The document provides information about the cement production process at Maple Leaf Cement Company Ltd in Iskanderabad. It discusses the key steps which include mining of raw materials like limestone and clay, crushing these materials, grinding them into a raw meal, heating the raw meal in a kiln to form clinker, grinding the clinker to form cement powder, and storing the final cement product. It also provides details about equipment used at different stages like raw mills, kilns, cement mills, as well as raw material requirements and specifications.

1. Page | 1
Maple Leaf Cement Company Ltd Iskanderabad
15
INTERNSHIPREPORT
PRODUCTION PROCESS

2. Page | 2
Contents
S.NO. TOPICS PAGE NO.
1 Acknowledgement 1
2 Executive summary 2
3 Introduction&history 3
4 Portland cement 4
5 Type of cements 4
6 Methodsof cementmanufacturing 5to 10
7 Raw Mill 11
8 workingprinciple 11
9 ClinkerizationorCementgrindingandstorage 12 to 13
10 High-performancegearunit 14
11
Hydraulicstationsprotected
14
12 Raw Mill Design 15 to 16
13 Mill Layout 17
14 Coal Mill (Line-II) 18
15 workingprinciple 18 to 20
16 Double screwfeederorgear unit 21
18 Rotary air separator 22
17 Coal Mill Design 23
18 Kiln (Line-II) 24

3. Page | 3
ACKNOWLEDGEMENT
All praises belong to almighty ALLAH who is the supreme Authority Knowing the
ultimate relations underlying all sorts of phenomenon going on in this universe
and whose blessings and exaltation flourished my thoughts and thrived my
ambitions to have the cherished fruit of my humblest thanks to the Holy Prophet
Hazrat Muhammad (Peace be upon him) who is forever a torch of guidance and
knowledge and knowledge for humanity as a whole.
I deem it my utmost pleasure to avail this opportunity to express gratitude and
deep sense of obligation to my reverend teachers, for their valuable and
dexterous guidance, scholarly criticism, untiring help, compassionate attitude,
kind behavior, moral support and enlightened supervision during the whole study
and completion of the project.
I am also gratitude to staff of Mepal Cement Limited. Especially
NASIR IQBAL (DGM-Process)
WAHAB-UR- REHMAN QURESHI (Senior Manager)
Who provides me useful information during the internship program. I am thankful
to all those people, who provide me valuable information.
Finally, I should like to extend heartfelt thanks to my adoring PARENTS, for their
day and night prayers, sacrifices, encouragement, moral and financial support
throughout the course of my study.
Muhammad Talha Majeed
B.E. (Chemical Engineering)INPROGRESS

4. Page | 4
EXECUTIVE SUMMARY
This report is based on the activities performed during the internship at Mepal
Cement Limited. Internship duration was 30 days and it provided practical
knowledge of working in professional environment. This learning experience is
described in detail in the various sections of this report.
In the first section, there is some detail about the company. The history and present
status of the company is explained. The organization structure and the details of its
management along with its location are also discussed. I have also discussed the
operations, process and machine use in cement manufacturing.
The second section provides information about the activities that I performed
during the internship. I worked as an internee mainly in production department.
The third and last section includes the conclusion.

5. Page | 5
GENERAL VIEW /History of MLCF
Mepal leaf Cement is the third largest cement factory in Pakistan. It was set up in
1956 as a joint collaboration between the West Pakistan industrial development
Corporation and the government of the Canada. Mepal leaf produces 11000 ten
cement per day.
• In1992, the capacity of Maple Leaf to produce Ordinary Portland Cement
(OPC) was 1000 tons/day.
• In 1997, Line-I was commissioned with the Capacity of 3300 tons/day.
• In 2004, Line-I was upgraded to 4000 tons/day.
• In 2006, White Cement Plant is in operation with Capacity of 500 tons/day.
• In 2007, Line-II came into operation with the Capacity of 7000 tons/day.
• At present total clinker capacity of OPC is 11000 tons/day & Cement
Capacity of OPC is 12100 tons/day.
Presently Maple Leaf cement has 9% of the market share of OPC and is a leading
brand in Pakistan.

