EPA-600/2-77-023r
February 1977
Environmental Protection Technology Series
INDUSTRIAL PROCESS PROFILES FOR
ENVIRONMENTAL USE: Chapter 18.
The Lime 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
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate 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-600/2-77-023r
February 1977
INDUSTRIAL PROCESS PROFILES
FOR ENVIRONMENTAL USE
CHAPTER 18
THE LIME INDUSTRY
by
A. C. Doumas, B. P. Shepherd and P. E. Muehlberg
Dow Chemical
Freeport, Texas 77451
Terry Parsons and Glynda E. Wilkins
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 18
Page
INDUSTRY DESCRIPTION 1
Raw Materials 2
Products 3
Companies 4
Environmental Impact 6
Bibliography 7
INDUSTRY ANALYSIS 8
Process No. 1. Mining/Conveying 11
Process No. 2. Crushing/Sizing 15
Process No. 3. Dredging/Washing 18
Process No. 4. Washing/Screening 21
Process No. 5. Calcination/Pulverizing 23
Process No. 6. Hydration/Packing 31
Appendix A - Raw Materials 35
Appendix B - Products 37
Appendix C - Companies and Products 39
m
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LIST OF FIGURES
CHAPTER 18
Figure Page
1 Lime Industry Product Tree 9
2 Lime Industry Flowsheet 10
IV
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LIST OF TABLES
CHAPTER 18
Table Page
1 Representative Chemical Analyses of Different Types of
U.S. Limestone 12
2 Typical Emissions from Crushing/Sizing 16
3 Composition of Rough-Washed Oyster Shells 18
4 Composition of Clean, Washed Oyster Shells 21
5 Composition of Commercial Quicklimes 26
6 Composition of Kiln Exhaust Gases 26
7 Volumes of Kiln Gas Generated in Calcining 27
8 Typical Fugitive Lime Emissions and Control Methods .... 28
9 Composition of Particulates from Natural Gas-Fired Kilns. . 28
10 Particle Size of Particulates from Natural Gas-Fired Kilns. 29
11 Typical Product Analyses of Commercial Hydrated Limes ... 31
12 Emissions and Control Methods for Hydration/Packing .... 32
A-l Typical Compositions of Raw Materials 36
B-l List of Products 38
C-l Companies and Products of the Lime Industry 40
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ACKNOWLEDGEMENTS
This catalog entry was prepared for EPA by Dow Chemical U.S.A., Texas Division,
under Contract 68-02-1329, Task 8. The contributions of A. C. Doumas, B. P.
Shepherd, and P. E. Muehlberg are gratefully acknowledged.
Helpful review comments from Gilbert C. Robinson were received and incorporated
into this chapter.
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LIME INDUSTRY
INDUSTRY DESCRIPTION
In the United States, production of lime and limestone are considered
two separate and distinct industries. This is exemplified by the fact
that nearly 95% of all limestone, exclusive of stone for cement, is pro-
duced by companies that do not make lime. The lime industry comprises
operations which mine dolomite or limestone deposits or dredge oyster
shells and process these carbonate materials into lump, crushed, or pul-
verized calcined products. The chief products in this category are quick-
lime, slaked or hydrated lime, dolime, and hydrated dolime. Approximately
90% of all lime produced and sold is used in chemical and industrial
applications. Lime's emergence as a chemical has occurred largely since
1930. Most of the lime produced is high-calcium lime derived from lime-
stone. Even though only about 5% of the limestone mined in the United
States is used to produce lime, the amount produced is immense. Next to
sulfuric acid, lime is the second-largest chemical product in tonnage
made in pure form. The United States ranks second in world lime produc-
tion, producing about 18% of the total.
Lime production operations are comparatively simple, as shown by the
flow diagram in Figure 2 (page 18-16). Depending upon whether shell or
stone is used as the raw material, almost all of the operations are similar,
employing basically the same processes in fundamentally the same sequence.
A small percentage of lime is manufactured from oyster shells, particularly
along the Gulf Coast. Mining of limestone rock or dolomite is by open-pit
(quarrying) methods and by underground mining techniques. Less than 8% of
the limestone produced is mined underground. Calcining is performed either
in stationary vertical kilns of various designs or in horizontal rotary
kilns. Other major operations involve size reduction, washing, and size
separations. Most of the equipment is standardized in the industry.
The industry included 172 producing plants in 1974 involving mining
and rock or shell handling facilities plus calcining and hydrating or
milling operations. These tend to be located near manufacturing and
industrial centers. One additional plant was located in Puerto Rico.
No two lime production facilities are alike. Each plant is individualized
and tailored to the particular limestone deposit, the lime products desired,
and the type of fuel available in each locale.
Total lime output in 1974 was 19.6 million metric tons. It was pro-
duced in 42 states and used by all, 50 states.
Plants range in size from those producing less than 10,000>metric
tons per year to giant facilities capable of output in excess of 350,000
metric tons per year. Using 1973 statistics, at least 67% of all lime
sold or used by producers in the United States was manufactured in plant
facilities each capable of producing more than 180,000 metric tons per year.
This involved only 39 plants out of a total of 176.
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Employment in this industry was approximately 7,300 in 1973, includ-
ing mines and plants. This is a reduction of approximately 2,000 people
since 1949.
Because of the low unit value (approximately $4.25 per metric ton)
of crushed limestone, shell, and other sources of lime, transportation
is an important factor in the economics of the industry. Long distance
shipments are usually impractical. Most shipments are made by truck
with some by rail or barge. The maximum distances that a producer can
ship economically varies considerably, 480-645 kilometers is considered
average.
The total number of plants has slowly dropped in recent years, while
total production and sales have trended upward slightly. This is due to
the shutting down of smaller, older and inefficient plants. For instance,
between 1972 and 1973 the number of lime plants decreased from 186 to 176,
yet the average output per plant increased from 99,135 metric tons per
year to 108,930.
Statistics for 1974 show that the leading lime-producing states were
Ohio, California, Texas, Colorado, and Pennsylvania. These five states
accounted for 38% of the total number of plants. In 1973, the states of
Ohio, Texas, Missouri, Michigan, and Pennsylvania accounted for 54% of the
country's total lime output.
A study made in 1973 showed that the lime industry used primarily coal
and natural gas for most of its energy requirements. Only 2% of the total
energy was purchased electricity. Approximately 46% of the total energy was
supplied with coal, and natural gas provided 45% of the requirements. Most
of the energy is used as heat in the calciners. Lime manufacture is a highly
fuel-intensive industry, requiring on the average 2.0 million kcal per metric
ton of product made. Next to the cost of the stone used to feed the kilns,
fuel costs are the most critical factor in lime production costs.
Raw Materials
Bedded deposits of limestone and dolomite rock used in manufacturing
lime are generally obtained from open pit quarries and underground mines
by conventional methods. Limestone is a sedimentary rock composed of
calcium carbonate (CaC03). Dolomite or dolomitic limestone contains mag-
nesium as well as calcium. Although limestone deposits are found in every
state in the United States, only a small portion is pure enough for in-
dustrial lime manufacture. In general, quarries are selected to furnish
rock containing low percentages of alumina, silica, clay, or iron oxide.
Lime manufacture requires stone of definite size ranges depending on the
type of kiln used.
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A small percentage Capproximately 8%) of lime is manufactured from
sea shells. Oyster and clam shells are the remains of marine animals,
consisting mostly of calcium carbonate. These shells are concentrated
in reefs along certain coastal areas, particularly along the Gulf Coast.
Shell is usually recovered by conventional dredging and washing operations.
More than 90% of the limestone mined is from open-pit operations with
the remainder from underground mines. Most lime producers own their source
of limestone and have ample reserves of ore.
To be classed as limestone, the rock must contain at least 50% calcium
carbonate. It is called high-calcium limestone when the rock contains less
than 5% magnesium carbonate. When the raw material contains 30 to 45%
magnesium carbonate, it is referred to as dolomite or dolomitic limestone.
Two general types of adverse environmental impact occur in producing
1imestone:
• Fugitive atmospheric emissions of particulates (dusting) in open-
pit mining and handling operations.
• Creation of mounds of stripped overburden, and cratering of land-
scapes in open-pit and underground mining operations.
A list of the raw materials used in this industry is included in
Appendix A. All the raw materials are considered non-toxic.
Products
Approximately one-third of the total tonnage of lime products man-
ufactured is used captively by the various producers. By far the largest
portion of this production is quicklime. Of the industry total for 1974,
17.3 million metric tons of quicklime was produced. Only 2.3 million tons
of hydrated lime was produced.
