United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Cincinnati OH 45268
EPA 600 2 79 1 1 1
May 1979
Research and Development
Multimedia
Assessment and
Environmental
Research Needs of
the Cement
Industry
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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 nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1 Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental 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-600/2-79-111
May 1979
MULTIMEDIA ASSESSMENT AND ENVIRONMENTAL
RESEARCH NEEDS OF THE CEMENT INDUSTRY
by
Ronald F. Smith
James E. Levin
A. T. Kearney, Inc.
Alexandria, Virginia 22313
Contract No. 68-03-2586
Project Officer
Ben Smith
Industrial Pollution Control Division
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 Environ-
mental Research Laboratory, 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 6r commercial products constitute endorsement or
recommendations for use.
11
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FOREWORD
When energy and material resources are extracted,
processed, converted, and used, the related pollutional
impacts on our environment and even on our health often
require that new and increasingly more efficient pollution
control methods be used. The Industrial Environmental
Research Laboratory-Cincinnati (lERL-Ci) assists in developing
and demonstrating new and improved methodologies that will
meet these needs both efficiently and economically.
This report provides a comprehensive assessment of the
cement industry, its economic characteristics and its
environmental research needs. Through this publication, it
is hoped that a coordinated research effort of maximum
applicability to the industry will be encouraged. The
Industrial Pollution Control Division should be contacted for
further information on this subject.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
111
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ABSTRACT
This project was initiated to obtain a comprehensive assess-
ment of the cement industry and its environmental research needs.
Specific areas of concern were: pollution problems encountered
by the industry; all alternatives for pollution reduction; and,
identification of possible research efforts to be conducted by
ISPA's Office of Research and Development.
In this project, a literature search was undertaken and
contacts were made with various cement manufacturers and the
cement industry trade association. This organization was
identified as a key source of R&D efforts for the U.S. cement
industry.
This report contains a profile of the U.S. cement industry;
an analysis of the cement manufacturing processes; a discussion
of waste stream characteristics and controls; and an assessment
of the U.S. cement industry's environmental research needs, the
steps taken toward addressing these needs, and the sufficiency
of these steps.
Recommendations for areas of further investigation were
proposed. These areas are: Waste Kiln Dust Management, Nitro-
gen Oxides Control, Use of Cement Kilns as Waste Incinerators,
and Sulfur Oxides Control.
This report was submitted in fulfillment of 68-03-2586, Work
Directive No. 1 by A. T. Kearney, Inc., under the sponsorship of
the U.S. Environmental Protection Agency. This report covers a
period from June to September, 1978, and work was completed as
of October 1, 1978.
IV
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CONTENTS
Foreword ill
Abstract iv
Figures vi
Tables vii
Acknowledgment ..... ix
1. Introduction 1
Study Objectives - 1
Report Contents 1
What is Cement? 1
2. Conclusions 4
3. Recommendations 6
4. Cement Industry Description 7
Introduction 7
Factors of Production 9
Market Structure and Performance .... 14
Industry Finance and Capital Investment. 28
5. Process Analysis 33
Overview 33
Manufacturing Process 33
Technological Developments . 38
Findings 40
6. Waste Stream Characteristics and Control . . 41
Introduction 41
Air Emissions 41
Kiln Dust 44
Clinker Cooler Dust 49
Other Sources 49
Nitrogen Oxides 50
Sulfur Oxides 51
Detached Plumes 51
Solid Waste 51
Water Pollution 54
Land Use 54
7. Environmental Research 57
Current Status 57
Procedure 58
Specific Environmental Research Projects 59
8. References . . . . ^ 66
Appendices
A. Cement Manufacturers and Plant Locations . . 68
B. Suggestions Received for Cement Industry
Environmental Research 78
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FIGURES
Number Page
1 Portland plants by producing capacity 15
2 Comparison of total construction put in place
with cement consumption 27
/
3 U.S. cement consumption per capita (1947-76). ... 28
4 Average annual rate of return for cement
industry and total manufacturing 29
5 Typical cement plant - dry process 34
6 Typical cement plant - wet process 35
7 Framework for analysis of issues concerning
hazardous waste combustion 64
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TABLES
Number Page
1 Portland Cement Production in 1975 ........ 3
2 Raw Materials Used in Portland Cement in 1975 . . 10
3 Cement Industry Employment ........... 12
4 Summary of Fuel Use Capabilities of the U.S.
Cement Industry as of January 1, 1977 ..... 13
\
5 Relative Company Capacities of the Ten Largest
Cement Producing States ............ 1$
6 U.S. Portland Cement Production Capacity and
Capacity Utilization .............. 18
7 Cement Plant Closings .............. 19
8 Kiln Distribution by Age ............. 20
9 Examples of Plant (Kiln) Size Distribution .... 21
10 Distance of Cement Shipments Compared with All
Manufactured Products (1972) .......... 22
11 .Trends in Mode of Transportation for Cement
Shipment .................... 23
12 Cement Use by Customer Categories ........ 23
13 Cement Use by Functional Area .......... 24
14 U.S. Cement Consumption, Imports, Exports, and
Total Cement Shipments ............. 26
15 Percent Return on Net Worth ........... 29
16 Capital Requirements of U.S. Cement Industry,
1976-85 . . .................. 30
17 Sources of Air Emissions ............. 42
vzi
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Number Page
18 Particle Size Analysis and Distribution of
Alkalies in a Specimen Kiln Dust 45
19 Dry Kiln Dust Analyses 46
20 Heavy Metals Contained in Kiln Dust Samples . . 47
21 Distribution of Kiln Dust Collection Systems in
Wet and Dry Process Cement Plants 48
22 Loadings of Pollutant Parameters for Leaching
Plants 55
23 Loadings of Pollutant Parameters for
Nonleaching Plants . 56
24 Work Elements for the Proposed Waste Kiln Dust
Management Study 60
25 Work Elements for the Proposed Nitrogen Oxides
Control Study 62
26 Work Elements for the Proposed Sulfur Oxides
Control Study 65
Vlll
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ACKNOWLEDGMENTS
The Portland Cement Association provided considerable infor-
mation and support in the conduct of this study. Mr. Cleve
Schneeberger, Vice President for Public Affairs, contributed
general information on the nature of the industry and helped
establish contact with industry personnel. Mr. N. R. Greening,
Director of the Chemical/Physical Research Department, supplied
valuable information on process technology and industrial re-
search programs. Mr. T. R. O'Connor, Director of the Economic
Research Department, provided economic and financial data, and,
finally, Mr. R. F. Gebhardt, Environmental Affairs Subcommittee
Chairman, contributed to our understanding of waste character-
istics and pollution control technology in the industry.
The following cement manufacturing companies were most coop-
erative in supplying technical information: _
Alpha Portland Cement Company
Citadel Cement Corporation
Martin Marietta Cement
Universal Atlas Cement Division of U.S. Steel
XX
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SECTION 1
INTRODUCTION
STUDY OBJECTIVES
Cement manufacturing involves the inherent generation of air
pollutants, water pollutants, and potentially hazardous solid
wastes. Some of these pollutants, such as particulate emis-
sions, are currently regulated by the U.S. Environmental Protec-
tion Agency (EPA) and by various state pollution control agen-
cies. Federal regulations on other cement industry pollutants
(e.g., kiln dust, nitrogen oxides) may be forthcoming.
The objectives of this study are to:
1. Characterize the cement manufacturing industry as
well as the nature and extent of its pollution problems.
2. Determine the status of pollution control programs
in the industry.
3. Identify the environmental research needs of the
industry.
REPORT CONTENTS
This introductory section offers a description of cement.
It is followed by conclusions and recommendations from the
study. The next two sections deal with the cement industry and
cement manufacturing process. Waste stream characteristics and
controls are then discussed. Finally, environmental research
programs and future needs are presented.
WHAT IS CEMENT?
Hydraulic cement is the basic binding agent in concrete and
masonry construction. There are several types of cement in use:
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1. Portland cement
2. Pozzolan cement
3. High alumina cement
4. Special or corrosion-resisting cements and mortars
5. Controlled cement
6. Slag cements*
Roughly 95 percent of cement production in the United States
is portland cement. Portland cement is produced by the high
temperature burning of calcareous material (e.g., limestone,
oyster shells), argillaceous material (e.g., clay), and sili-
ceous materials (e.g., sand, shale) to produce clinker. Ac-
cording to ASTM Specification C 150-60 and C 175-61, portland
cement is "the product obtained by pulverizing clinker consist-
ing essentially of hydraulic calcium silicates, to which no
additions have been made subsequent to calcination other than
water and/or untreated calcium sulfate (gypsum) except that
additions not to exceed 1.0 percent of other materials may be
interground with the clinker at the option of the manufacturer."
There are five basic types of portland cement. Type I is "reg-
ular" portland cement which is used in general construction, and
is produced in the largest quantities relative to the other
types of cement. Type II portland cement is formulated for
moderate heat-of-hardening and moderate sulfate-resisting appli-
cations. Type III is high-early-strength (HES) cement. Roads
constructed of HES cement can be put in service faster than
roads constructed from ordinary Type I cement. Type IV portland
cement has a 15-35 percent lower heat of hydration than other
types of cement. Finally, Type V portland cement is highly
sulfate-resistant.l
Air-entraining agents (e.g., resinous materials, greases)
can be added to portland cements in minute quantities. Air-
entrainment increases the resistance of hardened concrete to
scaling caused by alternate freezing and thawing and the use of
de-icing salts. Air-entraining cements are classified as Type
IA, IIA, etc-.1
The 1975 production of various types of portland cement is
shown in Table 1. It can be seen that Type I and Type II are by
far the most commonly manufactured cement types.
Special cements such as pozzolan, high alumina, corrosion-
resisting, and controlled cements are manufactured in relatively
small amounts and are not covered in this report.
* Note: According to the Bureau of Mines, no slag cement has
been produced in the United States since 1972.
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The standard unit of measure used by the cement industry is
the short ton. For this reason, short tons and similar English
units are used in presenting data in this report.
TABLE 1. PORTLAND CEMENT PROEOCTION IN 1975
Type Quantity Percent of Total
(thousand short tons)
General Use and Moderate
Heat (Types I & II) 62,816
High Early Strength
(Type III) 2,107
Special (including
Type IV) , 2,507
Sulf a te-Res i s t ing
(Type V) 346
Total 67,776
92.7
3.1
3.7
0.5
100.0
-
Source: Mineral Facts and Problems. 1975 Edition.
Bureau of Mines, Washington.
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SECTION 2
CONCLUSIONS
In conducting this program for EPA's Industrial Environ-
mental Research Laboratory, the contractor reached the following
major conclusions:
1. Research efforts in the U.S. cement industry are
limited. The industry's trade association and equipment sup-
pliers are relied upon for research. Foreign technological
developments, particularly in Japan and Germany, are also imple-
mented by the cement industry in this country.
2. The low emphasis on R&D by cement manufacturers is
primarily due to the ongoing activities of other organizations,
and the currently poor financial position of the industry.
3. New cement plants will probably implement the dry
process with suspension preheaters and some type of direct lime
precalcining system.
4. Air pollution control for particulate emissions can
be effected using conventional technology. This includes elec-
trostatic precipitators or baghouse collectors for kiln exhaust
gas and baghouse collectors for the various storage and material
transfer stations throughout cement plants.
5. The most significant pollution control problem
facing the industry is waste kiln dust management. Some sources
of this dust could be hazardous wastes as defined in EPA regula-
tions currently being developed pursuant to the Resource Conser-
vation and Recovery Act.
6. Nitrogen oxides emissions in kiln exhaust gas have
not been sufficiently characterized so that the significance of
NOX emissions from cement plants can be determined.
7. Since sulfur compounds are absorbed by calcareous
materials in the kiln to a large extent, SOX emissions from
cement plants probably do not pose a serious problem despite the
fairly rapid conversion by the industry to the use of coal.
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8. Point-source water pollution is not considered a
serious problem in the industry. Non-point-source water pollu-
tion (e.g., run-off from coal piles and raw material storage
areas) is a problem in some cement plants.
9. Fugitive dvjst emissions on or near the plant site
are a nuisance. Dust control pn plant roads is particularly
troublesome since water is ineffective and oil is environmen-
tally unacceptable, especially if plant run-off must be col-
lected.
10. Land use issues regarding quarries adjacent to
cement plants are not as yet defined since legislation pertain-
ing to this subject is pending in Congress.
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SECTION 3
RECOMMENDATIONS
The contractor's review identified a number of areas of
pressing concern for environmental research in the cement
industry. These areas are described in detail in Section 7 of
this report. Essentially, an environmental research program is
needed to address the most significant pollution problems
affecting the cement industry. The following are suggestions
for specific projects.
-1-' Kiln Dust. Waste kiln dust would be characterized
and environmentally sound methods to dispose, recycle, and reuse
this material (as generated in various locations) would be iden-
tified.
2. Nitrogen Oxides. A characterization of NOX gen-
eration would be run and methods of control both process
controls and external systems investigated. This could
include a demonstration program for one or more NOX control
technologies.
i
3. Use of Cement Kilns as Waste Incinerators. Tests
have been conducted to demonstrate the technical feasibility of
burning certain organic wastes such as PCB's and waste oil in
cement kilns. The feasibility of more widespread use of cement
kilns should be ascertained. This would include not only tech-
nical factors, but regulatory, economic, social, and institu-
tional factors as well.
4. Sulfur Oxides Control. In view of the capability
of calcareous materials in the kiln to remove sulfur oxides from
combustion gases, the extent and feasibility of burning high-
sulfur coals in cement plants without compromising product
quality or air pollution control regulations should be inves-
tigated. This should include a determination of whether such
plants can meet state air pollution control regulations prom-
ulgated to help achieve National Ambient Air Quality Standards
(NAAQS).
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SECTION 4
CEMENT INDUSTRY DESCRIPTION
INTRODUCTION
Cement production is both capital- and energy-intensive.
The product itself is relatively undifferentiated among manufac-
turers and production technology is widely diffused.
