process.  The mixing is conducted in the
    batch kiln-feed stream.  A subsequent step of cooling,  or
    "soaking," is  also included.

    Essential equipment consists of an externally fired, up-
    right, cylindrical pot or kettle of steel  or cast iron,
    provided internally with rotating horizontal stirrer arms.
    Cooling pits  are rectangular steel boxes.

2.  Input Materials

    The process is fed ground gypsum rock from Process 2,
    having a particle size of approximately 95$ minus 100
    mesh.  Between 1 and 1.03 metric tons are  required per
    metric ton of gypsum present in the wallboard product.

    Approximately  1 to 2 kg CaCl2 per metric ton of gypsum
    present in wallboard product is added to the charge.
    This is probably added as a 35% solution.   Its function
    is to hasten  rehydration to the hemihydrate of any an-
    hydrite formed.  The addition of CaCl2 is  omitted when
    "soluble" anhydrite is the intentional product.

3.  Operating Parameters

    Both CaSOu'-lHaO (plaster of paris or "first-settle"
    stucco) and anhydrous CaSOu (anhydrite or "second-settle"
    stucco) are produced in the identical pot-kilns (in
    different batches) of the following description:
                            15

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    •Kiln sizes range from 3 m diameter by 3 m deep to
     5 m diameter by 6 m deep.
    •Weight of charge ranges from 10 to 30 metric tons of
     ground gypsum rock.
    ^Kilns are operated batchwise at substantially atmos-
     pheric pressure.
    •Stirrer revolves at approximately 20 rpm.
    In producing CaSOn'fHaO, the controlled parameters are
    temperature and residence time:

    •Empty kiln preheated to about 100°C.
    •Batch charge remains at 120° to 130°C for period of 1
     to 2 hours.
    •Kiln is discharged at temperature of approximately l60°C.

    In the small number of cases where anhydrous CaSOtt is
    produced, the charge is allowed to undergo the same se-
    quence as described above and then allowed to remain in
    the kiln during a constant-temperature period at about
    190°C.  This requires an additional 30 to 60 minutes.
    The kiln is discharged at a temperature of approximately
    220°C.

    Exact temperatures and residence times required are a
    function of the particular kiln.

4.  Utilities

    Quantities are expressed per metric ton of gypsum present
    in wallboard product.

    •Heat, as either coal, natural gas, or fuel oil -
     between 2.5xl05 and 3-5xl05 kcal.
    •Electrical energy - between 2 and 5 kWh.

5.  Waste Streams

    During charging and discharging operations of the kiln,
    fugitive emissions of particulate CaS04-2H20, CaSCU'^H20,
    or CaS04 to the atmosphere are surmised.  No information
    is available on either absolute quantity or particle
    size.   Estimated quantity is less than 3 kg per metric
    ton of gypsum present in wallboard product, with dust
    control equipment operating, and approximately 20 kg per
    metric ton of gypsum in wallboard product without dust
    control equipment.

    Fuel combustion may result in emissions of sulfur oxides,
    nitrogen oxides, particulates and hydrocarbons, depending
    on fuel burned and combustion efficiency.


6.  EPA Source Classification Code

    3-05-015-03  Calciner
                              16

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References

Cement, Lime and Plaster.  In:  Rogers' Industrial
Chemistry, Furnas, C. C.  (ed.).  New York, Van Nostrand
& Co., 1942.  p. 872-877.

Hammond, W. A.  Calcium Compounds.  In:  Kirk-Othmer
Encyclopedia of Chemical Technology, 2nd Edition,
Standen. A. (ed.).  New York, Interscience Publishers,
1964.  4_:20-23.

Havighorst, C. R.  A Quick Look at Gypsum Manufacture.
Chem. Eng.  72.:52-54, January 4, 1965.

Reed, A. H.  Gypsum.  In:  Minerals Yearbook, 1971,
Schreck, A. E. (ed.).  Washington, U. S. Dept. of the
Interior, 1973-  I.: 569-576.

Riegel, E. R.  Portland Cement, Lime and Gypsum Plaster.
In:  Industrial Chemistry, 5th Edition.  New York,
Reinhold Publishing Corp., p. 173-175.

Schroeder, H. J.  Gypsum.  In:  Mineral Facts and
Problems.  Washington, U. S. Dept. of the Interior, 1970.
p. 1039-1048.

Shreve, R. N.  Gypsum.  In:  Chemical Process Industries,
3rd Edition.  New York, McGraw-Hill, Inc., 1966.
p. 180-182.

Taggart, A. F.  Gypsum.  In:  Handbook of Mineral Dress-
ing.  New York, John Wiley & Sons, Inc., 1945.  p. 3-40
to 3-42.
                          17

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 GYPSUM AND WALLBOARD  INDUSTRY                  PROCESS NO.
                      ROTARY CALCINATION*

 1.   Function

     The process removes combined water from lump gypsum
     (CaSOu «2H20) rock received from Process 2.  The product
     is forwarded to Process 6 for size reduction.  In addi-
     tion  to calcination, two steps are included:

     •Addition  of CaCl2 to the kiln feed and mixing.
     •Cooling,  or "soaking," the calcined product in silos.

     Essential  equipment consists of a continuously operating
     rotary kiln and at least several "aging" silos, provided
     with  means of ventilation.

