Internship Report DG Cement Khairpur

Internship Report 2010


Khair Pur Plant, Chakwal

Prepared by :Tutmash Shafi Akhtar

Reg No :

SP07-BEC-85 , Batch-4 , Section A

Department Of Chemical Engineering,

Tutmash Shafi Akhtar (SP07-BEC-85)Department Of Chemical Engineering, CIIT Lhr

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Internship Report 2010COMSATS Institute Of Information

Technology, Lahore

:: Table Of Contents :: Serial No.

Area Page No

1 Quarry and lime stone crusher 4

2 Storage yard (Operation of stacker, reclaimer & side scrapper)

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3 Raw mill feed area, Raw mill, EP & conditioning tower 7

4 Labortories 9

5 Coal yard, Coal mill feed area, coal mill, storage of coal

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6 CF Silo, low bin, preheaters cyclones and precalciner 11

7 Kiln and cooler 12

8 Cement mill feed area, gypsum crusher 14

9 Cement mills 14

10 Packing plant 15

Acknowledgement

My greatest thanks to Allah Almighty. Allah who bestowed me with the ability and potential to complete this Internship. Before I go into thick of the things, I would like to add a few deepest words for the people who were part Tutmash Shafi Akhtar (SP07-BEC-85)Department Of Chemical Engineering, CIIT Lhr

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Internship Report 2010of this report in numerous ways… people who gave unending support right from the stage the report was assigned. Particularly I also wish to thank the

managerial staff at DG Cement who helped me to gain a lot of information regarding the company and cement industry and also who provide me an opportunity to learn and understand the working of organization as an internee. I am also thankful to Mr. Aleem (Trainee Engineer) and Mr.Umar Rehman (Trainee Engineer) who played a role of polar star for me in the organization and whose experience taught me a lot about the industry and the organization.And finally deepest and warmest appreciation to the whole team of DG Khan Cement Company

Executive Summary

Dera Ghazi Khan Cement Company Limited is a strategic business unit of Nishat Group, which is the largest industrial group in Pakistan. D.G. Khan Cement Co. is market leader with respect to market share with about 11.4% market share. Apart from its competitors; its product is high priced yet it has highest market share because of good quality. Its plant is situated in Dera Ghazi Khan and Khair Pur and head office is situated at Lahore. Factory site Unit 1and 2 that is situated in very remote area of Punjab, yet it proved a blessing for the company. Because it has all three basic raw materials i.e. Lime stone, Shale, and Gypsum at one place. It has three plants working two in D.G. khan and one in Khair Pur. First plant is old one and it is Japanese plant. The other two plants are of F.L.Smiths, Denmark. Presently it has a total Installed capacity of 14000 tpd(tons per day).Presently the company is also exporting the cement to Afghanistan, Iraq, UAE and Russia. The team of the D.G. Cement is story of success of D.G. Cement. The whole team is self-motivated and had played a vital role in the success of the company.

D.G. Khan Cement Company Ltd

Introduction

D.G. Khan Cement Company:

D.G. Khan Cement Company Limited (DGKCC), a unit of Nishat group, is the second largest

cement-manufacturing unit in Pakistan with a production capacity of 13,400 tons clinker per day. It


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Internship Report 2010has a countrywide distribution network and its products are preferred on

projects of national repute both locally and internationally due to the unparallel and

consistent quality. It is list on all the Stock Exchanges of Pakistan.

DGKCC was established under the management control of State Cement Corporation of Pakistan

Limited (SCCP) in 1978. DGKCC started its commercial production in April 1986 with 2000 tons

per day (TPD) clinker based on dry process technology. Plant & Machinery was supplied by UBE

Industries of Japan.

Expansion -Khairpur Project

The Group has also set up a new cement production line of 6,700 TPD clinker near Kalar Kahar,

Distt, Chakwal, the single largest production line in the country. First of its kind in cement industry

of Pakistan, the new plant have two strings of pre-heater towers, the advantage of twin strings lies

in the operational flexibility whereby production may be adjusted according to market conditions.

