[rahul saini]

Limestone also has many other uses:
1. to make glass
2. in the production of paper and iron
3. as a building material
4. to make cement and to neutralise acidic soils and lakes.


Glass

Glass is made by heating a mixture of sand, limestone and soda (sodium carbonate) until it melts.
When the mixture cools it comes out as glass.
Glass is used for many everyday things such as windows, glasses and mirrors.

Neutralisation
Ordinary limestone, ground into a powder, can be used to neutralise acidity in lakes and soils caused by acid rain.
The calcium carbonate is a base (an insoluble alkali), and so can neutralise the the acid.
Slaked lime works in the same way but is much faster.


Cement

When limestone is heated with clay it forms cement, a substance that sets gradually when it reacts with water.
Cement can be made into mortar by adding sand and water. Mortar is used to set the bricks in walls, as when it dries it acts as an adhesive between the bricks.
Cement can also be made into concrete by adding water, sand and small stones or gravel.
Concrete is used for all kinds of building work, including paths, walls and large buildings.