Cement has an extremely low value relative to weight. As a
result, transportation costs are high, limiting market areas
which can profitably be served by individual production facil-
ities. Manufacturing establishments are therefore widely dis-
persed, and markets tend to be regionally isolated. Transporta-
tion cost barriers permit regional production surpluses and
deficits to coexist.
Demand for hydraulic cement is derived from construction
requirements, which provide the ultimate consumption source for
nearly all domestic cement production. Widespread availability
of raw materials and the significance of transportation costs,
together with the dependence of production on construction
activity, result in a locational distribution of production
facilities which conforms to areas of regional population con-
centration.
Supply and demand factors influencing distribution costs
have historically limited the market range and production
capacity of individual establishments. However, the increasing
importance of economies of scale in production and in pollution
control have resulted in a tendency toward construction of
larger, more capital-intensive facilities serving somewhat
larger markets. Despite this tendency toward increased scale of
operations, transportation cost barriers remain a major limiting
factor in the size and location of production facilities.
Pollution control costs tend to be relatively higher for
smaller, older establishments. Industry investment in pollution
control amounts to roughly 10-15 percent of total capital in-
vestment. Competitive and regulatory pressures for investment
in both productive and non-productive capital have resulted in
recent closures among marginal facilities, typically older,
smaller plants situated in declining markets.
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Market power in the cement industry appears to be widely
dispersed at the national level. However on a regional basis,
the industry is highly concentrated. The industry is also
characterized by a significant degree of vertical integration,
often extending from extraction through distribution to inter-
mediate or end-users. Recent years have witnessed the diver-
sification of cement manufacturers into more lucrative markets,
both related and unrelated to construction materials. At the
same time, a number of conglomerates previously inactive in this
market have chosen to diversify into cement production.
Cement industry profitability is dependent upon several
major factors. These include demand-capacity relationships;
construction activity; and manufacturing costs, most notably
energy and labor costs.2 Since the industry is highly cap-
ital-intensive, fixed costs are extremely high, constituting
70 to 75 percent of total costs at full capacity. , Industry
financial performance is therefore quite sensitive to operating
rates, which in turn depend directly on construction activity.
Cyclical movements in construction activity tend to be reflected
in cement industry profit performance.
Cement industry profits have consistently fallen short of
the standard for manufacturing industries since the early
1960's, although the industry's profit record has improved in
recent years. The industry's poor performance in the 1960's can
largely be attributed to over investment in production capacity
toward the close of the post-war construction boom.
Market projections for the cement industry assume increasing
market penetration and a healthy construction industry, result-
ing in a generally favorable outlook for cement. Continued
improvement in cement industry financial performance is antic-
ipated. Regional capacity shortages may be increasingly evident
as near-capacity operating levels are approached. Regional
production shortfalls are most likely in areas where new capital
investment has lagged in response to market or regulatory pres-
sures. Energy conservation and pollution control will continue
to exert demands for new capital investment beyond that required
for additions to production capacity.
Research and development in the cement industry has origin- -
ated largely from the industry's trade association; equipment
manufacturers; and foreign industry sources. The primary thrust
of industry R&D in recent years has been in the area of energy
conservation. For example, four countries, including the United
States, are jointly funding a $1.5 million study through the
International Energy Agency of energy conservation possibilities
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in cement manufacture.* Cement manufacturing is highly energy-
intensive, and production costs are extremely sensitive to
changes in energy input requirements. Profit motives provide
strong incentive for research and development in this area.
These incentives are much less evident in pollution control
technology, although efficiency and cost considerations are of
interest in situtations where competitive advantage is sensitive
to pollution control regulations. Future research and develop-
ment efforts within the industry are likely to remain strongly
biased toward energy conservation and production technology,
where potential cost savings justify continued investment.
FACTORS OF PRODUCTION
Raw Materials
Raw materials must provide, in suitable form and propor-
tions, compounds containing lime, silica, and alumina. Natural
calcareous deposits such as limestone and shell beds, are common
sources of lime. Natural argillaceous desposits, such as clay,
shale, and slate, supply both silica and alumina. Natural
deposits of limestone or marl (a calcareous clay) can occasion-
ally supply all three basic ingredients at the correct propor-
tion for the manufacture of "natural cement". Usually, however,
it is necessary to combine raw materials to produce the desired
mix. As a general rule, approximately 1.8 tons of raw materials
are required to produce one ton of cement. Table 2 lists the
types and relative quantities of different materials used to
achieve the proper blend of mineral components for the industry
as a whole.
Table 2 shows that the calcareous component, particularly
limestone, is the largest constituent in cement. Limestone and
clay are abundant all over the world. Limestone is generally
quarried at or near the cement plant since the low value-to-
weight ratio results in high transportation costs. Underwater
deposits of materials are excavated by barge-mounted dredging.
Material is pumped or loaded onto barges and moved by tugboats
to cement plants. Although a few limestone and gypsum deposits
are mined underground by rooin-and-pillar methods, most raw
materials for the cement industry are quarried using surface
mining methods.
News items Chemical Engineering Magazine August 28, 1978,
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TABLE 2. RAW MATERIALS USED IN
PORTLAND CEMENT IN 1975
Quantity Percent of
Raw Material (thousand tons) Total
Calcareous:
Limestone
Cement rock (including marl)
Oystershell
Argillaceous:
Clay
Shale
Other
76,414
17,869
3,006
6,659
3,447
208
84.6
9.0
Siliceous: 2.1
Sand 1,813
Sandstone and quartz 582
Ferrous: 0.7
Iron ore, pyrites, millscale, 772
and other material
Other: 3.6
Gypsum and anhydrite 3,527
Blast furnace slag 465
Fly ash 180
Miscellaneous other 2 _
Total 114,944 100.0
Source: Mineral Facts and Problems. 1975 Edition.
Bureau of Mines, Washington.
Capital and Labor
Requirements
The cement industry is highly capital-intensive. Recent
estimates^ of the rates of capital required per dollar of
revenue are in the range of 3:1. In 1971, a ratio of $7 cap-
ital to $4 revenue was cited in an EPA study.3 increased cost
for energy has been a significant portion of the higher capital
to revenue ratios.
10
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In 1973, new construction costs for a medium-sized cement
plant were $53 per ton of annual operation capacity.3 By
1974, this figure had increased to $70 per ton.^ Interviews
with industry personnel during plant site visits indicate that
in 1977-78 between $90 and $110 are required per ton of annual
capacity.
Due to these increasingly high costs, established cement
manufacturers are the most important entrants into new cement
markets. They enter new markets by building new plants, ex-
panding cement capacity or through market extension mergers.
Since the cement industry is among the most capital-intensive,
it is difficult for newly formed firms to successfully enter
the industry. In addition, market share tends to be relatively
stable, difficult to change, and closely related to capacity
share. Historical supplier relationships tend to be build up
over the years, with major customers limiting significant pur-
chases to several sources of supply.
Labor requirements in a cement plant are a function of plant
size and design. In 1974, the total number of employees per
cement plant ranged from 94 to 292, with an average of 180
employees per plant.5 AS of 1975, there were almost 29,000
employees in the cement industry, of which roughly 22,000 were
production workers.
If a plant is of a sufficiently large size, the designer
has the option of labor-capital substitutions. Capital invest-
ment in plant modernization was the primary reason for the 30
percent drop in total employment between 1958 and 1971 that is
shown in Table 3. During the same period, output rose by 31
percent. It is apparent that improving technology has led to
consistent gains in labor productivity in the cement industry
over recent years. In 1975, production per man-hour was 40
percent higher than in 1960. Between 1958 and 1971, production
employment fell from 34,800 workers to 23,200 workers. Produc-
tion workers' wages accounted for about 14 percent of value
added by manufacturer in 1975, and total labor costs (all
employees) amounted to 40 percent of value added to manufacture
and 22 percent of the value of 1975 shipments. Average hourly
earnings of cement production workers increased 148 percent in
the period 1960-1975 while average mill prices of portland
cement increased 14 percent in the same period.
11
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TABLE 3. CEMENT INDUSTRY EMPLOYMENT
Year
Total Number of
Employees
(thousands)
Number of
Production Employees
(thousands)
Total
Wages
($ million)
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
41.1
41.1
39.4
36.4
35.5
34.9
34.7
34.6
33.6
32.6
30.8
30.4
30.2
28.8
34.8
35.0
33.2
30.5
29.7
28.7
28.0
27.9
26.9
26.2
24.9
24.6
24.3
23.2
$170.2
183.0
180.2
170.6
171.1
173.9
176.9
181.5
186.1
184.4
190.5
211.3
224.7
233.9
Source: U.S. Department of Commerce, The Hydraulic Cement
Industry in the United States: A State-of-the-Art
Review, 1976.
Energy Requirements
Cement manufacture has been identified as one of the six
most energy-intensive industries by the U.S. Department of
Commerce, ranked by the energy required to produce one ton of
product. Energy amounts to 35 percent to 40 percent of the
total cement manufacturing cost. As a result, the conversion
of plants to coal firing is proceeding rapidly. In 1972,
approximately 39% of cement production was manufactured with
coal or coke as the kiln fuel. By 1976, this increased to 55
percent. In the same year cement producers used 24 percent more
coal, 41 percent less natural gas, and 30 percent less oil than
in 1972. It is expected that by 1980 about 90 percent of cement
production capacity can be fueled by coal. The Table 4 summa-
rizes fuel-use capabilities of the U.S. cement industry as of
January 1, 1977.
12
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TABLE 4. SUMMARY OF FUEL USE CAPABILITIES OF THE
U.S. CEMENT INDUSTRY AS OF JANUARY 1, 1977
Fuel Type or
Combination
Coal
Oil
Natural Gas
Coal, Oil
Coal, Natural Gas
Oil, Natural Gas
Coal, Oil, Natural
Gas
TOTAL
Number of
Plants
44
6
10
16
41
18
23
158
Clinker Capacity
(Thousand Tons)
25,665
1,704
2,669
11,828
20,301
11,161
14,825
88,153
Percent
of Total
Capacity
29
2
3
13
23
13
17
100
Source: Portland Cement Association, Economic Research
Department.
In addition to conserving oil and gas through a greater
reliance on coal, the cement industry has made significant pro-
gress in overall energy conservation through the implementation
of technological improvements (e.g., the installation of steel
chains as heat recuperative systems in kilns, conversion from
wet to dry process, use of preheaters and precalciners, and ad-
justment of chemical proportions of raw materials used). From
1950 through 1976 energy consumption per ton of production was
reduced from 7.75 million BTU to 6.30 million BTU, a 19 percent
increase in energy efficiency. U.S. industry conversion from
the wet process has been slow due to the capital restraints
cited earlier. However, industry experience shows that con-
version to the dry process is desirable because of the energy
usage savings and will probably proceed as plant expansions and
modernizations are required.
13
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MARKET STRUCTURE AND PERFORMANCE
Fifty-three companies operating 160 plants in 40 states
comprise the cement industry in the United States. Appendix A
lists the companies by the location and the production capacity
of each plant. Figure 1 illustrates the geographic distribution
of these cement plants throughout the United States. Total de-
mand for cement may vary independently from local demand due to
divergent local trends in construction activity. It is not un-
usual for shortages in one region to persist while surpluses are
evident elsewhere. Transportation costs limit the possibilities
for exchange between surplus and deficit regions. As a result,
and in order to minimize risk, cement manufacturers serve many
markets through the development of a network of geographically
scattered plants. The ten leading cement-producing states,
listed in Table 5, account for 63 percent of the country's total
cement production capacity.
Concentration
The structure of the hydraulic cement industry can be char-
acterized as oligopolistic a market in which the number of
competitors is small, yet a single firm has enough power and
initiative to work independently of the others. Concentration
ratios (the percentage of total market sales accounted for by
the largest sellers in an industry) are commonly used to indi-
cate the degree of competition in a particular market. In the
cement industry, the eight leading companies account for about
47 percent of total industry sales. This concentration ratio
indicates that the U.S. cement market, viewed as a whole, is
fairly competitive and is not dominated by several large pro-
ducers.
However, cement manufacture is a regional industry. Due
to the low value-to-weight ratio of the product, cement plants
tend to be located within 200 miles of their principal markets.
Since cement manufacturers generally serve local markets, re-
gional concentration levels (as opposed to the national level
shown above) are more representative of true market conditions.
Using total company production capacity as an indication of
relative market share, Table 5 shows concentration ratios for
the ten largest cement producing states.
These figures show relatively high concentration levels in
many of these states, even where the presence of several com-
panies would indicate a more competitive market. Reviewed from
a regional or state-by-state perspective, competition in the
cement industry appears to be limited by the presence of large
dominating firms.
14
-------
PORTLAND CEMENT PLANTS
BY PRODUCING CAPACITY
ANNUAl PRACTICAL CAPACITY
UNDER 400.000 TONS
400.000 TO 700.000 TONS
700,000 TO 1.000,000 TONS
OVER $1,000,000 TONS
*GfllNDING ONLY
SOURCE:
Economic Reamrch Department
Portland Cement Ajioclatlon
5420 Old Orchard Road
Shohle, Illinois 60076
-------
TABLE 5. RELATIVE COMPANY CAPACITIES
OF THE TEN LARGEST CEMENT PRODUCING STATES
Rank
1
2
3
4
5
6
7
8
9
10
Number of
State Companies
California
Pennsylvania
Texas
Michigan
New York
Missouri
Alabama
Florida
Indiana
Iowa
8
12
13
8
6
6
6
4
4
5
Number of
Plants
12
18
21
8
7
7
7
15
5
5
Total State
Capacity
10,108
9,373
8,607
6,785
5,634
5,016
4,119
3,918
3,866
3,074
% Capacity
of Largest
25.6
14.2
14.0
35.1
27.4
26.2
25.5
41.8
45.8
34.1
% Capacity
2 Largest
45.8
27.5
27.1
49.8
42.6
51.3
45.4
72.4
65.2
53.8
% Capacity
3 Largest
64.8
37.1
39.6
61.2
55.9
75.3
64.8
86.7
84.6
70.5
Source: Portland Cement Association, "U.S. Portland Cement Industry:
Plant Information Summary"; 1977.