The project equipped with two vertical cement grinding mills. The cement grinding mills are first

vertical Mills in Pakistan. The new plant is not only increasing the capacity but also providing

proximity to the untapped market of Northern Punjab and NWFP besides making it more

convenient to export to Afghanistan from northern borders.

Power Generation

For continuous and smooth operations of the plant uninterrupted power supply is very crucial. The

company has its own power generation plant along with WAPDA supply. The installed generation

capacity is 23.84 MW.

Environmental Management

DG Khan Cement Co. Ltd., production processes are environment friendly and comply with the

World Bank’s environmental standards. It has been certified for “Environment Management

System” ISO 14001 by Quality Assurance Services, Australia. The company was also certified for

ISO-9002 (Quality Management System) in 1998. By achieving this landmark, DG Khan Cement

became the first and only cement factory in Pakistan certified for both ISO 9002 & ISO 14001...

Quarry:

Quarry is the place from where raw material in extracted. Drilling and blasting is done to extract

the material.A hole of about 10-15 m is drilled and ammonium nitrate in filled as an explosive in

these holes. When this explosive is ignited the rocks are broken into pieces of different sizes. These


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Internship Report 2010pieces sre then loaded on the dumper trucks and conveyod to the crusher. It is

located about 3-4 Km from the plant.

Quarry and raw materials:

The following raw material is required in the production process:

1. Lime stone: This raw material is company owned and is extracted from the

nearby quarry Unit. Limestone has the highest composition in the cement

product. 76% of the cement constitutes of limestone.

2. Clay: Clay is another natural resource. This raw material is also company

owned. 24% of cement composition comprises of clay

3. Iron Ore, Bauxites and silica sand: Iron Ore is the only resource that is bought from

contractors. Iron Ore, Bauxites and silica sand are added in small quantities less then one percent

and it helps to strengthen the cement.

4. Gypsum: Gypsum acts as a retarding agent. It slows down the hardening

process which in turn gives the constructor enough time to use it.

Proportions of different Raw Materials:

There are basically three main raw materials that are used for the production of cement.

In addition to that, a small proportion of other additives such as silica and Bauxites are also added.

1. Limestone 76%

2. Clay 24%

3. Iron ore (less than 1%)

4. Silica sand (less than 1%)

5. Bauxites (less than 1%)

Lime stone and clay are extracted from the same place. Iron ore is bought from a contractor.

Limestone Crusher: (EV 200*300) :

Capacity : 1500 tons/hr

Supplier : FLSmidth


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Internship Report 2010Description:

Raw material such as limestone, clay, marl and shale are dumped into hoppers by dump trucks and

entered into a hammer crusher through an apron feeder. Inside hammer crusher there are hammers

each having a weight of 100-102 kg. They rotate at a speed of 1200-1300 rpm and is capable of

crushing feed of very large sizes.

Bag Filter :

The dust produced by crushing process can

cause damage to the equipment and may

produce dust, to overcome this problem a

bag filter is employed. A fan blows air and

all the dust goes to the bag filter. Inside the

bag filter a special type of canvas cloth is

used. When air passes through this filter

cloth, the dust particles stick to the cloth

and clean air passes through. The dust

particles are then collected and sent to the

conveyor. After sometime when the filter

is choked with particles, Purging system is

used in which high pressure air is used, this air removes all particles from the filter

cloth.

Composition analyzer ;

A composition analyzer is installed upon the feed conveyor belt. This analyzer

detects the composition of the feed before it goes to the storage pile. The radioactive

material used id “Clifornium”. Its half life is 2.5 years and its price is 84,00000. This

element emits rays which pass

through the feed and are deflected back to the analyzer, which then checks the

composition. The composition of eacs material is specific.

Magnetic separator :


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Internship Report 2010A magnetic separator is installed on the feed belt. It attracts and removes

metal objects from the feed which are collected in the bin.

Storage Yard:

The crushed material is stored in the form of piles in the storage yard. There are 6

piles in the storage yard. Mixed piles are used in larger quantity where as high grade

and additive piles are used in small quantity.

2 Mixed piles (limestone & clay)

2 High grade (pure limestone)

Iron ore (additive)

Bauxite (additive)

Stacker :

A stacker is a device which form conical piles of the

crushed material. Feed is conveyod to the stacker through

conveyor belts. This stacker then moves too an fro to make

a pile. The stacker belt is called “Jib” in engineering terms.

