Pure kaolin: These kaolins are known for their milky white colour and they do not contain more than 2% of fluxes and 5% of free silicious materials. These clays are mainly used in the manufacturing of ceramic porcelains and ceramic fine earthenware. These are also used in several non-ceramic industries like pharmaceutical, paper, health care applications, etc.
Alkaline kaolin: They contain more alkalis, feldspar and mica and iron up to 2% . These are inferior to pure kaolin and are mainly used for making ceramic earthenware and ceramic fine pottery.
Silicious kaolin: They contain very high percentage of free silica which may vary up to 25%. These clays are semi plastic clays and are mainly used in the manufacturing of ceramic porcelain and some kinds of faience.
Alkaline silicious kaolins: These clays are a mixture of alkaline kaolins and silicious kaolins and are mainly used for making inferior grade ceramic articles.
Ferruginous kaolin: These clays contain very high amount of iron oxide and are mainly used in the manufacturing of refractory materials.