 2.   Input Materials

     Crushed gypsum rock, between 0.3 and 1.5 cm in diameter,
     is fed continuously to the kiln.  Between 1.0 and 1.03
     metric tons (estimated) of kiln feed are required per
     metric ton of gypsum present in wallboard product.

     Approximately 1 to 2 kg of CaCl2 are added to the kiln
     feed for "pre-aging" the product.

 3.   Operating Parameters

     Kilns are direct fired.  The charge attains a tempera-
     ture of between 175° and 200°C.   "Aging" the product in
     the "aging" silos is a necessary step to allow the de-
    hydration to complete itself in the "underburned" por-
     tions of the charge and to allow rehydration of any
    anhydrous  calcium sulfate to occur.

    Kilns are  in the same size range as cement kilns —
    approximately 3.5 m diameter by  100 to 125 m in length.

4.  Utilities

    Quantities  are  expressed per metric ton of gypsum present
    in wallboard product:
*This process is an alternate to Process 3, Pot Calcination.
 The latter is used in the majority of the operations process-
 ing gypsum.  The use of rotary kilns for calcining is declining,
                            18

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    •Heat, supplied by coal, natural gas, or fuel oil -
     between 3x105 and 3.5xl05 kcal (estimated).
    •Electrical energy - 3 to 6 kWh (estimated).

5.  Waste Streams

    Calcination in rotary kilns results in a greater amount
    of fugitive particulate emissions to the atmosphere than
    does pot calcination.

    With dust control equipment operative on the kiln ex-
    haust, estimated total weight of particulates emitted to
    the atmosphere is estimated to be less than 5 kg of
    anhydrite per metric ton of gypsum in wallboard
    product.

    Fuel combustion may result in emissions of sulfur oxides,
    nitrogen oxides,  particulates and hydrocarbons,  depending
    on fuel burned and combustion efficiency.


6.  EPA Source Classification Code

    3-05-015-03  Calciner

7.  References

    Cement, Lime and Plaster.   In:  Rogers'  Industrial
    Chemistry. Purnas, C. C.  (ed.).   New York,  Van Nostrand
    & Co., 1942.  p.  872-877.

    Hammond, W.  A.  Calcium Compounds.   In:   Kirk-Othmer
    Encyclopedia of Chemical Technology, 2nd Edition,
    Standen, A.  (ed.).  New York, Interscience  Publishers,
    1964.   4k20-23.

    Havighorst,  C. R.   A Quick Look at  Gypsum Manufacture.
    Chem.  Eng.  72.: 52-54, January 4, 1965.

    Riegel, E. R.  Portland Cement, Lime and Gypsum Plaster.
    In:  Industrial Chemistry, 5th Edition.  New York,
    Reinhold Publishing Corp., p. 173-175.

    Schroeder, H. J.  Gypsum.  In:  Mineral Pacts and
    Problems.  Washington, U. S. Dept.  of the Interior, 1970.
    p. 1039-1048.

    Shreve, R. N.  Gypsum.  In:  Chemical Process Industries,
    3rd Edition.  New York, McGraw-Hill, Inc., 1966.  p.  180-
    182.

    Taggart, A. P.  Gypsum.  In:  Handbook of Mineral
    Dressing.  New York, John Wiley & Sons, Inc., 1945.
    p. 3-40 to 3-42.
                              19

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GYPSUM AND WALLBOARD INDUSTRY                  PROCESS NO. 5


                          PULVERIZING

1.  Function

    The process further reduces the particle size of the
    calcined gypsum received from either Process 3 or
    Process 4.   The product, if "first-settle" stucco or
    calcium sulfate hemihydrate (CaSO.* -%H20) ,  is forwarded
    as follows in order of increasing tonnage:

     Directly to sales, as plaster of paris.
     To Process 7 for blending to wall plasters.
     To Process 8 for fabrication into wallboard products.

    In a small fraction of instances, the calcined gypsum is
    "second-settle" stucco or soluble anhydrite (CaSCU) and
    is sold as the end product.

    Air separation and screening are usually steps in the
    process.

    If the feed material is received from Process 4, equip-
    ment may consist of Raymond mills or rod mills in combina-
    tion with ball mills, plus shaking screens and cyclone
    separators.  If fed from Process 3,  equipment usually
    consists of ball mills and cyclone separators.

2.  Input Materials

    The calcined gypsum (both CaSOu--|H20 and CaS04) fed to
    the process has a particle size approximating 90 to 95%
    minus 100 mesh, if received from Process 3, or 1- to 2-cm
    diameter lumps plus fines, if received from Process 4.
    Approximately 0.85 metric ton of "first-settle" stucco
    is required per metric ton of gypsum present in wall-
    board.   Approximately 1 metric ton of "second-settle"
    stucco is needed per metric ton of soluble anhydrite end
    product.

3.  Operating Parameters

    The process is conducted at above-ambient temperatures
    (40°-60°C)  and at essentially atmospheric pressure.

    The product discharged by the process is 100% minus 100
    mesh and may be as fine as 60% minus 200 mesh.
                             20

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4.  Utilities

    Electrical energy consumption is estimated to be between
    10 and 20 kWh per metric ton of gypsum in wallboard
    product.

