INDUSTRY PROFILE #13
PORTLAND CEMENT
Prepared By
Dave F. Smith
H.W. Goodwin
Published By
VOLUNTEERS IN TECHNICAL ASSISTANCE
1600 Wilson
Boulevard, Suite 500, Arlington, Virginia 22209 USA
Telephone: (703) 276-1800,
Fax: (703) 243-1865
Telex: 440192 VITAUI, Cable:
VITAINC
Internet: vita@gmuvax.gmu.edu,
Bitnet: vita@gmuvax
Portland Cement
ISBN: 0-86619-300-6
[C]
1988, Volunteers in Technical Assistance
INDUSTRY PROFILES
Introduction
This Industry Profile is one of a series briefly describing
small or medium-sized industries. The
Profiles provide basic information for starting
manufacturing plants in developing nations.
Specifically, they provide general plant descriptions,
financial, and technical factors for their
operation, and sources of information and expertise.
The series is intended to be useful in
determining whether the industries described warrant further
inquiry either to rule out or to
decide upon investment.
The underlying assumption of these Profiles is that the individual
making use of them already has some knowledge and experience
in industrial development.
Dollar values are listed only for machinery and equipment
costs, and are primarily based on
equipment in the United States.
The price does not include shipping costs or import-export taxes,
which must be considered and will vary greatly from country
to country. No other investment
costs are included (such as land value, building rental,
labor, etc.) as those prices also vary.
These items are mentioned to provide the investor with a
general checklist of considerations for
setting up a business.
IMPORTANT
These profiles should not be substituted for feasibility
studies. Before an investment is made
in
a plant, a feasibility study should be conducted.
This may require skilled economic and
engineering expertise.
The following illustrates the range of questions to which answers must
be obtained:
*
What is the extent of the present demand for
the product, and how is it now being
satisfied?
*
Will the estimated price and quality of the
product make it competitive?
*
What is the marketing and distribution plan
and to whom will the product be
sold?
*
How will the plant be financed?
*
Has a realistic time schedule for
construction, equipment, delivery, obtaining
materials
and supplies, training of personnel, and the start-up time for the plant
been
developed?
*
How are needed materials and supplies to be
procured and machinery and
equipment
to be maintained and repaired?
*
Are trained personnel available?
*
Do adequate transportation, storage, power,
communication, fuel, water, and
other
facilities exist?
*
What management controls for design,
production, quality control, and other
factors have
been included?
*
Will the industry complement or interfere
with development plans for the area?
*
What social, cultural, environmental, and
technological considerations must be
addressed
regarding manufacture and use of this product?
Fully documented information responding to these and many
other questions should be
determined before proceeding with implementation of an
industrial project.
Equipment Suppliers, Engineering Companies
The services of professional engineers are desirable in the
design of industrial plants even though
the proposed plant may be small.
A correct design is one that provides the greatest economy in
the investment of funds and establishes the basis of
operation that will be most profitable in the
beginning and will also be capable of expansion without
expensive alteration.
Professional engineers who specialize in industrial design
can be found be referring to the
published cards in various engineering magazines.
They may also be reached through their
national organizations.
Manufacturers of industrial equipment employ engineers
familiar with the design and installation
of their specialized products.
These manufacturers are usually willing to give prospective
customers the benefit of technical advice by those engineers
in determining the suitability of their
equipment in any proposed project.
VITA
Volunteers in Technical Assistance (VITA) is a private,
non-profit, volunteer organization
engaged in international development.
Through its varied activities and services,
VITA fosters
self-sufficiency by promoting increased economic
productivity. Supported by a volunteer
roster
of over 5,000 experts in a wide variety of fields, VITA is
able to provide high quality technical
information to requesters.
This information is increasingly conveyed through low-cost advanced
communication technologies, including terrestrial packet
radio and low-earth-orbiting satellite.
VITA also implements both long- and short-term projects to
promote enterprise development and
transfer technology.
PORTLAND CEMENT
==================================================================================
PREPARED BY: Dave F.
Smith
Alfred
Bush
REVIEWED BY: G.
Robert Fuller
H.W.
Goodwin
==================================================================================
DESCRIPTION
The Product. To make
Portland cement, a crushed mixture of limestone
and clay is heated to form "clinker," which is
mixed with
gypsum and ground to a fine, dehydrated powder.
