cement process and cement manufacturing ppt

1. Cement Production

2. Portland Cement
By definition —
a hydraulic cement
produced by pulverizing
clinker consisting
essentially of hydraulic
calcium silicates, usually
containing one or more of
the forms of calcium
sulfate as an interground
addition

3. Source: PCA, 2003

4. Raw Materials Necessary for
Portland Cement Manufacture
Must Provide the Following
Calcium
Silica
Alumina
Iron

5. Calcium Iron Silica Alumina Sulfate
Alkali waste
Aragonite
Calcite
Cement-kiln
dust
Cement rock
Chalk
Clay
Fuller’s earth
Limestone
Marble
Marl
Seashells
Shale
Slag
Blast-furnace
flue dust
Clay
Iron ore
Mill scale
Ore washings
Pyrite cinders
Shale
Calcium silicate
Cement rock
Clay
Fly ash
Fuller’s earth
Limestone
Loess
Marl
Ore washings
Quartzite
Rice-hull ash
Sand
Sandstone
Shale
Slag
Traprock
Aluminum-ore
refuse
Bauxite
Cement rock
Clay
Copper slag
Fly ash
Fuller’s earth
Granodiorite
Limestone
Loess
Ore washings
Shale
Slag
Staurolite
Anhydrite
Calcium
sulfate
Gypsum
Source: PCA, 2003

6. Traditional Manufacture of
Portland Cement
1. Stone is first reduced to 125 mm (5 in.)
size, then to 20 mm (3/4 in.), and stored.
Source: PCA, 2003

8. 2. Raw materials are ground to powder and blended.
or
2. Raw materials are ground, mixed with water to form slurry,
and blended.
Source: PCA, 2003

9. 3. Burning changes raw mix chemically into cement clinker.
Source: PCA, 2003

10. Source: Mindess, Young, and Darwin, 2004

11. Source: Mindess, Young, & Darwin, 2004

12. 3. Burning changes raw mix chemically into clinker. Note
four stage preheater, flash furnaces, and shorter kiln.
Source: PCA, 2003

13. Pyro-
Processing

15. Source: PCA, 2003

16. 4. Clinker is ground with gypsum into portland cement and
shipped.
Source: PCA, 2003

17. Clinker Gypsum
Source: PCA, 2003

18. Grinding
Clinker is ground with
gypsum (calcium sulfate) to
produce portland cement
Fine grinding is necessary
for high early strength
– 85-95% -325 mesh (45
microns)
– ~ 7 trillion particles per
pound
Gypsum absorbs water and
prevents setting of C3A
during shipment

19. Source: van Oss and Padovani, 2002

20. Process of Clinker Production
Source: PCA, 2003

21. Source: PCA, 2003

22. Source: PCA, 2003

23. Source: Taylor, 1997

24. Source: MacLaren and White, 2003

25. Source: MacLaren and White, 2003

26. Clinker Phases
Alite or 3CaO•SiO2 or C3S
– Hydrates & hardens quickly
– High early strength
– Higher heat of hydration
(setting)
Belite or 2CaO• SiO2 or C2S
– Hydrates & hardens slower
than alite
– Gives off less heat
– High late strength (> 7 days)
Modern cements are
manufactured to be higher in
alite for early strength

27. Clinker Phases
Aluminate or 3CaO• Al2O3
or C3A
– Very high heat of hydration
– Some contribution to early
strength
– Low C3A for sulfate
resistance
Ferrite or 4CaO• Al2O3 •
Fe2O3 or C4AF
– Little contribution to strength
– Lowers clinkering
temperature
– Controls the color of cement

28. Microscopic Images of Clinker

29. Microscopic Images of Clinker
Alite

30. Microscopic Images of Clinker
Belite

31. Microscopic Images of Clinker
Aluminate

32. Microscopic Images of Clinker
Ferrite

33. Types of Portland Cement
I Normal
II Moderate sulfate resistance
III High early strength
IV Low heat of hydration
V High sulfate resistance
ASTM C 150 (AASHTO M 85)

34. Source: Mindess, Young, and Darwin, 2004

35. Source: Mindess, Young, and Darwin, 2004

36. Source: Mindess, Young, and Darwin, 2004

37. Source: Mindess, Young, and Darwin, 2004