The technology of cement production involves several unit operations, and are complex to enumerate. However, the major unit operations are the following:-
- Preparation of raw mix
• Quarrying, crushing and transportation
• Proportioning of the ingredients
• Grinding of raw mix
- Calcinations and storage
• Homogenizing of raw mix
• Burning of raw mix in vertical shaft kiln and storing of clinker
- Production of cement
• Grinding of clinker and gypsum (96/4%)
• Packing of cement
Raw Materials
The major raw materials required for the production of cement are limestone, clay, sandstone, gypsum and pumice.
The dry process of cement production is employed here although
the wet process also exist. The major difference between the two is the method of raw material preparation and handling before it is fed into the calcinations unit. Wet process do require high fuel oil consumption due to which there is a high shift to dry method of cement production in modern times. For the purpose of this project, therefore, the dry process is preferred to the wet process. In a dry process, the moisture content of the raw materials is kept below 6%. Quarrying, crushing and transportation of limestone, sandstone and clay is carried at the site of the raw materials. These materials are, then, stored in their respective storage yards, and are fed to proportioning equipment (bunkers and weigh scales). The proportioned materials are transported by a belt conveyor and fed to raw grinding mill. The output of the mill called raw mix or raw meal - is fed into homogenizing silos where high pressure air mixes the raw mix to a high degree of homogeneity. This is then transported to VSK, where calcinations at a temperature of 1100oC - 1400oC take place in order to produce the required grade of clinker.
The clinker thus produced is cooled either in a silo(s) or open air. The clinker together with gypsum are ground in a cement mill to finally produce cement. It is then packed and dispatched into market.
I Preparation Section
1 Drilling Rig.
2 Loaders
3 Crusher
4 Bucket Elevator
5 Silos
6 Grinding Mill
7 Dust collector
8 Pumps
9 Roller mill
10 Dump trucks
II Burning Section
1 Fan
2 Dust collector
3 Preheater
4 Vertical shaft kiln
5 Grate cooler
6 Bucket elevator
7 Storage tanks
III Clinker Grinding
1 Silos
2 Grinding mill
3 Air separator
4 Dust collector
5 Bucket elevator
IV Auxiliaries
1 Power supply system
2 Fuel storage tanks
3 Water supply unit
4 Compressed air system
5 Workshops