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Caesars "F"
A HeadStarter in Lafarge
Cement Egypt
By/MohamedReda
Chemical engineer

Summary
This document concerns with the importance of health and safety in any
organization, and ways that could be helpful in improving health and safety rules
implementation in Lafarge Cement Egypt (LCE). Beside this I will explain and talk
about Pyro-processing (mechanical part), cement production and plant operation,
how is any cement plant can be created based on presence of raw materials quarries
such as limestone and clay, and finally the quality role in LCE starting from the
extraction of the raw material till delivering the finalized product (packaged product).

Contents
Summary........................................................................................................................ 2
1. introduction................................................................................................................. 5
2. Health and safety.......................................................................................................... 6
2.1. Safety Improvementin LCE..................................................................................... 6
3.Quarry .......................................................................................................................... 9
3.1. Quarry types, and reserves ..................................................................................... 9
3.1.1 Quarry types.....................................................................................................9
3.1.2. Types of reserves ........................................................................................... 10
3.2 Limestone Quarry planning.................................................................................... 11
3.2.1 Block model.................................................................................................... 11
3.3 material extraction, crushing, and storage.............................................................. 12
3.3.1 material extraction.......................................................................................... 12
3.3.2. material crushing........................................................................................... 13
3.3.3. material storage............................................................................................. 13
4.Pyro-processing (mechanical part)................................................................................ 14
4.1 Raw milling or raw grinding.................................................................................... 14
4.1.2 Main components of ball mill........................................................................... 14
4.2.1. the dynamic separator.................................................................................... 15
4.2.2 Multi cyclonic stage......................................................................................... 15
4.2.3 The EP filter.................................................................................................... 16
4.3. Storage of the raw mix.......................................................................................... 16
4.5 The rotary kiln....................................................................................................... 16
4.5.1 mechanical design of the rotary kiln................................................................. 16
4.5.2 Mechanical operation of the kiln...................................................................... 17
4.6 the cooler............................................................................................................. 17
4.6.1. mechanical components of the cooler............................................................ 17
4.6.2. cooler mechanical operation and dedusting system......................................... 17
4.7 Auxiliary equipment .............................................................................................. 18
4.7.1 types of auxiliary equipment in LCE.................................................................. 18
5. Pyroprocessing (Operation)......................................................................................... 20
5.1. Raw material grinding stage.................................................................................. 20
5.2. Preheater, rotarykiln, and the cooler .................................................................... 21
5.2.1. Calcination process ........................................................................................ 21

5.2.2. Chemical reaction inside the preheater and the rotary kiln............................... 22
5.2.3. cooler function............................................................................................... 24
5.2.4. Kiln zones and refractory................................................................................ 25
5.3. Fuel preparation and operation............................................................................. 25
5.3.1. HFO preparation ............................................................................................ 26
5.3.2. Petcoke preparation....................................................................................... 26
6. Quality in LCE.............................................................................................................. 27
6.1. the difference between quality control and quality assurance................................. 27
6.2. main parameters checked at each step of the manufacturing process..................... 27
6.3. The major customers of LCE.................................................................................. 29
7. References ................................................................................................................. 30

1. introduction
 What is LafargeHolcim ?
LafargeHolcim is considered to be the leading manufacturer of building material all
over the world.
It is a result of a merger between the top two companies in building materials in the
world Lafarge and Holcim.
Recently this company has a total production capacity of cement reaches to 365.5
million ton/ year and a total number of 115,000 employee.
In this report we will concern about cement production in Lafarge Cement Egypt
(LCE).
 What is the cement ?
Cement is considered to be the main leap or jump in the world of bounding materials
together specifically in building. Without cement we wouldn't never see the high
towers, landscapes, tunnels, bridges, underwater tunnels…..etc.
Cement was first discovered in the isle of Portland when lava was exposed to a
stream of running water and found to be solidified for no reason. By analysis and
research at this time it was found that materials composing the lava reacts with water
to produce a very hard material that called Portland cement later. After that engineers
and chemists worked in developing a specific manner for production of cement so it
can be used in building.
Cement production depends mainly on the availability of limestone which represent
about 70:75 % from the raw materials used, the remaining percentage is represented
in clay. This mix produces clinker which can't be directly used as a finished product
due to its very low setting time. Gypsum is added to clinker to adjust its setting time,
and some other additives are used according to the final usage of cement.
Limestone in nature is present in form of mountains that form a quarry patch can be
used in cement industry for a specific period of time. Cement plants can't be created
unless geologists find a convenient quarry can be used for a long time with good
material composition.