Quality control
is essential during manufacture.
The cement is shipped in
moisture-resistant bags or other containers, or in bulk.
When mixed with sand, gravel, and water in proportions that
depend upon the application, it sets to a dense, rock-like
material,
called concrete or mortar.
Additives may accelerate or
retard the set, increase strength, or make it resistant to
acid,
sulphate, shrinkage, or freeze-thaw cracking.
The Facility. This
Profile describes a small plant producing
35,000 metric tons of cement a year.
GENERAL EVALUATION
In most developing countries, concrete is an increasingly
important
construction material.
It is basic to the construction of
roads, dams, canals, water and sewer ducts, houses and
factories.
Since the raw materials are often readily available, cement
production can improve a country's living standards and
decrease
its dependence on imports.
Economic and Technical Outlook
Economic. Starting a
cement industry depends on the availability
of power, fuel, and water.
Sufficient raw materials must be
available to justify investment in even the smallest plant.
Because cement manufacture is a continuous process and consumes
much energy, access to a reliable supply of fuel or electric
power is required.
Depending on local conditions, the running costs of a small
plant
may be higher than those of a much larger plant of exactly
the
same type, per ton of cement produced.
Potential local demand and
cost of transport of cement from outside the region are
important
in deciding whether to build a new plant and what size it
should
be.
Technical. The basic
process is age-old; no technological breakthroughs
are expected. Raw-material
costs can be reduced if the
plant is built where limestone can be quarried.
Limestone quarries
can be used by a small plant even if their yield is only
moderate. Coral
dredged from a nearby underwater source can be
used instead.
Manufacturing Equipment Flexibility.
Some of the equipment and
machines required for this operation, such as the crushers,
grinders, batchers, and kiln, are used in other industries
and
may be purchased secondhand.
Large, complex cement plants in industrial countries are
designed
for automation and high energy efficiency.
They require specially
qualified staff. In
developing countries, small and medium sized
plants can be planned using modern knowledge.
Such plants use
less automation and staff that is less specially qualified.
Process and maintenance should be simple and reliable.
Knowledge Base.
Cement technology requires knowledge and skills,
some of which may best be acquired by working for a time in
an
industry outside the home country.
Market analysts should determine
whether the potential growth of the country is likely to
support the industry.
Geologists should determine the adequacy
of the mineral resources; power and water supplies must be
investigated.
The technical staff required to operate a cement plant
includes
an operating engineer and a manager.
Quality control requires
training in analytical chemistry.
Successful continuous operation
depends on mechanics, trained technicians, and plant
operators
who have some understanding of chemical processing.
Quality Control.
Sampling for quality control may be needed
several times per hour.
A test lab must be part of the plant.
It
should be furnished with sampling, curing, and test
equipment to
ensure uniformity at each stage of production and to meet
international
standards. A
well-run lab is essential to keeping a
competitive market position and maintaining confidence in
the
product.
Constraints and Limitations.
These are as follows:
high investment
in equipment and land; limited range of product output; high
cost of transport of raw materials to plant and product to
market; the need to use the product in a short time after
manufacture,
because it is unavoidably damaged by high humidity and
moisture; and the need for a reliable source of power to
maintain
continuous and efficient operation, thus lowering the high
costs
of start-up and shut-down.
MARKET ASPECTS
Users. Small users
need bagged cement. Cement can be bulk
shipped
in tank, truck, or railroad cars, and sold to precasters of
large
structural parts (pipes, posts, blocks, railroad ties,
etc.), and
builders of industrial, commercial, or residential
structures.
Cement may be sold directly to public-sector organizations,
private contractors in the largest urban areas, and local distributors.
If nearby countries need the material and the plant has
excess capacity, it may export a portion of its production.
However, most export sales are either spot sales or by
short-term
contract.
Suppliers. If a
country or region now depends on imported cement
supply, a first step may be to improve the efficiency of
local
distribution, whether by land or water.
If the expected market
demand justifies a larger plant than that described here, a
next
step may be the importation of clinker, to be pulverized and
mixed with gypsum; then bagged for distribution.
Or, depending
on resources and market conditions, local planners may want
to
build a plant for complete manufacture.