In terms of broad end-use applications, all types of lime products
(1973) were distributed as follows:
Million Metric Tons Used
Agriculture 0.127
Construction 1.461
Chemical and Industrial 16.445
Refractory 1.134
TOTAL 19.167
Chemical and industrial uses constitute approximately 90% of the con-
sumption of all lime products sold or used. Representative of these end-
use applications are:
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Basic oxygen furnace steel
Various alkalies
Water purification
Pulp and paper
Sugar refining
Open-hearth steel
Electric steel
Copper ore concentration
Sewage treatment
Aluminum and bauxite
Glass
Calcium carbide
Petrochemicals
Acid mine water neutralization
Precipitated calcium carbonate
Miscellaneous metallurgy
Magnesium metal production
Petroleum refining
Chrome products
Plastics
Food processing
Tanning operations
Miscellaneous ore concentration
Insecticides
Oil well drilling
Fertilizer manufacture
Rubber manufacture
Wire drawing
Silica brick
A complete list of the products made by the lime industry is presented
in Appendix B.
Companies
Lime products are manufactured both by companies that employ the mat-
erials in captive uses and by merchant producers that sell their products
commercially to others. Traditionally, the companies comprising this
industry have been intensely competitive.
In terms of production the leading individual plants for 1974 were:
Ste Genevieve plant of Mississippi Lime Co. in
Ste Genevieve County, Missouri
Buffington plant of Marblehead Lime Co. in
Lake County, Missouri
\
Syracuse plant of Allied Chemical Corp. in
Onondaga County, New York
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Lorain plant of U.S. Steel Corp. in
Lorain County, Ohio
Painesville plant of Diamond Shamrock Corp. in
Lake County, Ohio
Annville plant of Bethlehem Steel Corp. in
Lebanon County, Pennsylvania
Wyandotte plant of BASF Wyandotte Corp. in
Wayne County, Michigan
Woodville plant of Martin-Marietta Corp. in
Sandusky County, Ohio
Thorton plant of Marblehead Lime Co. in
Cook County, Illinois
Grand River plant of Republic Steel Corp. in
Lake County, Ohio
These 10 plants accounted for 29% of the total lime produced in 1974.
Leading companies in terms of production according to 1973 figures were:
Marblehead Lime Company
Mississippi Lime Company
Allied Chemical Corporation
Bethlehem Steel Corporation
Martin-Marietta Corporation
Pfizer, Incorporated
Warner Company
United States Gypsum Company
Diamond Shamrock Corporation
United States Steel Corporation
These ten companies operated 28 plants and accounted for 42% of the
total lime produced.
A complete list of the companies in the lime industry is presented
in Appendix C.
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Environmental Impact
Fugitive emissions of participate limestone from mining, handling,
crushing, and screening operations are common in the industry. Also
other fugitive emissions of particulate quicklime and hydrated lime result
from kiln discharges, hydrator operations, milling, handling, packing,
and shipping operations. These particulates are generally considered
more a nuisance than a health hazard. Silicosis and respiratory illness
have not been problems with employees in lime plants. Lime products,
being alkaline, can cause irritation to eyes, the respiratory system, and
moist skin. A wide variety of dust control equipment is available for
employment in the various processing steps. Where such devices have been
used, serious health and emission problems have been minimized. However,
some of the devices utilize wet recovery techniques, i.e., water scrubbers
etc., which generate alkaline waste liquors difficult to dispose of.
The dredging of sea shells results in potential ecological problems
due to the upsetting of marine life in or near shell reefs.
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Bibliography
Boyton, R. S. Chemistry and Technology of Lime and Limestone. New York,
John Wiley and Sons, Inc., 1966. 520 p.
Cotter, P. G. Lime and Calcium. In: Mineral Facts and Problems.
U. S. Dept. of the Interior, 1965. 9 p.
Lewis, C. J., and B. B. Crocker. The Lime Industry's Problem of Airborne
Dust. Journal of Air Polution Control. 9_:31-39. January 1969.
Lime and Limestone. In: Kirk-Othmer Encyclopedia of Chemical Technology,
Standen, A. (ed.). New York, John Wiley and Sons, Inc., 1967. 12^:414-460.
Minerals Yearbook, 1971, Schreck, A. E. (ed.). Washington, U.S. Dept.
of the Interior, Vol. II, 1973. 811 p.
Reed, A, H. Lime. In: Minerals Yearbook preprint, 1973, Schreck, A. E.
(ed.). Washington, U.S. Dept. of the Interior, 1973. 10 p.
Reed, A. H. Lime, Monthly. In: Mineral Industry Surveys. Washington,
U.S. Dept. of the Interior, February 19, 1975. 4 p.
Reed, A. H. Lime, Monthly. In: Mineral Industry Surveys. Washington,
U.S. Dept. of the Interior, April 28, 1975. 12 p.
Shreve, R. N. Portland Cements, Calcium, and Magnesium Compounds. In:
Chemical Process Industries. New York, McGraw-Hill Book Company, Inc.,
1967. p. 174-180.
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INDUSTRY ANALYSIS
Manufacture and use of quicklime and hydrated lime is almost as old
as recorded history. Quicklime was produced locally in the United States
as early as 1635 in Rhode Island. However, it was not until 1733 that
lime manufacturing became established as a significant industry in commerce.
The commercial hydration of lime is a comparatively recent development,
initiated in 1904. Technical progress has rapidly advanced the entire
industry during the last 70 years. The current technology as found in the
technical literature is in general, widespread use by all of the companies
representing this industry. The data obtained from the various sources
listed in the bibliographies of the Process Descriptions are generally
valid for all installations.
Data on emissions has, in most cases, been sufficient to reasonably
define the physical characteristics and quantities of such wastes.
Published technological data for the lime industry are shown diagram-
matically in the flowsheet of Figure 2.
The interior of each of the rectangular "process blocks" appearing
on the flowsheet represents at least one, and usually several, of the
sequential, real processes of the prototype operations depicted in the
flowsheet. In the process descriptions presented, the word "process"
refers to what occurs inside the process block.
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, dis-
charged from the process - a circle for atmospheric emissions, a triangle
for liquid wastes, and a rhombus for solid wastes. The flags do not dif-
ferentiate between inadvertent (fugitive) and designed wastes.
A verbal process description has been written to characterize each
process further, to relate it to other processes, and to quantify its
operating parameters. These process descriptions immediately follow the
flowsheet. More emphasis has been put on the processing of high-calcium
limestone from above-ground quarries, rather than from underground mines.
For this reason, most of the data and information reported is in the
context of lime manufacture from high-calcium limestones obtained from
open-pit quarries. However, the techniques and equipment employed also
apply to dolomitic limestones obtained from both types of mining. Similarly,
the production of lime from oyster shell is shown in the process flow
diagram for the sake of completeness, even though use of this source of lime
is declining.
As a qualitative overview of the material flow of the entire industry,
a chemical tree, Figure 1, has been included with the introductory section
for the Lime Industry Processes. This diagram shows the myriad of end-
uses for a comparatively small number of lime products, originating from
only one or two basic raw materials.
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Raw Materials Industry End Products End Uses
I I
Dolomitic
Limestone
Sea
Shells
High-
calcium —
Limestone
Dolime
Hydrated Dolime
Quicklime
Chemical & Industrial
Hydrated Lime
Construction
Refractories
A\ Agricultural
ron and Steel
Metallurgical
•Paint manufacture
.ubber processing
Tanning
'ulp and paper processing
•Petrochemicals
Sewage treatment
Soda ash manufacture
Sugar refining
Brick manufacture
Glassmaking
Water softening and purification
Neutralization
Dehydration processes
Calcium carbide manufacture
ement manufacture
Stucco manufacture
Soil stabilization
Masonry mortars
General construction
Plaster manufacture
Sand-lime brick manufacture
Dolomite brick
Furnace bottom lining
Food processing
Acidity reducers
Animal Feeds
Soil nutrients and fertilizer
Self-fluxing ores
Open-hearth furnaces
Basic oxygen converters
Electrical furnaces
Blast furnaces
Bauxite ore beneficiation
Copper smelting
Reduction of magnesium
Ore concentration
Wire Drawing
FIGURE 1. LIME INDUSTRY PRODUCT TREE
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Dolomite
deposit
-[TO Sales
W 11
Dredging/
washing ,
Mining/
conveying
-A i
Washing/
screening
Crushing/
sizing
Calcination/
pulverizing
FIGURE 2. LIME INDUSTRY FLOWSHEET
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LIME INDUSTRY PROCESS NO. 1
Mining/Conveying
1. Function - This process is the beginning step in the manufacture of
lime. The object is to remove rock from the bedded deposit of lime-
stone in the form of broken stone and transfer the material to the
Crushing/Sizing Process (No. 2). The typical operations involve the
drilling of holes for loading of explosives, blasting the limestone
loose, loading the stone into cars or trucks, and the conveying of
the stone to a primary crusher. In most cases, the primary crusher
will be located at the quarry or mine. Underground mining is cost-
lier than open-pit mining, but does not involve the extensive stripping
of overburden as required in open-pit mines.