5.  Waste Streams

    Fugitive atmospheric emissions of particulates, consist-
    ing of calcined gypsum dust, are surmised during periods
    of equipment malfunctioning and from imperfect duct-to-
    equipment seals.  The total quantity of material escaping
    is estimated to be less than 0.5 kg per metric ton of
    gypsum contained in wallboard product.

    Normally, atmospheric emissions are not a problem, since
    grinding and size-separation equipment  are closed-
    circuited and sealed from the atmosphere, except for the
    bleed stream which is passed through a  bag filter prior
    to venting.

6.  EPA Source Classification Code

        None established

7.  References

    Cement, Lime and Plaster.  In:  Rogers' Industrial
    Chemistry, Purnas, C. C. (ed.).  New York, Van Nostrand
    & Co., 1942.  p. 872-877.

    Hammond, W. A.  Calcium Compounds.   In:  Kirk-Othmer
    Encyclopedia of Chemical Technology, 2nd Edition,
    Standen, A. (ed.).  New York, Interscience Publishers,
    1964.  4.:20-23.

    Havighorst, C. R.  A Quick Look at Gypsum Manufacture.
    Chem. Eng.  72.:52-54, January 4, 1965.

    Reed, A. H.  Gypsum.  In:  Minerals Yearbook, 1971,
    Schreck, A. E. (ed.).  Washington, U. S. Dept. of the
    Interior, 1973.  ^:569-576.

    Riegel, E. R.   Portland Cement, Lime and Gypsum Plaster.
    In:   Industrial Chemistry, 5th Edition.  New York,
    Reinhold Publishing Corp., p. 173-175.

    Shreve, R. N.   Gypsum.  In:  Chemical Process Industries,
    3rd  Edition.  New York, McGraw-Hill, Inc., 1966.  p. 180-
    182.
                             21

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Taggart, A. F.  Gypsum.   In:   Handbook of Mineral
Dressing.  New York, John Wiley & Sons, Inc.,
p. 3-^0 to 3-^2.
                         22

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GYPSUM AND WALLBOARD INDUSTRY                  PROCESS NO. 6


                           PACKAGING

1.  Function

    Pulverized calcined gypsum (plaster of paris in almost
    all instances), received from Process 5 in bulk, is
    packaged in bags or in bulk in rail cars.  The bagged
    product is one of the six major end products of the
    industry.

    Automatic weighing-bagging machines, retractable belt-
    or roller-conveyors, and fork trucks are used.

2.  Input Material

    An estimated 98 to 99% of the tonnage of input material
    is plaster of paris (CaSCU '|H20).  The remainder of the
    tonnage is "soluble anhydrite," a form of anhydrous CaSO*.

    The particle size of both materials is 100% minus 100 mesh
    and 60% minus 200 mesh.

    One metric ton of input material is required per metric
    ton of end product.

3.  Operating Parameters

    The material is usually warm (40° to 50°C) during the
    packaging process.

    The usual bag used is paper or multi-walled paper with
    plastic interliner and contains 45.3 kg of product,
    either plaster of paris or "soluble anhydrite."

    Bulk shipments in rail cars are also made.

    Unadulterated plaster of paris is usually produced in
    operations also producing wall plasters and wallboard.
    The tonnage produced is usually considerably less than
    that of mixed wall plaster.  A typical operation produc-
    ing all three products produces 50 metric tons per day
    of plaster of paris.

4.  Utilities

    Electrical energy consumption is 0.5 to  2.0 kWh per
    metric ton of product.
                             23

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    Waste Streams

    Fugitive atmospheric emissions  (surmised)  of fine
    particulate CaSC^-i-HaO result  from "puffing" at  the
    filling valve  of the bag.   Atmospheric  emissions are
    estimated to be  less than  0.2  kg per metric  ton  of
    product.

    EPA Source Classification  Code

    3-05-015-04 Conveying
7.   References

    Cement, Lime and Plaster.   In:   Rogers'  Industrial
    Chemistry,  Furnas,  C.  C.  (ed.).   New York,  Van Nostrand
    & Co.,  1942.  p. 872-877.

    Hammond, W.  A.  Calcium Compounds.   In:   Kirk-Othmer
    Encyclopedia of Chemical Technology, 2nd Edition,
    Standen, A.  (ed.).   New York,  Interscience  Publishers,
    1964.   4:20-23.
                             24

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GYPSUM AND WALLBOARD INDUSTRY                  PROCESS NO. 7

                           BLENDING

1.  Function

    The process blends relatively small quantities of addi-
    tives into plaster of paris ("first-settle" stucco or
    CaSOu'|H20) received from Process 6.  The product is
    wall plaster and is sold as one of the major end products
    of the industry.

    The step of packaging is included in the process.

    Equipment consists of several continuous-flow mixing
    devices, such as the Broughton mixer, airveyor systems,
    continuous-flow weighing devices, bagging equipment, and
    bag conveyors.

2.  Input Materials

    The major input material is "first-settle" stucco or
    plaster of paris.  Between 0.9 and 0.99 metric ton is
    required per metric ton of bagged plaster, depending on
    the particular formulation.

    Additives to the plaster of paris,to impart specific
    properties, include the substances listed below.
    Quantities are expressed as kilograms per metric  ton of
    bagged wall plaster.