Now, for conveying this material from piles to the

conveyor follweing equipment sre used :

Side scrapper

Reclaimer

Side scrapper :

Side scrapper is a device which picks the crushed feed from

the piles through its feed belt called “Hoist”. This belt has a

number of small buckets of low capacity. When this belt

moves, the buckets picks feed from the pile and put it on

the belt conveyor. Side scrapper in used for those piles

which are required in low quantity like bauxite and iron

ore.

Reclaimer :

Reclaimer is an equipment which is used to throw feed dowm from the pile. It has

two ams called “Harrows” These harrows are inserted into the pile, when they move

sideward, the feed drops down the pile. This feed in then collected by high capacity


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Internship Report 2010buckets installed in the bottom of the reclaimer. These buckets pick the feed

and put it on the the belt conveyor. It is a large capacity equipment and for those

piles which are required in high quantity like Mixed Pile.

Raw mill Feed area :

The raw mill feed area consists of 4 feed hoppers:

Mixed feed hopper

Pure limestone hopper

Bauxite hopper

Iron ore hopper

The capacity of first two hoppers is 800 tons

while the other two hoppers have a capacity of

600 tons. The feed from each pile is conveyed to

the hoppers through conveyor belts in relevant hoppers. Each hopper has 4 load cells.

Load Cells : These are sensing devices which tells the load being put on the hopper

by the feed.

From these hoppers, the feed in required proportions is transferred by the belt

conveyor to the Raw Mill. A lot of dust is produced during the conveying of material,

to avoid this problem Bag Filters are installed. A Magentic separator is also intalled

to reomove metal impurities.

Raw Mill:

Capacity: 500 tons/hr

Motor power : 4300 kw

Supplier : FLSmidth

Sections Of Raw Mill:

There are 3 sections of a raw mill.

Table with 3 rollers

Bottom scrapper

Separator

Table:


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Internship Report 2010The raw feed from the belt conveyor directly falls on the rotating table of the

raw mill. The table contains 3 crushing rollers. The raw fed is crushed to fine

powder with these rollers. The coarse particles are collected at the bottom of raw mill

and are sent to to the vibrator from where they are sent to to the raw feed belt

conveyor and again recycled to the ram mill for recrushing. The vibrator is use to

handle the quantity of the material being put on the belt.

Seperator :

At the top of the raw mill, there is separator section. Hot

gases from the kiln comes from the bottom of the raw mill

and lift very fine particles with it. A suction fan with motor

power of 4500 kw produces suction and sends dusty air into

the cyclones at the top. Here the dusty air rotates and

particles are separated from the air. These particles are

collected at the bottom of the cyclone and sent to the CF

silo with the help of air slides. The air which still contains

dust particles are separated in Conditioning tower and

Electrostatic precipitator.

Bottom separator:

Some fine particles from raw feed fall on the table, these particles are collected by

means of a bottom scrapper and sent to the CF silo.

Conditioning tower:

The air from the cyclones still contains the dust particles which must be separated

before the air is exhausted to the atmosphere. Air from the separator is passed

through conditioning tower. In conditioning tower, water is sprinkled through very

fine nozzles. The particles in the air get wet and settle down. These particles are then

conveyed to the CF silo via screw conveyor.

Electrostatic precipitator :

The clean air from the conditioning tower still contains some particles which have to

be removed. These particles are separated from air by passing it through the

Electrostatic precipitator.

In Electrostatic precipitator there are 2 corona wires which are mesh like. These wires

are negatively charged. There is a positively charged electrode in the centre which is

equidistant from


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Internship Report 2010both corona wires. Dusty air passes through these corona wires and the

particles get negatively charged. The negatively charged particles in air are then

attracted by the positively charged electrode and the particles stick with it and clean

air is exhausted from the chimney.

Cleaning of the electrostatic precipitator:

In order to remove particles from the electrode . A “Wrapping” device is used. This

device hits the electrode as a hammer and particles fall down from it. These particles

are collected and conveyod to the CF silo via screw conveyor.