6. Page | 6
Portland Cement
Portland cement is made by heating a mixture of limestone and clay, or Other
materials of similar bulk composition and sufficient reactivity, Ultimately to a
temperature of about 1450°C. Partial fusion occurs, and Nodules of clinker are
produced. The clinker is mixed with a few per cent of calcium sulfate and finely
ground, to make the cement. The calcium sulfate controls the rate of set and
influences the rate of strength development. Itis commonly described as gypsum,
but this may be partly or wholly replaced by other forms of calcium sulfate. Some
specifications allow the addition of other materials at the grinding stage.
Types of cement
 Ordinary Portland Cement (OPC)
Step for the Manufacture of Cement
 Mining
 Crushing
 Raw milling and homogenization (uniform quality of raw
materials)
 Clinkerization
 Cement grinding and storage
 Packing

7. Page | 7
Mining
The cement manufacturing process starts fromthe mining of raw materials that
are used in cement manufacturing, mainly limestone and clays.
Crushing
The limestone is crushed in the first crusher called a jaw crusher and then fed into
the second crusher called an impact crusher with mixing of clays to reduce
particle size below 50mm. The discharged raw mix (limestone 70%, clays 30%) is
fed onto a belt conveyor and passed across a bulk material analyzer.

8. Page | 8
Raw milling and homogenization
The raw mix, high grade lim0estone, sand, and iron ore are fed from their bins to
raw mills, called air sweptmills, for drying and fine grinding. The raw mill contains
two chambers, separated by diaphragm, namely a drying chamber and a grinding
chamber. The hot gases coming from a preheater (preheater / kiln system) enter
the mill and are used in raw mills for drying. Then the drying materials enter the
grinding chamber of raw mills for fine grinding. The grinding chamber contains a
certain quantity of ball charge in a different sizes ranging from 30mm to
90mm. The hot gas and grinding materials mill outlet feeds to a separator which
separates fine and course product. The latter, called reject, is sent to the mill inlet
via an air slide for regrinding. The hot gas and fine materials enter a multistage
"cyclone" to separate a fine materials and gases. The fine material, called raw
meal, is collected from the multi-cyclone and then fed into an air slide for lifting
called an Aeropol . The hot gases with very fine materials enter an electrostatic
precipitator to separate the fine materials from gases. The very fine materials
called preheater dust or electrostatic separator dust is collected from filters and
fed into screw conveyors and are then mixed with the fine material in an air slide
and transported to an air lift vessel via air slide. In the air lift, the raw meal is
lifted to the silo by compressed air to the air slide and then stored and
homogenized in a concrete silo. Raw meal extracted from the silo, now called kiln
feed, is fed to the top of the preheater via an air lift called the Poldos for pyro-
processing.
Raw material required for cement industry
 LIMESTONE (75-80%)
 CLAY (15-20%)
 GYPSUM (5%)
 IRON

9. Page | 9
Limestone Crusher (Line-II)
 Hammer Mill EV 200 x 200 (1 Nos)
o Output
 1000 tons/hr
o Specific consumption of Electrical Energy
 Maximum 1.2 kWh/ton
Limestone Storage (Line-II)
Storage Capacity (Pile)
o 2 x 35000 tons=70000
 Standard Deviation of Output
o Maximum 1% of CaCO3
Clay Storage (Line-II)
• Storage Capacity (Pile)
o 2 x 13,000 tons=26000

10. Page | 10
Storage Bins (Line-II)
• BinCapacity (3 Nos)
 1 x Iron Ore 625 tons
 1 x Clay 195 tons
 1 x Limestone 500 tons
( limestone,clay,iron)