Loading of stone is done with power shovels almost exclusively.
Generally, the size of the shovel is coordinated with the size of the
primary crusher. Diesel, gasoline and electric shovels are employed,
but the electric shovel is usually favored for sizes 2.3 cubic meters
or larger. The stone is loaded onto inclined rail-type cars for
transport from the quarry proper to the primary crusher. Rugged
rubber-wheeled off-highway trucks are very commonly employed.
Description of the crushing steps will be described in the Crushing/
Sizing Process Description (Process 2).
2. Input Materials - Quantities based on one metric ton of quicklime
produced:
•Broken high-calcium limestone rock, 1.79 tons (theoretical). This
quantity is never achieved because of handling and dust losses, plus
rejection due to over- or under-sized material.
•Table I shows the chemical analyses of various types of limestones
found in the United States.
•Broken dolomitic limestone rock, 1.90 tons (theoretical).
•Practically speaking, at least 2 tons of stone is needed for one ton
of lime produced, since there is an attrition loss of material as
solid particulates during the Mining and Crushing/Sizing Processes.
3. Operating Parameters
Roughly 9 metric tons of stone can be blasted loose per kilogram of
explosive used. Typical range of operation is 4 to 12 tons per kilogram.
11
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Table 1. REPRESENTATIVE CHEMICAL ANALYSES OF DIFFERENT TYPES OF U.S. LIMESTONE
CN5
Component
CaO
MgO
C02
Si02
A1203
Fe203b
S03C
P205
Na20
K20
H20
Other
-^-
Limestone, %d
1
54.54
0.59
42.90
0.70
0.68
0.08
0.31
0.16
2
38.90
2.72
33.10
19.82
5.40
1.60
3
41.84
1.94
32.94
13.44
4.55
0.56
0.33
0.22
0.31
0.72
1.55
0.29
4
31.20
20.45
47.87
0.11
0.30
0.19
0.06
5
29.45
21.12
46.15
0.14
0.04
0.10
0.05
0.01
0.01
0.16
0.01
6
45.65
7.07
43.60
2.55
0.23
0.20
0.33
0.04
0.01
0.03
0.23
0.06
7
55.28
0.46
43.73
0.42
0.13
0.05
0.01
0.08
8
52.48
0.59
41.85
2.38
0.57
0.56
n.d.
0.20
b
c
1 = Indiana high-calcium stone
2 = Lehigh Valley, Pa., "cement rock"
3 = Pennsylvania "cement rock"
4 = Illinois Niagran dolomitic stone
Includes some Fe as FeO
Includes some elemental S.
5 = Northwestern Ohio Niagran dolomitic stone
6 = New York magnesian stone
7 = Virginia high-calcium stone
8 = Kansas Cretaceous high-calcium stone (chalk)
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•Primary blasts can release anywhere from 27,000 to 227,000 metric
tons of stone per blast.
•Shovel size varies from 0.4 to 3.8 cubic meters.
•Capacity of hauling trucks: up to about 55 metric tons payload,
although the average is 22 to 27 tons.
4. Utilities
•Total energy requirement in all forms:
Underground mining: 1-20 kWh/metric ton (estimated) of stone.
Open-pit quarry: 2-20 kWh/metric ton (estimated) of stone.
•Fuel oil: approximately 4.5-6.5 kWh/metric ton of material mined or
quarried (estimated).
5. Waste Streams
•Fugitive emissions of particulate limestone from blasting, handling,
crushing, and hauling of stone. These emissions have the same com-
position as the original stone. Emissions due to blasting explosives
are internittent.
•Solid wastes in the form of mounds of stripped overburden incident
to preparation of open-pit quarries for removal of stone.
•Dust suppression is achieved by water sprays on rock and wetting
of roads with calcium chloride solution and road oil.
•Emissions (typical):
Bulk loading: 0.02 grams/cubic meter of air, concentration.
Crushed stone stockpile: 0.004 grams/cubic meter of air, concentration.
6. EPA Source Classification Code
3-05-020-06 Screen/Convey/Handling
3-05-020-07 Open Storage
3-05-020-09 Blasting-general
7. References
Boynton, R. S. Chemistry and Technology of Lime and Limestone.
New York, John Wiley and Sons, Inc., 1966. 520 p.
Lewis, C. J., and B. B. Crocker. The Lime Industry's Problem of
Airborne Dust. Journal of Air Pollution Control, January 1969.
9:31-39.
13
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Herod, D. C. Woodville Lime Takes Aim at Premium Market. Pit and Quarry,
1975. 67(5):90-93.
Krohn, B. J. U.S. Lime Division's Dust Abatement Efforts. Pit and Quarry,
1974. 66_(5):87-92.
Lime and Limestone. In: Kirk-Othmer Encyclopedia of Chemical Technology,
Standen, A. (ed.). New York, John Wiley and Sons, Inc., 1967. 12:414-460.
Stowell, F. P. Limestone as a Raw Material in Industry. New York
Oxford University Press, 1963. p. 9.
Truffner, W. E. Allied Product Company's Expanded Montevallo Plant.
Pit and Quarry, 1975. 67J5):98-103.
14
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LIME INDUSTRY PROCESS NO. 2
Crushing/Sizing
1. Function - This processing step involves the crushing, pulverizing or
grinding, and sizing of the raw quarry or mine feedstock from Mining/
Conveying, Process 1. Lime manufacture requires stone of definite size
ranges depending on the type of kiln used. The greatest influence on
lime quality is the size gradation of limestone used to feed the kilns.
Narrow gradations such as 10 x 20 cm, 2.5 x 5 cm, 0.5 x 1 cm, or
narrower are very conducive to uniform calcination. Preparation of
crushed stone requires a series of crushing, screening, and classifica-
tion operations. Primary crushers employed may be either the jaw or
gyratory type. Reduction in the primary crusher is generally not
greater than 6 to 1. Depending on rock hardness, roll crushers and
hammer mills may also be used. In most cases, the primary crusher will
be located at the quarry or mine.
Secondary crushing of stone to sizes 2.5 cm and under is achieved in
cone crushers and high speed, flat-angle gyratory crushers. Sometimes
hammer mills are employed on the lesser abrasive stone varieties.
Depending upon current lime demand, some of the crushed limestone may
be sold as by-product incidental to the main calcining process. Some
pulverizing is done to further reduce undersize stone that is generally
unsuitable for feed to the kilns. The material from this operation is
sold as by-product agricultural limestone. Occasionally the stone may
be dried in a rotary drier to facilitate better pulverizing.
Vibrating screens of various types are the most prevalent method of
classifying all sizes of limestone. The type and size of machine and
the frequency of vibration is determined by the size gradation of the
stone to be screened. Many lime plants are able to reduce the im-
purities in their lime product by careful screening and selecting the
stone for burning. It should be noted that the percentage of impurities
in a quicklime is nearly double that in the original stone.
Provisions are usually made in every plant layout to store very large
quantities of processed or semi-processed stone. This is to allow for
balancing the fluctuating demand for lime products against the produc-
tion and availability of raw material. Crushed stone is kept in huge
stockpiles or surge piles. Material is conveyed to these piles by
conveyor belt. A tunnel conveyor under the pile allows withdrawal for
further processing in all types of weather. The most prevalent stone-
conveying equipment is the rubber belt conveyor in conjunction with
bucket elevators.
2. Input Materials
Broken stone from Mining/Conveying, Process 1, 2.0 metric tons,
approximately, of stone per ton of quicklime produced.
15
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3. Operating Parameters
•Primary crushers will reduce stone to lumps 2.5 to 7.6 centimeters
in size and are sized to handle broken stone in sizes measuring up
to 60 to 90 centimeters.
•Secondary crushers are used to reduce stone to sizes below 2.5 centi-
meters; capacities up to 3,000 metric tons per hour.
•Most vertical kilns require limestone feed in sizes of 15 to 20 centi-
meters to minimize pressure drop in the unit.
•Rotary kilns require a more carefully classified and smaller size
limestone feed, generally ranging from about 0.5 to 1.25 centimeters,
although multi-kiln operations may employ one unit using feed in the
2.5 to 6.0 centimeter range.