Labortories :

There are different laboratories for the determination of quality and strength of the

cement. Different types of tests are conducted to determine different properties of the

product. Also different types of fuels are tested for their inherent properties: for

example:

Fineness of coal

Humidity level of coal

Calorific value of coal

Composition of feed material and product

Settling time of cement

Residual material

Following are the different labs avalible.


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Sample prepration lab:

In sample prepration lab, different samples of cement are prepared and tested. Raw

material in put in an equipment called “Swing mill”. A swing mill is a grinding mill.

This grinding mill has a special type of vessel in which material is ground to very

fine powder.

Press mill :

The ground material is put into a circular dye and placed into a press mill. The mill

exerts pressure on it and a rigid dye is produced which a metallic circular outer layer.

The press mill exerts a pressure of 150 KN on the dye to produce a sample.

X-ray analysis :

Now, the sample dye is put into an x-ray analysis machine to determine its

composition. Thesample is place for 2 mins in the machine. The x-ray machine is

controlled by a computer software. This software restricts the machine to determine

upto a limit of 6 to 8 elements. After 2 mins , the percentage of each element in a

particular sample is shown on the computer screen. The x-ray machine is very fast in

producing accurate results.

Chemical testing lab :

Chemical testing of a cement sample is done to determined its composition. It was a

slow and time consuming process, but nowdays x-ray analysis is used due to its speed

and accuracy.

In chemical testing lab inspite of x-ray analysis, samples are also tested by manual

experimentation.

For this purpose a distillation unit with a capacity of 25 litrers is used to get distilled

water for experimentation. If normal tap water is used, it may be hard,it can alter the

sample composition and may produce errorful results. Two muffle furnaces at 1200

°C and 1600 C° are used to determine the residual matter, volatile matter and

moisture content.

Physical testing lab :

In physical testing lab, physical tests of different cement samples are done to check

its properties.

Following are the equipment available is physical testing lab:


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Internship Report 2010 Weigh balance

Turbula mixer

Tensile strength machine

Water bath and curing tank

Compression testing machine

Motor mixer

Coal yard :

Coal yard is the area where coal is stored which is used for burning purposes. There

are different piles for the storage of local and imported coal. The coal is impoted

from South Arica, and Indonesia. The coal is handled by a loader, the loader picks up

the coal and throws on a sieved net which separates bigger pieces of coal and stones

form it, before it goes to the tunnel.

From the tunnels the coal is placed on the belt conveyor which takes it to the coal

mill feed area. Pet coke which is hard is also used in the coal feed.

Coal mill feed area :

After the impurities are removed from the coal, it is chuted on the belt conveyor .A

bag filter is employed which sucks the coal dust and thus prevents the coal from

being wasted. The coal is then shifted to the coal storage hopprs.

Coal storage hoppers :

There are 3 hoppers for the storage of coal. Two hoppers are for the storage of local

coal and the other is for the imported coal. All the three

hoppers have a capacity of 250 tons. The coal required

in different proportions are chuted on the belt conveyor

from the hoppers. A bag fiter is employed to remove

coal dust. A magnetic separator is employed to remove

metal impurities. This belt conveys the raw coal to the

raw coal mill.

Coal mill: ATOX 25

Specifications of coal mill :

Capacity : 52 ton/hr (coal mix)


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Internship Report 2010 26 ton/hr (pet coke)

Supplier : FLSmidth

Motor : 600 KW

Sections of a coal mill :

There are 3 sections of a coal mill similar to the raw mill.

(1) Table (2) Rollers (3) Bottom scrappers

The coal on the belt conveyor falls on the table of the mill where rollers grind it to a

fine powder. A blower of very high power pushes very fine particles towards the two

fine storage bins. From the 1st storage bin the coal is sent to the kiln for its use in the

burner and from 2nd storage bin it is sent to to the precalciner for calcinations.

CF Silo (continuous flow) :

The fine particles from the conditioning tower

and electrostatic precipitator and the powdered

feed from the raw mill are conveyed to the

bucket elevator. The bucket elevator picks this

feed and take it to the top of the CF silo and

then throws it in.

