Cement is topic;like and give credit for my free work cement cement and its types Manufacturing of cement uses of cement wet process dry process portland cement raw materials used in cement field tests for cement

1. CEMENT

2. Definition:
“Cement is a crystalline compound of calcium silicates and
other calcium compounds having hydraulic properties”
(Macfadyen, 2006).

3. Another Definition:
Cement is a powdery substance made by calcining lime and
clay, mixed with water to form mortar or mixed with sand,
gravel, and water to make concrete.

4. History:
Lime and clay have been used as cementing
material on constructions through many centuries.
Best known surviving example is the Pantheon in
Rome
In 1824 Joseph Aspdin from England invented the
Portland cement
The word "cement" can be traced back to the Roman
word termed as Caementicium,

5. CEMENT INDUSTRY In Pakistan :
 The annual production of the cement at the time of the
creation of Pakistan was only 300000 tones per year.
 Pakistan has inexhaustible reserves of limestone and clay,
which can support the industry for another 50-60 years.
 At present there are more than 28 cement plants in Pakistan with
installed capacity of over 19.5 million tonnes per annum. The
present demand for cement in Pakistan is around 9.5 million
tonnes per annum.

6. CEMENT INDUSTRY In Pakistan :
Province No. of Units Capacity
(Mil.Ton)
Sindh 8 3.364
Punjab 12 7.894
KPK 5 4.351
Baluchistan 2 0.723
Islamabad 1 0.990
Total 28 17.312

7. Cement production in the World

8. PORTLAND CEMENT
Portland cement is the most common type of cement in
general use around the world, used as a basic ingredient of
concrete, mortar, stucco(plaster), and most non-speciality
grout.

9. SOURCE ROCKS
Calcareous Rocks(Limestone) Argillaceous Rocks(Clay)

10. RAW MATERIALS:
Lime or calcium oxide, CaO: from limestone, chalk, shells, shale or calcareous rock
Silica, SiO2: from sand, old bottles, clay or argillaceous rock
Alumina, Al2O3: from bauxite, recycled aluminum, clay
Iron, Fe2O3: from from clay, iron ore, scrap iron and fly ash
Gypsum, CaSO4.2H20: found together with limestone
GYPSUM

11.  The materials, without the gypsum, are proportioned to produce a mixture with
the desired chemical composition and then ground and blended by one of two
processes - dry process or wet process.
 The materials are then fed through a kiln at 2,600º F to produce grayish-black
pellets known as clinker.

12.  The alumina and iron act as fluxing agents which lower the melting
point of silica from 3,000 to 2600º F.
 After this stage, the clinker is cooled, pulverized and gypsum
added to regulate setting time. It is then ground extremely fine to
produce cement

13. Decomposition of raw materials -
- Reactions at temperatures up to about 1300 °C
- It includes
I. Water evaporation in the raw feed, if any.
II. Loss of carbon dioxide from the limestone (ie: calcining).
III. Decomposition of the siliceous and aluminosilicate fractions of
the feed.
IV. Formation of a sulfate melt phase.
V. The decomposition products react with lime to form intermediate
compounds which in turn form other compounds as clinkering
proceeds.

14. CaCO3 → CaO + CO2
The calcium oxide is then spent (slaked) mixing it with
water to make slaked lime (calcium hydroxide):
CaO + H2O → Ca(OH)2
Once the excess water is completely evaporated (this
process is technically called setting), the carbonation
starts:
Ca(OH)2 + CO2 → CaCO3 + H2O

15. Chemical Composition of Portland Cement:
• Portland cement is composed of four major oxides
(CaO, SiO2, Al2O3, Fe2O3 ≥90%) & some minor oxides.
Minor refers to the quantity not importance.
• The proportions of these oxides determine the proportions
of the compounds which affect the performance of the
cement.

16. Compound Composition of Portland
Cement:
• Oxides interact with eachother in the kiln to form more complex products
(compounds). Basically, the major compounds of P.C. can be listed as:
Name Chemical Formula Abbreviations
Tri Calcium Silicate 3CaO.SiO2 C3S
Di Calcium Silicate 2CaO.SiO2 C2S
Tri Calcium Aluminate 3CaO.Al2O3 C3A
Tetracalcium Aluminoferrite Ca4Al2Fe2O10 C4AF

17. Tricalcium aluminate, C3A:-
It liberates a lot of heat during the early stages of hydration, but has little strength contribution. Gypsum slows down
the hydration rate of C3A. Cement low in C3A is sulfate resistant.
Tricalcium silicate, C3S:-
This compound hydrates and hardens rapidly. It is largely responsible for portland cement’s initial set and early
strength gain.
Dicalcium silicate, C2S:-
C2S hydrates and hardens slowly. It is largely responsible for strength gain after one week.
Tetracalcium Aluminoferrite :-
This is a fluxing agent which reduces the melting temperature of the raw materials in the kiln (from 3,000o F to
2,600o F). It hydrates rapidly, but does not contribute much to strength of the cement paste.
.

