Prepare a short note on the manufacture and uses of cement.

Manufacture:

i. The main raw materials for the manufacture are limestone and clay.

ii. The powdered limestone (3 parts) and clay (1part) are mixed.

iii. The mixture is heated at about 1770-1870K in a rotary kiln.

iv. Limestone decomposes to give lime and CO₂.

v. Due to very high temperature about 20%-30% mass melts and combines with solid mass to form pebbles known as cement clinkers.

vi. The clinkers are cooled and mixed with gypsum.

vii. The gypsum slows down the setting of cement so that it gets hard.

The pictorial representation of important process takes place

Uses:

i. It is an important construction material.

ii. It used in the construction of buildings, bridges and dams.

iii. It is a major building material.

iv. It is used in the construction of road, footpaths, courts for various sports.