Specifications of a CF silo :

Length = 54 m Dia = 22.4 m Capacity =

25,500 tons

Air circulations :

After the feed is stored in the silo bin. Now for the movement of feed in the bin, air is

blown from the bottom through different points in CF silo. These points are located at

the base of the CF silo.

Due to air circulations, fine particles are sent to air slides

from where they are transferred to Low bin (Loss of

weight bin). The capacity of low bin is 118 tons. The feed

from the low bin is sent to a bucket elevator which lifts it

to the preheator.

Pre-heaters:

The bucket elevator puts the material on the top of of 2nd

cyclone. The hot gases from the kiln flow with very high

velocity in countercurrent direction. The hot gasses lift


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Internship Report 2010the particles from the particles from the top of 2nd cyclone and put it on the top

of the 1sr cyclone. From there the material falls on the top of the 3rd cyclone and

sends it into the 2nd cyclone. Then the material falls on the top of 4th cyclone and hot

gases take it into the 3rd cyclone.. then the material falls on the top of the 5th cyclone

and hot gases take it into the 4th cyclone and finally into the 5th cyclone preheater.

During this complete cycle, the hot gases foe in the countercurrent direction. Thses

cyclones serve the purpose of preheating the feed material with hot gases of kiln.

There are total 10 cyclone preheaters . 5 are on the right side of the precalciner and 5

on the left of the precalciner. The temperature of feed increases as the feed flows

downwards the preheaters.

Pre-calciner:

The feed from the 5th cyclone preheater falls into the

precalciner which has burner with a supply of coal and

furnace oil. Here the calcinations of feed material takes place

due to burning. Exchange of heat also takes place in the pre-

calciner. CO2 is evolved and exhausted in the atmosphere

and the feed is entered into the kiln riser at high temperature.

Some of the feed directly goes to the kiln without going to

the pre-calciner through separate pipes.

Kiln :

The preheated feed from the kin and the preheaters enter into

the kiln riser. From the kiln riser the feed enters into the kiln.

Specifications of the rotary kiln :

The rotary kiln has a length of 66 m and dia of 5.5 m.its inclination is 4 %.

Its rotating spped varies according to the quantity of feed entered. Around the inner

dia of the kiln there is refractory lining to prevent the shell from damage and to


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Internship Report 2010control the environment temperature. Outside the kiln there are induced draft

fans which turn on automatically when the shell temperature increase more then a

certain limit.

Kiln Motors:

There are two kiln bases on which motors are installed which impart rotary motion to

the kiln.

Kiln burner :

On the other end of the kiln , there is huge

burner having a supply of coal, furnace oil

and air. The burner emits a flame which is

prolonged with high pressure air. The

flame burn the material and the product is

formed.

Zones of a rotary kiln :

There are different zones in the rotary kiln

namely :

(1) Alex (2) Victor (3) Magkor.

Alex : In this zone, feed from the precalciner and preheaters enter into the

kiln.

Victor : It is the main reaction zone where the conversion takes place by

burning.

Magkor : In this section clinker formation takes place of the burned material

Sections of a rotary kiln

The ash due to the burning of coal also goes with the product which causes LSF

(limestone factor) to reduce from the required limit. That’s why the material which

enters the kiln has a higher %age of limestone because it is balanced with the ash of

coal. The hot gases from the kiln are not wasted but used in different equipment in


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Alex Victor Magkor

Internship Report 2010the plant.

Kiln hood:

The hot material form the kiln falls into the kiln hood at the end which has an angular

sieve. When material passes through it it attains the shape of clinker. Now this clinker

is sent to the cooler.

Clinker cooler :

The clinker cooler is used to lower the clinker temperature. There are ID fans which

take fresh air from the atmosphere and send it to the cooler. At the bottom of the

cooler there are reciprocating rails which move with the help of hydraulic motors.

These rails convey the clinker forward to the clinker crusher.

Dust collection :

A suction fan is installed which sucks the product dust from the cooler and send it to

the electrostatic precipitator. In EP dust is removed and clean air is exhausted to the

atmosphere through a chimney. The dust particles are to the deep pan conveyor by a

screw conveyor.

