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
Fig Aerial view of a cement plant. (70000)

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
Iron ore
Mill scale
Ore washings
Pyrite cinders
Calcium silicate
Fly ash
Loess
Quartzite
Rice-hull ash
Sand
Sandstone
Traprock
Aluminum-ore refuse
Bauxite
Copper slag
Granodiorite
Staurolite
Anhydrite
Calcium sulfate
Gypsum
Source: PCA, 2003
Table 2-1. Sources of Raw Materials Used in Manufacture of Portland Cement
Sulfate, often in the form of gypsum, is added during the grinding of the clinker to regulate the setting time of the cement and to improve shrinkage and strength development properties.

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
Fig Steps in the traditional manufacture of portland cement

7. Natural Cement Rock
Two Benches
No Blasting only Ripping
5- 10 hour shifts
Haul trucks
2 – 796C cat
1 – 35R Euclid
988 Cat Loaders

8. 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
Fig Steps in the traditional manufacture of portland cement

9. 3. Burning changes raw mix chemically into cement clinker.
Source: PCA, 2003
Fig Steps in the traditional manufacture of portland cement

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

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

12. 3. Burning changes raw mix chemically into clinker
3. Burning changes raw mix chemically into clinker. Note four stage preheater, flash furnaces, and shorter kiln.
Source: PCA, 2003
Fig Steps in the modern dry-process manufacture of portland cement.

13. Pyro- Processing Modernized in 1999 by HBZ and Fuller
1500 tpd to 2000 tpd
Fuel Consumption decreased by 15%
Modern – State of the Art Preheater / Precalciner System with down draft calciner/ & DeSox

14. Kiln –2,000 stpd
12’ x 165’
3.1 RPM

15. Source: PCA, 2003
Fig Rotary kiln (furnace) for manufacturing portland cement clinker. Inset view inside the kiln. (58927, 25139)

16. 4. Clinker is ground with gypsum into portland cement and shipped.
Source: PCA, 2003
Fig Steps in the traditional manufacture of portland cement

17. Clinker Gypsum Source: PCA, 2003
Fig Portland cement clinker is formed by burning calcium and siliceous raw materials in a kiln. This particular clinker is about 20 mm (3¼4 in.) in diameter. (60504)
Fig Gypsum, a source of sulfate, is interground with portland clinker to form portland cement. It helps control setting, drying shrinkage properties, and strength development. (60505)

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
Fig Process of clinker production from raw feed to the final product (Hills 2000).

21. Source: PCA, 2003
Fig Process of clinker production from raw feed to the final product (Hills 2000).

22. Source: PCA, 2003
Fig Process of clinker production from raw feed to the final product (Hills 2000).

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 Belite or 2CaO• SiO2 or C2S
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
ASTM C 150 (AASHTO M 85)
I Normal
II Moderate sulfate resistance
III High early strength
IV Low heat of hydration
V High sulfate resistance

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