-------
Company Diversification
Companies in the cement industry are highly diversified;
only 18 percent of all the companies are solely involved in
cement. Five percent are diversified to include construction-
related products. Activities of divisions or subsidiaries of
the enterprises comprising the remaining 77 percent include
construction, real estate, transportation, aerospace, oil and
gas, mining and chemicals.
Capacity
Historically, increases in cement production capacity have
closely paralleled increases in cement demand, with the industry
operating at an average capacity utilization rate of approxi-
mately 80 percent. As of 1977, the total production capacity of
the industry was approximately 97.1 million tons per year.
Appendix A lists the estimated capacities of individual plants
and companies. During the late 1950's, when industry profit-
ability was above average, production capacity increased signif-
icantly. However, when the post-war boom ended, the industry
found itself with excess capacity and low utilization factors.
When EPA air and water pollution control regulation for the
cement industry were implemented in the early 1970's, large
amounts of capacity were shut down because it was not considered
economical to invest in pollution equipment for plants which
were felt to be obsolete. In spite of these reductions, the
industry has continued in an overcapacity situation, except for
brief periods. Table 6 illustrates the trend in capacity utili-
zation since 1960, and Table 7 documents cement plant closing
over the past eleven years. While 19 plants with about 7.5
million tons of annual capacity have been closed down by the
industry, the Portland Cement Association estimates conserva-
tively that an additional 18 plants having roughly 6.5 million
tons of capacity will close during the next ten years.* How-
ever, it is believed that the rate of closings will decrease in
the next few years because the heavy environment/energy con-
version costs of the past are not expected to reoccur, and most
of the less efficient plants have already closed.
* Letter from T. R. O'Connor, Portland Cement Association,
to J. E. Levin, A. T. Kearney, Inc., August 4, 1978.
17
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TABLE 6. U. S. PORTLAND CEMENT PRODUCTION
CAPACITY AND CAPACITY UTILIZATION
Production
Year (Million Tons)
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
59.0
59.8
62.1
64.9
67.8
68.5
70.8
68.0
72.6
73.4
71.4
75.0
78.8
81.5
77.5
65.2
70.8
Apparent Capacity Percent Capacity
(Million Tons) Utilization
72.6
74.0
78.4
80.0
80.2
80.6
82.8
84.5
84.7
84.4
85.6
87.7
87.8
88.6
93.6
93.4
93.4
81
81
79
81
85
85
86
80
86
87
83
86
90
92
83
70
76
Source: Portland Cement Association, "The U.S. Cement
Industry: An Economic Report", 1978.
18
-------
TABLE 7. CEMENT PLANT CLOSINGS
Capacity
Year
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
Number of Closures
4
0
0
1
2
2
0
4
5
1
0
(Thousand Tons)
1,675
0
0
696
676
593
0
1,467
1,930
450
0
Source: Letter from T. R. O'Connor, Portland Cement
Association, to J. E. Levin, A. T. Kearney, Inc.,
August 4, 1978.
Since the cost of opening a new plant is estimated at $85 to
$120 per ton of annual capacity, few companies are seriously
considering building in the present economic environment. How-
ever, as conditions improve, there is a possibility that some
plants may be constructed in markets where the long term outlook
appears relatively attractive and/or to protect market share in
existing markets. It is estimated that producers, proceeding
cautiously, will add four to five million tons of capacity by
1981. Therefore, it appears that the most significant changes
in future capacity will come about through modernization and
conversion of existing facilities.
19
-------
Plant Size and Age Distribution
The U.S. Cement Industry exhibits a relatively advanced age
structure, with 80 to 90 percent of its production facilities
constructed prior to 1965. Table 8 presents the number of cur-
rent plants in various age brackets and each bracket's percent-
age of the total.
TABLE 8. KILN DISTRIBUTION BY AGE
Year Built
1976-
1971-1975
1966-1970
1961-1965
1956-1960
1951-1955
1946-1950
1941-1945
1936-1940
1931-1935
Before 1931
Total
No. of Kilns
Wet
0
14
24
24
48
26
24
7
5
2
33
207
No. of Kilns
Dry
9
20
10
23
32
29
9
2
2
4
20
160
Total
Kilns
9
34
34
47
80
55
33
9
7
6
53
367
Percent of
Total
2%
9%
9%
13%
23%
15%
9%
2%
2%
2%
14 %
100%
Source: Portland Cement Association, U.S. Portland Cement
Industry: Plant Information Summary, December 31,
1977.
20
-------
A sharp trend toward larger plant size has developed over
the past three decades. In 1950, the average cement plant
capacity was 335,000 tons/year. In contrast, today's average
plant capacity is 563,000 tons/year. This is primarily due to
two factors: 1) production costs are less for larger plants;
and 2) increasing current plant capacity is the most viable way
of increasing regional market share. Plant size may vary ex-
tremely, depending on the number of kilns in operation, and each
kiln's clinker capacity. However, based on PCA data, there does
not appear to be an appreciable difference in capacity between
wet-process kilns and dry-process kilns. Examples of the range
are given below.
TABLE 9. EXAMPLES OF PLANT
(KILN) SIZE DISTRIBUTION
Clinker Capacity Cement Plant
Per Kiln Capacity
Process # of Kilns (Thousand Tons) (Thousand Tons)
Plant A Wet
Plant B Dry
3
1
120
640
300
660
Source: PCA, U.S. Portland Cement Industry; Plant
Information Summary, December 31, 1'9T6~.
Transportation & Methods
of Distribution
Transportation is a significant factor in the delivered cost
of cement because of low value-to-weight ratio of cement. On
the average, freight costs appear to be approximately 25 percent
of the total cost of cement. For inland plants, the market is
regional, usually within a radius of 200 miles (see Table 10).
Beyond this distance, overland transportation costs become ex-
cessive in relation to the value of the product. Plants on
waterways may have terminals in market areas at distances 1,000
miles or more, but these distribution centers must be located on
navigable waterways. Waterborne shipping is becoming increas-
ingly important because of its significant cost advantages and
energy efficiency. The relative cost of shipping by barge was
in the magnitude of 0.3 cent per ton-mile compared with 1.5
cents per ton-mile by rail and 6.0 cents per ton-mile by truck.
21
-------
This disparity is pointed up in the current (Summer, 1978) ce-
ment shortages in the midwest. The shortage in the Chicago area
was aggravated by the fact that locks on the Illinois River/ a
major cement transportation route for Chicago producers, were
closed for repairs. Local concrete producers were forced to
have cement shipped in by truck from St. Louis, at a cost of $20
more per ton than by barge.
TABLE 10. DISTANCE OF CEMENT SHIPMENTS
COMPARED WITH ALL MANUFACTURED PRODUCTS (1972)
Distance Shipped Percentage of Percentage of
(miles) Cement Shipped All Manufactured Products
0 -
100 -
300 -
500 -
1,000
99
299
499
999
or more
57.5%
37.6%
3.5%
1.2%
0.2%
100.0%
28.7%
28.6%
13.7%
16.4%
12.6%
100.0%
Source: Portland Cement Association, "The U.S. Cement
Industry: An Economic Report," 1978.
Significant changes in the way cement is distributed have
accompanied growth of cement capacity and production in the
post-war years. The general effect of these changes has been
to provide faster and more convenient service to the customers.
Changes in cement packaging illustrate the above point. Cement
can be shipped in bulk or in containers (bags). The use of bag
shipments has declined from 70 percent of all cement shipped in
1946 to 8 percent in 1973. Bulk shipments provide greater cost
savings to customers because the cost of the bags is eliminated
and because loading and unloading costs are substantially re-
duced.
Equally significant changes have been made in the modes of
transportation used to ship cement to the consumer. Table 11
illustrates the transition from rail to truck shipments in the
last 25 years.
22
-------
TABLE 11. TRENDS IN MODE OF
TRANSPORTATION FOR CEMENT SHIPMENT
Rail
Water
Truck
Total
Percent of Shipments
in 1950
75
1
24
100
l*BMMMAi*MV«MHV«BIB^BBBIIMI^W*^M^BB»>1^VWB*^»^^HM^MI^»
Percent of Shipments
in 1975
13
1
86
100
Source: Portland Cement Association, "The U.S. Cement
Industry: An Economic Report," 1978.
Purchases and End Uses
Virtually all Portland cement is sold for use in concrete
for construction. Producers of ready-mix concrete are the
primary customers and the remainder is purchased by concrete
products manufacturers, highway contractors, building materials
dealers and government agencies. Table 12 lists these customers
and their relative share of total cement consumption.
TABLE 12. CEMENT USE BY CUSTOMER CATEGORIES
)
Percent of
Customer Total Purchases
Ready Mixed Concrete Producers
Concrete Products Manufacturers
Highway Contractors
Building Material Dealers
All Others
Source: Portland Cement Association, "The U-S. Cement
Industry: An Economic Report," 1978.
23
-------
Table 13 presents the various end uses of cement. Resi-
dential construction comprises the largest share of the end-use
market.
TABLE 13. CEMENT USE BY FUNCTIONAL AREA
Functional Area Percent of Total
Residential Construction 29%
Industrial-Commercial Markets 19%
Public Building 10%
Public Works 20%
Transportation 17%
Miscellaneous 5%
Source: Standard & Poor's Industry Surveys;
Bu iId ing-Basic Analy sis, September 15, 1977.
Purchase Methods
Prices in the cement industry are likely to be based on a
"cost-plus" mechanism. For a level of output above the break-
even point, the average cost per ton is estimated and a given
percentage of this cost is added to cover fixed costs and
desired profits per ton. The price based on this formula is
called the normal price. The actual price per ton charged by a
given firm is the normal price, plus the published freight
charge per ton from the mill to the customer location, minus any
discounts and allowances. Therefore, cement prices tradition-
ally vary between market areas. Since it is a basic commodity
product with little product differentiation from one producer to
another, the lowest price in the market prevails. Competitors
tend to meet price competition to preserve market share and
customer relationships.
24
-------
Cement appears to be a relatively price inelastic com-
modity. The lack of competitive substitutes, its small portion
of total construction cost (generally 5% or less) and its avail-
ability from a number of different producers in any market area
cause total demand to be relatively insensitive to price changes.
Imports and Exports
Because of the weight versus transportation cost rela-
tionship, portland cement is not an important factor in inter-
national trade. Typically, imports account for less than 3
percent of total U.S. consumption. (See Table 14). Cement
shortages caused by construction booms have occasionally caused
this figure to rise much higher (7.7 percent in 1973). It is
projected that imports of cement will show a steady increase
through the year 2000, although they will still account for only
approximately 4.6 percent of consumption. Canada is the leading
exporter to the U.S., supplying 49% of the imported cement and
clinker*, followed by Norway with 10 percent; Bahamas 9%; and
France and Spain with 8 percent each.
U.S. cement exports are a small fraction of imports, pri-
marily because the U.S. cement industry historically could not
compete in price with most overseas countries. Table 14 also
shows exports contrasted with total U.S. shipments.
* On September 29, 1978, the U.S. International Trade Commis-
sion published a notice in the Federal Register stating that
the U.S. portland cement industry was not being injured as the
result of importation of portland cement from Canada that is
being, or likely to be, sold at less than fair value. The
Commission conducted this investigation based on advice re-
ceived from the U.S. Department of the Treasury on June 23,
1978.
25
-------
TABLE 14. U. S. CEMENT CONSUMPTION,
N)
Year
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
U.S. Cement
Consumption
(Thousand Tons)
58,515
59,938
62,186
65,135
67,967
69,382
70,555
69,005
73,540
75,750
72,625
78,089
80,840
86,253
79,113
67,243
70,696
77,081
Imports
(Thousand Tons)
770
681
1,038
758
683
1,035
1,328
1,112
1,386
1,821
2,597
3,088
4,911
6,683
5,702
3,637
3,074
3,981
Imports as
Percent of Total
1.3%
1.1
1.7
1.2
1.0
1.5
1.9
1.6
1.9
2.4
3.6
4,0
6.1
7.7
7.2
5.4
4.3
5.2
U.S. Cement
Shipments
(Thousand Tons)
61,500
63,400
65,200
68,600
72,000
73,500
74,500
73,600
77,800
78,637
74,607
80,396
83,336
88,467
80,500
67,000
N/A*
N/A*
Exports
(Thousand Tons)
35
54
71
86
134
141
201
184
177
67
123
84
83
268
N/A*
N/A*
N/A*
N/A*
Exports as
Percent of Total
0.06%
0.09
0.11
0.13
0.19
0.19
0.27
0.25
0.23
0.09
0.16
0.10
0.10
0.30
N/A*
N/A*
N/A*
N/A*
* N/A = Not Available
Sources: Portland Cement Association, "The U.S. Cement Industry: An Economic Report," 1978.
U.S. Department of Commerce, "The Hydraulic Cement Industry in the United States:
A State-of-the-Art Review," 1976.
-------
Growth Trends
Cement consumption historically has closely followed total
construction volume. This is clearly indicated in Figure 2
below. Total volumes consumed therefore depend on trends in
construction activity. For example, with the current boom in
construction, it is estimated that the demand for cement in 1978
will reach 81 million tons. However, the Portland Cement Asso-
ciation forecasts a slowdown in homebuilding in 1979, which may
reduce 1978 consumption levels by as much as 2-3 percent. De-
mand is expected to rebound in 1980, and may possibly reach 82
million tons.
100
90 h
so
Cement.
millions
of tons
60
50
40
30
Total construction/--*./
Cemenl
100
90
80 Construction
put in place,
70 billions of
constant
60 dollars
(1967= 100)
50
1950
60
65
70
75
Source: Portland Cement Association, "The U.S. Cement Industry;
An Economic Report," 1978.
Figure 2. Comparison of total construction put in place
with cement consumption.
To get a picture of long range historical growth in the
industry, analysts commonly look at per capita consumption.
Recent national per-capita cement consumption data is presented
in Figure 3. The actual data in the figure clearly illustrate
the variations caused by changes in construction volume. How-
ever, the long term trend line indicates that per-capita use
nationally has grown approximately 4% in the period 1947-1977.