       Retarder (glue, tankage, starch, etc.)    2-8
       Accelerator (usually alum; sometimes
         omitted)                                1-3
       Animal hair, chopped glass fiber, or
         wood fiber                              1-5
       Sand or perlite (for "ready-mix"
         plasters)                              10 -  100

3.  Operating Parameters

    The operation is conducted at atmospheric pressure arid,
    usually, the plaster of paris is still warm (40°  to 50°C)
    from the calcining process.

    Wall plaster is usually one of the products of an in-
    tegrated operation also producing wallboard and unadul-
    terated plaster of paris.  One typical integrated plant
    produces about 100 metric tons per day of wall plasters.
                             25

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4.  Utilities

    Electrical power consumption,  including  that  for  the
    packaging step, is estimated between  5 and  10  kWh per
    metric ton of product.

5.  Waste Streams

    Fugitive atmospheric emissions (surmised) of  fine par-
    ticulate CaSOu-^E20S originate at  the bagging  machine
    filling spout and at loading hatches  of  railroad  cars
    during bulk-loading periods.   The  total  quantity  is
    estimated to be less than 1 kg per metric ton  of  product.
    No factual information  is available.

6.  EPA Source Classification Code

    3-05-015-04  Conveying


7.  References

    Cement, Lime and Plaster.  In:  Rogers'  Industrial
    Chemistry, Furnas, C.  C.  (ed.).  New  York,  Van Nostrand
    & Co., 1942.  p.  872-877.

    Hammond, W. A.  Calcium Compounds. In:  Kirk-Othmer
    Encyclopedia of Chemical Technology,  2nd Edition,
    Standen, A. (ed.).  New York,  Interscience  Publishers,
    1964.   4_:20-23.

    Havard, J. F.  Gypsum.   In: Industrial  Minerals  and
    Rocks, 3rd Edition, Gillson, J.  L. (ed.).   New York,
    Am.  Soc. of Min.  Met.  & Petr.  Eng., I960.   p.  471-476.

    Reed,  A. H.  Gypsum.  In:  Minerals Yearbook,  1971,
    Schreck, A. E. (ed.).   Washington, U. S. Dept. of the
    Interior, 1973.   1:569-576.

    Riegel, E. R.  Portland Cement,  Lime  and Gypsum Plaster.
    In:   Industrial Chemistry, 5th Edition.  New  York,
    Reinhold Publishing Corp., p.  173-175.
                             26

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GYPSUM AND WALLBOARD INDUSTRY                  PROCESS NO. -8


                       FABRICATION PLANT

1.  Function

    The process fabricates wallboard-type products from pul-
    verized, calcined gypsum ("first-settle" stucco,
    CaSOi»--2H20) received from Process 6, with additions of
    various other materials.  The products, chiefly gypsum
    board, rock lath, and laminated panels, constitute the
    major end products of the industry.

    The principal process steps are:

    •Blending
    •Board fabrication
    •Drying
    •Packaging

    Major equipment usually consists of:

    •Pulping tanks
    •Wet mixers and proportioning equipment
    •Forming rolls
    •"Setting-up" conveyor belt
    •Tunnel dryer
                  j
 2.  Input Materials

    The principal input material, "first-settle" stucco, is
    required in the ratio of approximately 0.85 metric ton per
    metric ton of gypsum in the fabricated product.  This
    corresponds to a ratio of between 0.5 and 0.8  (estimated)
    metric ton of "first-settle" stucco per metric ton of
    finished fabricated product, depending on the  specific
    type of the latter.

    Materials mixed with the stucco are listed below.  The
    approximate quantity of each is given per metric ton of
    finished product.

       Process water, to slurry the  stucco     0.6  m3
       Lignin                                  1    kg
       Raw gypsum  (accelerator)                5    kg  (est.)
       Starch                                  5    kg
       Fiber glass                             2    kg
       Paper pulp                              4-8  kg
       Soap (to produce foam)                  1    kg
       Sawdust  (may replace paper pulp)        4-8  kg
       Potassium sulfate                       0.5  kg
       Perlite                                 4-6  kg


                             27

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    Other materials used in board fabrication may be paper,
    chip-board, wood veneer or aluminum foil, depending on
    the specific type of board produced.

3•  Operating Parameters

    The process is conducted at essentially atmospheric pressure.
    Temperatures at selected points in the process are:

    •Slurry in mixer:  40-50°C (estimated)
    •Air at feed end of dryer: 150-l60°C
    •Air at discharge end of dryer: 120°C

    Residence times:

    •Slurry in mixer: 2-40 seconds
    •"Green" board on conveyor: 4-7 minutes

    The daily capacity of a typical three-product operation is:

    •45 metric tons of plaster-of-paris
    •90 metric tons of wall plaster
    •56,000 square meters of 1.27-centimeter thick wallboard,
     equivalent to approximately 550 metric tons of wallboard.

    The plant mentioned has a wallboard production line (setting
    conveyor plus dryer) approximately 420 meters long.

4.  Utilities

    Estimated total electrical energy consumption is between
    10 and 20 kWh per metric ton of average product.

    Heat, supplied as steam at 18 kilograms per square centimeter
    gage pressure, is required at an approximate ratio of
    300 x 103  kcal per metric ton of average product.

5.  Waste Streams

    Fugitive atmospheric emissions of particulate CaSOu«2H20
    are surmised to originate at feed ports of mixers.  No
    factual information is available.  Their quantity is
    estimated to be less than 0.5 kilogram per metric ton of
    average product.