11. Page | 11
Pile Completion
Crusher
o Working hours (Limestone & Clay) 10 Hours a day
o Capacity of Crusher
 Lime stone = 1000 t/hr * 10 hr = 10000 Tons
 Clay = 400 t/hr * 10 hr = 4000 Tons
o Time taken to complete 1 pile
 Lime stone = 30000 tons/10000 tons = 3 days
 Clay = 11000 tons/4000 tons = 3
days(Approx.)
Clay Limestone Iron

12. Page | 12
Clinkerization
Cement clinker is made by preprocessing of kiln feed into the preheater-kiln
system. The preheater-kiln system consists of a multi-stage cyclone preheater
with five stages, combustion chamber, riser duct, rotary kiln, and grate cooler. In
the preheater, the kiln feed is preheated by hot gas coming from the combustion
chamber and rotary kiln. Then the preheated kiln feed is partially calcined (made
powdery) in a combustion chamber and riser duct and then completely calcined in
a rotary kiln as well as heated to approximately 1400 C to form clinker
components. The main source of heat is natural gas. The fuel is used to provide
the heat required to convert the kiln feed into clinker. Hot clinker discharge from
the kiln drops onto the grate cooler for cooling from approximately 1350-1450 C.
In the cooler, the quantity of cooling air required for clinker cooling is extracted
from the atmosphere by different cooling fans and fed into the cooler chambers
and pressurized through the cooler plate and clinker bed. The cooled clinker
discharges from the cooler into the pan conveyor and it is transported to the
clinker storage. The clinker is taken from the clinker storage to cement ball mill
hoppers for cement grinding. Part of the hot air extracted from the cooler is
utilized as a secondary and tertiary air for combustion in rotary kiln and
combustion chamber, respectively.
Why does the manufacture of cement produce CO2?
Cement manufacturing is the source of 5% of global CO2 emissions. The cement industry is a
natural producer of CO2.

13. Page | 13
 60% of emissions are due to the transformation of raw materials at high temperatures (the
"carbonation" of limestone)
 40% result from the combustion required to heat the cement kilns to 1500°C
Cement grinding and storage
Clinker and gypsum for OPC, limestone for limestone cement, and slag for slag
cement are all extracted from their respective hoppers and fed to the cement
mills. The ball mill grinds the feed to a fine powder in two chambers, namely the
first and second chambers. The two chambers have a certain quantity of ball
charge of different sizes from 17mm to 90 mm. The mill discharge is fed to a
bucket elevator which takes the material to a separator which separates fine and
coarse product. The latter is sent to the mill inlet for regrinding and the final
product is stored in concrete silos.
(Storage silo) (grinding)
Packing
Cement extracted from silos is conveyed to the automatic electronic packers
where it is packed in 50 kg bags and dispatched in trucks.

14. Page | 14
Raw Mill (Line-II)

15. Page | 15
Working principle
The ATOX raw mill uses pressure and shear generated between the rollers
and the rotating table to crush and grind raw materials. Feed material is directed
onto the grinding table by the feed chute. The rotation of the grinding table
accelerates the material towards the grinding track and passes it under the
rollers. Partially ground material passes over the dam ring encircling the grinding
table and into the hot gas stream coming from the nozzle ring.
 Mill: Atox 52.5 Motor: 4300 kW
 Separator RAR-LVT 52.5 Motor: 232 kW
 Output
o Minimum 540 tons/hr
 Specific Consumption of Electrical Energy
 18.3 kWh/ton of Raw Meal
( The three cylindrical rollers are rigidly connected to a common centerpiece

16. Page | 16
This highly efficient separator results in the following benefits:
 Lowestspecific power consumption for the mill motor
 Highest mill capacity
 High grinding bed thickness and low vibrations
The required fineness of the raw meal is obtained by adjusting the rotor speed.
(
Seperator top view)
High-performance gear unit
The axial thrust bearing supporting the grinding table and the grinding force is a
reliable hydrodynamic/semi-hydrostatic bearing of segmented design. All the
thrust pads are immersed in an oil bath. The lubricant for the thrust pads and for
the internal gearings/bearings is conditioned and filtered in a separate pump
station.
(Gear unit)
Hydraulic stations protected
For all ATOX mill installations the hydraulic and lubrication stations are located in
indoor facility. The benefit is that operation and maintenance takes place in clean
and tempered conditions and that trouble free and long life can be obtained.
Apart from the lubrication station for mill gear and grinding rollers also the
hydraulic station for the tensioning system as well as pump station for the water
injection is located in the hydraulic room.