2. Healthand safety
Health and safety law is a body that protects a certain group of people in any
organization from being harmed by any of surrounding conditions. It consists of a
combination of some rules that should be implemented to avoid unsafe actions or
unsafe conditions.
No doubt that health and safety should be the first priority for any company, and in
LafargeHolcim it is already.
2.1. Safety Improvement in LCE
Improving safety in LCE isn't about creating new rules or new laws, but it is about
how to make it better to be implemented.
Most of our problems with respect to safety side in LCE is that most of people have a
kind of carelessness towards implementing the safety rules, enhance or eliminate the
unsafe conditions, and taking disciplinary actions towards unsafe acts. So, I'm going
to suggest some solutions for these problems to be avoided in LCE.
 First let's clarify what can the carelessness about safety lead to :
1- harming people which are in contact with the plant.
2- damaging or failure of any equipment.
3- increasing cost required for medical expenses, or repairing the equipment.
4- losing time (each second is a treasure could be lost forever).
 Types of injuries in LCE
1- First aid injury
Injury that can be can be overcome by first aid.
2- Lost time injury (LTI)
In which the injured person can't continue doing his work, and a recovery period is
needed.
3- Fatality
Injures which lead to death.
So, by taking in consideration the previous points, we find that it is very important to
implement all of health and safety rules.
 How to make it better to be implemented?
We can make Lafarge a better plant with zero tolerance in safety side by :
1- giving all workers in Lafarge safety sessions to;
- clarify the safety importance.

clarify what would happen if we don't respect safety rules.
- prevent un safe acts
2- weekly assessment for each employee with respect to safety side.
3- working on improving and eliminating all of unsafe conditions.
4- providing continuous supervising for each job to be done.
5- providing surveillance cameras covering all areas in the plant so that each
employee would know he is being supervised all the time so that he wouldn't act
unsafely.
 What is meant by unsafe condition, or unsafe act?
- Unsafe condition is defined as any condition that could cause any damage for the
equipment or could harm/injure persons.
- Unsafe action is defined as the act is provided by persons leading to any injury or
damage of the equipment.
 Examples of unsafe condition in LCE and how to overcome it
The unsafe condition Hazard type, how to overcome it?
- these wires can be uncovered so, it can
cause electrical shock
- they can make any to tumble causing an
injury.
 We can overcome this by fixing a
guard on each wire, or by digging
and make them underground.
- this is very steep cliff that can cause an
accident for any moving equipment
 We can overcome this by putting a
warning sign, or by filling it
- all of these unsafe conditions can cause
any one to tumble and fall down leading to
an injury
 We can overcome this by
continuous housekeeping of the
plant

This side of unsafe conditions can lead to many incidents that can ham people and
make time to be lost.
So, by taking in our consideration the straight implementation of health and safety
rules, LCE will become a better plant.

3.Quarry
When we come to quarry we find it the main parameter affecting the cement plant
existence.
Limestone quarry is that most important quarry to be studied and the all plant design
calculations are based on its position, type, composition, purity, and the ease of
getting a license to start working in that quarry.
3.1. Quarry types, and reserves
3.1.1 Quarrytypes
When we get to quarry types we are talking about four types:
1- limestone quarries.
Limestone (CaCO3) is the main raw material used in production of clinker, it
represents about 75 % of the raw mix introduced to the raw mill. But limestone itself
isn't the main reactant in clinkeriztion reaction, the main reactant is calcium oxide
(CaO). So, limestone is first calcinated to get rid of Carbon dioxide (CO2).
The variation in chemical composition in the limestone quarry isn't sensible to that
degree as the limestone is very inert material.
Fig (1) : Limestone quarry in LCE
2- Clay quarries.
- clay is a mixture of Al2O3, SiO2, Fe2O3
- The material is said to be clay if it contains alumina (Al2O3) in a percentage equals
to or above 12 %.
- Clay represents about 20 % of the raw mix introduced to the raw mill, and the
remaining 5 % of the raw mix can be correctives.

There is many types of clay :
3- sand quarries.
Sand quarry contains material reach in silica with a percentage can reaches to 95 %.
4- Gypsum quarries.
Quarries contain the material of hydrated calcium sulfate (CaSO4.2H2O) in high
grades.
3.1.2. Typesofreserves
Reserve is defined as the amount of raw material that can be convenient for usage in
production and can be reachable.

