Cement Production Stages

Cement production technology consists of five main stages;

Preparation of the Raw Material
Raw Meal Blending
Baking
Production of the Cement 
Packaging 

Preparation of the Raw Material
The primary raw materials of the cement are limestone and clay. Auxiliary materials such as iron ore, bauxite, sand, etc. are also used in the production of the cement and of the clinker, the intermediate substance of cement. These materials are taken from the natural environment by quarrying. These materials are subjected to stocking, pre-mixing and various crushing operations at the plant site and they are scaled down as such.

Raw Meal Blending
Materials such as limestone, clay, iron ore, etc. with certain chemical compositions are grinded into a fine powder. This powder is called "raw meal". It is homogenized in order to obtain a good clinker, and then stocked in silos.

Baking
The raw meal is fed to the preheater from the raw meal silos. In the preheater, the raw meal moves downwards, whereas the hot gas from the kiln moves upwards. The raw meal comes into contact with the hot gas in the preheater that consists of several stages of cyclone combination, and precalcination takes place as a result.

The raw meal, which has undergone precalcination, enters the rotary kiln. Combustibles such as pulverized coal, natural gas and fuel oil are burned via the flame pipe available at the way out of the kiln. The temperature inside the kiln rises up to 1500-1600 °C due to burning the fuel and clinker reactions. The material starts to liquefy as it approaches the outlet of the kiln. Fine grains combine to form large clinker particles. The clinker particles formed are moved to the cooling unit from the kiln outlet and subjected to shock cooling. The temperature of the shock cooled clinker particles is lowered below 100 °C before they are stored in the clinker stock hall.

Production of the Cement 
Cement is produced by grinding the Portland cement clinker with some gypsum, and with some additives such as pozzolana, limestone, fly ash, etc. depending on the cement type. Ball mills are commonly used for grinding the cement. Cement milled into fine powder is stored in silos.

Packaging
Cements, which are stored in silos depending on the type of cement, are supplied to the market as bulk or bagged in line with the demands of the market.