17. Page | 17
Raw Mill Design

18. Page | 18
1.Mill motor 2.Gear box
3. Grinding table 4. Split scrapers for external circulation
5. Hydraulic cylinder with accumulators 6. Reject sluice
7. Rotary split sluice in heated or non-heated
version
8. Reject cone
9. Mill house with lining 10. Nozzle ring
11. Air guide cone 12. Segmented grinding roller
13. Roller hub and wear cover 14. Joint head
15. Torque rod 16. Reject cone
17. Mill and separator outlet 18. Tension rod
19. Hydraulic cylinder with accumulators

19. Page | 19
Mill Layout
As a one-source supplier of complete plants, FLSmidth supplies the ATOX raw mill
as well as all other equipment needed for the raw mill department. Mill layout is
based on a standardized concept and modules that ensurethe most cost-effective
raw mill installation. Because gas enters the ATOX mill from one side, the ducting
arrangement is as small as possible, resulting in a very compact layout. The
dimensioning and selection of cyclones, mill fan and connecting ducting are
optimized for low energy consumption.
The number of cyclones will be 2, 4 or 6, increasing with the mill size. The raw
material feeding and recirculation system is preferably placed at the left side of
the ATOX mill, seen from the mill motor. Lubrication stations for main gear,
hydraulics and roller lubrication are placed with the pump station inside the
structure, below the cyclones. The layout is furthermore prepared for easy access
to machinery and components needing overhaul or replacement.

20. Page | 20
Coal Mill (Line-II)

21. Page | 21
Working principles
The raw coal enters the mill via a feed screw and is discharged onto the center of
the rotating grinding table. The rotation of the table accelerates the flow of
material towards the grinding track, where the coal is ground between the table
and the three rollers. The coal then continues over the dam ring and is entrained
in the hot drying gas that enters the mill house through the nozzle ring. The gas
lifts the coarser particles back onto the grinding table and sweeps the finer
particles up to the separator. The separator lets the final product proceed to the
mill outlet while returning the coarse fraction to the table for further grinding.
Having left the mill at the top, the final product continues with the gas to a
cyclone or a bag filter, where it is collected.
 Mill: Atox 25 Motor: 600 kW
 Separator RAKM 27.5 Motor: 83 kW
 Output
o Minimum 52 Tons/hr
 of Electrical Energy
 Max 26.5 kWh/ton of Coal Meal
Non-inert operation
When grinding low-explosive to moderately explosive coal types, the system may
operate under non-inert conditions. Non-inert operation allows using excess air
from the clinker cooler or from the heat generator for drying and conveying.
Neither recirculation of air nor water injection for the purpose of inertisation in
the mill is required. This is because atmospheric air can be used to any extent to
maintain the necessary flow for drying, transportation and separation without risk
of explosion.
Inert operation
A common safety precaution is to operate the coal grinding system under inert
conditions. This can be achieved at a cement plant by using exit gases from the
kiln preheater to dry and convey the material through the mill. A variable amount
of cleaned gas can be recycled from the grinding system filter to maintain the
required flow for separation and conveying through the mill, independent of the