3.2 Limestone Quarry planning
Cement plants are constructed near to limestone quarries to reduce raw material
transportation cost. So, the quarry is first well studied and analyzed going though
many steps:
1- exploration of the quarry thought taking many surface samples to get a primary
indication for the material composition.
2- applying disk study through creating pore holes to get exact chemical
compositions for the material
3- overall investigation is carried out if the quarry accepted to get the block model.
Fig (2) : Block diagram of exploration of limestone quarries
3.2.1 Blockmodel
Block model is created for any limestone quarry by a software (Surpac software in
LCE) to get an estimated values of the chemical composition at any point of the
quarry.
To create a block model we have to introduce 4 sheets to the software used to get
very near composition to the actual chemical composition.
These four sheets are divided by
sequence into :
1- lab analysis sheet
Lab analysis sheet is obtained through
making pore holes in different places.
The distance between each hole and
another one ranges between 200:300
m. Each pore hole is taken as all
column to be analyzed geologically and
chemically.
The pore hole is first divided into trailing
sections according to their positions by
extractions, and the whole sections are
placed in a box called sample box to be
analyzed.
2- survey sheet
To get an accurate block model we, the
survey team is getting the each pile

height from the surface.
3- coordination sheet
In this sheet we introduce all coordination for each pile to get a very accurate
estimation for each pile and its chemical composition.
4- orientation sheet
All quarries are composed of layers
over each other. Layers in some
quarries are present in inclined
position so, the pore hole being
taken can be in inclined position
with respect to the layers. But the
quarry layers in LCE are being in parallel position not inclined position.
By introducing all these sheets to the Surpac system we can obtain the block model.
3.3 material extraction, crushing, and storage
3.3.1 material extraction
By planning the quarry and creating the block
model, we need to extract the raw material and
introduce to the production line. The extraction of
the raw material carried out on weekly plan by
drilling and blasting the quarry.
Drilling is carried out to plant explosive materials
to apply blasting process to get high amounts of
raw material introduced to production line starting
from the jaw crushers.
- The blasting process starts with drilling a deep pore hole to plant the explosion
capsules which has two wires to be attached to –ve and +ve poles of the explosion
device.
- the drilling is carried out in a manner gives a pore hole inclined with angle 100
:150
.
This inclined angle is created to avoid formation of any caves or leaving hanging
rocks that could fall above the equipments during loading after the blasting is carried
out.
- we apply sub drill to ensure
the explosion of the level toe.
 Drilling and blasting
plan
1- planning work: weekly plan is carried out to determine the dimensions and
positions of the blasting process.

2- survey work: in which the survey team determines coordinates, dimensions,
positions in the site according the weekly plan.
3- drilling work: drilling teams start to create pore holes with specified conditions
(depth and inclined angle) to put the explosive materials.
4- checking work: the formed pore holes are checked if they are identical to applying
the blasting process or not.
5- blasting work: after checking the pore holes and capsules blasting work is carried
out with specific timing to avoid to blasting in the same time to avoid any huge
vibrating wave that could affect the work and site badly.
6- the exploded material is loaded finally and transported to the crushers.
3.3.2. material crushing
Material is extracted in large blocks can't be used directly in cement production so, its
size is reduced to an optimum size. First material is crushed through two stages of
crushing, the first stage is carried out using the jaw crusher, and the second stage is
carried out using the impact crusher. The impact crusher isn't used for crushing
limestone only, but it is only used to crush the clay materials and mixing it with the
limestone in a first stage of mixing to be ready to stored.
3.3.3. material storage
Material from crushers is stored either in a circular storage of a longitude storage.
Circular storage is used in storing the raw mix (limestone + clay) in a specific manner
as layers over each other by using a stacker so, while reclaiming the raw mix using
the reclaimer we can insure homogenous material introduced to the raw mill.
Longitude storage is used to store three types of materials, high grade limestone (in
this case, the crushers are used to crush limestone only), Iron ore, and sand.

4.Pyro-processing (mechanical part)
4.1 Raw milling or raw grinding
Materials in large particles can't be used in clinkeriztion reaction so, these particles
have to be reduced in size to get fine particles which have high specific surface area
that contributes in increasing the rate of chemical reaction.
The size reduction can be applied by many techniques depending on, inlet and outlet
required flowrate, feed or raw mix particle size, required size of the final product from
milling stage, the inlet and outlet temperatures, moisture content in the feed (raw
mix), size of the equipment to be used, operating cost, and maintenance of the
equipment.
In LCE the mill used is an air swept horizontal ball mill.
4.1.2 Maincomponentsofball mill
4.1.2.1 External components ofball mill
The ball mill in Pyro section composed
externally of :
1- mill shell
2- driving motor with a power of 4.9 mega watt.
3- gear box which is coupled with the motor to provide the rotating motion to the ball
mill. Gear box is used to reduce speed obtained from the motor to the optimum
speed required to drive the mill.
4- girth gear fixed on the mill from the outside and meshed with the gear box to get
the rotating motion (13.6 rpm).

