raw materials for cement plaster cement manufacturing

1. PLASTER,CEMINT,CHEMISTR
OF RAW MATERIALS USED IN
CEMENT MANUFACTURING
BY
BLESSY EBENEZER
1st M.sc CHEMISTRY

2. PLASTER
 Plaster is a mixture of lime or
gypsum, sand and water,
sometimes with fiber added, that
hardens to a smooth solid and is
used for coating walls and
ceilings.

3.  Plaster of paris is a fine white
powder of calcium sulphate . It is
a dehydrated gypsum.
The chemical formula of plaster
of paris is CaSO4.½H2O.

4. PLASTERING MATERIALS
 Ordinary Portland cement
 Lime or clay
 Aggregates
 Water
 Admixture

5. PLASTERING
Plastering is the process of covering
rough surfaces and uneven surfaces
with a plastic material, called plastering

6. OBJECTIVES OF PLASTERING
To provide an even, smooth, regular,
clean and durable finished surface
with improved appearance.
To preserve and protect the surface.

7. To cover up the use of porous
materials of the masonry work.
To conceal defective
workmanship.

8. PROPERTIES OF GOOD PLASTERING
It is should be hard and durable.
It should be possible to apply it
during all weather conditions.
It should be cheap and economical.

9. It should adhere to the background and
should remain adhere during all climatic
change.
It should offer good insulation against
sound and high resistance against fire.
It should effectively chek the penetration
of moisture form the surfaces.

10. USES OF PLASTER
 CONSTRUCTION
It is commonly used in the construction
industry as a building material.
 MEDICINE
Plaster of paris is commonly used in the
medical industry to make casts of broken bones
and other injuries.

11.  DENTISTRY
It is also used in dentistry to macke molds of
teeth and gums. these molds are used to create
dental appliances such as dentures and braces.
 AGRICULTURE
It is used in agriculture to improve soil quality.
It can help to reduce soil erosion and improve the
soil’s ability to retain water and nutrients.

12. CEMENT
DEFINITION
cement is a powdery substance formed
by calcinating limestone and clay which binds
aggregates together, sets and harder.
cement is the general term given to the
powdered materials which initially have plastic
flow when mixed with water or

13. other liquid, but has the property of setting
to a hard solid structure in several hours
which varying degree of strength and
bonding properties.
The most important compounds present in
cement are 3CaO.Al2O3, 3CaO.SiO3, 2CaO.SiO3,
and CaO.

14.  Josep Aspdin is considered the inventor of
"modern" Portland cement. Portland cement,
the most common type of cement in general
use around the world as a basic ingredient of
concrete, was developed in England in the
mid 19th century, and usually originates from
limestone.

15. TYPE OF CEMENTS
Sulphate resistant cement
This is a cement with higher C2S/C3S ratio
and can resist sulphate attack and corrosion by
sea water.
High alumina cement
It is essentially a calcium aluminate
cement and can be prepared by heating a mixture
of lime stone and bauxite at1550–1600 c.

16. Water proof cement
Waterproof cement is the name given to a
portland cement to which a water-repellent
agent has been added.
Hydraulic cement
Hydraulic cement is a type of cement that
sets and hardens when mixed with water. This
type of cements are low priced and has good
strength .[e.g 2CaO.SiO2,CaOH2]

17. Acid resisting cement
Silicate cements are the first acid resisting
materials known and widely used in chemical
resistant masonry. It resists many minerals acids
except Hydrofluoric acid, Fluorosilicic acids, and
their salts. Basically two types - based on
Potassium Silicate or Sodium silicate.

18. Slag cement
Portland blast furnace cement (simply
called slag cement) refers to the hydraulic
binding material ground by mixing Portland
cement clinker, granular blast furnace slag, and
appropriate amount of gypsum .

19. White cement
White cement is a variation of Portland
cement. During production, iron and manganese
are added to give it its characteristic white hue.
Portland cement
Portland cement (OPC) consists of tri and
dicalcium silicates, tricalcium aluminate, and
tetracalcium alumino ferrite and calcium sulfate
as gypsum.

20. RAW METERIALS USED IN CEMENT
MANUFACTURING
 The raw materials used in cement production
vary depending on the type of cement being
manufactured and the process used. Generally,
the main raw materials used in the production
of cement are:

21. Limestone: Limestone is the primary source of
calcium oxide used in cement manufacturing.
It is abundant and widely available in many
regions of the world. Calcium oxide is a crucial
ingredient in cement as it contributes to the
cement's strength and durability.

22. Clay or Shale: Clay and shale are also
important sources of silica, alumina, and iron
oxide, which are essential components of
cement. These materials are usually mixed
with limestone in the cement manufacturing
process.
Gypsum: Gypsum is added to control the
setting time of cement. It regulates the rate of
hydration and prevents the cement from
setting too quickly.

23. Fly Ash: In some cement manufacturing
processes, fly ash, a byproduct of coal-fired
power plants, is used as a supplementary
cementitious material. It enhances the
cement's properties and reduces the amount
of clinker required, thereby reducing
greenhouse gas emissions.

24. Silica Fume: Silica fume is another
supplementary cementitious material that is
sometimes used in cement production. It is a
byproduct of silicon and ferrosilicon alloy
production and helps improve the strength
and durability of concrete.
Iron ore or Mill Scale: These materials provide
the necessary iron for the production of
cement.

25. Bauxite: Bauxite is used as a source of
aluminum in the production of some types of
cement, like calcium aluminate cement.

26. The exact composition of the raw materials
and the manufacturing process can vary
depending on the type of cement being
produced, such as Portland cement, white
cement, or blended cements. Cement
manufacturers carefully control the raw
material composition to achieve specific
properties and characteristics in the final
product.