22. Page | 22
amount of hot gas needed for drying.
Grinding segments
Both the grinding table and rollers are fitted with segmented wear parts.
Segmentation allows the use of very hard and wear-resistant material without
running the risk of thermal cracks occurring in the wear segments. The cylindrical
shape of the rollers makes it possible to reverse the segments, enabling a high
degree of material utilisation even in the case of uneven wear. Using wear-
resistant, high-chromium white cast iron, high-chromium white caste iron with
ceramic inserts or hardfacing ensures long life of the grinding segments.
Effective lubrication
An oil circulation system effectively lubricates the bearings of the grinding rollers.
Each roller is fed individually with conditioned oil from a common supply station
in which a separate circulation system provides filtration and temperature
conditioning. High-temperature grease is used to lubricate the bearings of the
smallest mill sizes.
The simple, lightweight loading arrangement ensures the lowest possible inertial reactions to
gear and foundation parts. & Mill drive and grinding parts.

23. Page | 23
Double screw feeder
The raw coal enters the mill from the raw coal hopper and enclosed extraction
equipment used a double feed screw. The double screw design and the selection
of stainless steel for the screw flights and shafts make the feeder capable of
handling wet and sticky material.
(Double screw feeder)
High-performance gear unit
The standard main gear unit for an ATOX mill is the sturdy bevel-helical or more
compact bevel-planetary type gear from FLSmidth MAAG Gear. The gears are
designed for high dynamic loads with a generous service factor. The axial thrust
bearing supporting the grinding table and the grinding force is of a segmented
design in which all thrust pads are immersed in an oil bath. The lubricant for the
thrust pads and for the internal gearings/bearings is conditioned and filtered in a
separate pump station.

24. Page | 24
Rotary air separator
The rotary air separator is flanged to the top of the mill housing. The rotor shaft is
driven by a variable-speed AC motor via a gear unit. The rotor runs inside a ring of
guide vanes. The material entrained in the air from the mill enters the rotor
through the guide vanes. The rotor rejects the coarse particles to be collected by
the guide vanes and returned via the reject cone to the grinding table for further
grinding, while the air and the finished material leave the separator via the outlet
duct. The fineness of the ground product can be adjusted by varying the speed of
the rotor.

25. Page | 25
Coal Mill Design
1.Main gear unit 2.Hydraulic cylinder, incl.
accumulators
3.Tension rod 4.Grinding table with scrapes
5.Torquerod connection 6.Grinding roller assembly
7.Oiland air connection 8.Water injection
9.Doublefeed screw 10.Rejectbin
11.Rejectcone with return pipe 12.Separator outlet
13.Rejectcone with return pipe ……..
……. …….

26. Page | 26
Kiln (Line-II)
Cement kilns are used for the preprocessing stage of manufacture
of Portland and other types of hydraulic cement, in which calcium reacts
with silica-bearing minerals to form a mixture of calcium silicates. Over a billion
tonnes of cement are made per year, and cement kilns are the heart of this
production process: their capacity usually defines the capacity of the cement
plant.
A typical process of manufactureconsists of three stages:
 grinding a mixture of limestone and clay or shale to makea fine "rawmix".
 heating the rawmixto sintering temperature (up to 1450 °C) in a cement kiln;
 grinding the resulting clinker to makecement.
 Output
o 7000 tons/Day
 Specific Consumption of Heat Energy
o Maximum 805 kCal/kg of clinker
 Specific Consumption of Electrical Energy
o Maximum 28.5 kWh/ton of clinker
• Capacity: 40,000 tons
• Time Marginof OK Mills w.r.t. Clinker Dome-II
 Capacity of Dome/Clinker Demandin OK Mills
 = 40,000 tons
 = 5 days (approx)

27. Page | 27
Personal Comments
1. Maple leaf is a very good and third largestcompany
of Pakistan.
2. Employees are well mannered and their behavior is
ideal.
3. The control system of company is excellent.
4. The Senior manager is very good and he guided me
very well.
5. I must have to mention the excellent condition of
cleanliness in this company.
6. I wish I could join this company after the
completion of my engineering.
7. Overall this company is remarkably good but
transport system needs some improvements
and can be made better.