Chemical composition of cement is

Options

A. Limestone and clay
B. Limestone,clay and gypsum
C. Limestone and Gypsum
D. Clay and Gypsum

Answer

B

Explanation

The two important raw materials used for the preparation of cement are:
Limestone:The chemical formula of limestone is `CaCO_(3)` and it is used in the manufacture of cement just to provide CaO.
Clay:Clay is hydrated aluminium silicate and iron (iii)oxide having chemical formula A12O3SiO2Fe203.2H2O.
Thus,clay consists of aliminium oxide `(Al_(2)O_(3))`.silicon dioxide `(SiO_(2))` ,and iron (iii) oxide `(Fe_(2)O_(3))` along with water molecules.
In addition of limestone and clay.gypsum is also used during preparation of cement to slow down the hardening of cement when water is added into it.