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Information on Cement

Cement Production Stages
Cement production technology consists of five main sections:
  • Raw material preparation
  • Raw meal grinding
  • Firing
  • Cement Production
  • Packing

Raw material preparation

Main raw materials of cement are limestone and clay. Auxiliary materials such as iron ore, bauxite, sand, etc. are additionally used in the production of cement and clinker, which is the intermediate of cement. Such materials are taken from its natural origin through mine administration. Such materials are subjected to stocking, premixing and various breaking processes and material size is reduced in the plant area.

Raw meal grinding

Materials such as limestone, clay, iron ore, etc. having specific chemical composition are grinded and turned into a fine dust. Such dust is called as “raw meal”. Raw meal is homogenized to obtain good limestone and stocked in silos.

Firing

Raw meal is fed to pre-heater from raw meal silos for the firing process. In the pre-heater, while raw meal moves downwards, hot gas coming from the inside of furnace moves upwards. Raw meal and hot gas contacts with hot gas and pre-calcination process occurs in the pre-heater consisting of cyclone combination of some grades.

Raw meal subjected to pre-calcination enters the rotary furnace. Fuel such as dust coal, natural gas, and fuel-oil are burned by means of flame tube at the exit of furnace. The temperature inside the furnace increases to 1500-1600 C with the burnt fuel and clinkering reactions. The material inside the furnace starts liquidizing as it comes close to the exit. Fine particles combine and form large size clinker particles. Such clinker particles are shock cooled by passing through the cooling unit from the furnace exit. The temperature of shock cooled clinker particles is reduced under 100 C and stocked in clinker stock hall.

Cement Production

Cement is obtained as a result that Portland cement clinker is grinded with limestone of some amount and additives such as pozzolana, limestone, fly ash, etc. based on the type of cement. Ball mills are used commonly for grinding cement. The cement grinded as fine dust is stocked in silos.

Packing

The cement being stocked in silos is presented to market in bulk form or in sacks in line with the demands of market according to the types of cement.