Ceramic – Glass
Raw materials for Glass Manufacturing:
Next to Silica Sand and Soda Ash, Limestone is the major raw material used for manufacturing glass. About 14 - 18% of the raw material batch weight consists of limestone. Limestone is nothing but Calcium Carbonate (CaCO3). The limestone is added to the batch to provide the Calcium oxide for glass formation. The limestone when heated gets converted to Calcium oxide (CaO). That is the Calcium Carbonate releases Carbon dioxide on heating and thereby forms Calcium oxide.
CaCO3 (on heating) ————> CaO + CO2
The limestone is commonly referred to as Carbonate Rock. Also the mineral dolomite falls in the carbonate rock variety. Limestone is sedimentary rock category and is mined from the earthen crust. Both open pit and underground mining is popular for mining limestone. There is not much processing required to the natural limestone. Generally the mined limestone mineral is first sawed for removing impurities and then crushed in Grinding Mills followed by screening to check uniform size distribution. The size of the mineral limestone varies from application to application.
To be Contd….