Clinker crusher :

When the clinker cools and hardens then it is sent to the clinker crusher installed after

the cooler. Big stones of clinker are crushed to small pieces. The crushed clinker is

dropped on the deep pan conveyor at the bottom of the conveyor which conveys it to

the clinker storage.


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Internship Report 2010Clinker storage :

The clinker from the deep pan conveyor is stored in the

clinker storage. Its capacity is 110,000 tons. Its length is

60 m and its width is 46 m. There are 3 gates at the

bottom of the clinker storage from where the clinker is

sent to cement mill through belt conveyor. Besides the

main clinker storage bin, there is a temporary clinker

storage hopper with a capacity of 1400 tons. If the

temporay hopper is also full then the clinker is removed

from the hopper and dumped into clinker storage yard.

Cement mill feed area :

There are 2 cement mills and 6 hoppers (3 for each mill) in the cement mill feed area.

The 1st hopper contains the clinker which is major constituent of the cement. The

cement contains 95 % clinker which is conveyed through weigh feeder to the main

belt conveyor which takes it to the cement mill.

Gypsum addition :

The crushed gypsum from a separate crusher is conveyed by belt conveyor to the

cement mill. It is mixed in the clinker while crushing. Gypsum is added to about 4 – 5

%. Its purpose is to increase the settling time of the cement.

Mixing of additive :

The additive which is pure limestone is also added in the cement mill. Its added to

about 2 %. Its function is to increase strength of cement.

A bag filter collects dust from the main belt and a magnetic separator remove

metallic impurities from entering into the cement mill.

Metal detector ;

To protect the cement mills from damage, a metal detector is installed which analyzes

the feed and if a metal object is found it opens the dividend gate automatically and

sends the feed containing metal objects to the rejected bin, which is again recycled to

the main belt and magnetic seperatoe removes it.


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Internship Report 2010Cement Mills :

Cement mills specifications OK 36-4 :

Capacity : 175 ton/hr

Motor power : 3400 kw

Supplier : FLSmidth

The feed which is free from impurities falls on the

table of cement mill which contains three rollers.

Each roller has weight of 35 tons and the clearance

between table and rollers is 0.5 mm. These rollers

move hydraulically using nitrogen gas as hydraulic

fluid. The rollers crush the feed to a very fine powder.

The air slides conveys the ground product to the

bucket elevator which lifts it to enter into the 1st

storage silo.

Storage silos :

Specifications of storage silos :

Capacity : 21,000 tons

Length : 45 m

Dia : 22.4 m

There are 3 cement storage silos in which crushed

cement is stored uptill packing.. To convey the cement

to the other 2 silos air slides are used. From these silos

the cement enters air slides by air circulations through

blowers. Now these air slides take the cement to the

packing plant.


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Schematic view of silo. The old cement was blocking the air slides as well as bridging preventing the flow of cement from the silo. Sockets installed above discharge gates and lower air slides proved the ideal solution to blocking of silo and can be used whenever there is build-ups.

Packing Plant :

The packing plant comprises of 6 packers and 12

terminals. Each packer has a capacity of 100 tons/hr.

The cement bags are attached manually to the rotating

packer which fills the cement bag. When the bag is

filled upto the required weight , it automatically falls

on the conveyor balt which takes the bags to the roller

conveyor. From these rollers the bags slide to

different channels and finally cement bags are loadsed

on the trucks fro dispatch.


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Refrences :

www.sick.com/.../cement/Pages/cement.aspx

www.siamrefractory.com/cement_cyclone.php

www.freepatentsonline.com

www.freepatentsonline.com

www.lwbref.de/en/markets/cement-lime-industry/

Prepared By :

Tutmash Shafi Akhtar

Chemical Engineering,CIIT Lahore

Batch-4

Section-A


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http://www.lwbref.de/en/markets/cement-lime-industry/

http://www.freepatentsonline.com/

http://www.freepatentsonline.com/6875015.html

http://www.siamrefractory.com/cement_cyclone.php

http://www.sick.com/group/EN/home/solutions/industries/cement/Pages/cement.aspx

Documents

Internship Report DG Cement Khairpur