Some analysts believe that these historical gains in per-capita
use of construction materials will level off as the U.S. economy
matures. Others feel that per-capita use of cement will con-
tinue to grow and perhaps accelerate as environmental
needs and energy costs create a higher demand for concrete,
which takes less energy to produce and install than most other
materials serving similar functions.
27
-------
Pounds
per capita
850
800
750
700
650
600
550
500
450
400
1947 50
60
70
76
Source: Portland Cement Association, "The U.S. Cement Industry:
An Economic Report," 1978.
Figure 3. U.S. cement consumption per capita (1947-1976) .
INDUSTRY FINANCE AND CAPITAL INVESTMENT
Cement Industry Profit Record
Since the late 1950's, when the cement industry achieved
above-average profitability relative to manufacturing indus-
tries, overall industry profitability has been declining. Over
the past ten years, profit performance has been significantly
below that of U.S. industry in total, although there have been
significant variations in profitability by individual cement
companies. This trend is shown in Figure 4. Since 1967, profit
margins have been at or below 5 percent and cash flow as a
percent of investment has been in the 6-7 percent range.
Declines in profitability have taken place despite the fact
that capacity utilization has been increasing. Industry expan-
sion in the middle 1970's came at a time when construction was
in one of its worst depressions. The cement industry found
itself with excess capacity and low returns. Return on invest-
ment dropped to 8.5 percent in 1974, and to 6.5 percent in 1975,
far below the 15 percent return necessary to attract the capital
needed for capacity modernization, energy conversion and envir-
onmental modifications.
28
-------
Percentage
25
0 Ii i Ii i t it.
1947 50
55
60
65
70
7576
Source: Portland Cement Association, "The U.S. Cement Industry:
An Economic Report," 1978.
Figure 4. Average annual rate of return for cement
industry and total manufacturing. (Net income after
taxes as percentage of net worth.)
Since the 1975 low, the industry picture has improved some-
what, as seen in Table 15 below.
TABLE 15. PERCENT RETURN ON NET WORTH
1972
1973
1974
1975
1976
1977
7.4
9.9
8.8
7.1
9.8
13.0
Source: Portland Cement Association, "The U.S. Cement Industry;
An Economic Report," 1978.
29
-------
Industry Research
and Development
Poor profitability and low rates of return in the cement
industry have restricted corporate investments in research and
development. The Portland Cement Association estimates that
less than $15 million is spent by cement firms annually on
direct research activities. A few of the larger producers
employ people to do process-oriented research on a part-time
basis. However, the majority of the firms in the industry
contribute to the Portland Cement Association to support its
research efforts in the areas of product development, environ-
mental and energy conservation. Beyond research undertaken by
the industry's trade association, industry participants have
relied upon research performed by equipment manufacturers and
foreign industries as major sources of technological innova-
tion. The U.S. cement industry has typically lagged behind its
foreign counterparts in implementing new production technolo-
gies. For example, conversion from wet to dry processing has
been slow, due to high construction costs which result in a low
return-on-investment.
New Capital Investment
The following table outlines the capital needs of the cement
industry projected by the Portland Cement Association for the,
period 1976 to 1985.
TABLE 16. CAPITAL REQUIREMENTS
OF U.S. CEMENT INDUSTRY, 1976-1985
$ Billion
New Capacity Additions 1.00
Replacement and Modernization of Plants
Built Before 1946 0.74
Process Conversion and Modernization from
Wet Process to Dry Process 2.15
Modernization of Existing Dry Process
Capacity
Total for 10-year period
Work in Process 1976-1980
Remaining Needs 1981-1985 (stated as 1976 dollars)
(continued)
30
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TABLE 16. (continued)
$ Billion
Remaining Needs 1981-1985 - restated to reflect
5% annual inflation over 10-year period
(assuming 1981-1985 needs are spread equally
over 5 years)
Work in Process 1976-1980
Total Capital Needs 10-year period
Source: Portland Cement Association, "The U.S. Cement
Industry: An Economic Report," 1978.
Sources of Capital
According to the Economic Research Department of the Port-
land Cement Association, financing for past capital projects in
the cement industry has depended heavily on internally generated
funds (retained earnings and depreciation) as well as on debt
issues. Since equity prices in the industry remain below or
near book value, equity funding will probably not be a viable
source for generating new capital. Therefore the industry will
probably continue to rely on its internal cash flow and the debt
market as the primary souces of new capital.
Pollution Control Investments
Pollution control facilities have been financed in many
cases by municipal guarantee of tax-exempt bonds. Loan repay-
ment is typically accomplished through leasing arrangements.
The tax-exempt status of municipal bonds provide a low-cost
source of capital for pollution control investments.
After the passage of the Clean Air Act Amendments of 1970,
and subsequent development by EPA of new source performance
standards, the cement industry was required to restrict the
amount of particulate matter emitted in kiln exhaust gas as well
as any other area of the cement plant. Prior to 1970, the
cement industry invested almost $216 million in air pollution
control equipment. In 1974, an estimated 8-14 percent of the
capital cost of new construction was attributable to pollution
control requirements. Based on plant interviews, it is esti-
mated that 1978 costs for pollution control equipment are 10-15
percent of new plant capital costs. Industry representatives
have also indicated that pollution control activities account
for roughly 6-10 percent of total operating costs.
31
-------
Plant closings in recent years may be seen as a response
partially to the increasing demand for capital dollars in non-
producing pollution control facilities. The Federal Energy
Administration Energy Conservation Potential in the Cement
Industry, pg.21, indicates that the cement industry has more
readily invested in energy conservation technology. Fuel con-
version expenditures are ultimately recovered in production cost
savings due to reduced fuel requirements.
32
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SECTION 5
PROCESS ANALYSIS
OVERVIEW
There are basically two commercial cement manufacturing
processes: the wet process and the dry process. The wet process
involves the grinding of raw materials with water to form a
slurry containing 30 to 40% moisture. The slurry is blended, as
required, and subsequently fed to the kiln. The dry process, on
the other hand, does not introduce water during grinding and the
raw materials are fed to the kiln in the form of a dry powder.
The wet process was the original cement manufacturing pro-
cess, and until recently, had advantages over the dry process
due to ease of handling and blending of raw materials as well as
yielding higher quality clinker; However, improvements in dry
blending and material handling techniques, in combination with
lower energy consumption used in the dry process, has served to
minimize the advantages of the wet process over the dry process.
Most new plants or production lines have turned to dry processes
in light of increasing energy pressures and the favorable shifts
in dry process technology. In fact, eight of the last ten new
kilns built have utilized the dry process.
According to the Minerals Yearbook, the concept of larger
single-kiln plants will have to be adopted for new plants. This
will reduce manpower requirements and yield significant improve-
ments in energy efficiency.^
MANUFACTURING PROCESS
Cement manufacturing involves four basic processing stages:
1. Quarrying and Crushing
2. Mixing and Grinding
3. Burning
4. Finish Grinding, Packaging, and Shipping
Typical cement plants using the dry process and wet process are
shown in Figures 5 and 6, respectively. Each processing stage
is briefly described in the following paragraphs.
33
-------
co
ROCK DRILL
WATER SPRAYS
DUST
COLLECTOR ,
(BAG)
DUST
COLLECTOR
(BAG)
FEED PIPE-ALUMINA
CONVEYOR
BELT CONVEYERS
STONE CRUSHING & SCREENING
VIBRATING
SCREEN ADDITIVES CONVEYOR
HOPPER
TRIPPER
RAW MATERIAL STORAGE
GAS FURNACE
CONVEYOR
CLINKER STORAGE
FINISH GRINDING
SCALE SCALE
CEMENT STORAGE
OTRUCK
=fei- (OFF-
LOADING)
Source: Environmental Protection Service, Canada, "Air Pollution Emissions
and Control Technology. Cement Industry," Air Pollution Control
Directorate, April 1974.
Figure 5. Typical cement plant - dry process.
-------
Ul
MATERIAL FLOW
QUARRY
PRIMARY CHUSHiR
STONE CRUSHING & SCREENING
KILN FEED ft DUST COLLECTION
CLINKER COOLING
MATERIAL FLOW
DUST
COLL.
BULK CEMENT STORAGE «
TRUCKS BULK LOADING SILOS
BULK LOADING
PACKHOUSE
CLINKER STORAGE
FINISH GRINDING
Source: Environmental Protection Service, Canada, "Air Pollution Emissions
and Control Technology. Cement Industry," Air Pollution Control
Directorate, April 1914.
Figure 6. Typical cement plant - wet process.
-------
Quarrying and Crushing!
Cement production begins with raw materials extraction,
generally from a quarry at or near the cement plant. The raw
material is comprised of some combination of limestone, cement
rock, marl, shale, clay, and iron ore.
Rock is transported to a crushing plant either at the quarry
or the cement plant. The primary crusher reduces rock from
roughly five feet in diameter to about five inches in diameter.
A further reduction in size to about one-half-inch diameter is
effected using the second crusher. This material is then stored
in silos prior to mixing with other stored raw materials such as
clay, silica, alumina, or iron ore.
Other than fugitive dust generation and exhaust gas produced
by vehicles in the quarrying and transporting operations, there
is little pollution emanating from these operations. Overburden
is the material above, and possibly between, seams of limestone.
It usually consists of soft clay or soil that would clog the
crushers if too much were removed from the quarry with the lime-
stone. Overburden is either hauled away and dumped in some type
of land disposal site or piled in an abandoned section of the
quarry.
Dust, which can be generated in material transfering opera-
tions, is commonly collected by baghouse dust collectors.
Mixing and Grinding
The preparation of raw materials for the kiln involves dry-
ing, proportioning, grinding and blending of the various raw
materials. Due to the variations in the chemical compositions
of these raw materials, no single formula for cement manufacture
can be appplied.
This stage of the cement manufacturing process differs
depending on whether the dry process or the wet process is
implemented. In the dry process, the free moisture content of
the crushed raw materials is generally reduced to less than one
percent before or during grinding. Direct-contact rotary dryers
(6-8 feet in diameter and 60-150 feet long) are widely used in
the industry, although the trend in newer plants is for simulta-
neous drying and grinding. Heat for either process may be
derived from kiln gases, clinker cooler exhaust, or directly
fired fuels. Figure 5 shows a gas furnace providing hot process
air in a system with a rotating raw mill which mixes and grinds
the various raw materials. After grinding, the raw material
particle size is equivalent to about 200 mesh.
36
-------
In the wet process, the raw materials are usually propor-
tioned, ground with water in a raw mill, and slurried with
approximately 30-40 percent water in large basins. The mixture
is fed to agitated storage basins.
With either the wet or the dry process, no significant
pollution problems are encountered in the mixing and grinding
operation. However, Figure 5 shows baghouse dust collectors in
use for material transfer operations.
Burning
Blended and ground raw materials are fed to a kiln. Rotary
kilns are most commonly used in both the wet and dry manufactur-
ing processes. Kiln length can be 60-760 feet with diameters of
6-25 feet.
Raw materials are fed into the raised end of the kiln and
travel down the incline to the other end where coal, oil, or gas
is burned as a fuel. The retention time in the kiln is roughly
1-4 hours, and the temperature range at the lower end of the
kiln is 2500°- 3000°P.
Product from the kiln consists of dark, hard nodules called
clinker. These nodules are 3/4-inches or less in size and are
cooled with air in a clinker cooler prior to storage and further
processing. The recovered heated air from the cooler serves as
secondary air in firing the kilns.
Air from the clinker cooler, along with combustion gases and
water vapor introduced in wet process syterns, passes from the
higher end of the kiln through some form of dust collection
system, and finally out the stack. These gases carry entrained
dust and volatilized matter from the kiln into the dust collec-
tion system. The gases also contain,varying concentrations of
nitrogen oxides (NOX) and sulfur oxides (SOX), making this
gas stream the most significant source of pollutants in the
cement plant. The characteristics of these pollutants and the
controls being used are described in Section 6 of this report.
Dust is generated in the clinker cooler where collection
devices must be used. Dust collectors are also used on the
conveying systems from the clinker cooler to the clinker storage
area.
Finish Grinding, Packaging, and Shipping
Clinker is ground into cement with about 3-6 percent gypsum
(calcium sulfate) which retards the cement's setting time.
Other additives such as air-entraining, dispersing, and water-
proofing agents can be added.
37
-------
Two basic types of grinding circuits can be used. Clinker
can be grouped in an open circuit mill or a closed circuit (with
recycle of large particles) mill. The final product is about 10
microns in size, similar to the consistency of facial powder.
Cement is stored for eventual shipment via rail, truck, or barge,
As shown in Figure 5 and 6, dust collectors are used to
control particulate emissions during transfer operations.
TECHNOLOGICAL DEVELOPMENTS
Hew technology being implemented by the cement industry in
the United States deals mainly with the burning stage, but new
developments are also taking place regarding raw materials
processing and manufacturing process automation. These major
developments are briefly reviewed here. A detailed documenta-
tion of ongoing world-wide process technology innovations is
presented in "Energy Conservation Potential in the Cement
Industry."10
Preheaters
One of the most significant technological developments in
recent years concerns the suspension preheater. This unit can
only be used in dry processes, where it is installed just
upstream of the kiln. The preheater consists of a series of
cyclones connected by pipes through which gases from the kiln
pass upward and counter-current to the dry raw material flowing
down and around the cyclones.
Suspension preheaters* offer a number of advantages. First,
they provide conservation of energy through the transfer of heat
from the gas into the raw material feed dust. This, in turn,
leads to roughly 40 percent calcination of the feed before it
enters the kiln. In designing new plants, the use of pre-
heaters means that the rotary kiln only needs to be about half
the length as would be required without a preheater. Detailed
descriptions of various types of preheaters used in cement
plants are presented in another recent EPA report.^
The 1975 Minerals Yearbook reports that an improved pre-
heater system, termed the reinforced suspension preheater (RSP),
has been developed by Kawasaki Heavy Industries, Ltd. and Onoda
Cement Co. It was claimed that the RSP sytem makes possible the
production of cement at rates three times those of conventional
supension preheaters. The RSP process is also claimed to be
able to reduce atmosphere emission during cement production.^
* Sometimes referred to as air suspension preheaters,
38
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This process is essentially a small direct-fired furnace
located between the air suspension preheater and the kiln.