18. Types of Cement Manufacturing
Processes
• Wet Process
• Dry Process

20. Manufacturing Process of Cement:
• Quarry
• Grinding
• Burning
• Grinding
• Storage
• Packing
• Dispatch

23. THE CEMENT MANUFACTURING PROCESS
1. BLASTING : The raw materials that are used to manufacture cement (mainly limestone and clay) are
blasted from the quarry.
Quarry face
1. BLASTING 2. TRANSPORT
3. CRUSHING AND TRANSPORTATION : The raw materials, after crushing, are
transported to the plant by conveyor. The plant stores the materials before they are
homogenized.
quarry
3. CRUSHING & TRANSPORTATION
2. TRANSPORT : The raw materials are loaded into a dumper.
crushing
conveyor
Next
dumper
storage at
the plant
loader

24. THE CEMENT MANUFACTURING PROCESS
1. RAW GRINDING : The raw materials are very finely ground in order to produce the raw mix.
1. RAW GRINDING
Raw grinding and burning
2. BURNING
2. BURNING : The raw mix is preheated before it goes into the kiln, which is heated by a flame that can
be as hot as 2000 °C. The raw mix burns at 1500 °C producing clinker which, when it leaves the kiln, is
rapidly cooled with air fans. So, the raw mix is burnt to produce clinker : the basic material needed to
make cement.
conveyor
Next
Raw mix
kiln
cooling
Back
preheating
clinker
storage at
the plant
Raw mill

25. THE CEMENT MANUFACTURING PROCESS
1.GRINDING : The clinker and the gypsum are very finely ground giving a “pure cement”. Other secondary
additives and cementitious materials can also be added to make a blended cement.
1. GRINDING
Grinding, storage, packing, dispatch
2. STORAGE, PACKING, DISPATCH
2. STORAGE, PACKING, DISPATCH :The cement is stored in silos before being dispatched either in
bulk or in bags to its final destination.
Back
clinker
storage
Gypsum and the secondary additives are added
to the clinker.
silos
Home page
dispatch
bags
Finish grinding

26. Manfacturing Process :

27. TYPES OF CEMENT:
 Rapid hardening cement:
The initial and final setting times of this cement are same as those of
ordinary cement. But it attains high strength in early days. It contains
high percentage of tricalcium silicate C3S to the extent of about 56%.
 Sulphate resisting cement:
In this cement, the percentage of tricalcium aluminate C3A is kept below 5
percent and it results in the increase in resisting power against sulphates.

28. TYPES OF CEMENT:
 Rapid hardening cement:
The initial and final setting times of this cement are same as those of
ordinary cement. But it attains high strength in early days. It contains
high percentage of tricalcium silicate C3S to the extent of about 56%.
 Sulphate resisting cement:
In this cement, the percentage of tricalcium aluminate C3A is kept below 5
percent and it results in the increase in resisting power against sulphates.

29. TYPES OF CEMENT:
 Coloured cement:
The cement of desired colour may be obtained by intimately mixing
mineral pigments with ordinary cement.
These types of coloured cement are widely used for finishing of
floors, external surfaces, artificial marble, window sill slabs,
textured panel faces, stair treads, etc.
White cement is prepared from such raw materials which are practically free
from colouring oxides of iron, manganese or chromium.
It is white in colour and is used for floor
finish, plaster work, ornament work, etc.
 White cement:

30. TYPES OF CEMENT:
 Low heat cement:
The considerable heat is produced during the setting of cement. In order to
reduce the amount of heat, this type of cement is used. It contains lower
percentage of tricalcium aluminate C3A of about 5% and higher percentage
of dicalcium silicate C2S of about 46%.
 Pozzolana cement:
Pozzolana is a volcanic powder. It is found in Italy near Vesuvius. This type
of cement is used to prepare mass concrete of lean mix and for marine
structures. It is also used in sewage works ad for laying concrete under water

31. The difference between ordinary cement
and white cements
 The amount of chromium, manganese, iron compounds is
significantly less in white cement in comparison to gray cement
 Production of white cement consumes significantly more energy
in comparison to gray cement.

32. Field Tests of Cement:
 Date of Manufacturing: As the strength of cement reduces with age,
the date of manufacturing of cement bags should be checked.
 Cement Color: The color of cement should be uniform. It should be
typical cement colour i.e. grey colour with a light greenish shade.
 Whether Hard Lumps are Formed: Cement should be free from
hard lumps. Such lumps are formed by the absorption of moisture from
the atmosphere.

33. Field Tests of Cement:
 Temperature Inside Cement Bag: If the hand is plunged into a
bag of cement, it should be cool inside the cement bag. If hydration
reaction takes place inside the bag, it will become warm.
 Smoothness Test: When cement is touched or rubbed in between
fingers, it should give smooth feeling. If it felt rough, it indicates
adulteration with sand.
 Water Sinking Test:. If a small quantity of cement is thrown to the
water, it should float some time before finally sinking

34. USES OF CEMENT:
 Cement is a very useful binding material in construction.
 It is used in mortar for plastering, masonry work, pointing, etc.
 It is used for making joints for drains and pipes.
 It is used for water tightness of structure.
 It is used in concrete for laying floors, roofs and constructing lintels, beams,
stairs, pillars etc.

36. USES OF CEMENT:
 It is used for precast pipes manufacturing, piles, fencing posts etc.
 It is used in the construction of important engineering structures
such as bridges, culverts, dams, tunnels, light houses etc.
 It is used in the preparation of foundations, water tight floors,
footpaths etc.
 It is employed for the construction of wells, water tanks, tennis
courts, lamp posts, telephone cabins, roads etc.

37. THANK YOU