6.  EPA Source Classification Code

    3-05-015-04  Conveying
                             28

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References

Cement, Lime and Plaster.  In:  Rogers' Industrial Chemistry,
Purnas, C. C. (ed.).  New York, Van Nostrand & Co., 1942.
p. 872-877.

Hammond, W. A.  Calcium Compounds,  In:  Kirk-Othmer
Encyclopedia of Chemical Technology, 2nd Edition. Standen,
A. (ed.).  New York, Interscience Publishers, 1964.
4_:20-23.

Havard, J. P.  Gypsum.  In:  Industrial Minerals and Rocks,
3rd Edition.  Gillson, J. L. (ed.).  New York, Am. Soc.
of Mln. Met. & Petr. Eng., I960.  p. 471-476.

Havighorst, C. R.  A Quick Look at Gypsum Manufacture.
Chem. Eng. (N.Y.).  7j2:52-54, January 4, 1965.

Niles, B.  W.  Gypsum Board.  In:  Kirk-Othmer Encyclopedia
of Technology, 2nd Edition. Standen, A. (ed.).  New York,
Interscience Publishers, 1970.  21:621-625.

Reed, A. H.  Gypsum.  In:  Minerals Yearbook, 1971,
Shreck, A. E. (ed.).  Washington, U.S. Dept. of the
Interior,  1973.  I_:569-576.

Riegel, E. R.  Portland Cement, Lime and Gypsum Plaster.
In:  Industrial Chemistry, 5th Edition.  New York, Reinhold
Publishing Corp., p. 173-175.
                          29

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GYPSUM AND WALLBOARD INDUSTRIES                PROCESS NO.  9


                   CALCINATlON/PULVERIZING


1.   Function

    The process produces finely ground  (<100  mesh)  dead-burned
    gypsum, or anhydrite (CaSCU) from 5-cm diameter lumps
    of gypsum received from Process 2.   The pulverized product
    of the process is an end product of  the industry.

    The principal process steps, in sequence, are,  in general:

    •Calcination
    •Cooling
    •Pulverizing

    In special cases, where the product  is Keene's  cement,  the
    sequential process steps are:

    •Calcination
    •Cooling
    •Soaking in alum solution
    •Recalcination
    •Cooling
    •Pulverizing

    Major equipment consists of:

    •Stack kilns or beehive ovens
    •Soaking tanks (used only if product is Keene's cement)
    •Raymond mill, or rod-ball mill

2.   Input Materials

    Lumps of gypsum rock, inferred to be about 5 cm diameter,
    are fed to the process.  The quantity is  estimated  to  be
    approximately 1.3 metric ton per metric ton of  dead-burned
    gypsum produced.

3.   Operating Parameters

    The process is conducted at atmospheric pressure and at
    temperatures in the range of 600° to 700°C.  Calcination
    time is about four hours.

    No information is available pertaining to the physical size
    of kilns, or on the parameters relating to the  soaking in
    alum solution in the case of production of Keene's  cement.
                             30

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This process is used in the production of products which
account for less than 2% of the total consumption of all
crude gypsum.  The principal products in this category are:

•Specialty plasters (including Keene's cement)
•Paint pigments
•Paper filler

Utilities

Heat, usually supplied by coal, is required in the calcina-
tion step.  The quantity is estimated between 3 x 105 and
5 x 105 kcal per metric ton of dead-burned gypsum.

Total electric energy consumption is estimated between
1 and 3 kWh per metric ton of dead-burned gypsum.

Waste Streams

Fugitive atmospheric emissions of particulate anhydrite
are surmised to originate at the stack-kiln exhaust.  No
quantitative information is available.  The total quantity
of solids emitted is estimated to be less than 5 kg of
anhydrite per metric ton of dead-burned gypsum produced,
with dust abatement equipment operative.

Fuel combustion may result in emissions of sulfur oxides,
nitrogen oxides, particulates and hydrocarbons, depending
on fuel burned and combustion efficiency.

EPA Source Classification Code

3-05-015-03  Calciner

References

Cement, Lime and Plaster.  In:  Rogers' Industrial Chemistry,
Furnas, C. C. (ed.).  New York, Van Nostrand & Co., 1942.
p. 872-877.

Hammond, W. A.  Calcium Compounds.  In:  Kirk-Othmer
Encyclopedia of Chemical Technology, 2nd Edition.  Standen,
A. (ed.).  New York, Interscience Publishers, 1964.
4_:20-23.

Havard, J. F.  Gypsum.  In:  Industrial Minerals and Rocks,
3rd Edition.  Gillson, J. L. (ed.).  New York, Am. Soc.
of Min. Met. & Petr.. Eng., I960.  p. 471-476.

Reed, A. H.  Gypsum.  In:  Minerals Yearbook, 1971, Shreck,
A. E. (ed.).  Washington, U.S. Dept. of the Interior,  1973.
1:569-576.

Schroeder, H. J.  Gypsum.  In:  Mineral Facts and Problems.
Washington, U.S. Dept. of the Interior, 1970.  p. 1039-1048.
                           31

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                  Table A-l.  LIST OF RAW MATERIALS
1.  Gypsum (CaSOu»2H20)

   •Bedded gypsum rock (most important source)

   •General composition range:

        CaS04-2H20            85 to 95%
                              occasionally to 99%
        Impurities are:       clay
                              shale
                              limestone
                              anhydrite
                              silica

2.  Gypsite (gypsum intermingled with clay)

   •Usually secondary, surface deposits (less important source)

   •General composition range:

        CaSO^»2H20            70 to 8*5%

        Clay                  10 to 20%

        Other impurities are as for gypsum

3.  Selenite (large gypsum crystals in clay gahgue)

   •Usually secondary, surface deposits (minor source)

   •General composition similar to that of gypsite.

