What is cement? What are its raw materials?
Cement is a fine gray powder of calcium silicate and calcium aluminate which becomes hard when mixed with water and dried for some time.
Its raw materials are:
> Limestone CaCO3 ( 2/3 part )
> Special type of clay AI2O3 . SiO2 ( 1/3 part )
> Gypsum CaSO4 . 2H2O ( only about 2 - 3% )