Sales Channels and Methods.
Producers and/or suppliers are directly
contacted, or through advertising in local technical
publications and other channels.
Generally, cement companies sell
directly to the users.
Geographic Extent of Market.
If the market area is extended too
far, transport costs make the cement noncompetitive with the
cement from other sources or with other materials.
This may be up
to 300 km from the plant by land, and farther by water.
Competition.
Competition from other materials will depend on
relative costs. In
regions of high rainfall, lumber will be
competitive. Close
to industrial centers or major ports, steel
and other structural metals will compete.
Brick, soil cement or
adobe, sometimes traditionally used in housing, may compete
because of their low cost.
Market Capacity.
Market capacity depends on local purchasing
power, potential for growth (including new businesses and
tourism),
availability of competing materials, and attitudes toward
acquiring new technologies.
Therefore, annual per capita consumption
of cement may vary from 5 to 150 kg for an agrarian society
and from 300 to 700 kg for an industrial society.
The cement market follows the downturns and booms of the
construction
industry. Prices of
cement can fall and rise, often
dramatically.
PRODUCTION AND PLANT REQUIREMENTS:
SMALL PLANT (Note 1)
_________________________________________________________________________
Requirements
Amount
-------------------------------------------------------------------------
Annual Output
35,000 T
1. Infrastructure,
Utilities
Land (not
including quarry)
2 ha
Building and
structures (Note 2)
4,600 sq m
Power (can be
hydro) 2 - 3
Mw
Fuel (expressed
as coal) 20 T/d
Water
400 T/d
Materials
input
4,000 T/mo.
(Road access
required; rail or waterway access desirable.)
--------------------------------------------------------------
2. Major Equipment
and Machinery
Production tools
and equipment
Including
principal items: air drills,
compressor,
shovels, crushers, hammer
mill, conveyor
& elevator, rough mill &
slurry tanks,
kiln, feed tank, clinker
cooler,
conveyors, silos, finish mill
elevator,
bagging equipment, lab
equipment,
pumping equipment, water
storage,
maintenance equipment, power
plant; other
tools and equipment,
furniture and
fixtures. (Note 3)
$5 million
-----------------------------------------------------------------
3. Materials &
Supplies
Raw Materials
limestone &
clay
175 T/d
gypsum
5 T/d
Supplies
grinding
balls
varies
Packaging
bags @ 50% sales
in bags
3,800/d
4. Labor (varies
with local conditions)
Skilled
plant operators,
instrument technicians 10
Semiskilled
mechanics,
equipment operators
20
Unskilled
general
labor
20
Indirect
administration,
manager, supervisors, chemist,
sales/marketing
20
-------------------------------------------------------------------
5.
Distribution/Supply flow
Materials in per
day
180 T/d
Materials out per
day 100 T/d
--------------------------------------------------------------------
6. Market
Requirements
Market area
population
varies
-------------------------------------------------------------------
7. Other
Requirements
Raw material
reserves 15
years
===================================================================
Notes:
1. These estimates
refer to the 35,000 T/y plant. To build
and
operate a plant
twice as large may require a little less than
twice as much in
space and financial resources. The
amount of
the saving will
depend on local conditions.
2. Buildings need to
be designed for the specific process selected.
Silo height may
be 8 - 12 m. Stack height will depend
on local safety
and environmental rules.
3. Estimated US$
cost in the United States in 1985, based on
1965 prices and
an inflation multiplier of 4 for the elapsed
period.
The actual cost in the country of use may
vary considerably
from this figure,
depending on local conditions
and and process
requirements. Used production tools and
equipment from
reliable sources can often be obtained at much
lower prices.
PROCESS DESCRIPTION
1. Diagrams
A.
Flow sheet/plan
<FIGURE>
04p06.gif (600x600)
B.
Elevation diagram
<FIGURE>
04p07.gif (600x600)
2. Remarks
The flow sheet/plan is for the medium plant.
It uses a single
stage preheater (for fuel economy).
Dust collectors are included
for pollution abatement; a clinker silo also reduces
pollution.
Dashed lines show key sampling points for quality control.
REFERENCES
Unless otherwise stated, the addresses are in the United
States.