4.  Anhydrite (CaSOu)

   •Usually mined only for use as cement retarder.

   •General composition range:

        CaSOu                 85 to 95%

        Identity of impurities same as for bedded gypsum.
                              32

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APPENDIX B





 PRODUCTS
    33

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                  Table 3-1.   LIST OF PRODUCTS
Prefabricated gypsum-core board products:
    Paper-covered wallboard
    Chipboard-covered wallpanels
    Paper-covered "rock"-lath
    Exterior sheathing
    Pormboard (for poured industrial roofs)
Wall plasters
Plaster of paris
"Soluble anhydrite"
Dead-burned gypsum
Agricultural gypsum (land plaster)
Portland cement retarder
                             34

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      APPENDIX C




COMPANIES AND PRODUCTS
          35

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            Table C-l.  GYPSUM MINES AND CALCINING PLANTS IN THE UNITED STATES IN 19731
         Company
                             Location of Operation
                             	County  & State
                               Type of Operation
CJ
01
Agro Minerals, Inc.
  Box 279
  Droville, WA 98855

American Gypsum Company
  Box 6345
  Albuquerque, NM 87107

California Gypsum Company
  37851 Cherry St.
  Newark, CA  95460

Duke City Gravel Products
  2421 Iris Road, NW
  Albuquerque, NM 87104

The Celotex Corporation
  1500 N. Dale Mabry
  Tampa, PL 33607
          Consumers Co-op Association
            502 Pioneer Rd.
            Weiser, ID 83672

          Cox Enterprises, Inc.
            50 E. Main N.
            Manti, UT 84642

          Dulin Bauxite Company, Inc.
            835 Valley
            Hot Springs, AR 71901

          Fannin-Superior Gypsum
          Company
            Route 1, Box 7, Hwy. 46
            Wasco, CA 93280
                                         Okanogan,  Washington
                                         Bernalillo,  New Mexico
                                         Almeda, California
                                         Sandoval, New Mexico
Webster, Iowa
Bergen, New Jersey
Ottawa, Ohio
Fisher, Texas
Park, Wyoming

Washington, Wyoming
                                Sanpete, Utah
                                Pike,  Arkansas
                                Kern,  California
                                 Mine Only
                                 Plant Only
                                  Plant Only
                                 Mine Only
Mine & Plant
Plant Only
Mine2 & Plant
Mine & Plant
Mine & Plant

Mine Only
                                  Mine  Only
                                  Mine  Only
                                  Mine Only

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          Table C-l (Continued)   GYPSUM MINES AND CALCINING PLANTS IN THE UNITED STATES IN 1973l
co
           Company
'Location  of  Operation
    County &  Sta_t_e	
           The  Plintkote  Company
             480  Central  Avenue
             E. Rutherford,  NJ 07073
           Predericksburg Gypsum Company
             Mason Route
             Predericksburg,  TX 78624

           Georgia-Pacific Corporation
             900 S.W.  Fifth Avenue
             Portland, OR 97204
           Grand Rapids Gypsum Company
             201 Monroe Avenue, NW
             Grand Rapids,  MI 49502

           Harrison Gypsum  Company, Inc
             Box 176
             Lindsay,  OK 73052

           H.  M.  Holloway,  Inc.
             714  Sixth Street
             Wasco,  CA 93280
  Alameda, California
  Fremont, Colorado
  Chatham, Georgia
  Clark, Nevada
  Camden, New Jersey
  Nolan, Texas

  Gillespie, Texas
  New Castle, Delaware
  Glynn, Georgia
  Webster, 'Iowa
  Marshall, Kansas
  Kent, Michigan
  Erie, New York
  Westchester, New York
  Hardeman, Texas
  Sevier, Utah
  Big Horn, Wyoming

  Kent, Michigan
  Caddo, Oklahoma
  Kern, California
Type of Operation
                                                                         rn
  Plant Only
  Mine & Plant
  Plant Only
  Mine & Plant
  Plant Only
  Mine & Plant

  Mine Only
  Plant
  Plant
  Mine
  Mine
  Mine2
  Mine2
  Plant
  Mine
  Mine
  Mine
 Only
 Only
& Plant
& Plant
& Plant
& Plant
 Only
& Plant
& Plant
& Plant
  Mine2& Plant
  Mine Only
  Mine Only

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         Table C-l  (Continued).   GYPSUM MINES AND CALCINING PLANTS IN THE UNITED STATES  IN 19731

         Company
                              Location of Operation
                                 County 8c State
                               Type  of  Operation
00
         Johns-Manville  Corporation

         Kaiser  Gypsum Company,  Inc.
            300 Lakeside  Drive
            Oakland,  CA 94604
Michigan Gypsum Company
  2840 Bay Road
  Saginaw, MI 48601

