CLASSIFICATION OF CLAY ON THE BASIS OF RESISTANCE TO HIGH TEMPERATURE

CLASSIFICATION OF CLAY

Clay is the finess material of soil with finess size 0.002 mm.after the application of water it shows plastic behaviour. It is soft, moist, earthy material that  made from eroded rocks. It can be moulded when wet, and is dried and baked to make bricks, pottery, and ceramics.
Bulk specific gravity of clay brick ranges from 1.6 to 2.5.

Clay is the most Important Raw Material Used For Making Bricks. It is An Earthen mineral mass or fragmentary rock capable of mixing with water and forming a plastic viscous mass which has a property of retaining it shape with Moulded and dried. when such mass are heated to redness, they acquire hardness and strength. the purest clay consist mainly of kaolinite with small quantity of minerals such as quartz mica, felspar, calcite, magnesite etc. by there origin clay are subdivided as residual and transported clays. residual clay, known as kaolin or china clay, are formed from the decay of underlying rocks and are used for making pottery. transported or sedimentary clays result from the action of weathering agencies. these are more disperse, contain impurities, and free from large particles of mother rocks.

CLASSIFICATION :

On The Basis Of Resistance To High Temperature :

on the basis of resistance to high temperatures( more than 1580°C),clay are classified as

• Refractory Clay
• High melting clay
• Low melting clay

• Refractory Clay : The refractory clays are highly Disperse and Very Plastic. These have high content of alumina and low content of impurities, such as fe2O3, tending to lower the refractoriness.

Note : refractory clay burned at 1000 °C-1400 °C and crushed

• High Melting Clay : It have high refractoriness and contain small amount of impurities such as quartz, felspar, mica,calcium carbonate and magnessium carbonate. These are used for manufacturing facing bricks, floor tiles, sewer pipes etc.

• Low melting clay :  It have refractoriness less than 1350 °C and have varying compsition. These are used to manufacturing bricks, blocks, tiles etc.