China Clay for White ware Industry:
Required Specification for general Vitreous Ware:
China clays are generally large particle, medium plastic, medium drying Shrinkage, poor dry strength but white fired colour minerals. China clays of relatively plastic type are the preferable choice in porcelain manufacture. Crude Clay after washing will have the following theoretical composition.
Silica (SiO2) – 46.3 %
Alumina (Al2O3) – 39.8%
Water – 13.9%
For usage in white ware body, it is essential that the china clay should not have presence of free silica content. The China Clay has to be processed and washed thoroughly for using in white ware body. This is necessary to ensure uniform and consistent content of silica, and thereby help maintaining optimum silica content in body. The clay should have good plasticity and fineness. The percentage content on 45 micron sieve should be a maximum of only 2%.
To be contd…