5- two slide shoe bearings one is fixed at the drive end, and free one at the another
end to allow thermal expansion.
4.1.2.2.Internal components ofballmill
The ball mill internally is divided into two chambers:
- the first chamber is drying chamber
- the second chamber (grinding chamber) contains the
grinding media
Internally, ball mill is composed of:
1- ball mill liners which are used to protect the mill shell from any cracks.
2- grinding medium (in the second chamber) which is represented in a ball charge
with various sizes range from 90mm to 30 mm in diameter.
3- internal diaphragm used to:
- prevent passage of ball charge from the grinding
chamber to the drying chamber.
- regulate the flowrate of raw mix from drying chamber
to the grinding chamber.
- regulate the flow of air used to transport material by
suction.
- prevent the passage of large particles of the raw mix
from the drying to the grinding chamber.
4.2.1. the dynamicseparator
The dynamic separator in the Pyro section consists of :
1- Rotor cage that rotates in a variable speed depends
on the required size of the raw mix.
2- cyclonic body that contains the rotor cage and allow the coarse material to be
returned to the ball mill through it.
By operating the rotor cage in the required speed :
- the air and the raw material passes through the inlet duct,
the fine material with air can pass through the cage due their
high kinetic energy.
- the coarse material can't pass and colloid with cage to
settle down to the recycle duct and introduced to mill again.
4.2.2 Multi cyclonicstage
It consists of four cyclones used in separating the fine
material from super fine material. The fine and super fine

materials are mixed with air. So by separating the fine material first in the multi
cyclonic stage, it can be easy to separate the super fine material then in the EP filter.
4.2.3 TheEP filter
The EP filter is used to purify the dirty air
(dedusting the air stream) from super fine
materials so it can be directed to the main stack
and released as a clean air not affecting the
environment. We have to get rid of this air to
avoid build up inside the system which leads to
line failure. by leaving the EP filter, the
separating process is said to be done, and then
we head to material storage.
4.3. Storage of the raw mix
The raw mix is stored in a large silo to many purposes :
1- to provide a continuous feed to the preheater and the
kiln in case of raw mill stopped.
2- material obtained from the raw milling process doesn't
have the same chemical composition so, there is a
spider unit locates above the silo used in
homogenization process to get the maximum quality of
the raw mix that introduced to the rotary kiln.
4.5 The rotary kiln
The rotary kiln is considered to be the main
equipment in the whole Pyro processing
stage.
Inside the kiln, formation of clinker take place
through a series of chemical reactions.
4.5.1 mechanical designofthe rotarykiln
Main components of the kiln :
1- kiln shell which is a cylindrical body made of a specific type of steel that can
withstand the high temperatures. The kiln body
has a length of 74m with a slope of 3.5 %. That
slope contributes in facilitating the materials
exit.
2- a single girth gear fixed on the outer surface
of the kiln.
3- three tires that are used to support the kiln,
each tire is supported on two rollers, each roller
is supported on two slide shoe bearings.

4- kiln from inside is lined with firebricks to protect the inside kiln from high
temperature evaluated as a result of burning materials.
5- inlet and outlet seals that prevent material from leakage and escape.
4.5.2 Mechanical operationofthekiln
- The kiln is drived by a motor with a power of 950 kw. This motor is coupled with a
gear box which is meshed with the girth gear of the kiln.
- The kiln runs on a speed of 4.5 rpm to allow a good contact of the material with the
flame, and provide a good time that should be proper for getting the clinkerzed
material.
- The girth gear of the kiln connected to a lubricant system that is used to reduce
friction and wearing with time.
- Each shoe bearing in the kiln area is connected to a hydraulic oil system, to prevent
it from failure.
- Clinker from the kiln in introduced to the cooler to get the maximum utility of the
contained heat and to make it
suitable for storage.
4.6 the cooler
In LCE the cooler type used is
the grate cooler.
4.6.1. mechanical
componentsofthe cooler
1- three levels of perforated
grates.
2- about 14 blower fan used to
get an ambient in high
amounts to introduce it inside the cooler.
3- each grate consists of a number of perforated plates.
4- hummer crusher at the end of the cooler to crush large particles.
5- receiving (dust) hopper downside the cooler to store the fine material obtained
through the perforated plates and introduce it to the apron conveyor.
4.6.2. coolermechanical operationanddedustingsystem
- each grate level in the cooler is supported on two hydraulic piston pumps that
causes a reciprocating motion inside the cooler.
- when liquid material passes over the perforated plates, the ambient air causes it to
solidify into large solid particles and fine dust.

