What is China clay and Ceramics?

China Clay:


Ceramics is derived from the Greek words "Keramos' which means potter's clay. Ceramics is a type of clay which contains the compound of carbon, hydrogen, nitrogen, oxygen and silica. It is used to make cups, plate, dishes etc. The clay contains mainly hydrated alumina silicate (AL2O3.SiO3.2H2O). This may also contain other substances like limestone, magnesium carbonate, oxides of manganese and iron. The pure white clay is called kaolin, or China clay. It is used for making cups, plates, dishes, etc. 


In order to make ceramic materials, the clay is crushed, ground and sieved to obtain fine clay. The clay is mixed with water to make a paste and then cast into different shapes. The objects of various shapes are allowed to dry in sunlight for several days. After drying, the products are heated in furnace. At high temperature, the soil hardens due to chemical reaction and becomes porous. A little amount of salt is added to make the objects shiny. Some objects of ceramics are coated with oxides of tin or lead and are heated again. The coat of tin oxide or lead oxides melts and forms a thin layer over their surface. This process is called glazing. Glazing makes the articles smooth, attractive and waterproof. Color and polish are also added in order to make the ceramic items more attractive. Ceramics are poor conductor of heat and electricity, it is used in an electrical appliances. Ceramics is used in making crockery like cups, bowls, plates, dishes, etc. Ceramics is resistance to the chemical reactions. So it is also used to make the laboratory apparatus. 

 

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