Roughly 90 percent calination of the raw materials is achieved
in the RSP process which effects an increase in production
capacity or a reduced load on the kiln. In the case of a new
cement plant, an RSP system allows the use of much shorter
kilns. Similar preheating systems have been developed by other
Japanese firms.
Fluid Bed (Flash) Calciner
The fluid bed calciner was developed in Japan by Mitsubishi
Mining and Cement Company. A fluid bed reactor is fed from the
air suspension preheater system to precalcine raw material
before feeding them to the kiln. Gagan notes that "the degree
of precalination and the specific production is not improved to
the same degree with this system as with other precalcining
processes although the system is claimed to give improved
continuity of operation and better brick life with comparable
economy."^
Similar systems have been commercially implemented in Japan
and Europe. A flash calciner installation is now in the start-
up phase at a cement plant in Alabama, the first such unit in
the United States.
Roller Mills
A new type of roller mill for the mixing and grinding stage
has been implemented in recent years, primarily to improve pro-
ductivity and improve energy efficiency. The crushing, grinding,
drying, mixing, and classifying of raw materials is combined in
a single unit which is located between the storage of separate
dry raw materials and blended raw materials. Roller mills are
used only in dry processes.2
Automation
New and modernized cement plants are incorporating rela-
tively sophisticated instrumentation to monitor and, in some
cases, control certain aspects of the manufacturing process.
Centralized air-conditioned control rooms are being installed
where plant personnel can monitor and control ongoing production
operations.
39
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FINDINGS
Some of the key points of this section are as follows:
1. Although both wet-process and dry-process plants
are presently in operation, practically all new plants will use
the dry process with an air suspension preheater.
2. Changes in manufacturing technology are primarly
caused by the need to improve energy efficiency.
3. The major source of pollutant emissions is kiln
off-gas which contains dust, nitrogen oxides, and sulfur oxides
to varying degrees.
4. There is a large number of places in the manufac-
turing process from which fugitive dust can escape.
5. Much of the new technology has been developed in
Japan and in Europe.
40
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SECTION 6
WASTE STREAM CHARACTERISTICS
AND CONTROLS
INTRODUCTION
Cement plants generate air pollutants, solid wastes, and
water pollutants during the course of their operation. Some of
these waste streams offer significant control problems while
others are controlled by conventional means. The purposes of
this section are to describe each of the waste streams generated
by cement plants and to discuss the types of pollution abatement
technology applied to the waste streams.
Air emissions are discussed first. These include particu-
late matter (dust), nitrogen oxides, and sulfur dioxide. Next,
solid waste (i.e., waste kiln dust) is covered. The final major
area is water pollutants, comprising both point-source and non-
point source waste water generation.
AIR EMISSIONS
There are a large number of potential sources of air emis-
sions from cement plants as shown in Table 17. The two most
significant sources of emissions are the kiln and clinker cooler
where particulate matter is discharged to the atmosphere.
EPA has promulgated new source performance standards (NSPS)
limiting the quantities of particulate allowed to be discharged
from new or expanded cement plants built or expanded after
August 17, 1971. Allowable particulate matter from cement kilns
is 0.15 kg/metric ton of feed on a dry basis (0.30 Ibs./tons).
Clinker cooler emissions must not contain particulate matter
in excess of 0.050 kg/metric ton of feed on a dry basis (0.100
Ibs./ton). In addition, for all other operations within the
cement plant, no emission source should have an opacity of 10
percent or greater.
41
-------
Although EPA has not issued NSPS for cement plants covering
any other air pollutants, such as nitrogen oxides or sulfur
dioxide, the states have developed regulations covering plants
built prior to August 17, 1971. All states regulate particulate
emissions, and a growing number are regulating nitrogen oxides
and sulfur dioxide as well.
TABLE 17. SOURCES OF AIR EMISSIONS
1. Quarry Operations
2. Crushing Operations
3. Preparation of Raw Materials
(a) Drilling
(b) Blasting
(c) Loading broken rock
(d) Transporting or
conveying to cement
plants
(a) Unloading rock from
quarry
(b) Crushing rock
(c) Screening rock
(d) Conveying to and
from storage
(e) Storage
(a) Drying operations
!
(b) Conveying and feed-
ing to grinding
circuit
(c) Grinding of raw
materials and con-
veying of ground
material (dry
process)
(continued)
42
-------
TABLE 17. (continued)
4. Kiln Operation
5. Clinker Cooling
6. Finish Grinding
7. Waste Dust Handling and Disposal
8. Fugitive Dust
(a) Feeding raw material
to kiln(s) - dry
process
(b) Gases exhausted from
kiln(s)
(a) Excess air exhausted
from clinker
cooler(s)
(b) Conveying clinker
from cooler(s) to
finish-grinding
mill(s)
(a) Conveying clinker
from storage to
finish-grinding
mill(s)
(b) Finish grinding of
clinker, gypsum, and
additives
(c) Air classification
of finished product
and conveying to
storage
(d) Storage
(e) Bulk loading
operations
Source: Gagan, E. W. Air Pollution Emissions and Central Tech-
nology. Cement Industry Report EPS 3-AP-74-3, Environ-
mental Protection Service, Department of the Environ-
ment, Ontario, Canada 1974.
43
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KILN DUST
Cement kiln exhaust gas contains substantial quantities of
particulate matter and is the largest source of air pollution in
the plant. In fact, approximately 12 percent of the kiln feed
exits from the kiln with the gas (upstream of any air pollution
control equipment). As of 1975, about 16.4 million tons of dust
are collected annually from cement kiln exhaust gas. Throughout
the industry, roughly 73 percent is returned to the cement-mak-
ing process, while the remaining 27 percent is discarded in some
manner.H
Thus, for the average portland cement plant in the United
States, having an average production rate of 1,670 tons/day,
about 325 tons/day of kiln dust are generated. To comply with
EPA new source performance standards of 0.3 Ibs/ton of feed,
about 324.6 tons/day of dust must be collected. This assumes an
air pollution control device collection efficiency of 99.88
percent.
Collected kiln dust has a wide particle size range as shown
in Table 18. Over 90 percent of the dust particles in this
sample were less than 12 microns in diameter. The dust, from
which this sample was taken, was collected by an electrostatic
precipitator.
Table 18 also shows the concentration distribution of
alkalies (sodium and potassium compounds) in the dust sample.
The alkali content of collected kiln dust is the most important
factor in determining whether the dust can be recycled to the
cement manufacturing process. High alkali concentrations in
kiln feed can upset kiln operation and may result in off-speci-
fication product when low-alkali cement is being produced.
Little analytical information is available on the chemical
characteristics of kiln dust. The composition will depend on
the particular raw materials used in the kiln feed and the con-
ditions that the dust particles encounter in the kiln. Thus,
there is no typical dust composition.
44
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TABLE 18. PARTICLE SIZE ANALYSIS (A) AND
DISTRIBUTION ALKALIES IN A SPECIMEN KILN DUST (B)
Particle Size
Range (Microns)
+68
-68+48
-48+34
-34+24
-24+17
-17+12
-12+6
-6
MMBBiW^PBHV^MVi^B*W^H^^^H
Weight
Percent
0
0.3
0.4
0.7
1.8
5.1
27.3
64.4
^^^^^^MHVBVMMMMM^^IiaMMVIi^^VtAHPIBI
Total Alkalies
Percent
Na*
-
0.30
0.31
0.35
0.38
0.40
0.33
0.42
K20
-
3.62
3.46
4.51
5.08
5.15
5.35
10.72
^^^WMWMMIIMMMMMMaaHHH
Water Soluble
Alkalies
Percent
Na20
-
(C)
(C)
0.094
0.117
0.134
0.134
0.242
K20
-
(C)
(C)
1.927
2.560
3.072
3.252
8.191
^MIMMi^^ ^M*
Water
Insoluble
Percent
K20
-
-
-
2.58
2.52
2.08
2.10
2.53
Notes: (A) Particle size analysis was carried out by
the Allis-Chalmers Corporation using an
"infrasizer" particle size analyzer.
(B) Low chloride precipitator kiln dust cf.
Table 18 No. 2.
(C) Insufficient sample for analysis.
Source: Greening, N. R., F. M. Miller, C. H. Weise, and
H. Nagao Elimination of Water Pollution by Re-
cycling Cement Plant Kiln Dust, EPA-600/2-76-194,
U.S. Environmental Protection Agency, Cincinnati,
Ohio, 1976. 69 pp.
Analyses of two dust samples, one from Germany and the other
from Polk County, Georgia, are shown in Table 19. Heavy metals
concentrations for these two samples are shown in Table 20.
These tables demonstrate that the concentrations of specific
cations and anions can vary widely and that some heavy metals,
such as lead and zinc, can be present in relatively high concen-
trations.
45
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TABLE 19. DRY KILN DUST ANALYSES*
Concentration,
Weight Percent
"A*
B+
Cations
Lithium
Sodium
Potassium
Rubidium
Magnesium
Calcium
Aluminum
(Li)
(Na)
(K)
(Ru)
(Mg)
(Ca)
(Al)
0.0064
12.25
24.50
0.475
Trace
9.26
0.0064
0.23
0.40
0.52
27.31
4.16
Anions
Fluoride
Chloride
Bromide
Iodide
Carbonate
Sulfate
Borate
Phosphate
Sulfide
Sample A - Dust
(P)
(CD
(Br)
(I)
(C03)
(S04)
(B03)
(P04)
(S)
collected in
Sample B - Cement dust from
0.46
1.43
0.040
0.0552
29.59
9.06
0.152
Not detected
Trace
Blaubeuren, Germany.
Polk County, Georgia used in
Note:
Sources:
animal feeding study. Complete elemental anal-
ysis not published.
(#) The total number of constituents present in
the samples was not reported. Thus, the
values shown above do not add up to 100
percent.
(*) Davis, T. A., and D. B. Hooks. Disposal and
Utilization of Waste Kiln Dust from Cement
Industry. EPA-670/2-75-043, U.S. Environ-
mental Protection Agency, Cincinnati, Ohio,
1975.
(+) Wheeler, W. E., and R. R. Oltjen - Cement
Kiln Dust in Diets for Finishing Steers
Agricultural Research Service, U.S. Depart-
ment of Agriculture. ARS-NE-88. Beltsville,
Maryland, 1977.
46
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TABLE 20. HEAVY METALS CONTAINED IN
KILN DUST SAMPLES, PARTS PER MILLION
" ' '" ' "i < -'" ' i»«i«»i^ ! HMMIM n i n .1 ! .. i in ^^^-^^ immm » ^^M 11 .
A* B+
Copper
Cobalt
Zinc
Chromium
Lead
Cadmium
Manganese
Selenium
Molybdenum
Iron
Strontium
Mercury
Arsenic
Cesium
Rubidium
42
3
16,200 145
110 110
5,620 124
4
130 152
17
5
8,400 11,100
150 15
0.5
7
74
4,750
Sample A - Cement dust collected in Blaubeuren, Germany.
Sample B - Cement dust collected in Polk County, Georgia.
Sources: (*) Davis, T. A., and D. B. Hooks. Disposal and
Utilization of Waste Kiln Dust from Cement
Industry. EPA-670/2-75-043, U-S. Environ-
mental Protection Agency, Cincinnati, Ohio,
1975.
(+) Wheeler, W. E., and R. R. Oltjen. Cement
Kiln Dust in Diets for Finishing Steers.
Agricultural Research Service, U.S. Depart-
ment of Agriculture. ARS-NE-88. Beltsville,
Maryland, 1977.
47
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Kiln dust is separated from exhaust gases using one or a
combination of the following types of equipment:
1. Cyclone separators
2. Electrostatic precipitators
3. Baghouse collectors
4. Wet scrubber (one known location)
5. Settling chambers
The distribution of dust collection equipment in 101 cement
plants surveyed by Southern Research Institute in 1975 is shown
in Table 21.
TABLE 21. DISTRIBUTION OF KILN DUST
COLLECTION SYSTEMS IN WET AND DRY
PROCESS CEMENT PLANTS *
Type of Process
and
Number of Plants
Kiln-Dust Collection System
Single dust collector
Cyclones
Precipitators
Baghouses
Wet scrubbers
Settling chamber
Combinations of Dust Collectors
Wet
Dr
Dry_
31
3
1
1
3
3
0
0
Precipitators and wet scrubbers
Cyclones and wet scrubbers
Cyclones and precipitators
Cyclones and baghouses
Cyclones, baghouses, and precipitators
Baghouses and precipitators
Baghouses and wet scrubbers
1
1
14
4
2
1
0
0
0
12
16
2
1
1
Source: Davis, T. A., and D. B. Hooks. Disposal and Utili-
zation of Waste Kiln Dust from Cement Industry.
EPA-670/2-75-043, U. S. Environmental Protection
Agency, Cincinnati, Ohio, 1975.
48
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Industry personnel interviewed during the course of this
study generally speculated that electrostatic precipitators
probably would be used in the design of most future cement
plants. They advised that precipitators, along with certain
other systems, generally allow them to meet existing federal and
state air pollution control standards for kiln dust.
CLINKER COOLER DUST
The clinker cooler is the second largest air pollution
source in cement plants. Dust collected from this source is
returned to the process (usually clinker storage) rather than
wasted. The types of air pollution control equipment used to
handle clinker off-gas include the following:
1. Granular bed filters
2. Baghouse collectors
3. Electrostatic precipitators
Interviews with industry personnel indicated that granular
bed filters were popular because of cost, dust collection
efficiency (air pollution control standards are being met using
this equipment), and ease of operation. Granular bed filters
are relatively maintenance-free and are able to withstand higher
temperatures than baghouse collectors and electrostatic precipi-
tators.13
OTHER SOURCES
There are numerous other sources of air pollution generating
dust within the cement plant, although they are less significant
than kiln exhaust gas and clinker cooler off-gas. These sources
were previously listed in Table 17.