large particles are transported to the hummer crusher to be crushed into the
required size for the storage, and the fine particles goes through the perforated
plates to the dust hoppers.
- dedusting is carried out to prevent air building up inside the cooler leading to
system failure.
4.7 Auxiliary equipment
Choosing the transportation method depends mainly on many parameters that
should be taken in our consideration such as :
1- Material type that will be transported.
2- The amount of material to be transported (material flowrate).
3- The inlet and outlet temperature.
4- The distance of transportation.
5- The particles' size of the material to be handled.
6- the equipment cost to be used in transportation.
7- the size of equipment to be used.
By determining all of these criteria we can choose a transportation equipment can be
proper with our industry.
4.7.1 types ofauxiliaryequipmentinLCE
Fig.Mechanical
components
Equipment
1- Endless loop of a
rubber belt.
2- Steel rollers that carry
the belt.
3- Steel guard fixed on
the belt to protect
conveyed material from
the environment.
Belt conveyor
1- steel case divided into
two chambers.
2- Fabric clothe
separating between the
two chambers.
3- A blower fan for the
purpose of aeration.
Air slide

1- Casing steel tube.
2- Helical screw.
3- Steel shaft to fix the
screw on.
4- Drive motor coupled
with a gear box to
provide the rotating
motion.
Screw conveyor
1- steel belt divided into
many pans attached
together.
2- drive station to provide
the required motion.
3- Roller guide-rails in
the curve area.
4- Sprockets with double
tooth pitch meshing with
the sprocket
teeth only
Pan conveyor
The apron conveyor has
almost the same
components of the pan
conveyor, but with small
pan type.
Apron conveyor
1- Vertical huge pressure
vessel made of steel.
2- Aeration pad at the
bottom.
3- Air nozzles passing
through the air pad.
4- Rising pipe.
5- Feeding tube.
Air lifter

5. Pyroprocessing (Operation)
In Pyro processing, the raw mix (limestone, clay, and correctives) in large particles is
introduced to the raw mill. The raw mill used to get fine particles of raw mix which can
be used in the kiln to produce clinker which is the main component of the finished
cement product.
The raw mix is calcined to get rid of carbon dioxide, then it is introduced to the rotary
kiln to be heated and at a very high temperature to get the clinker in a endothermic
chemical reaction.
Clinker from rotary kiln passed through the cooler to utilize the heat content of clinker
and make it suitable for storage.
So, Pyro processing starts from size reduction process (raw milling) and ends by
storing the clinker in circular storage units.
5.1. Raw material grinding stage
Raw material obtained from quarry storages in large particles. These large particles
can't be used directly in cement production as the cement production depends mainly
on producing the clinker, and the clinker is obtained through a series of chemical
reactions takes place in the rotary kiln. To make that chemical reaction takes place
with a high rate, the raw material used should be in fine particles to increase its
specific surface area.
To get the desired size of the raw material it has to be grinded in the ball mill.
Grinding is carried out using the ball charge inside the mill. While the raw material is
introduced to mill inlet, the is rotating with a specific speed to get the desired size.
The speed in which the mill is rotating with is less than the mill critical speed.
Critical speed is defined as the speed at which no grinding of material takes place as
the ball charge, and the material became sticky to the mill liners from inside.
The ball mill is composed of two chambers :
1- drying chamber
It's the first chamber in the ball mill, contains no ball charge, it is used to get rid of
moisture present in the raw material. This drying process is carried out to insure good
grinding of the material, and to lose the thermal energy later used in the preheater to
get rid of over moisture present in the material.
2- grinding chamber