•Both jaw crushers and gyratory crushers have openings approximately
2 x 2.5 meters. A gyratory crusher has between 3 and 4 times the
capacity as a jaw crusher, but also uses about two times the energy
requirement; capacities up to 3,000 metric tons per hour.
•By-product limestone used for agricultural applications is usually
pulverized to 60 to 100%, -200 mesh.
4. Utilities
Total power consumption is estimated at 10 to 200 kWh/metric ton of
material processed, depending upon the crushing/grinding and classifica-
tion steps required.
5. Haste Streams
•Fugitive emissions of solid particulate limestone from crushed and
pulverized limestone operations and screening; approximately 12 grams
per kilogram or rock produced without controls in primary crushing
operations and 1.0 gram per kilogram in secondary crushing and screening.
•Emissions from this process are summarized in Table 2.
Table 2. TYPICAL EMISSIONS FROM CRUSHING/SIZING
Source or Operation Particulate Emissions, Collection
gms/cu meter Efficiency,
Limestone Primary
Crushing
Limestone Secondary
Crushing
Limestone Screening
Pulverized Limestone
Drier
0.04
0.12
0.38
4.67
poor
good
60-70
Method of
, % Control
water sprays
cyclone &
filters
none
cyclone c<
bag
Dllect
16
-------
•Solid or wet limestone participates removed from various air emission
abatement devices used. Because of the heterogeneous nature of the
materials collected, profitable disposal is difficult. Materials are
usually held at the plant site and eventually used as landfill.
6. EPA Source Classification Code
3-05-020-01 Primary Crushing
3-05-020-02 Secondary Scushing/Screening
3-05-020-03 Tertiary Crushing/Screening
3-05-020-05 Fines Mill
3-05-020-06 Screening/Conveying/Handling
3-05-020-07 Open Storage
7. References
Boynton, R. S. Chemistry and Technology of Lime and Limestone.
New York, John Wiley and Sons, Inc., 1966. 520 p.
Herod, D. C. Woodville Lime Takes Aim at Premium Market. Pit and Quarry,
1975. 61(5) :90-93
Krohn, B. J. U.S. Lime Division's Dust Abatement Efforts. Pit and Quarry,
1974. 66_(5):87-92.
Lewis, C. H., and B. B. Crocker. The Lime Industry's Problem of Airborne
Dust. Journal of Air Pollution Control, January 1969. 9_:31-39.
Lime and Limestone. In: Kirk-Othmer Encyclopedia of Chemical Technology,
Standen, A. (ed.). New York, John Wiley and Sons, Inc., 1967. 12:414-460.
Shreve, R. N. Portland Cements, Calcium, and Magnesium Compounds. In:
Chemical Process Industries. New York, McGraw-Hill Book Company, Ind.,
1967. p. 174-180.
Truffner, W. E. Allied Product Company's Expanded Montevallo Plant.
Pit and Quarry, 1975. 67J5):98-103.
17
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LIME INDUSTRY PROCESS N°' 3
Dredging/Washing
1 Function - This process involves the use of sea-going suction dredges
to "mine" oyster or clam shells found in beds or reefs located along
sea coasts, particularly the Texas-Louisiana Gulf Coast, where no
limestone deposits of any consequence are to be found within 200 miles
of the coast. Sea shell beds may be classed as unconsolidated lime:
stone deposits. In practice, large suction pipes on the dredge, equipped
with rotary cutting heads revolving at 9 to 15 rpm, are dropped onto
the reef. Large pumps pick up the dislodged shell and transport it
to the top of the dredge for rough washing.
The dredged up shells are rough-washed on board with fresh high pressure
seawater to dislodge silica, silt and mud. The washing step is facili-
tated using single- or two-stage screens or trommels. High pressure
seawater is directed at the raw shells using fish-tail spray nozzles.
The rough washed shells are transported by a boom conveyor and stacked
on barges alongside the dredge. Barges are moved by tugboat to the
offloading dock some 50 to 100 kilometers distant. At the dock, shel1
is offloaded using derrick clamshell buckets and dumped onto surge or
stockpiles.
Most shell-lime producers purchase their shell under contract from pro-
fessional shell dredgers. Some rough-washed shell is sold for secondary
road construction uses. Further expansion of lime proudction from shells
appears quite limited, since the supply of shell is being depleted at
a rapid rate due to extensive withdrawal from the reefs in the past 30
years.
2. Input Materials
•Raw shell: between 1.1 and 1.2 metric tons per ton of rough-washed
shell produced.
Typical ranges of analysis of rough-washed oyster shells are presented
in Table 3.
Table 3. COMPOSITION OF ROUGH-WASHED OYSTER SHELLS
Component Wt. %
CaC03 91.9 - 95.0
MgC03 0.89 - 1.44
Si02 2.2 - 4.5
SO* (as CaSOj 0.43 - 0.51
A1203 0.11 - 0.28
Fe203 0.17 - 0.27
18
-------
3. Operating Parameters
•A typical dredge is about 92 meters long, not including a 20-meter
boom, and has a beam about 12 meters long. When empty, the unit will
draw about one meter of water and two meters when loaded.
•Shell reefs run in thickness between 0.6 and 12 meters. 0.6 meter
is the minimum economic thickness.
•One dredge can provide, on the average, between 133,000 and 172,000
cubic meters of washed, unsized shell per month.
•Raw shell density (drained): between 925 and 945 kilogram per cubic
meter.
•Typical dredge pump specifications:
casing diameter, 1.8 meters
suction x discharge size, 40 x 46 centimeters
speed, 345 rpm
4. Utilities
•Approximately 227 cubic meters per hour of seawater, continuous, for
rough shell washing on a dredge, typical.
•820 kilowatt diesel engine to power the dredge pump and cutter head.
•Approximately 1600 kW with diesel engine-driven electric generators
(usually two) for lights, seawater pumps, conveyors, and accessories.
5. Waste Streams
The only waste stream from the Dredging/Washing process consists of
the seawater washings mixed with sand, mud, and silt or gumbo washed
off the raw shells as they are dredged up. These washings are returned
to the sea. No quantitative figures are available, but it has been
estimated that 10 to 20% of the solids dredged from the shell reef is
returned to the sea as waste.
6. EPA Source Classification Code
None
7. References
Boynton, R. S. Chemistry and Technology of Lime and Limestone.
New York, John Wiley and Sons, Inc., 1966. 520 p.
19
-------
Lime and Limestone. In: Kirk-Othmer Encyclopedia of Chemical
Technology, Standen, A. (ed.). New York, John Wiley and Sons, Inc.,
1967. 1^:414-460.
Taggart, A. F. Industrial Minerals. In: Handbook of Mineral Dressing.
New York, John Wiley and Sons, Inc., 1966. 3^:46-60.
20
-------
LIME INDUSTRY PROCESS NO. 4
Mashing/Screening
1. Function - In this process, sea shells are unloaded from barges and
given a fresh water wash to remove residual seawater and salts. For
high purity commercial chemical lime, shell washing is mandatory. In
some cases, the shell user must "scrub" the incoming material in order
to remove encrustations of silica that would otherwise lower overall
purity of the final lime product.
Washing is done using rotary screens or trommels. These may be either
single- or two-stage washer screens. Prior to feeding into the kilns,
the shells go through a second screening process to separate out the
fines. These fines are generated as a result of mechanical breakage
while handling. Some of the washed and sized shell fines are sold
for chicken grits and as agricultural limestone by-products.
Finally, the washed and screened coarse shells are transported and
dumped onto surge piles to await conveying to the rotary kilns. Load-
ing and feeding is usually done with a combination of stocking con-
veyors, stockpile loaders, and inclined belt conveyors.
2. Input Materials
•Rough-washed shells, between 1.1 and 1.2 metric tons per ton of clean,
washed shell.
•A typical analysis of clean, washed oyster shells is given in Table 4.
Table 4. COMPOSITION OF CLEAN, WASHED OYSTER SHELLS
Component
CaC03
MgC03
SiC2
SO* (as CaSOu)
A1203
Fe203
3. Operating Parameters
•Typical revolving screen washer: 0.9 x 8.5 meters revolving screen,
approximately 7 to 20 rpm, 30 mm opening.
•Capacity can be as high as 100 metric tons per hour.
•Occasionally two-stage wash trommels are employed using 2| -mesh and 8-
mesh screen; 0.9 x 5.5-meter and 1.5 x 5-meter sizes.
•Water spray pressure: 1.75 to 5.0 kilogram per cm2 with nozzles
separated 15 to 20 cm apart.
21
-------
4. Utilities
•6 to 10 cubic meters high-pressure fresh water per metric ton of
rough-washed shell feed to the process.