E. W. Munroe
  101 E. Vine Drive
  Fort Collins, CO 80521

National Gypsum Company
  325 Delaware Avenue
  Buffalo, NY 14202
Clark, Nevada

Contra Costa, California
Los Angeles, California
Duval, Florida
Burlington, New Jersey
King, Washington

losco, Michigan
                                         Larimer, Colorado
                                         Maricopa, Arizona
                                         Final, Arizona
                                         Contra Costa, California
                                         Los Angeles, California
                                         New Haven, Connecticut
                                         Hillsborough, Florida
                                         Chatham, Georgia
                                         Lake, Illinois
                                         Martin, Indiana
                                         Webster, Iowa
                                         Barber, Kansas
                                         Jefferson, Louisiana
                                         Baltimore, Maryland
                                         losco, Michigan
                                         Rockingham, New Hampshire
                                         Burlington, New Jersey
                                         Bronx, New York
                                         Erie, New York
                                         Lorain, Ohio
                                         Fisher, Texas
Mine & Plant

Plant Only
Plant Only
Plant Only
Plant Only
Plant Only

Mine Only
                                  Mine Only
                                  Plant Only
                                  Mine Only
                                  Plant Only
                                  Plant Only
                                  Plant Only
                                  Plant Only
                                  Plant Only
                                  Plant Only
                                  Mine2& Plant
                                  Mine & Plant
                                  Mine & Plant
                                  Plant Only
                                  Plant Only
                                  Mine & Plant
                                  Plant Only
                                  Plant Only
                                  Plant Only
                                  Mine2 & Plant
                                  Plant Only
                                  Mine & Plant

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       Table C-l (Continued).  GYPSUM MINES AND CALCINING PLANTS  IN THE  UNITED STATES  IN 1973
         Company
                             Location  of  Operation
                                 County &  State
Type of Operation
co
Final Mammoth Gypsum Company
  2020 S. 9th Street
  Coolidge, AZ 85228

Quad-Honstein Joint Venture
  5770 Mclntyre St.
  Golden, CO 80401

Raymond Schweitzer Gypsum
  Route 2
  Okarche, OK 73762

Republic Gypsum Company
  1100 Mercantile Bank Bldg.
  Dallas, TX 75201

South Dakota Cement
Commission
  Drawer 351
  Rapid City, SC 57701

Southwestern Portland
Cement Company
  Box 392
  El Paso, TX 799^3

Superior Companies
  Box 6497
  Phoenix, AZ 85005

Temblor Gypsum Company
  Carrisa Plains Star Rt.
  Box 80
  St. Margarita, CA 93^53
                                         Final, Arizona
                                         Larimer, Colorado
                                         Canadian, Oklahoma
                                         Santa Pe, New Mexico
                                         Jackson, -Oklahoma
                                        Meade, South Dakota
                                        Hudspeth, Texas
                                         Final, Arizona
                                         Yavapai, Arizona
                                         Kern, California
  Mine Only
  Mine Only
  Mine Only
  Mine & Plant
  Mine & Plant
  Mine Only
  Mine Only
  Mine Only
  Mine Only
  Mine Only

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     Table C-l (Continued).   GYPSUM MINES AND CALCINING PLANTS IN THE UNITED STATES  IN 19731
        Company
Lo c a 11o n  o f  Operaticn
	County &  State
       Temple Industries,  Inc.
         Box 368
         Diboll, TX

           Temple Gypsum Company,
           Subsidiary
             West Memphis,  AK

           Texas Gypsum Company,  Inc.,
           Subsidiary
             Box 768
             Irving, TX 75060

       United States Gypsum Company
         101 South Wacker  Drive
         Chicago, IL 60606
CD
    Critenden> Arkansas
    Comanche, Ohlahoma
    Dallas, Texas
    Imperial, California
    Duval, Florida
    Lake, Indiana
    Martin, Indiana
    Des Moines, Iowa
    Webster, Iowa
    Orleans, Louisiana
    Baltimore, Maryland
    Suffolk, Massachusetts
    losco, Michigan
    Wayne, Michigan
    Fergus, Montana
    Pershing, Nevada
    Washoe, Nevada
    Genesee, New York
    Richmond, New York
    Rockland, New York
    Ottawa, Ohio
    Elaine, Oklahoma
    Philadelphia, Pennsylvania
    Harris, Texas
    Nolan, Texas
    Sevier, Utah
    Chesapeake, Virginia
    Washington, Virginia
Type of Operation
    Plant Only
    Mine Only
    Plant Only
    Mine & Plant
    Plant Only
    Plant Only
    Mine2 & Plant
    Mine & Plant
    Mine & Plant
    Plant Only
    Plant Only
    Plant Only
    Mine Only
    Plant Only
    Mine2 & Plant
    Mine Only
    Plant Only
    Mine2 & Plant
    Plant Only
    Plant Only
    Mine2 & Plant
    Mine & Plant
    Plant Only
    Plant Only
    Mine 8= Plant
    Mine & Plant
    Plant Only
    Mine2 & Plant

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Table C-l (Continued).  GYPSUM MINES AND CALCINING PLANTS  IN THE UNITED STATES  IN 1973
  wompany
 United  States  Steel
 Corporation
    Universal Atlas  Portland
    Cement  Division
      600 Grant  Street
      Pittsburgh,  PA 15230