Ball charge with size ranges from 90 : 30 mm is present in this chamber.
By getting rid of the moisture, material progresses to the grinding chamber. As the
mill is being operated, material flows axially inside the mill to be crushed and grinded
to the optimum size.
The flow inside the mill takes place under suction by using the raw mill fan (3.2
M.W.). This fan is providing a negative pressure of an air stream inside the mill
system to allow material to flow through mill, and separators heading to the air lift
(Aeropol) to be delivered to the storage unit (homogenization silo).
As there is no process can being carried out in a 100 % of completion, the outlet
stream of the mill contains 3 types of material:
- Suction air - Fine material - Coarse material
So, we need to separate these materials from each other.
The separation of fine from coarse is carried out inside the dynamic separator. The
reject from the dynamic separator is recycled back to the ball mill to be regrinded,
and the fine material with air progresses towards the mutli-cyclonic stage.
By separating the coarse from fine, and air from fine, there is very fine material
remains with the air stream. This super fine material need to be separated from air
for two purposes :
1- To purify air from any contamination so it can be introduced to the main stack and
evoluted to the atmospheric air.
2- to recycle all material in the process to reduce losses of materials.
By applying all of these separation processes, air passes through the main stack,
and the material collected inside the Aeropol to be lifted to the storage unit.
5.2. Preheater, rotary kiln, and the cooler
Limestone is considered to be one of the most inert compounds can't be used in a
chemical reaction. So, to get the required clinker limestone must be calcined at first
to get rid of contained carbon dioxide.
This calcination reaction carried out in the preheater.
5.2.1. Calcinationprocess
1- An airlift (Poldose) takes the raw material from the silo in specific amounts to
deliver it to the preheater tower.
2- the raw mix progresses first through the riser duct of cyclones 5A & 5B.

3- hot air from tertiary duct, kiln, and the precalciner flows counter current to the
material, progresses through the all riser ducts in the preheater.
4- the hot air is mixed with the raw mix in the riser duct, taking the material in co-
current flow towards the
cyclone to be separated from
each other.
5- while the material and air
are being mixed in the riser
duct, heat transfer takes place
between them leading the
material to be heated to a
higher temperature, and
making air cool down to a
lower temperature.
6- precalciner is present
between cyclone 1 & 2.
7- along the preheater tower, by direct contact between hot air and the raw mix
calcination of material occurs by 95 % in the all of preheater stages.
By calcination of material, it progresses towards the rotary kiln so the chemical
reaction can occur to produce the clinker.
5.2.2. Chemical reaction insidethepreheaterandthe rotarykiln
Reaction heat
(exothermic/endothermic)
Type of reactionTemperature Range (0
C)
EndothermicEvaporation of free water
(moisture) → Preheater
20 – 100
EndothermicDehydration → Preheater100 – 400
EndothermicDecomposition of
carbonates → 95 % in the
preheater
400 – 900
EndothermicBurning (Belite
formation)→Kiln
900 – 1250
EndothermicClinkering (Alite
formation)→Kiln
1250 – 1450
ExothermicQuenching (phase change
from liquid to solid
crystals)→Kiln
1450 – 1200

When it comes to clinker production we can talk about many types of reactions
divided according their thermal ranges and the type of reaction.
- these reactions start to occur in the preheater, passing through the kiln to the
cooler.
- theses reactions are divided into (according to Temperature ranges):-
Stage (1) : 20 - 100 0
C
- evaporation of free water (moisture) in the raw mix, takes place in cyclones 5A, and
5B.
- it is an endothermic reaction.
Stage (2) : 100 – 400 0
C
- dehydration reaction.
- in this reaction we get rid of combined water in the raw material (crystallization
water).
- it is an endothermic reaction takes place in cyclones 3 & 4
2SiO2.Al2O3.2H2O → 2SiO2.Al2O3 + 2H2O
Stage (3) : 400 – 900 0
C
- in this range we have two types of decomposition reactions at two different
temperatures (at 650 0
C & 900 0
C).
- at 650 0
C decomposition of magnesium carbonate to magnesium oxide
(magnesia) and carbon dioxide takes place which is an endothermic reaction.
- takes place in cyclone 2
MgCO3 → MgO + CO2
- at 900 0C decomposition of calcium carbonate (limestone) to calcium carbonate
and carbon dioxide takes place, which is an endothermic reaction.
- takes place in cyclone 1
CaCO3 → CaO + CO2 (calcination reaction)
Stage (4) : 900 – 1250 0
C
- in this range free lime reacts with silica to form belite. Also the fluxing agents are
formed (C3A, and C4AF), "C" refers to CaO, "A" refers to Al2O3, and "F" refers to
Fe2O3.
2CaO + SiO2 → 2CaO.SiO2 "C2S or Belite"
- it is an endothermic reaction takes place in the kiln