Baghouse collectors appear to be most frequently used to
control dust emissions from these various sources. According to
industry personnel contacted during the course of the study,
baghouse collectors allow compliance with applicable federal and
state dust emission standards. One of the plants visited had 25
baghouse collectors in use at various locations in the plant.
An addition 15 baghouse collectors were being installed at other
locations. Another plant had approximately 20 baghouse collec-
tors in use.
Fugitive dust emanates from a variety of sources including
raw material storage, clinker storage, coal files, and material
transfer operations. Fugitive dust settles on plant property
and outside the plant boundaries resulting in varying degrees of
damage. For example, alkaline dust can damage automobile fin-
ishes. Dust is also a nuisance on roads within cement plants.
Either water or oil are used for dust control although neither
have proven very effective.
49
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NITROGEN OXIDES
Nitrogen oxides (NOX) are comprised of nitric oxide (NO)
and nitrogen dioxide (N02) These gaseous pollutants are
formed in combustion processes in quantities that are affected
by the following factors:
Flame temperature
* Kiln temperature profile
Length of time combustion gases are
maintained at high temperatures
Rate of gas cooling
Percentage of excess air (particularly
in the flame zone
Nitrogen content in the fuel
McCutchen estimated that the cement industry overall generates
120,500 tons/yr. of NOX- This compares with a total estimated
NOX generation rate in the United States in 1975 of just over
11.15 million tons/yr., the majority of which comes from steam
bo ile r s.
NOX emissions from three different cement kilns using a
dry process were in the range of 43-1,050 ppm, based on tests
reported by Daugherty and Wist.8
No "end-of-pipe" treatment is presently used by the cement
industry to reduce NOX levels. In fact, little is presently
known about how to better operate cement kilns or modify the
process to minimize NOX generation without sacrificing cement
product quality.
The Portland Cement Association is currently planning a
study to gather additional data on NOX generation in cement
kilns and to determine how various operating conditions affect
the formation of NOX.
Under the Clean Air Act, EPA has the authority to issue
NOX regulations for cement plants as well as other industries.
While EPA has not yet specified NOX standards for the cement
industry, such standards have been promulgated for nitric acid
plants and certain types of steam boilers. Additional indus- ,
tries will probably be regulated in the future. Also, a growing
number of states (e.g., Alabama, Connecticut, Illinois) are
regulating NOX emissions.
50
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As noted previously, little "end-of-pipe" technology has
been applied to nitrogen oxides removal. However, automobile
manufacturers have reduced NOX emissions from cars through a
combination of engine modifications, exhaust gas recirculation,
plus the use of special catalysts to reduce NOX back to ele-
mental nitrogen and oxygen.
SULFUR OXIDES
Sulfur oxides may be generated in cement kilns from sulfur
introduced from the fuel or raw materials. However, these
oxides react with oxides of sodium, potassium, or calcium to
form sulfate salts inside the kiln. Thus, the emission of
sulfur oxides from the stacks are generally minor.
With the trend toward increased use of coal as the primary
fuel in cement plants continues, it is expected that larger
quantities of high-sulfur coal will be used. The effects of
high sulfur coal on cement kiln stack emissions are unknown.
No federal regulations for SOX removal apply specifically
to cement plants. Only one state, Arizona, presently regulates
sulfur oxides emissions (6 pounds per ton of cement kiln feed).
DETACHED PLUMES
Stacks from some cement plants periodically exhibit detached
plumes which form 20-30 feet above the top of the stack. On-
line opacity meters monitoring inside the stack indicate that
the plume is not particulate matter as does the fact that there
is no visible plume up to 20 feet above the stack. The plume,
when it develops, remains visible for unusually long distances
down-wind of the stack, suggesting that the plume is probably
not simply water vapor. Industry personnel have advised that
detached plumes have been observed at cement plants in Alabama,
California, Colorado, and Texas.
The exact nature of detached plumes is unknown although it
is speculated that they are the result of "smog" formation
(i.e., complex reactions among hydrocarbons, ozone, nitric
oxide, and nitrogen dioxide). There is little, if any, work
presently underway to formally characterize detached plumes.
SOLID WASTE
Dust collected from cement kiln exhaust gas is the principal
solid waste generated in cement plants. The physical/chemical
characteristics of cement dust were described earlier in this
section under "Kiln Dust".
51
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Davis and Hooks have estimated that roughly 73 percent of
cement kiln dust that is collected is recycled back to the
cement manufacturing process. The dust that is not recycled
generally has excessive concentrations of alkali (sodium and
potassium oxides) and sulfates that could prevent the final
cement product from meeting specifications.
Some plants have installed leaching systems to reprocess
collected kiln dust for alkali removal, so that the dust can be
recycled to the cement manufacturing process. Leaching involves
mixing kiln dust with water, than clarifying the mixture. Clar-
ifier underflow is recycled to the cement kiln while the over-
flow (which contains most of the sodium and potassium salts)
goes to some form of waste water treatment process (to be dis-
cussed later in this section).
The use of leaching processes has declined over the past
five years due to the need for treating process waste water.
Less than a dozen plants in the industry presently have leaching
operations.* Other leaching methods have been researched, but
none have been commercialized.
The most prevalent method for discarding waste kiln dust is
dumping it on or near the plant site. This may be done in piles
on unused areas or may be in abandoned sections of near-by quar-
ries from which raw materials have been extracted. Davis and
Hooks report that leachate and run-off from kiln dust piles have
been found to have pH values in the range of 12-13.H. This
is highly alkaline. No information was found on the extent to
which any heavy metals leach from the dust into the run-off or
leachate streams, but low metals leaching rates are expected,
based on the high pH levels.
Fugitive dust problems from the kiln dust piles do not
appear to be severe. At some plants, the dust is wetted down,
thus forming cement-like nodules on the surface of the piles
which prevents significant amounts of dust from blowing away.
One plant reported that morning dew provides sufficient moisture
at the surface of their dust pile to generate nodules and mini-
mize fugitive dust problems.
Personal communication J. Levin, A. T. Kearney, Inc., and J.
Riley, EPA Effluent Guidelines Division. July 19, 1978.
52
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Kiln dust has been or can be used in a number of different
ways, including those listed below. The Portland Cement Asso-
ciation is conducting experimental work in the use of waste kiln
dust for a number of these applications.
Landfill and soil stabilizer
Sub-base for roads
Dump in strip mines to neutralize acid
mine drainage
Fillers for bituminous paving materials
and asphaltic roofing materials
Neutralize acidic waters of bogs, lakes,
and streams (as appropriate)
Neutralize certain industrial wastes
such as spent pickle liquor, leather
tanning waste and cotton seed delinting
waste
Waste sludge stabilization
Substitute for lime in waste water
treatment systems
Absorption of S02 from stack gas in
wet scrubber slurries
Replacement of soda in green glassll
Agricultural uses of cement kiln dust are being researched
world-wide, and a number of research studies have been conducted
by the U.S. Department of Agriculture. For example, researchers
have found that some types of dust have 80 percent of soil neu-
tralizing capacity of lime and about the same liming qualities
as pulverized limestone.15' 16 Dust also provides an inexpen-
sive source of certain fertilizer nutrients, particularly potas-
sium, l^
Cement dust has also been used in cattle feeding experiments
by the Department of Agriculture. The experiments have shown
that steers fed cement dust as part of a complete mixed diet had
a higher average daily weight gain and an improved feed/gain
ratio compared to steers fed a normal control diet.1* These
experiments are continuing. Dust used in these experiments has
been taken from a single source.
53
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It is not now known whether any heavy metals present in the
dust used for agricultural purposes will have adverse environ-
mental health effects.
WATER POLLUTION
Water pollution is not generally considered a serious
problem by the cement industry either for wet-process or dry-
process plants. One of the most significant sources of waste
water is from leaching operations. However, as noted earlier in
this section, less than a dozen of the 172 plants in the United
States have leaching operations.
EPA has issued effluent guidelines for cement plant leach-
ing operations. For leaching streams, the limitations to be
achieved by 1977 are a pH of 6.0 to 9.0 and total suspended
solids of not more than 0.4 kg/kkg (0.8 Ibs/ton) of dust
leached. These limitations were estimated to be achievable by
neutralization and sedimentation. By 1983, no discharge of
pollutants will be permitted. The technology recommended to
attain zero-discharge is based on electrodialysis.
Non-leaching cement plants were to attain essentially no
discharge of pollutants by 1977.1^
Run-off from coal piles, raw materials piles, and kiln dust
is the other main type of waste water generated by cement
plants. Effluent guidelines call for containment or treatment
of run-off from material storage piles by 1977 to neutralize and
reduce suspended solids prior to discharge.
Analysis of waste water from both leaching and non-leaching
plants are shown in Tables 22 and 23, respectively. Most cement
plants presently do not discharge process waste water into navi-
gable waterways.
LAND USE
Eventually, quarries and mines, from which cement plant raw
materials are extracted, are abandoned. Presently, there is
little or no attempt to reclaim or backfill these areas. Since
quarries are worked for fifty years or more, back-filling would
be a long and expensive task.
Land use is also concerned with the location of new cement
plants, mines, quarries, and other raw material extraction oper-
ations. Bills are presently pending before Congress which would
establish a national policy and perhaps call for the promulga-
tion of regulations regarding land use.
54
-------
TABLE 22. LOADINGS OF POLLUTANT PARAMETERS FOR LEACHING PLANTS
Parameter
PH
Total Dissolved
Solids
Total Suspended
Solids '
,_ Alkalinity
Ul
Potassium
Sulfate
Temperature
Rise
Number
Units of Plants
Loading/Products Reporting
kg/kkg
kg/kkg
kg/kkg
kg/kkg
kg/kkg
°C
11
(Ib/ton)
(Ib/ton) 10
(Ib/ton) 10
(Ib/ton) 4
(Ib/ton) 6
(°F) 9
Leaching Plants
Mean
9.9
6.621
0.906
1.381
3.298
6.667
4.45
Value
(13.24)
( 1.81)
( 2.76)
( 6.59)
(13.33)
( 8.0)
Standard
Deviation
2.125
3.260
1.552
1.307
4.624
5.413
3.525
( 6
( 3
( 2
( 9
(10
( 6
.52)
.10)
.61)
.25)
.83)
.3)
Minimum
6.0
0.056 (0.11)
0 0
0 0
0.178 (0.36)
0.614 (1.23)
0 0
Maximum
12.
13.
4.
4.
11.
15.
11.
0
056
497
013
291
677
0
(26.11)
( 8.99)
( 8.02)
(22.58)
(31.35)
(19.8)
Source: Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Cement
Manufacturing Industry. EPA-440/l-74-005-a, U.S. Environmental Protection Agency, Washington, D.C., 1974, 123 pp.
-------
TABLE 23. LOADINGS OF POLLUTANT PARAMETERS FOR NONLEACHING PLANTS
cn
Nonleaching Plants
Parameter
pH
Total Dissolved
Solids
Total Suspended
Solids
Alkalinity
Potassium
Sulfate
Temperature
Rise
Units
Loading/Products
kg/kkg
kg/kkg
kg/kkg
kg/kkg
kg/kkg
°C
(Ib/ton)
(Ib/ton)
(Ib/ton)
(Ib/ton)
(Ib/ton)
Number
of Plants
Reporting
77
60
58
61
11
56
58
Standard
Mean Value Deviation
8.2 1.011
0.272 (0.54) 1.374 (2
0 0 4.114 (8
0.087 (0.17) 0.628 (1
0.078 (0.16) 0.389 (0
0 0 0.448 (0
4.53 (8.2) 3.51 (6
.75)
.23)
.26)
.78)
.90)
-3)
Minimum
6.0
0 (0)
0 (0)
0 (0)
0 (0)
0 (0)
0 (0)
Maximum
12.3
7.870
7.337
3.866
1.212
1.619
17.0
(15
(14
( 7
( 2
( 3
(30
.74)
.67)
.73)
.42)
.24)
.6)
Source: Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Cement
Manufacturing Industry. EPA-440/l-74-005-a, U.S. Environmental Protection Agency, Washington, D.C., 1974, 123 pp.
-------
SECTION 7
ENVIRONMENTAL RESEARCH
CURRENT STATUS
Most of the environmental research applicable to the cement
industry in the United States is carried out by the Portland
Cement Association, pollution control equipment manufacturers,
and foreign cement manufacturers and engineering firms. As
discussed previously in Section 4, few cement manufacturers in
this country devote significant in-house resources to research
in the areas of product, process, energy, or environment. This
seems to be due to low industry profitability and rate of return
on investment. Another factor contributing to relatively low
expenditures in R&D is that larger, diversified firms engaged in
cement manufacture preferentially devote their research efforts
to what are considered higher technology areas with a better
promise for profitability such as aerospace, chemicals, and
transportation.
Of course, research for the cement industry is ongoing,
including environmental R&D. The Minerals Yearbook, 1975, notes
that a Japanese firm has developed a highly efficient electro-
static precipitator termed the EP-ES type. This precipitator
has been demonstrated to reduce kiln dust concentration in ex-
haust gas to less than 0.03 grams per normal cubic meter under
full operating conditions. Precipitator performance was ex-
tremely stable during fluctuations in cement plant operating
conditions.
The Portland Cement Association is engaged in a number of
environmental research programs including the following:
1. PCA has recently started a small program to measure
NOX emissions at cement plants and determine methods for con-
trol, particularly in terms of kiln operating parameter adjust-
ments.
2. A program is being developed with a solid waste
management firm to test the feasibility of burning municipal
refuse mixed with other fuels in cement kilns.
57
-------
3. A potential contract with Babcock & Wilcox and the
EPA to study the use of FGD scrubber sludge in cement plants.
4. A research program to develop and improve methods
of high-alkali kiln dust disposal, treatment, and reuse, in-
cluding zero-discharge leaching is underway.
Certain environmental research currently being conducted by
the U. S. Environmental Protection Agency's Office of Research
and Development is expected to be beneficial to the cement
industry. For example, a pulverized coal burner is being de-
veloped in El Toro, California under an ORD contract which
apparently has the potential to reduce nitrogen oxide emissions
80-85 percent over uncontrolled levels.* ORD is also investi-
gating catalytic reduction systems and wet scrubbing devices to
effect NOX removal from industrial and utility combustion
systems.