•Estimated total power: up to 1.5 kWh per metric ton of washed shell.
5. Waste Streams
Shell washings: These consist mainly of fresh water with dissolved
residual salt, plus minor quantities or mud and silica not previously
removed by the seawater washing step in Process 3.
6. EPA Source Classification Code
None
7. References
Boynton, R. S. Chemistry and Technology of Lime and Limestone. New
York, John Wiley and Sons, Inc., 1966. 520 p.
Lime and Limestone. In: Kirk-Othmer Encyclopedia of Chemical Tech-
nology, Standen, A. (ed.). New York, John Wiley and Sons, Inc., 1967.
12.: 414-460.
Taggart, A. F. Screen Sizing. In: Handbook of Mineral Dressing.
New York, John Wiley and Sons, Inc., 1966. 7^:27-34.
Taggart, A. F. Industrial Minerals. In: Handbook of Mineral Dressing.
New York, John Wiley and Sons, Inc., 1966. 3_:46-60.
22
-------
LIME INDUSTRY PROCESS NO. 5
Calcination/Pulverizing
1. Function - Crushed limestone rock or sized shell from process steps 2
or 4 is heated to a high temperature to convert the carbonate to oxide.
Carbon dioxide is driven off as a by-product and may or may not be
recovered for other uses. In the early stages of calcination, moisture
and volatile organic matter are driven off. As the temperature of the
limestone (or shell) rises, decomposition begins, releasing carbon
dioxide. Rapid decomposition does not take place until a temperature
of 700° to 800°C is reached for dolomitic limestone and 830° to 930°C
for high-calcium raw materials.
A number of types of kilns are used for carrying out calcination. The
two most widely used are the rotary kiln and the vertical kiln. Both
types are made up of steel shells lined with refractory brick. The
oldest and most numerous type of continuous kiln is the vertical or
shaft kiln. These are the most efficient in terms of fuel economy, but
are limited in capacity per individual unit. An inclined skip-hoist
conveys feed to the top where it is charged in batches. The kiln is
usually fired with gas or ore burners in the side. Older kilns use coal
as fuel. Calcined lime is taken out at the bottom continuously or in
batches. Flue gas exhausts at the top of the kiln. Vertical kilns
generally yield a lump lime product.
Horizontal rotary kilns are used to produce slightly more than 80% of
total lime production in the United States. About 50% of all the captive
lime produced is calcined in rotary kilns. Even though fuel economy is
lower and the capital investment is greater for rotary kilns, the trend
is toward these types because of their high capacity per unit. Con-
sequently the manpower requirement per ton of product made is much lower
than for vertical kilns. Rotary kilns are generally fired with natural
gas, fuel oil, or pulverized coal. The flow of limestone (or shell) and
combustion products is countercurrent through the kiln.
In recent years, several new types of kilns have been developed with
goals of improving capacity, fuel economy, temperature control, and
capital costs. Of increasing interest is the development of techniques
which will reduce attrition and solid particulate emissions. Some of
the more noteable of these developments are the Dorrco Fluosolids kiln
and the Calcimatic kiln.
Regardless of the type of kiln employed, after being discharged, the
quicklime is conveyed by belt conveyor to screens where the fines and
undersized particles are removed.
Most quicklime is shipped in bulk, with covered hopper-bottom rail cars
being the preferred method. Less than 1% is packed in bags. The product
23
-------
is available in various mesh sizes, varying all the way from fine pul-
verized grades to lumps. In general, lumps from vertical kilns will
range from 6 to 25 cm. Pebble lime usually comes from rotary kilns
in the 0.5 to 7.0 cm range, with the high end obtained sometimes from
crushed lumps from the vertical kilns. Air-swept hammer mills are
commonly used for grinding, although impact breakers, small gyratory
crushers, and cone mills are also used. Screening steps similar to
those in the Crushing/Sizing process (No. 2) are also applied to some
lime milling operations.
If hydrated lime is to be made, grinding equipment is employed to
pulverize and reduce the lump or pebble quicklime to 0.5 to 1.24 cm
or smaller. Also, waste quicklime fines that are screened off at
the kiln discharge are also normally used as feed to the hydration
process.
Dead-burned dolomite (refractory grain) is the commercial name for
refractory lime. This product, with few exceptions, is made in rotary
kilns. It is a highly sintered form of dolomitic lime that has been
calcined at temperatures up to 1635° to 1820°C. Usually 5 to 8% of
iron oxide is added. The MgO component is converted to periclase and
the entire product is rendered chemically less reactive than materials
calcined at lower temperatures. The product is grayish-brown in color
and is available in various granular sizes from about 1 cm to -20 mesh.
Primary use of this material is for lining basic open-hearth steel
furnaces. Before shipment of this product, a light spray of asphaltic
based oil is added to enhance stability of the product and reduce dusting.
2. Input Materials
Quantities are based on one metric ton of quicklime produced, unless
otherwise specified:
•Crushed, dried, and graded limestone or sea shells from processes
2 or 4:
1.79 tons (theoretical)
•Only 1.35 tons (theoretical) of raw material are required to produce
one ton of dry hydrated lime. This is because of the water added to
quicklime in process step 6.
•Coal: approximately 0.3 tons (as fuel), or equivalent amounts of
natural gas or fuel oil, based on heating value.
•Practically speaking, about 2 metric tons of stone or shell are required
per ton of quicklime produced because of kiln losses and fines generated
in the raw material preparation and product screening and pulverizing
steps.
24
-------
3. Operating Parameters
a. Vertical Kilns
•3 to 7 meters diameter by 10 to 23 meters high.
•Capacity: 6 to 14 metric tons per day (older units), trend is
toward 68 to 73 tons per day.
•Heat requirements: about 0.78 million kcal per metric ton of
lime produced. Generally more efficient than rotaries.
•Kiln temperatures: 1200° to 1300°C
•More difficult to control than rotary kilns. On the average,
vertical kiln lime is not as uniform or high in quality as rotary
kiln lime.
•Vertical kilns generally yield lower outputs of lime per man-hour
of labor worked.
•Feed requirements: 7.6 to 30 cm lumps, with 7.6 x 15 or 10 x 20
cm being typical.
b. Rotary Kilns
•5.4 to 10.4 meters diameter by 18 to 120 meters long. A common
length is 45 meters.
•Capacity: up to 500 metric tons per day.
•Heat requirements: between 0.9 and 2.77 million kcal per metric
ton of lime, depending on types and sizes of stone and kiln design.
Preheat sections, lime coolers, and intermediate heat exchangers
are all used to improve kiln heat economy.
•Kilns are generally installed at 3° to 5° inclination to the
horizontal.
•Rotational speed: 30 to 50 seconds per revolution.
•No more than 10% of the inside of the kiln is filled with stone
or lime.
•Oyster shells are almost always calcined in rotary kilns. The
flat nature and small size (0.6 to 3.0 cm) of shells generally
precludes their use in vertical kilns.
•Typical analyses of commercial quicklimes are given in Table 5.
-------
Table 5. COMPOSITION OF COMMERCIAL QUICKLIMES
Component High-Calcium Quicklimes Dolomitic Quicklimes
% range % range
CaO
MgO
Si02
Fe203
A1203
H20
C02
93.25
0.30
0.20
0.10
0.10
0.10
0.40
- 98.00
- 2.50
- 1.50
- 0.40
- 0.50
- 0.90
- 1.50
55.50
37.60
0.10
0.05
0.05
0.10
0.40
- 57.50
- 40.80
- 1.50
- 0.40
- 0.50
- 0.90
- 1.50
aThe values given in each range do not necessarily represent minimum
and maximum percentages.
•Typical ground quicklime product size:
100% -8 mesh
40 to 60% -100 mesh
•Typical pulverized quicklime product size:
100% -20 mesh
80 to 90% -100 mesh
•Capacities of size reduction machinery: (typical)
Hammer mills, 1.5 to 20 metric tons per hour
Ring roller mills, 1 to 40 metric tons per hour
•A typical composition of kiln exhaust gases (average temperatures,
420° to 980°C) is presented in Table 6.
Table 6. COMPOSITION OF KILN EXHAUST GASES
Component Volume %
Nitrogen 59.7
Carbon dioxide 24.3
Water 15.3
Oxygen 0.7
.Typical kiln exhaust gas generation for a coal-fired rotary kiln
producing 182 metric tons per day is presented in Table 7.
26
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Table 7. VOLUMES OF KILN GAS GENERATED IN CALCINING
Fuel/Lime Ratio kg gas per metric ton of lime
1:3 4,445
1:4 3,555
1:5 2,970
4. Utilities
•Power required to drive rotary kilns: 3 to 225 kW (estimated), for
kilns (rotary) producing from 15 to 450 metric tons per day.