Stage (5) : 1250-1450 0
C
- the formed Belite start to react with the free lime to form the Alite compound in the
presence of the fluxing agents.
- it is an endothermic reaction takes place in the kiln.
C2S + CaO → C3S "Alite"
Stage (6) : 1450 – 1200 0
C
- in this range we can't call it a reaction, but it is a phase change.
- in this range the formed belite and Alite start to change from liquid phase to solid
phase and crystallization takes place in the presence of the ambient air used to reach
this state and to get the final clinker which can be used as a cement product.
- this phase change is accompanied with heat libration which acts as an exothermic
change takes place in the cooler.
5.2.3. coolerfunction
The cooler is used for Quenching of liquid material obtained from the kiln.
2- the air used in the quenching process is heated to higher temperature so, it can be
used in preheater (tertiary air), and in the kiln (secondary
air).
 Cooler operation
- each grate level in the cooler is supported on two
hydraulic piston pumps that causes a reciprocating motion
inside the cooler.
- when liquid material passes over the perforated plates,
the ambient air causes it to solidify into large solid particles and fine dust.
- large particles are transported to the hummer
crusher to be crushed into the required size for the
storage, and the fine particles goes through the
perforated plates to the dust hoppers.
- that huge amount of air progresses through the
cooler is being heated to a high temperature by
heat transfer from hot clinker to the ambient air.
This amount of air is divided into three streams:
1- secondary air stream which is recycled back to
the kiln.
2- tertiary air stream which is introduced to the
tertiary air duct and progresses to the preheater.

3- heavy dusted air (waste air) stream which is reach with super fine clinkerized
material. This stream is introduced to an EP filter to get rid of unwanted air and
recycle the fine material.
5.2.4. Kilnzonesandrefractory
While the material is flowing along the kiln, chemical reactions occur on stages.
These stages can divide the kiln from inside into 6 zones
- Safety zone is defined as the zone that is exist to insure the complete calcination of
material, and getting rid of contained sulfur and chlorine.
- the kiln from inside has to be lined with a material for purposes of protection from
inside of the shell, avoid overheating of the kiln body, and to save thermal energy
from being wasted with no use. So, refractory materials are used for this purpose.
 Refractory
Each zone inside the rotary kiln is lined with a specific type of a refractory depending
on many parameters control this selection :
1- temperature ranges at this zone.
2- material type present in this zone (Liquid or Solid).
3- Probability of coating at this zone.
4- chemical resistance and mechanical strength needed at this zone.
- for calcination, safety, upper, lower, cooling zones we need a material has high
mechanical strength, high chemical resistance, and low coatability tendency.
- for burning we need a material has high coatability tendency.
So, selection of lining material will depend upon temperature ranges at the zone.
- for cooling and safety zones alumina bricks are used.
- Spinel bricks are used in upper and lower transition zones.
- Dolomite bricks are used in the burning zone.
5.3. Fuel preparation and operation

Fuel is defined as the any material used for combustion to get a thermal energy can
be used in any purpose. Fuel can be liquid, solid, or gas.
Fuel is also divided according to heat value, moisture content, and impurities into :
1- high grade fuel
2- low grade fuel
HFO, Petcoke, and natural gas are classified as high grade fuel while the AFR is
classified as low grade fuel.
5.3.1. HFO preparation
- the HFO is stored in two main tanks each one has a capacity of 5000 ton.
- each line has its own daily tank with a total capacity 500 ton.
- the consumption of the HFO in LCE is about 20 ton/hr (8 tons/hr in the main burner
+ 12 tons/hr in the precalciner).
- thermal preparation of the HFO is carried out in the main tank by using a thermal oil
heated in a boiler. This thermal preparation in the main tank is carried out to make
the HFO to be transported inside pipe lines heading to the main burner.
- another step of heating is carried out by the thermal oil in a heat exchanger to make
the HFO easy to be burned.
5.3.2. Petcokepreparation
- Pet-coke is the petroleum coke which is the heaviest product result from the
fractional distillation of the petroleum oil.
- It became the main fuel resource used in Lafarge.
- It is obtained in large particles so, it must be grinded first.
- The grinded Petcoke is then delivered to a buffer silo to be stored.
- The buffer silo has two spouts outlet one of them is blocked and two screw pumps
are used instead of it and the other one still present in as a standby in case of any
unexpected conditions.
- The buffer silo delivers the grinded Petcoke to both of the calciner and the main
burner.
- Each calciner and main burner has its own storing silo for the Petcoke.
- In case of firing start stage, Petcoke can’t be used as it takes it is difficult to be
combusted so, HFO is used in start firing.