Coal cleaning systems to remove sulfur, both chemical and
physical in nature, are being tested in the lab and at power
plants. Flue gas desulfurization (FGD), or scrubbing tech-
nology, is still under development.
The U. S. Department of Agriculture is continuing its test-
ing program on the use of kiln dust in cattle feeding programs
at the Meat Research Center in Nebraska. Tests conducted to
date in Beltsville, MD, on steers and lambs have shown that
cement dust as a diet supplement enhances growth. Chemical
analyses of the animals' vital organs (e.g., heart, brain,
liver, kidneys) indicate no apparent uptake of heavy metals
from the dust.**
PROCEDURE
Determining current environmental research activities rele-
vant to the cement industry was useful in providing a base-line
for estimating the need for future work in this area. Recom-
mendations for future environmental research projects for the
cement industry were requested from the following sources:
1. Industry personnel during site visits.
2. The Portland Cement Association.
* EPA Press Release. September 22, 1978.
** Telephone conversation between Dr. W. E. Wheeler, USDA,
and J. E. Levin, A. T. Kearney, Inc., September 21, 1978,
58
-------
3. EPA personnel familiar with the industry.
4. Other U. S. government personnel working in areas
related to cement industry environmental research.
5. Environmental Protection Service, Department of the
Environment, Canada.
6. Equipment manufacturers.
7. Kearney personnel familiar with the industry.
A complete listing of the ideas received for environmental
research needs of the cement industry from the above sources are
listed in Appendix B. In evaluating these ideas in terms of
their significance, the following subjective criteria were
applied.
1. Research that could have a short-term impact on
cement plant pollution control requirements.
2. Research that could have general use by a signifi-
cant number of cement plants.
3. Research that could help improve national environ-
mental quality.
SPECIFIC ENVIRONMENTAL RESEARCH PROJECTS
This sub-section describes specific environmental research
projects which appear to be of most pressing concern. The pro-
jects are listed in order of priority as measured against the
selection criteria.
Waste Kiln Dust Management
Waste ki'ln dust is probably the most serious pollution
control problem facing the cement industry at this time.
Relatively little is known about the dust, so environmentally
adequate management techniques are difficult to specify. There-
fore, the principal objectives of the proposed project are to
(1) characterize waste kiln dust, and (2) determine environmen-
tally adequate waste dust management techniques. Work elements
for this project are shown in Table 24.
The project basically consists of data and information com-
pilation, plant visits, sample collection, chemical analytical
work, data assessment, and report preparation. About 12-18
months would be required to conduct this work at a level of
effort approaching six person-years. Reductions in time and
resource requirements could be obtained by minimizing or
eliminating some sub-elements.
59
-------
TABLE 24. WORK ELEMENTS FOR THE
PROPOSED WASTE KILN DUST MANAGEMENT STUDY
I. Waste Dust Characterization
A. Quantities Generated
1. Estimate national, regional, and state waste gener-
ation rates.
2. Identify factors affecting generation rates (e.g.,
raw materials, product specifications).
3. Differences in dust generation between plants using
wet process, dry process, dry process with pre-
heaters.
4. Project generation rates over the next ten years.
B. Physical Chemical Properties (includes heavy metal
concentrations, particle size analysis, alkalies, etc.)
1. Variation in properties between plants.
2. Variation in properties at a single plant over
time.
3. Variation in properties between manufacturing
processes.
4. Ascertain if any sources of dust are hazardous
pursuant to draft Section 3001 regulations being
developed by EPA under RCRA.
C. Current Disposal Methods and Costs
1. Onsite vs. offsite disposal.
2. Most common disposal method.
3. Other methods used.
4. Estimated trends.
(continued)
60
-------
TABLE 24. (continued)
II. Adequate Storage, Handling, Disposal/Reuse Practices
(dependent on results of the waste characterization).
1. Description of adequate options and practices.
2. Costs (capital; O&M).
3. Onsite vs. offsite considerations.
4. Availability of sites (where appropriate).
5. Environmental impacts.
6. Economic impacts.
7. Specifically address the adequacy of using waste
dust in agricultural/food chain applications (i.e.,
use on farmland as a lime and nutrient supplement
or use as a diet supplement for cattle, sheep,
etc.).
Nitrogen Oxides Control
The generation of nitric oxide and nitrogen dioxide appears
to be a significant nation-wide air pollution problem, most
particularly in urban areas. Since EPA data currently show that
cement plants are one of the major stationary sources of NOX
generation, it is appropriate to analyze cement plant NOX
generation.
Like the waste kiln dust project described previously, the
NOX control project would begin with a detailed characteriza-
tion of NOX emissions by cement plants. The work elements
suggested for this project are listed in Table 25. The emphasis
in this project is placed on stack gas testing to determine
nitric oxide and nitrogen dioxide concentrations and emission
rates under a wide variety of processing conditions. After the
plant testing program, options to minimize NOX generation
would be identified and a plant-scale demonstration program
undertaken.
61
-------
TABLE 25. WORK ELEMENTS FOR THE
PROPOSED NITROGEN OXIDES CONTROL STUDY
I NOX Characterization (both NO and N02)
A. Current Emissions Rates
B. Variations Among Processes and Fuels in Use
C. Relationships Between Operating Conditions
(i.e., flame temperature, excess air, etc.)
and NOX Generation
II Review of Control Options and Their Costs
A. Process Modifications
B. Special Burners
C. External Physical/Chemical Systems
III Plant-Scale Demonstration of Most Attractive Option(s)
The entire project would require roughly two years to com-
plete, assuming one year for the first two phases and another
year for the third (demonstration) phase. A level of effort of
5-6 person-years is estimated, excluding demonstration equipment
and installation costs.
Use of Cement Kilns as
Waste Incinerators
The U.S. Environmental Protection Agency has conducted
studies to demonstrate the' capability of cement kilns to burn
hazardous organic wastes such as waste oils, PCB's and pesticide
wastes. This project would determine the overall feasibility of
burning such hazardous wastes from other industries in cement
kilns.
While this project does not directly address pollution con-
trol problems of the cement industry itself, it deals with cer-
tain serious nation-wide pollution problems which the cement
industry seems to be technologically suited to solve.
62
-------
The first element to this project is to determine what types
of wastes have been successfully disposed of in cement kilns and
under what conditions. Further technical demonstrations are not
an objective of this project. The key objective is to determine
the feasibility of burning hazardous wastes in cement kilns on a
long-term commercial scale. What issues must be identified and
resolved before commercial operation can take place? How can
they be resolved?
The issues that could arise are classified in four basic
areas: regulatory, economic, institutional, and social. A few
issues are presented as examples.
1. Who would be responsible for conducting burning
operations: cement company employees, contractors, government
employees, or others? Would labor unions allow non-company
employees to conduct burning operations?
2. What would be the price/cost structure for carrying
out these operations?
3. What added monitoring, reporting, and control
activities would be required? What new regulations would be
imposed?
4. What additional liabilities must be assumed by
cement manufacturers to carry out these operations?
An illustration of problems that could be encountered is
presented in Figure 7.
The project would be conducted by meeting with industry
executives, the trade association, government agency personnel
and other relevant parties to identify issues and determine how
to resolve them. About one year is required to complete the
project and prepare a final report. Approximately three person-
years of effort would be required.
Sulfur Oxides Control
This project, considered as having the lowest priority of
the four presented in this section, is similar in nature and
structure to the nitrogen oxides control study. A key reason
for conducting this project, however, is that cement plants
could prove to be a way to use high-sulfur coal without causing
air pollution control problems or adversely affecting product
quality. Lime in the raw materials tends to react with sulfur
compounds, removing them from the combustion gas. The practical
limit to which this phenomenon takes place should be ascertained.
63
-------
Physical Flow
Physical Functions
Potential
Problem Areas
Cost Areas
Regulatory/
Personnel Interface
Hazardous
Waste
Generator
Containerize
Store
Ship
Accidents, spills
DOT, EPA
Cement
Plant
Unload
Store
Move from Storage
Feed Kiln
Personnel exposure, spills
Corrosion, seepage
Personnel exposure.
Accidents, spills
Handling,
Facilities,
Insurance
Personnel
training
Onion, EPA,
OSHA
its.
Cement
Kiln
Container
Disposition
Burn
Store
Transport,
Recondition
Product quality
Equipment damage
Operational upsets
Corrosion, Personnel
exposure, Lack of
local options
Labor,
Controls,
Fuel savings
Transportation,
Disposal
Union, EPA,
OSHA
EPA, DOT
Air
Emissions
Exhaust
Air Pollution
Mon i tor ing.
Reporting
EPA
Figure 7. Framework for analysis of issues concerning
hazardous waste combustion.
-------
The work elements for the project are listed in Table 26.
Sulfur oxides emissions from cement plant stacks would be mea-
sured under varying conditions. Control options applicable to
sulfur oxides removal would then be determined and analyzed and
their interaction with other effluents elucidated.
TABLE 26. WORK ELEMENTS FOR THE
PROPOSED SULFUR OXIDES CONTROL STUDY
I SOX Characterization (particularly S02)
A. Current Emissions Rates
B. Variations Among Processes and Raw
Material Consumption
C. Variation with Percent Sulfur in Coal
D. Relationships Between Operating Conditions
and SOX Generation
E. Effect of SOX Changes on Particulate and
NOX Concentrations
II Review of Control Options and Their Costs
A. Process Modifications
B. Special External Physical/Chemical Systems
III Plant-Scale Demonstration of Attractive Options
(as appropriate)
Based on the results of the field monitoring and the review
of control options, a decision would be made on the need to
demonstrate the most attractive control technology at a cement
plant using high sulfur coal.
The first two phases of this program could be completed and
a report prepared within one year. About 3-4 person-years would
be needed. The time and effort required for a demonstration
program would depend on the nature of the system to be demon-
strated.
65
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SECTION 8
REFERENCES
1. Shreve, R.N,, and J.A. Brink. Chemical Process Industries
Fourth Edition. McGraw-Hill Book Company, New York, 1977.
814 pp.
2. The U.S. Cement Industry-an Economic Report. Second edition
Portland Cement Association, 1978. 26 pp.
3. Boston Consulting Group. The Cement Industry - Economic
Impact of Pollution Control Costs. Volume II. U.S.
Environmental Protection Agency, Washington, 1971
4. Mineral Facts and Problems. U. S. Department of the
Interior, Bureau of Mines, Washington, B.C. 1976.
5. Southern Research Institute. Economic Analysis of Effluent
Guidelines: Cement Industry. U. S. Environmental Protection
Agency, Washington, 1974.
6. Wall Street Journal, "Shortage of Cement is Delaying
Builders in the West and May Soon Spread to the East,"
August 18, 1978.
7. Massachusetts Institute of Technology. The Hydraulic Cement
Industry in the United States. A State-of-the-Art Review.
PB-265874. Agency for International Development, Washington,
1976. 60 pp.
8. Daugherty, K.E., and A.O. Wist. A Review of Cement Industry
Pollution Control. Ceramic Bulletin 54(2): p 190.
9. Gagan, E.W-, Air Pollution Emissions and Control Technology.
Cement Industry. Report EPS 3-AP-74-3, Environmental Pro-
tection Service, Department of the Environment, Ottawa
K1A OH3, Ontario, Canada, 1974. 50 pp.
10. Energy Conservation Potential in the Cement Industry. Con-
servation Paper Number 26. Federal Energy Administration,
Washington, 1975. 342 pp.
66
-------
11. Davis, T. A., and D. B. Hooks. Disposal and Utilization of
Waste Kiln Dust from Cement Industry. EPA-670/2-75-043,
U.S. Environmental Protection Agency, Cincinnati, Ohio, 1975
63 pp.
12. Wheeler, W. E., and R. R. Oltjen. Cement Kiln Dust in Diets
for Finishing Steers. Agricultural Research Service, U.S.
Department of Agriculture. ARS-NE-88. Beltsville, Mary-
land. 1977. 9pp.
13. Ford, R. Practicable Methods of Controlling Particulate
Emissions in the Cement Industry. In Proceedings of the Air
Pollution Control Association Symposiums, Quebec Section.
1975.
14. McCutchen, G. D. NOX Trends and Federal Regulation
Chemical Engineering Progress. August, 1977. pp. 58-63.
15. C. W. Whittaker, C. J. Erickson, K. S. Love, and D. M.
Carroll. Liming Qualities of Three Cement Kiln Flue Dusts
and a Limestone in a Greenhouse Comparison. Agronomy
Journal. 51:280-2, 1959.
16. Carroll, D. M., C. J. Erickson, and C. W. Whittaker.
Agronomy Journal. 56:373-76, 1964.
17. Simakin, A. I. Agrochemical Properties of Lime Dust of
Cement Plants. Vestn. Sel'skokhoz. Nauk. Ves. Akad.
Sel'skokhoz. Nauk (Budapest). 8(5):62-4, 1963.
18. Development Document for Effluent Limitations Guidelines and
New Source Performance Standards for the Cement Manufac-
turing Industry. EPA-440/l-74-005-a, U.S. Environmental
Protection Agency, Washington, D.C., 1974, 123 pp.
19. A. D. Little, Inc., Environmental Considerations of Selected
Energy Conserving Manufacturing Process Options, Volume X,
Cement Industry Report. EPA Contract No. 68-03-2198,
Cincinnati, Ohio, 1976.