•Water for lime cooling: about 70 cubic meters per hour for a typical
180 metric ton per day unit.
•For grinding or pulverizing quicklime: 4 to 25 kWh per metric ton of
material ground (estimated); this includes hammer mills, ring roller
mills, or ball mills, generally with air classifiers.
5. Waste Streams
•Gaseous emissions of carbon dioxide to the atmosphere (if not recovered
beneficially). For a pulverized coal-fired kiln using a 1 to 4 fuel-
lime ratio, COa represents approximately 42% of the total flue gases
by weight.
'Fluorine-containing minerals are found in some limestone deposits.
These may be a source of fluorine emissions, depending on their chemical
association.
•Gaseous emissions of S02 and S03 from the combustion of sulfur-containing
coal or fuel oil. Sulfur oxides may also be emitted from decomposition
and oxidation of sulfides and sulfates in the limestone itself. The con-
centration varies widely with the limestone in use.
•Gaseous emissions of S02 and SOa from the combustion of sulfur-containing
coal or fuel oil.
•Gaseous emissions of oxides of nitrogen from the combustion of fuel for
calcining.
•Emissions of particulate solids (fly ash) resulting from the burning
of coal as a heat source for calcining.
•Fugitive emissions of particulate quicklime from kiln discharge;
approximately 90 grams per kilogram of lime produced in rotary and
3.5 grams in vertical kilns.
•Airborne emissions of soot and tars resulting from incomplete combustion
of fuels used as heat source for calcining.
27
-------
•Table 8 summarizes fugitive emissions from calcination/pulverizing
and their control methods.
Table 8. TYPICAL FUGITIVE LIME EMISSIONS AND CONTROL METHODS
Source or Operation
Particulate
Emissions
Grams/cu meter
Collection
Efficiency,
Control Method
Vertical lime kiln
Rotary kiln
Rotary kiln
Rotary kiln
Rotary kiln
Rotary kiln
Rotary kiln
Calcimatic kiln
0.70 - 2.29
0.002
0.05 - 0.18
9.80
0.50
0.25 - 0.57
0.7 - 0.9
0.05
none
99.99 glass bag filter
99.7 - 97.5 4-stage cyclonic scrubber
70.0 high efficiency cyclones
95.0 single-stage precipitator
96 - 97 Venturi scrubber
97.5 Impingement scrubber
99.2 glass bag filter
•An analysis of solid particulate emissions from stacks in natural gas-
fired rotary kilns using primary collection devices is presented in
Table 9.
Table 9. COMPOSITION OF PARTICULATES FROM NATURAL GAS FIRED KILNS
Emission Component
Chemical Analysis
High-Calcium Dolomitic
Lime, wt. % Lime, wt.
Acid insoluble
Heavy metal oxides (R203)
CaC03
CaO
MgO
CaSOu
Ca(OH)2
0.66
0.97
23.06
66.32
1.40
1.22
6.37
0.45
0.35
64.30
7.23
28.20
0.27
— -— -
A typical screen analysis of the solid particulates described above is
shown in Table 10.
28
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Table 10. PARTICLE SIZE OF PARTICULATES FROM NATURAL GAS FIRED KILNS
Tyler mesh size
+65
-65 + 100
-100 + 150
-150 + 200
-200 + 270
-270 + 325
-325 + 400a
- 400a
wt.%
0.5
1.5
3.6
10.0
9.7
8.4
7.5
58.8
aAverage particle size: 5 to 6 microns
•Dust control is a greater problem with rotary than with modern
vertical kilns.
•Solid participate emissions from a rotary kiln generally range from
2 to 8% by weight of the limestone charge; can be as high as 15% of
the lime produced without proper controls.
•Lime dust collected from various air emission abatement devices is
heterogeneous with regard to size and composition. The solid waste
by-product is difficult to sell. Any wet sludge obtained from wet
collectors have the additional problem of requiring drying before
disposal. In most cases, these wastes are usually accumulated in
segregated waste piles or lagoons at the plant site.
6. EPA Source Classification Code
3-05-016-03 Calcining-vertical kiln
3-05-016-04 Calcining-rotary kiln
7. References
Boynton, R. S. Chemistry and Technology of Lime and Limestone.
New York, John Wiley and Sons, Inc., 1966. 520 p.
Cotter, P. G. Lime and Calcium. In: Mineral Facts and Problems.
U.S. Dept. of the Interior, 1965. 9 p.
Herod, D. C. Woodville Lime Takes Aim at Premium Market. Pit and
Quarry, 1975. 6_7(5):90-93.
Krohn, B. J. U.S. Lime Division's Dust Abatement Efforts. Pit and
Quarry, 1974. 66_(5) :87-92.
29
-------
Lewis , C. J., and B. B. Crocker. The Lime Industry's Problem of
Airborne Dust. Journal of Air Pollution Control, January 1969.
9_:31-39.
Lime and Limestone. In: Kirk-Othmer Encyclopedia of Chemical
Technology, Standen, A. (ed,). New York, John Wiley and Sons,
Inc., 1967. 12:414-460.
Truffner, W. E. Allied Product Company's Expanded Montevallo
Plant. Pit and Quarry, 1975. 67(5):98-103.
30
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LIME INDUSTRY PROCESS NO. 6
Hydration/Packing
1. Function - Hydrated lime (calcium hydroxide) is manufactured in this
process step by slowly adding water to ground quicklime in predetermined
proportions from process step 5 in a hydrator or slaker. Both batch
and continuous hydrators are employed. Mechanical agitation is used
to insure thorough mixing. Continuous hydrators are steadily replacing
batch units. Some lime dust is emitted from the stack of the hydrator.
This dust is recovered in a washer-scrubber collector and the resulting
milk of lime is recycled directly to the hydrator or its pre-mix chamber.
In this way, valuable lime is recovered and air emissions from this source
are minimized.
Normally hydrated dolomitic lime consists of calcium hydroxide and
magnesium oxide with little if any magnesium hydroxide. However,
dolime can be completely hydrated in an autoclave under pressure.
Closed circuit conveyors are used for transporting the semi processed
hydrate from the hydrator to the finishing part of the process. This
is done to prevent recarbonation of the hydrated lime. Usually a
system of horizontal screw conveyors and bucket elevators are employed.
Any uncalcined lime, overburned material or silica in the hydrated
products is removed in an air separator after the hydration step is
completed. Centrifugal air separators are universally employed in
the final milling and classification of the product.
Finished dry hydrate product is transported to product silos and from
there to bagging machines.
Some hydration of lime is also carried out with great excess of water
so that a slurry of "milk of lime" solution is produced instead of a
dry powder. This process is usually called slaking. Slaking equipment
is usually located at the plant site of the user. Only in cases where
the lime producer has a captive use for slaked lime will a slaker be
employed at the lime plant proper.
2. Input Materials
Quantities are based on one metric ton of dry hydrated lime:
•Quicklime: approximately 0.757 ton
•Water: approximately 0.243 ton
The above figures are theoretical quantities required to make a dry
hydrated lime from pure quicklime. Generally a slight excess of
water is added to offset losses from the steam formed and lost by the
heat of hydration.
31
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3. Operating Parameters
•Table 11 describes the composition of some commercial hydrated limes,
Table 11. TYPICAL PRODUCT ANALYSES OF COMMERCIAL HYDRATED LIMES
Component High-Calcium Hydrated
Limes, % Range
CaO
MgO
H20
C02
Si02
R203
71
0.5
24
0.3
0.2
(heavy metal oxides) 0.1
- 74
- 2
- 25
- 0.7
- 0.5
- 0.3
Highly Hydrated Dolomitic
Lime, % Range
41
25
27
0.3
0.2
0.1
- 45
- 30
- 28
- 0.7
- 0.5
- 0.3
•Standard hydrated lime has a fineness of 95% passing 200 mesh. A
"superfine" grade is produced by pulverizing and/or air classifica-
tion to a fineness of 95.5% through a 325 mesh.
•Capacities of hydrators: 1 to 15 metric tons per hour.
•Typical feedstock size: no larger than 5 cm top size; 1.25 cm size
works best in most hydrators.
•Storage facilities for raw quicklime feed to the hydrators consist
of tall silos with hopper bottoms having individual capacities
ranging from about 90 to 550 metric tons.
•Typical bagger operations: 12 to 15, 22.7-kilogram bags per minute.
4. Utilities
•Total energy requirement: 2.5 to 17.5 kWh per metric ton of hydrate
produced (estimated).
•Air classification energy requirement: 4 to 8 kWh per metric ton of
lime hydrate produced (estimated).