Technical Manuals and Textbooks
Bye, G. C. Portland
Cement, Composition, Production, and Properties,
1983, 156 pp., ISBN 0-08-029965-2, paper/text ed.
ISBN
0-08-029964-4, Pergamon Press, Inc., Maxwell House, Fairview
Park, Elmsford, New York 10523.
Kohlhaas, B. Cement
Engineers Handbook (4th ed.), 1982, 790 pp.,
ISBN 0-9915000-2-4.
Heyden & Sons, Inc., 247 S. 41st St.,
Philadelphia, Pennsylvania 19104.
Lea, F. M. Chemistry
of Cement and Concrete, 1971, 1100 pp.,
ISBN 0-8206-0212-4 Chemical Publishing Co., 80 8th Ave., New
York, New York 10011
Peray, K. Cement
Manufacturer's Handbook, 1979, ISBN 0-8206-0245-0
Chemical Publishing Co., 80 8th Ave., New York, New York
10011
Peray, K. Rotary
Cement Kiln (2nd edition) 1986, ISBN 0-8206-0314-7
Chemical Publishing Co., 80 8th Ave., New York, New York
10011
Periodicals
Minerals Yearbook.
Bureau of Mines, U.S. Department of Interior,
Washington, DC 20241.
ISBN 024-004-02024-1 Government Printing
Office, Washington, DC 20402
Pit & Quarry (Monthly), Harcourt, Brace, Jovanovich,
Inc., 7500
old Oak Boulevard, Cleveland, Ohio 44130
Rock Products (Monthly), 300 W. Adams Street, Chicago,
Illinois
60606
Trade Associations
American Concrete Institute, P. O. Box 4754, Redford
Station,
Detroit, Michigan 48219
American Society for Testing and Materials (ASTM), 1916 Race
Street, Philadelphia, Pennsylvania 19103
Portland Cement Association, 420 Old Orchard Road, Skokie,
Illinois 60077
Equipment Suppliers, Engineering Companies
Engineering for Improved Distribution Systems/Feasibility
Studies:
Bendy Engineering Co., 4260 Shoreline Drive Earth City,
Missouri 63045
Independent Process Engineers Kaiser Engineers, Kaiser
Center,
300 Lakeside Drive, Oakland, California 94666
Perry Equipment Co., Mt. Laurel Road, Hainesport, New Jersey
08036 [Used equipment.]
Project Services Co., Inc., P. O. Box 24628, Tempe, Arizona
85282
Process Engineers with Major Affiliations:
o
Holderbank Consulting, Ltd., 2310 Lakeshore
Road West, Mississauga,
Ontario, L5J
1K2, Canada
o
Lafarge Consultants Ltd., 606 Cathcart
Street, Montral,
Quebec, H3H 1L7,
Canada
o
Design, Supply, and Erect Small Scale Cement
Plants: Micro
Cemtech, S.A.,
Paseo de la Castellana 42-3', 28046 Madrid,
Spain (a
GATX-Fuller associate).
o
Design, Supply and Erect Full Scale Cement
Plants/Grinding
Plants:
Fuller Company, P.O. Box 2040, Bethlehem,
Pennsylvania
18001
o
Humboldt Wedag, 3200 Pointe Parkway, Atlanta
(Norcross),
Georgia, 30092
o
Polysius Corp., 180 Interstate, North
Atlanta, Georgia 30339
o
F.L. Smith & Co., 300 Knickerbocker
Road, Cresskill, New
Jersey 07626
Directories
American Cement Directory, Bradley Pulverizer Co., 123 South
Third Street, Allentown, Pennsylvania 18105 (covers North,
South
and Central America)
Used Equipment Directory, 70 Sip Avenue, Jersey City, New
Jersey
07306-3076
World Cement Directory, Cembureau, 1980, 2 vols.,
International
Publications Service, 242 Cherry Street, Philadelphia,
Pennsylvania
19106; or European Cement Association, 2 rue St. Charles,
F-75740 Paris, France
VITA Resources
VITA has documents on file and in microfiche dealing with
the
cement industry.
VITA Venture Services
VITA Venture Services, a subsidiary of VITA, provides
commercial
services for industrial development.
This service-for-fee includes
technology and financial information, technical assistance,
marketing, and joint ventures.
For further information,
contact VITA.
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