1. BY:Prof. Dr. Hossam Ibrahim El dossoky
El – Shorouk Academy The Higher Institute of Engineering Chemical Engineering Department
Engineering Chemistry
BY:Prof. Dr. Hossam Ibrahim El dossoky

2. Today’ Agenda
CEMENT

3. CEMENT 1- Hydraulic cement 2- Air Cement
Types: Natural cement, Pozzolanic cement, Portland cements, Super sulphate cement …….
Classification:
Hydraulic cement
Air cement
1- Hydraulic cement
What is meant ?
Cement + H2O Hardening Example:- ( N.P.C)
2- Air Cement
Cement + H2O Hardening Example:- limestone , gypsum
CEMENT
Air

4. Clay + Limestone Clinker Clinker + Gypsum portland cement (P.C)
Chemistry:-
Clay + Limestone Clinker
Clinker + Gypsum portland cement (P.C)
Raw Materials for portland cement (P.C)
Limestone (CaCO3)
Clay (SiO2, Fe2O3, Al2O3)
Gypsum (CaSO4.2H2O)
Burning
1500
الطمى
الحجر الجيرى
كلنكر
Cooling
Grinding
كلنكر
الجبس
الاسمنت البروتلاندى العادى
1- Hydraulic cement

5. Raw Materials for portland cement
Limestone

6. Raw Materials for portland cement
Clay

7. Technology:- Manufacture process
Mixing
2. Burning process (takes place in rotary kiln)
الخلط
الحرق

8. Technology:- Manufacture process
Temperature (°C)
Reactions
> 100
Evaporation of water
> 500
Removal of combined water from clay
> 800
Decomposition of CaCO3, MgCO3. Formation of CA, C2F and C2S begins.
800 – 900
C12A7 forms.
Decomposes to C3A at higher temperatures.
900 – 1100
Formation of C3A and C4AF commences, decomposition of CaCO3 completed, maximum CaO will be present.
1100 – 1200
Formation of C2S reaches maximum, major parts of C3A and C4AF form.
1250 – 1280
Formation of liquid phase
C3A, C4AF dissolve and recrystallize on cooling.
1280 – 1450
Formation of C3S, free-lime content decreases.

9. Summary A = Al2O3, C = CaO, F = Fe2O3 S = SiO2
100 – 500°C (Removement of water(
°C (Calcination)
CaCO CaO + CO2
800 – 1500°C
3CaO + Al2O CaO.Al2O3
3CaO + SiO2 3CaO.SiO2
2CaO + SiO2 2CaO.SiO2
4CaO + Fe2O3 + Al2O CaO.Al2O3.Fe2O3
A = Al2O3,
C = CaO,
F = Fe2O3
S = SiO2

10. Technology:- Manufacture process
3- Grinding
Clinker + Gypsum portland cement
(N.P.C)
- What is the function of Gypsum?
Retarding agent
الطحن

11. Manufacture of portland cementمخطط صناعة الاسمنت البورتلاندى
Clay
Crushed
Lime stone
Grinding
Water
Wet-grinding
Raw material mill
Slurry storage basin
Clinker cooler
Clinker Storage
Clinker mill
Cement silo
packaging
Flue gases
stack
Driving motor
gypsum
fuel
slurry
1450 0C
Hot air
Rotary drum kiln
blower
Cooling air

12. Composition range of Portland cement
Oxides
Formula
Per cent limit
Lime
CaO
60 – 67
Silica
SiO2
17 – 25
Alumina
Al2O3
3 – 8
Iron oxide
Fe2O3
0.5 – 6.0
For a perfect balance of the various cement constituents, the following relation should be satisfied. C
= 1
2.8 S + 1.1A + 0.7F

13. Setting and Hardening الـتـصـلـب Initial setting Final setting
3CaO.Al2O3 + 6H2O CaO.Al2O3.6H2O + heat.
3CaO.Al2O3 + CaSO4.2H2O + XH2O CaO.Al2O3. CaSO4.YH2O
Final setting
3CaO.SiO2 + XH2O CaO.SiO2.(X-1)H2O + Ca(OH)2 + heat
Hardening
2CaO.SiO2 + XH2O CaO.SiO2.XH2O

14. Metastable Colloidal gel Crystalline products
Cement + Water
Plastic mass
Metastable Colloidal gel
Crystalline
products
Stable gel
Crystalline Products of Coarser dimensions

15. Weathering of Cement and Concrete and its Prevention
Ca(OH)2 + CO2 CaCO3 + H2O
CaCO3 + H2O + CO2 Ca(HCO3)2
Ca(HCO3)2 + Ca(OH)2 2CaCO3 + 2H2O
to overcome this problem by coating the surface with:
Drying oils like linseed oil or
Bituminous rubber or epoxy resin paint. The surface can also be treated with SiF4 when insoluble CaF2 is formed.
Insoluble
soluble

16. Weathering of Cement and Concrete and its Prevention
Ca(OH)2 + CO2 CaCO3 + H2O
CaCO3 + H2O + CO2 Ca(HCO3)2
Ca(HCO3)2 + Ca(OH)2 2CaCO3 + 2H2O
to overcome this problem by coating the surface with:
Drying oils like linseed oil or
Bituminous rubber or epoxy resin paint. The surface can also be treated with SiF4 when insoluble CaF2 is formed.
Insoluble
soluble

17. 2- Air cement CaCO3 CaO + CO2 Setting and hardening of lime
CaO + H2O Ca(OH)2 + Heat
Ca(OH)2 + CO2 CaCO3 + H2O
CaO + CO2 CaCO3 Δ

18. Classification of lime
Fat Limes
95-98% CaO and the rest are SiO2, Al2O3 and MgO
Lean Limes
70-80% of CaO and the rest MgO, SiO2 and Fe2O3
Hydraulic Limes
70-80% CaO MgO < 2%.
Dolomitic Limes
dolomite (CaCO3.MgCO3)& (30-40%) MgO

19. Gypsum(CaSO4.2H2O) CaSO4.1/2H2O + 1 ½H2O CaSO4.2H2O Hardening 150°C
CaSO4.2H2O CaSO4.1/2H2O CaSO CaO + SO3
Gypsum plaster of Paris anhydrite
Hardening
CaSO4.1/2H2O + 1 ½H2O CaSO4.2H2O
600°C
>800°C

20. MODEL Questions

22. For any problem, Please contact me:
Prof. Dr. Hossam Ibrahim El dossoky
Head of department of chemical engineering
High Institute of Engineering
Shorouk Academy
Coordinator : Eng. Amr Atef
E.Mail :
“If You can not build your dreams in the atmosphere, You won’t build that in any other place”