 U.S.  Soil Conditioning
 Company
    Box 346
    Salida, CO 81201

 Victor  Material  Company
    Box 1024
    Victorville, CA  92392

 Walton  Gypsum Company
    Route 1
    Homestead, OK  73745

 Weyerhaeuser Company
    Route 4, Box 78
    Nashville, AR  71852

 White Mesa Gypsum  Company
    124 Jackson NE
    Albuquerque, NM  78108

 Art  Wilson Company
    Box 1160
    Carson  City, NV  89701

 E. J. Wilson & Sons
    Dubois, ID 83423
Location of "Operation
	County _& State
Type of Operation
    Elaine,  Oklahoma
   Fremont, Colorado
    San Bernardino, California
    Elaine,  Oklahoma
    Howard,  Arkansas
    Sandoval,  New Mexico
    Lyon,  Nevada
    Lemhi,  Idaho
    Mine Only
    Mine Only
    Mine Only
    Mine Only
    Mine & Plant
    Mine Only
    Mine Only
    Mine Only

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Table C-l (Continued).  GYPSUM MINES AND CALCINING PLANTS IN THE UNITED STATES IN 1973l
                               Location of Operation             m      „  n     , .
                                  County & State	Type  of  Operation

  Winn Rock,  Inc.                  Winn, Louisiana                  Plant Only
    Box 790
    Winnfield,  LA  71483
  Wyoming Construction            Albany,  Wyoming                  Mine Only
  Company
    Box 907
    Laramie,  WY 82070
   —  -        —
    Companies Producing Gypsum or Gypsum Products During 1973
    Company  operations listed below comprising a mine only, may  produce  one or more
    of the following forms of uncalcined gypsum:
         Lump gypsum rock (intermediate product)  for  use by other operations within
         the industry.
      .  Gravel-size gypsum rock for use as Portland  cement retarder.
         Pulverized gypsum for agricultural use (land plaster).
    Operations comprising only a plant produce:
         Fabricated products (wallboard, rock lath, or formboard),
         Wall plaster,
         Plaster of paris, and in addition, may produce small  quantities of "soluble
         anhydrite", or dead-burned gypsum.
    Operations comprising both a mine and a plant always produce lump gypsum  rock
    (intermediate  product) and fabricated products, almost always produce wall plaster
    and plaster of paris, and may produce any of the  other products mentioned above.
    Indicates underground mine;  otherwise open-pit operation.

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                                  TECHNICAL REPORT DATA
                           (Please read Instructions on the reverse before completing)
 REPORT NO.
 EPA-600/2-77-023q
2.
 . TITLE AND SUBTITLE
 Industrial Process Profiles  for Environmental Use:
 Chapter IT-  The Gypsum  and  Wallboard Industry
                             3. RECIPIENT'S ACCESSION-NO.
                              5. REPORT DATE
                                 February 1977
                             6. PERFORMING ORGANIZATION CODE
 . AUTHOR(S)
                                                          8. PERFORMING ORGANIZATION REPORT NO
 P.E.Muehlberg and B.P.Shepherd (Dow Chemical)
 Terry Parsons. Editor
 . PERFORMING ORGANIZATION NAME AND ADDRESS
 Radian Corporation
 8500 Shoal Creek Boulevard,  P.O.  Box 99U8
 Austin, Texas  78766
                              10. PROGRAM ELEMENT NO.
                                1AB015
                              11. CONTRACT/GRANT NO.
                                                            68-02-1319/Task
12. SPONSORING AGENCY NAME AND ADDRESS
 Industrial Environmental Research Laboratory
 Office of Research  and  Development
 U.S. ENVIRONMENTAL  PROTECTION AGENCY
 Cincinnati» Ohio  1+S268          	  	
                              13. TYPE OF REPORT AND PERIOD COVERED
                                Initial:  8/75-11/76
                              14. SPONSORING AGENCY CODE

                                EPA/600/12
15. SUPPLEMENTARY NOTES
 16. ABSTRACT
 The catalog of Industrial Process Profiles for Environmental Use was  developed as an
 aid in defining the  environmental impacts of industrial activity in the  United States.
 Entries for each  industry are in consistent format and form separate  chapters of the
 study.  The gypsum and wallboard industry comprises operations which  mine gypsum
 deposits and process the  mined gypsum rock into crushed or pulverized uncalcined
 gypsum, pulverized calcined gypsum and a diversity of prefabricated gypsum-core
 board products.   One chemical tree, one process flow sheet and nine process descrip-
 tions have been prepared  to characterize the industry.  Within each process descrip-
 tion available data  have  been presented on input materials, operating parameters,
 utility requirements and  waste streams.  Data related to the subject  matter, including
 company, product  and raw  material data, are included as appendices.
!7. KEY WORDS AND DOCUMENT ANALYSIS j
a. DESCRIPTORS
Pollution
Industrial Processes
Chemical Engineering
Gypsum
Wallboard
18. DISTRIBUTION STATEMENT
Release to Public
b.lDENTIFIERS/OPEN ENDED TERMS
Process Assessment
Environmental Impact
19. SECURITY CLASS (This Report)
Unclassified
20. SECURITY CLASS (Tills page)
Unclassified
c. COSATI Field/Group
13B
13H
07A
08G
11L, 13C
21. NO. Ot PAGES
49
22. PRICE
EPA Form 2220-1 (9-73)
               43
                                                                      fcUSGPO: 1978 — 757-086/0807

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