67
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APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
Company/
Total Capacit}
(thousan
pacity
d ton)
CTi
00
Arizona
Arkansas
Alpha Portland/2,050
Citadel/1,050
Ideal/6,310
Martin Marietta/4,940
National Cement/800
Universal Atlas/3,614
Amcord/3,952
California Portland/3,030
Arkansas Cement/850
Ideal/6,310
Plant Location
Birmingham
Birmingham
Demopolis
Mobile
Roberta
Ragland
Leeds
Total Alabama
Clarkstate
Rillito
Total Arizona
Foreman
Okay
Total Arkansas
Cement Capacity
(thousand ton)
345
300
750
470
820
800
634
4,119
620
1,100
1,726
850
395
1,245
-------
APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
f Continued)
en
vo
Colorado
Florida
Company/
Total Capacity
(thousand ton)
Amcord/3,952
California Portland/3,030
Flintkote/2,440
General Portland/4,892
Haiser/3,743
Lone Star/6,023
Monolith/700
South Western/2,660
Ideal/6,310
Martin Marietta/4,940
Florida Mining/Minerals/560
General Portland/4,892
Maule/1,200
Rinker Portland Cement/520
Plant Location
Riverside
Oro Grande
Cotton
Mojave
San Andreas
Redding
Lebec
Permanente
Lucerne Valley
Davenport
Monolith
Victorville
Total California
Portland
Boettcher
Lyons
Total Colorado
Brooksville
Tampa
Miami
Hialeah
Miami
Total Florida
Cement Capacity
(thousand ton)
733
1,147
780
1,150
630
290
610
1,598
1,015
395
500
1,128
885
325
436
1,646
560
1,110
528
1,200
520
-------
APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
(Continued)
Hawaii
Idaho
Illinois
Indiana
Company/
Total Capacity
(thousand ton)
Marquette/4,268
Martin Marietta/4,940
Medusa/3,656
Cyprus Hawaiian Cement/450
Kaiser/3,743
Oregon Portland/775
Centex/1,071
Marquette/4,268
Medusa/3,656
Missouri Portland/2,630
Lehigh/2,955
Lone Star/6,023
Louisville/2,360
Universal Atlas/3,614
Plant Location
Cement Capacity
Rockmart
Atlanta
Clinchf ield
Total Georgia
Ewa Beach
Waianae
Total Hawaii
Inkom
Total Idaho
La Salle
Oglesby
Dixon
Joppa
Total Illinois
Mitchell
Green Castle
Logansport
Speed
Buf f ington
Total Indiana
(thousand ton)
255
662
800
1,717
450
320
210
2TO"
376
509
611
1,314
2,810
750
752
520
1,250
594
3,866
-------
APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
(Continued)
State
Iowa
Kansas
Kentucky
Louisiana
Maine
Company/
Total Capacity
(thousand ton)
Lehigh/2,955
Marquette/4,268
Martin Marietta/4,940
Northwestern States/1,050
Penn-Dixie/2,281
Ash Grove/1,306
General Portland/4,892
Lone Star/6,023
Monarch/600
Universal Atlas/3,614
Flinkote/2,440
Lone Star/6,023
OKC/1,105
Martin Marietta/9,940
Plant Location
Mason City
Des Moines
Davenport
Mason City
West Des Moines
Total Iowa
Chanute
Fredonia
Bonner Springs
Humbolt
Independence
Total Kansas
Kosraosdale
Total Kentucky
New Orleans
New Orleans
Total Louisiana
Thornston
Total Maine
Cement Capacity
(thousand ton)
605
467
512
1,050
440
3,074
516
407
451
600
412
2,386
660
414
675
1,089
495
I9T
-------
APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
State
Maryland
Michigan
Mississippi
Missouri
Company/
Total Capacit
(thousand ton
Alpha Portland/2,050
Lehigh/2,995
Marquetta/4,268
Aetna/600
Amcord/3,952
Dundee/2,260
Jefferson Maine/270
Medusa/3,656
National Gypsum/3,468
Penn-Dixie/2,281
Wyandotte/400
Marquette/4,268
Texas Industries/1,543
Alpha Portland/2,050
Dundee/2,260
Marquette/4,268
Missouri Portland/2,630
River
Universal Atlas/3,614
Plant Location
Lime Kiln
Union Bridge
Hagerstown
Total Maryland
Essexville
Detroit
Dundee
Detroit
Charlevoix
Alpena
Petoskey
Wyandotte
Total Michigan
Brandon
Artesia
Total Mississippi
St. Louis (Lemay)
Clarksville
Cape Girardeau
St Louis
Kansas City
Selma
Hannibal
Total Missouri
Cement Capacity
(thousand ton)
420
900
541
1,861
600
752
1,000
270
769
2,382
612
400
6,785
288
415
TTTT
280
1,260
335
752
564
1,200
625
5,616
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APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
(Continued)
u>
State
Montana
Nebraska
Nevada
New Mexico
New York
Company/
Total Capacity
(thousand ton)
Ideal/6,310
Kaiser/3,743
Ash Grove/1,306
Ideal/6,310
Centex/1,041
Ideal/6,310
Alpha Portland/2,050
Atlantic/1,550
Flintkote/2,440
Hudson/750
Independent Cement/670
Lehigh/2,955
Marquette/4,268
Plant Location
Trident
Montana City
Total Montana
Louisville
Superior
Total Nebraska
Fernley
Total Nevada
Tijeras
Total New Mexico
Cementon
Jamesville
Ravena
Glens Falls
Howes Cave
Kingston
Hudson
Cementon
Catskill
Total New York
Cement Capacity
(thousand ton)
330
320
790
235
1,025
400
3TO
500
510
170
1,550
560
300
750
670
495
649
5,654
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APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
(Continued)
Oklahoma
Oregon
Company/
Total Capacit
(thousand ton
Ideal/6,310
Columbia/950
General Portland/4,892
Marquette/4,268
Medusa/3,656
Southwestern/2,660
Ideal/6,310
Martin Marietta/4,940
OKC/1,105
Oregon Portland/775
Plant Location
Castle Hayne
Total N. Carolina
Zanesville
Paulding
Superior
Sylvania
Fairborn
Total Ohio
Ada
Tulsa
Pryer
Total Oklahoma
Huntington
Lake Oswego
Total Oregon
Cement Capacity
(thousand ton)
610
6TO"
600
554
285
282
730
2,451
620
617
430
T76T7
205
360
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APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
(Continued)
en
S. Carolina
Company/
Total Capacit
(thousand ton
Plant Location
S. Dakota
Amcord/3,952
Copley/1,250
Keystone/660
Lone Star/6,023
Louisville/2,360
Marquette/4,268
Martin Marietta/4,940
Medusa/3,656
National Gypsum/3,468
Penn-Dixie/2,281
Universal Atlas/3,614
Whitehall/790
Giant/855
Gifford-Hill/I,410
Santee/1,270
South Dakota Cement/1,140
Stockertown
Nazareth
Bath
Nazareth
Bessemer
Neville Island
Northampton
Wampum
York
Evansville
Nazareth
West Winfield
Northampton
Universal
Cementon
Total Pennsylvania
Harleyville
Harleyville
Holly Hill
Total South Carolina
Rapid City
Total South Dakota
Cement Capacity
( thousand ton)
700
1,250
660
658
590
471
426
723
471
870
305
330
427
475
790
855
564
1,140
1,140
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APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
(Continued)
State
Tennessee
Texas
Company/
Total Capacit
(thousand ton
General Portland/4,892
Ideal/6,310
Marquette/4,268
Penn-Dixie/2,281
Alpha Portland/2,050
Capitol Aggregates/355
Centex/1,071
General Portland/4,892
Gifford-Hill/1,410
Gulf Coast/600
Ideal/6,310
Kaiser/3,743
Lone Star/6,023
San Antonio Portland/390
Southwestern/2,660
Texas Industries/1,543
Universal Atlas/3,614
Plant Location
Chattanooga
Knoxville
Nashville
Cowan
Kingsport
Richard City
Total Tennessee
Orange
San Antonio
Corpus Christi
Fort Worth
Dallas
Midlothian
Houston
Houston
San Antonio
Houston
Maryneal
Cementville
El Paso
Odessa
Amarillo
Midlothian
Waco
Total Texas
Cement Capacity
(thousand ton)
477
470
235
233
330
264
2,005
325
355
265
731
475
846
600
620
490
526
545
390
327
275
200
1,128
352
8,450
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APPENDIX A
CEMENT MANUFACTURERS AND PLANT LOCATIONS
Virginia
Washington
Wisconsin
Wyoming
Company/
Total Capacit
(thousand ton
Ideal/6,310
Utah Portland/350
Lone Star/6,023
Columbia/950
Ideal/6,310
Lehigh/2,955
Lone Star/6,023
W. Virginia Martin Marietta/4,940
Natural Gypsum/3,468
Universal Atlas/3,614
Monolith/700
Plant Location
Devil's Slide
Salt Lake City
Total Utah
Roanoke
Norfolk
Total Virginia
Bellingham
Seattle
Metaline Falls
Seattle
Total Washington
Martinsburg
Total West Virginia
Superior
Milwaukee
Total Wisconsin
Laramie
Total Wyoming
Total U.S.A.
Cement Capacity
(thousand ton)
360
350
Tiff
1,200
330
1,330
350
490
205
752
1,757
972
216
95
3TT
200
96,492
Source: Economic Research Department, Portland Cement Association,
December 31, 1977.
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APPENDIX B
SUGGESTIONS RECEIVED FOR CEMENT
INDUSTRY ENVIRONMENTAL RESEARCH
Air Pollution Control
1. Investigate the nature of detached plumes which occa-
sionally emanate from some cement plant stacks. How can these
plumes be controlled if they are potentially harmful to air
quality?
2. Characterize plume composition especially with respect
to nitrogen oxides (NOX) emissions from cement plants. How
can kiln operating variables be modified, without sacrifice to
product quality, to minimize NOX generation?
3. Assess the effects of high-sulfur coal on emissions
from cement plants as well as on the properties of the final
product. Should larger amounts of high-sulfur coal be used in
cement plants?
4. Conduct overall material balances for sulfur compounds
in the kiln system.
5. Analyze the physical and chemical characteristics of
stack emissions in plants where efficient dust collectors are in
use.
6. What are the effects of non-homogeneity of fuels and
other raw materials on kiln system dust collector performance?
7. Determine the disposition of trace elements (e.g.,
heavy metals) in kiln systems where non-premium or refuse-
derived fuels are used.
8. Characterize the emissions from a kiln system equipped
with an air suspension preheater and a flash calciner. Are
these emissions different from those of wet-process systems or
dry-process systems without preheaters?
78
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9. Evaluate the phenomenon of alkali flaking at the kiln
electrostatic precipitator. What are the effects on precipi-
tator performance?
Solid Waste Management
1. Find better ways to achieve fugitive dust control,
particularly from raw material storage piles, coal piles, and
clinker storage areas.
2. What is the benefit of controlling cement dust emis-
sions? Are they really harmful?
3. Develop environmentally acceptable dust control agents
for roads in cement plants.
4. Determine economically-feasible and environmentally
acceptable ways to dispose, reuse, or recycle waste cement kiln
dust.
5. Demonstrate the feasibility of burning municipal refuse
mixed with other fuels in cement kilns.
6. The chemical characteristics of waste kiln dust should
be assessed.
7. Determine the variation in heavy metal content in waste
kiln dust from various plants. What are the primary sources of
the heavy metals?
8. Where waste kiln dust is used on farmland, what is the
extent of metals uptake by various types of crops?
9. Assess the ecological and medical impacts of the trace
elements in waste kiln dust.
Hazardous Wastes Disposal
1. The technical feasibility of incineration of PCB and
other hazardous substances in cement kilns should be further
demonstrated.
2. Demonstrations for burning refuse-derived fuels and
waste fuels in cement kilns should be conducted.
3. Assess the regulatory, economic, social, and other
institutional factors associated with burning PCB's, waste
fuels, or other types of hazardous wastes in cement kilns.
79
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Water Pollution Control
1. Study non-point source water pollution generation at
cement plants and evaluate the costs and benefits of controls
implementation.
Process/Product Issues
1. Determine the feasibility of relaxing cement standards
for alkali content to some extent/ thereby reducing the amounts
of waste kiln dust generated.
2. Demonstrate use of cement plant waste dust as a substi-
tute for limestone in scrubbers, especially for power' plants.
3. Demonstrate the use of FGD sludge as a substitute for
gypsum in cement.
4. Define the institutional issues involved in changing
product specifications so that smaller amounts of low-alkali
cement would be required.
5. Demonstrate innovative kiln and furnace designs, and
determine the nature and quantities of their emissions.
6. Assess the feasibility of an increased use of non-
thermal cement.
7. To what extent and at what costs can kiln raw materials
be changed to reduce alkali problems?
8. Develop improved particulate collects which could stand
high temperature excursions and higher air-to-surface ratios,
possibly incorporating electrostatic precipitation.
Regulatory Issues
1. What are the overall effects of all government regula-
tions on the cement industry?
2. Establish a procedure to assure that regulations issued
by various Federal, state, and local agencies do not conflict
with each other.
80
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3. The standard-setting process for separate environmental
pollutants should be coordinated in a way that is likely to
achieve minimum adverse environmental impacts while recognizing
that tightening the standard for one pollutant may limit the
capability to reduce another pollutant below some regulated
level.
4. The feasibility of changing the units for gaseous
emissions regulations to mass per unit of production should be
investigated.
81
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
. REPORT NO.
EPA-600/2-79-111
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Multimedia Assessment and Environmental Research
Needs of the Cement Industry
5. REPORT DATE
May 1979 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Ronald F. Smith and James E. Levin
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
A. T. Kearney, Inc.
Alexandria, VA 22313
_L
601+
^CT/GF
11. CONTRACT/GRANT NO.
68-03-2586
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Lab.
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati,, OH 1*5268
- Cinn, OH
13. TYPE OF REPORT AND PERIOD COVERED
Final Report
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This project was initiated to obtain a comprehensive assessment of the cement
industry and its environmental research needs. This report contains a profile of
the U.S. cement industry; an analysis of the cement manufacturing processes; a
discussion of waste stream characteristics and controls; and an assessment of
research needs for the cement industry. Recommendations for further investigation
were proposed in several areas: waste kiln dust management, nitrogen oxides
control, use of kilns as waste incinerators, and sulfur oxides control.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
COS AT I Field/Group
Air pollution
Assessments
problem definition
research need assessment
solid waste
cement manufacturing
pollution control
8. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
92
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
82
* U.S. GOVERNMENTPRIITOG OFFICE: 1979-657-060/5312
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