5. Waste Streams
•Fugitive emissions of high dewpoint gases containing particulate lime
particles. Practically all lime hydrating plants are equipped with
recovery equipment of one type or another, i.e., direct spray scrubbers
and condensers.
32
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•Fugitive solid participate hydrated lime emissions from milling and
bag packing operations: approximately 2.5 grams per kilogram of
quicklime handled.
•Slaker processes do not contribute to air pollution problems, compared
to hydrator processes because of the large quantities of water used
in slakers. No steam or gases are discharged which can entrain solid
lime or emissions.
•No liquid wastes are generated from slaker or hydrator operations.
•Typical emissions and control methods are described in Table 12.
Table 12. EMISSIONS AND CONTROL METHODS FOR HYDRATION/PACKING
Source or
Operation
Hydration
Hydration
Hydrate milling
Hydrate loader
and packer
Particulate
Emissions
Grams/cu meter
0.02 - 2.15
0.02 - 0.16
no visible dust
0.02
Collection Control
Efficiency, %
Water sprays
Wet scrubber
99+ Bag filter
99+ Bag filter
Method
in stack
•Waste solid tailings from the hydrate milling step, composed of under-
and over-sized materials including silica, iron and aluminum oxides,
and calcium and magnesium oxides. This amounts to about 10% of the
total hydrate produced. Liquor from scrubbers and water sprays is
genera My recycled in the process for recovery of solid wastes.
6. EPA Source Classification Code
None
7. References
Boynton, R. S. Chemistry and Technology of Lime and Limestone.
New York, John Wiley and Sons, Inc., 1966. 520 p.
Lewis, C. J., and B. B. Crocker. The Lime Industry's Problem of
Airborne Dust. Journal of Air Pollution Control, January 1969.
9.: 31-39.
Lime and Limestone. In: Kirk-Othmer Encyclopedia of Chemical Tech-
nology, Standen, A. (ed.). New York, John Wiley and Sons, Inc., 1967.
12:414-460.
33
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APPENDIX A
RAW MATERIALS
35
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Table A-l. TYPICAL COMPOSITIONS OF RAW MATERIALS
Component Wt. %
Limestone Rock
CaO
MgO
C02
Si02
A1203
Fe203
S03
P205
Na20
K20
H20
Other
Dolomitic Limestone Rock
CaO
MgO
C02
Si02
A1203
Fe203
S03
P205
Na20
K20
H20
Other
Sea Shells
CaC03
MgC03
Si02
SO, (as CaSOj
A1203
Fe203
55.28
0.46
43.73
0.42
0.13
0.05
0.01
—
—
—
—
0.08
31.20
20.45
47.87
0.11
0.30
0.19
—
—
0.06
—
—
—
91.90 - 95.
0.89 - 1.
2.20 - 4.
0.43 - 0.
0.11 - 0.
0.17 - 0.
00
44
50
51
28
27
36
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APPENDIX B
PRODUCTS
37
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Table B-l. LIST OF PRODUCTS
Quicklime
Dolime
Hydrated lime
Hydrated dolime
Carbon Dioxide
Refractory grain
38
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APPENDIX C
COMPANIES AND PRODUCTS
39
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Table C-l. COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
Alabaster Lime Company
Allied Chemical Corporation
Allied Product Company
Aluminum Company of America
Amalgamated Sugar Company
American Crystal Sugar Company
Amstar Corporation
The Anaconda Company
Armco Steel Company
Ash Grove Cement Company
CITY OR COUNTY, AND STATE
Siluria, Alabama
East Baton Rouge Co., Louisiana
Onondaga Co., New York
Montevallo, Alabama
Saline Co., Arkansas
Calhoun Co., Texas
Canyon Co., Idaho
Malheur Co., Oregon
Minidoka Co., Idaho
Twin Falls Co., Idaho
Clay Co., Minnesota
Otero Co., Colorado
Pembina Co., North Dakota
Polk Co., Minnesota
Yolo Co., California
Maricopa Co., Arizona
Monterey Co., California
Yolo Co., California
Anaconda, Montana
Harris Co., Texas
Greene Co., Missouri
Multnomah Co., Oregon
TYPE OF OPERATION9
lime kiln and plant
quarry and plant
plant
plant
plant
plant
quicklime, shaft kilns
quicklime, shaft kilns
shaft kiln
two plants, quicklime, shaft kilns
shaft kiln
shaft and rotary kilns
shaft and rotary kilns
plant
plant
plant
plant
Austin White Lime Company
Travis Co., Texas
plant
-------
Table C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
J. E. Baker Company
S. W. Barrick & Sonss Inc.
BASF Wyandotte Corporation
Basic, Inc.
Basic Magnesia, Inc.
Battery Park Fish and
Oyster Corporation
Bethlehem Steel Corporation
Black River Mining Company
Bowaters Southern Paper
Corporation
C F & I Steel Corporation
Champion International
Chemstone Corporation
CITY OR COUNTY. AND STATE
Sandusky Co., Ohio
York, Pennsylvania
Frederick Co., Maryland
Wayne Co., Michigan
Seneca Co., Ohio
Port St. Joe, Florida
Louisa Co., Virginia
Adams Co., Pennsylvania
Erie Co., New York
Lebanon Co., Pennsylvania
Butler, Kentucky
McMinn Co., Tennessee
Pueblo, Colorado
Harris Co., Texas
Hernando Co., Florida
Shenandoah Co., Virginia
TYPE OF OPERATION
plant
plant
plant
quicklime, nine shaft kilns
plant
plant
quarry
plant
plant
natural-frequency-vibrating
kiln plant
227 tons per day rotary kiln,
hydrating facilities
plant
plant
Cheney Lime and Cement
Company
Shelby Co., Alabama
lime kiln and plant
-------
iflDle C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
C L M Corporation
Corchem, Inc.
G & W H Corson, Inc.
Cuyahoga Lime Company
Diamond Shamrock Corporation
Diamond Springs Lime Company
Dixie Lime and Stone
Company
Domtar Chemicals, Inc.,
Dow Chemical, U.S.A.
The Flintkote Company
W. S. Frey Company, Inc.
Gaspro, Ltd.
CITY OR COUNTY. AND STATE
Douglas Co., Wisconsin
Jackson Co., Mississippi
Montgomery Co., Pennsylvania
Cuyahoga Co., Ohio
Lake Co., Ohio
El Dorado Co., California
Sumterville, Florida
Pierce Co., Washington
Brazoria Co., Texas
Mason Co., Michigan
Clark Co., Nevada
Contra Costa Co., California
Frederick Co., Virginia
Los Angeles Co., California
Tooele Co., Utah
Yavapai Co., Arizona
Frederick Co., Virginia
Honolulu Co., Hawaii
TYPE OF OPERATION
quicklime and hydrated lime,
2 rotary kilns, one continuous
hydrator
plant
plant
plant
rotary kiln and continuous hydrator
plant
plant
quicklime, 3 rotary kilns,
continuous hydrator
quicklime, 3 rotary kilns,
continuous hydrator
2 plants, batch and continuous
hydrators, rotary kilns
shaft and rotary kilns
plant
shaft and rotary kilns
2 shaft kiln plants
plant
rotary kiln & continuous hydrator
-------
Table C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
CITY OR COUNTY. AND STATE
TYPE OF OPERATION
-P.
CO
Germany Valley Limestone Company Pendleton Co., West Virginia
Great Western United Corporation Adams Co., Colorado
Big Horn Co., Wyoming
Boulder Co., Colorado
Larimer Co., Colorado
Logan Co., Colorado
Morgan Co., Colorado
Morrill Co., Nebraska
Scottsbluff Co., Nebraska
Sedgwick Co., Colorado
Yellowstone Co., Montana
Hawaiian Commercial and Sugar
Company, Ltd.
Holly Sugar Corporation
Honey Creek Lime Company
Huron Lime Company
Inland Steel Company
Jones & Laugh!in Steel
Corporation
Sherman Co., Kansas
Weld Co., Colorado
Maui Co., Hawaii
Coshen Co., Wyoming
Deaf Smith Co., Texas
Delta Co., Colorado
Glenn Co., California
Imperial Co., California
Orange Co., California
Richland Co., Montana
San Joaquin, California
Washokie Co., Wyoming
MiffTin Co., Pennsylvania
Erie Co., Ohio
Lake Co., Indiana
Berkeley Co., West Virginia
plant
pot-kiln plant
pot-kiln plant
2 pot-kiln plants
2 pot-kiln plants
pot-kiln plant
shaft-kiln plant
pot-kiln
3 plants, 5 pot-kilns
pot-kiln plant
plant
2 pot-kiln plants
rotary kiln & continuous hydrator
shaft kiln
shaft kilns
shaft kilns
shaft kilns
shaft kilns
plant
plant
-------
Table C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
Kaiser Aluminum and Chemicals
Corporation
Kennecott Copper Corporation
CITY OR COUNTY. AND STATE
Monterey Co., California
Gila Co., Arizona
Grant Co., New Mexico
Salt Lake Co., Utah ,
TYPE OF OPERATION
Kerr*MeGee Chemical Corporation San Bernardino Co.,, California
Lee Lime Corporation *
Edward C. Levy Company
Pete Lien & Sons
Linwood Stone Products Company,
Inc.