6. Quality in LCE
Quality is considered to be the main element that affects any company's reputation.
Quality has many definitions, one of them is meeting the customers' needs.
6.1. the
difference
between
quality control
and quality
assurance
6.2. main parameters checked at each step of the manufacturing
process
- All of the following parameters are considered to be a quality control process.
Manufacturing
Step
Quality Parameters
Raw Mix Stockpile
(Circular Storage)
Through a cross-belt analyzer of full material stream by PGNAA
(Prompt Gamma Neutron Activation Analysis), stockpile
composition is controlled to ensure desired quality target level
with a maximum uniformity. Elements checked are;
 Major : SiO2, Al2O3, Fe2O3 and CaO
 MgO, SO3, K2O, Na2O, Cl, TiO2 and Mn2O3
And the compositions are displayed every minute, 10 minutes
and for whole pile.
Correctives Through XRF analysis on manually-grabbed samples, chemical
analysis is done to control and ensure high grade of corrective
materials; limestone, iron ore and sand.
Raw Mix/Raw Meal Done automatically, via XRF, using pressed/fused tablet
sample to;
 Target chemical composition :
- Achieve desired quality parameters such as LSF, SR, AR,
C2S, and C2A in clinker

Monitoring for SO3, Cl and Alkalies
- LSF standard deviation <= 2.5
 Target fineness :
- Sieve analysis (R200µm, R90µm)
 Monitor moisture :
- Check water percent.
 Ensure high uniformity
Kiln feed Done through manual or automatic sampling to re-check
previous parameters;
 Monitor LSF, SR, AR, and LSF standard deviation
 Monitor SO3, Cl and alkalies
 Carry sieve analysis; fineness (R200µm, R90µm)
 Monitor moisture (% water)
Hot meal after the
last cyclone in the
preheater
Manual sample used to test;
 SO3 (LECO test)
 K2O and Na2O (Flame photometry, XRF)
 Cl (potentiometry)
 Loss on ignition (in oven by burning to 975 0C)
 Calcination degree
Petcoke mill Semi-automatic or manual sampling is done to test petcoke
quality;
 Fineness test : sieves (R200µm, R90µm)
 Moisture and volatiles
 Calorific value (calorimeter)
 Sulphur (LECO sulfur analyzer)
Clinker To test clinker quality;
 Cement soundness (CaO free) : FL (free lime) <= 3
(using wet analysis or XRD)
 Cement strength : C3S >= 50
 Grindability
 Granulometry
 Microstructure
 Liter weight (manual weighting test)
 Complete chemical composition analysis
Additives at
cement mills
XRF analysis is done on manual samples to control chemical
composition of additive materials such as; gypsum, limestone,
and GBFS.
Cement (final
product)
Test cement quality for mill operation;
 Fineness : Blaine, residue (R45µm)
 SO3 : for gypsum dosage
 Color
 Temperature
 Complete chemical analysis
Cement at
dispatch/shipping
Manual samples are made to control;
 Fineness
 Chemical composition
 Physical testing

6.3. The major customers of LCE

7. References
All of these data is this report are self developed (I gained them through my training
period in the plant from directors, managers, team leaders, and engineers), and all of
the following references are for some figures only.
1.http://www.alibaba.com/product-detail/Mining-grinding-ball-mill-for-
gypsum_600307079.htmlhttp://www.alibaba.com/product-detail/Mining-grinding-ball-
mill-for-gypsum_600307079.html
2.https://www.google.com.eg/search?q=drilling+and+blasting+of+rocks&biw=1366&b
ih=667&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjI74-B2-rKAhXBhHIKHT-
PBZkQ_AUICSgE#tbm=isch&q=ball+mill&imgrc=0bgjYUUPSoz8WM%3A
3.http://www.zkg.de/en/artikel/zkg_2012-03_High-
efficient_cement_manufacturing_with_POLYCOM_and_SEPOL_PC_Machine_1386
888.html
4.http://www.utc.fr/ergun/cyclones.html
5. http://www.flowvision-energy.com/esp
6. http://www.cementkilns.co.uk/early_rotary_kilns.html
7. http://www.cementkilns.co.uk/cooler_grate.html
8. http://www.masycproject.com/product-1.html
9. http://farian.site/air-slide-conveyor-belt.html
10.http://www.alibaba.com/product-detail/LS400x19700mm-20t-h-Gravel-Screw-
Conveyor_60002606635.html
11.http://www.aumund.com/en/aumund/products/pan_conveyors/pivoting_pan_conve
yor
12.http://mutiarasintetis.ga/tag/cement-industry-blower

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