1. Courtesy: Class X 2007

2. Locations

3. Rohri
Khairpur
Hyderabad
Thatta
Karachi
Nooriabad
Dera Ghazi Khan
Dundot
Gharibwal
Jauharabad
Daud Khel
Attock
Rawalpindi
Nowshera
Cherat
Kohat

4. Location & Importance
Location
There are 20 cement industries producing 1.8 million tonnes
of cement. The plants are located in Hazara, Cherat, Jhelum,
Thatta, Kohat and Dera Ghazi Khan districts, and at Daudkhel,
Rohri, Hyderabad, and Karachi.
Importance
• There are many favourable factors for the development of
cement industries locally
• Availability of raw materials(limestone and gypsum)
• Good domestic market with high demand from the
construction industry
• Natural gas is used as a cheap fuel

5. The main raw materials used in the cement
manufacturing process are limestone, sand ,shale,
clay and iron ore. The main material, limestone, is
usually mined on site while the other minor
materials may be mined either on site or in
nearby quarries. Another source of raw materials
is industrial by-products. The use of by-product
materials to replace natural raw materials
is a key element in achieving sustainable
Development.

6. Raw Materials
CLAY
IRONORE SHALE LIMESTONE

7. Processes involved
• Mining of limestone requires the use of drilling and
blasting techniques.
• The blasting techniques use the latest Technology to
insure vibration, dust, and noise emissions are kept at a
minimum.
• Material is loaded at the blasting face into trucks for
transportation to the crush
ing plant.
• In the wet process, each raw
material is proportioned to
meet a desired chemical
composition and fed to a
rotating ball mill with water.

8. •Whether the process is wet or dry, the same chemical
reactions take place.
• Basic chemical reactions are: evaporating all moisture, and
reacting the calcium oxide with the minor materials (sand,
shale, clay, and iron).
• This results in a final black, product known as "clinker"
which has the desired hydraulic properties.
• In the wet process, the
slurry is fed to a rotary kiln.
•The rotary kiln is made of
steel and lined with special
refractory materials to
protect it from the
high process temperatures.

9. • In the dry process, kiln feed is fed to a preheated tower.
• Regardless of the process, the rotary kiln is fired with an
intense flame, produced by burning coal, coke, oil, gas or
waste fuels.
• The rotary kiln discharges the red-hot clinker under the
intense flame into a clinker cooler.
• The clinker cooler recovers heat from the clinker and
returns the heat to the preprocessing system thus reducing
fuel consumption and improving energy efficiency.

10. •The black, clinker is stored on site in silos or clinker domes
until needed for cement production.
•Clinker, gypsum, and other process additions are ground
together in
ball mills to form the final cement products.
•Cement can be distributed in bulk by truck, rail, or ships
depending on the
customer's needs.

14. • Production of cement is a continuous process. Raw materials
are dried, ground, proportioned and homogenized before
being burnt in rotary kilns. The resulting Product 'clinker' is
pulverised with
gypsum at the
grinding stage to
obtain cement.

15. The finished cement is then pumped into cement silos
from where it goes to packing plant for bag and bulk
loading. Bulk cement is loaded into special tank trucks for
delivery to customers' portable silos at construction sites
or is trucked to Indocement's port facilities.
Through road tankers
and rail wagons.

16. Products and uses
Motor for bonding bricks is made
up of one part by volume of
cement powder with 3-6 parts of
sand, and the minimum of water
to make the minimum workable. Cement and sand can also
be used to produce a thin skin or render, to protect the
outside of the buildings. The most important use of cement
is making concrete, which is used to stick together a mixture
of sand and rock fragments, i.e. aggregate.

17. Problems faced by the industry
• The major factors driving the
need for process optimization
in the cement industry are the
high costs of milling and the
effect of particle size on
product quality.
• With around 1% of the world’s electrical energy used in
crushing and grinding cement, all producers experience
financial and environmental pressures to reduce energy
consumption through process optimization.

18. • Over grinding uses excess energy, so it is important to
ensure the maintenance of an optimal particle size
distribution during the production process. Particle size
controls the final strength of the cement and so needs
careful monitoring at the time of manufacture.
• Improving consistency, reducing over grinding, and
adhering to tighter specifications are all process
optimization challenges for cement manufacturing.
• high frequency of power failures, shortage of coal,
inadequate availability of wagons for rail
transportation, limited availability of furnace oil were
the irritants which the industry was confronted with.
However, the industry is well placed today as compared
to the past.

19. Problems faced by the Environment
• Emission Of Harmful Gases In Air
• Noise Pollution
• Soil Pollution

20. Calcium
NOV 2003/Paper 2/Q:3 ::
Sulphate
powdered
coal (gypsum)
X
process B
process C
Clay or shale
process A
Q3: (a) rotary kiln
[i] Name the Inputs shown? [1]
cement
[ii] Name the important input X and state a
major source of that raw material. [2]
[iii] Give the letter and the name of 2 of the
processes A , B , C. [2]

21. [iv] Why is cement so important for the
development of Pakistan? [5]
NOV 2005/Paper 2/Q:4(c)[i][ii]
Q: [i] Give A location in Pakistan for the
Cement Industry? [4]
[ii] State TWO inputs and TWO Outputs
of The Cement Industry? [4]

22. Questions
Look at the fig. below, which shows a number of factors contributing to the development of
the cement industry in Pakistan.
Special
Machinery
Markets
Factors
influencing
Raw development Labour
of cement Supply
Material
industry
Energy
Supply
Using the information in fig. and from your own studies, explain why the cement industry has
developed at a number of locations in Pakistan during recent years. [6]
June 91/ P2 / Q4(c)