Magma Copper Company
Marblehead Lime Company
Martin-Marietta Corporation
Berkshire Co., Massachusetts
Wayne Co., Michigan
Pennington Co., South Dakota
Scott Co., Iowa
Pinal Co., Arizona
Adams Co., Illinois
Centre Co., Pennsylvania
Cook Co., Illinois
Lake Co., Indiana
Tooele Co., Utah
Wayne Co., Michigan
Sandusky Co., Ohio
Shelby Co., Alabama
rotary kiln & continuous hydrator
rotary kiln
lime kiln
plant
quicklime, shaft & rotary kilns
1 rotary kiln, 1 vertical kiln,
continuous hydrator
quicklime & hydrated lime,
3 rotary kilns
quicklime & hydrated lime,
3 shaft kilns, 1 calcimatic kiln
quicklime & hydrated lime,
8 rotary kilns
quicklime, 3 rotary kilns
rotary kiln
quicklime, 2 rotary kilns
plant
Mathis Mining & Exploration
Grant Co., New Mexico
-------
Table C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
McDonough Brothers, Inc.
Mercer Lime and Stone Company
Merck Chemical Company
Michigan Sugar Company
Mississippi Lime Company
Monitor Sugar Company
Corley L. Moore Lime Plant
Mountain States Lime, Inc.
National Gypsum Company
National Lime and Stone Company
Northern Ohio Sugar Company
Ohio Lime Company
01 in Corporation
Pacific Carbide and Alloys
Company
CITY OR COUNTY, AND STATE
Bexar Co., Texas
Butler Co., Pennsylvania
Tuolumne Co., California
Huron Co., Michigan
Saginaw Co., Michigan
Sanilac Co., Michigan
Tuscola Co., Michigan
Ste. Genevieve Co., Missouri
Bay Co., Michigan
Gile Co., Arizona
Utah Co., Utah
Centre Co., Pennsylvania
Giles Co., Virginia
Sandusky Co., Ohio
Wyandot Co., Ohio
Hancock Co., Ohio
Sandusky Co., Ohio
Sandusky Co., Ohio
Calcasieu Co., Louisiana
Multnomah Co., Oregon
TYPE OF OPERATION
plant
plant
plant
plant
plant
plant
plant
quarry and plant
plant
-------
Table C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
Paul Lime Plant, Inc.
Pfizer, Inc.
Phelps Dodge Corporation
CITY OR COUNTY. AND STATE
Cochise Co., Arizona
Berkshire Co., Massachusetts
Litchfield Co., Connecticut
San Bernardino Co., California
Sandusky Co., Ohio
Green!ee Co., Arizona
TYPE OF OPERATION
PPG Industries, Inc. Nueces Co., Texas
Puerto Rican Cement Company, Inc. Ponce, Puerto Rico
Rangaire Corporation
Republic Steel Corporation
Reynolds Metals Company
Rockwell Lime Company
Round Rock Lime Company
Santa Rita Mining Company
Independence Co., Arkansas
Giles Co., Virginia
Knox Co., Tennessee
Lake Co., Ohio
Saline Co., Arkansas
Manitowoc, Wisconsin
Hill Co., Texas
Williamson Co., Texas
Pima Co., Arizona
St. Mary Co., Louisiana
5 rotary kiln plants
plant
plant
fluidized-bed kiln & continuous
hydrator
plant
1 rotary kiln, 1 fluidized-bed
kiln plant
plant
plant
plant
plant
plant
plant
quicklime & hydrated lime,
1 rotary kiln, 1 continuous
hydrator
plant
plant
mine & calciner
S. I. Lime Company
Shelby Co., Alabama
-------
Table C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY
St. Clair Lime Company
Texas Lime .Company
Union Carbide Corporation
Union Sugar Company
U. S. Gypsum Company
U. S. Steel Corporation
Utah-Idaho Sugar Company
Valley Mineral Products
Corporation
Vulcan Materials Company
Warner Company
Weatherly and Morrison Lime
Company
Western Lime and Cement
Company
CITY OR COUNTY. AND STATE
Sequoyah Co., Ohlahoma
Johnson Co., Texas
Ashtabula Co., Ohio
Santa Barbara Co., California
Coma! Co., Texas
Orleans Co., Louisiana
Ottawa Co., Ohio
Lorain Co., Ohio
Bonneville Co., Idaho
Box Elder Co., Utah
Grant Co., Washington
Yakima Co., Washington
St. Francois Co., Missouri
Cook Co., Illinois
Center Co., Pennsylvania
Chester Co., Pennsylvania
White Pine Co., Nevada
Brown Co., Hisconsin
Dodge Co., Wisconsin ~-
TYPE OF OPERATION
quarry and plant
plant
plant
shaft kiln
plant
quarry and plant
plant
plant
plant
plant
plant
rotary kilns
quicklime and hydrated lime,
5 rotary kilns, 1 batch hydrator
hydrated lime, 5 shaft kilns,
1 continuous hydrator
-------
Table C-l (Continued). COMPANIES AND PRODUCTS OF THE LIME INDUSTRY
COMPANY CITY OR COUNTY. AND STATE TYPE OF OPERATION
Western Lime and Cement Company Fond DuLac Co., Wisconsin quick & hydrated lime,
(continued) 5 shaft kilns, 1 batch hydrator
Williams Lime Manufacturing
Company Knox Co., Tennessee plant
Woodville Lime and Chemical
Company Sandusky Co., Ohio
aThe following list of companies, comprising the lime industry, either make quicklime or dolime and
may or may not make the hydrated versions. Information sources do not differentiate between the
different producers. All producers generate carbon dioxide, but it is not known which ones recover
the material beneficially.
00
-------
TECHNICAL REPORT DATA
ff'lcasc read Instructions on the reverse before completing)
1. REPORT NO. 2
EPA-600/2-TT-023r
4 ~ITLE AND SUBTITLE
Industrial Process Profiles for Environmental Use;
Chapter 18. The Lime Industry
7. AUTHOR(S)
A.C.Doumas, B. P. Shepherd and P.E.Muehlberg (Dow Chem. )
Terry Parsons and Glynda E. Wilkins, Editors
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Radian Corporation
8500 Shoal Creek Boulevard, P.O. Box 991+8
Austin, Texas 78766
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. ENVIRONMENTAL PROTECTION" AGENCY
Cincinnati, Ohio ^5268
3. RECIPIENT'S ACCESSION«NO.
5. REPORT DATE
February 1977
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION
REPORT NO.
10. PROGRAM ELEMENT NO.
1AB015
11. CONTRACT/GRANT NO.
68-02-1319/Task 31*
13. TYPE OF RE PORT AND PERIOD COVERED
Initial: 8/75-11/76
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
15. ABSTRACT
The catalog of Industrial Process Profiles for Environmental Use was developed
aid in defining the environmental impacts of industrial activity in the United
Entries for each industry are in consistent format and form separate chapters
as an
Stares .
of the
study. The lime industry comprises operations which mine dolomite on limestone
deposits or dredge oyster shells ana process these carbonate materials into lump,
crushed or pulverized calcined products. The chief products in this category are
quicklime, slaked or nydrated lime, dolime, and hydrated dolime. One chemical tree,
one process flow sheet and six process descriptions have been prepared to characterise
the industry. Within each process description 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.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Pollution
Industrial Processes
Chemical Engineering
Calcium Oxides
Dolomite (Rock)
Limestone
Oysters
Carbonate:
h.IDENTIFIERS/OPEN ENDED TERMS
Process Assessment
Environmental Impact
Lime Industry
Oyster Shells
Quicklime
Slaked Lime
Dolime
COSATl Held/Group
13B
13H
07A
07B
08G
06C
13. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (Thh Report!
Unclassified
21. NO. OE PAGES
55
20. StCUHITY CLASS
Unclassified
22. PRICG
EPA Form 2220-1 (9-73)
«U.S. GOVERNMENT PRINTING OFFICE: 1979-659-510/31
49
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