Table 2. The Types and General Formula of Clay Mineral Used.

Clay General formula
Kaolin Al2O3·2SiO2·2H2O
Halloysite Al2Si2O5·(OH)4·2H2O
Montmorillonite (AI, Mg)2Si4O10·(OH)2·4H2O
Bentonite Al2O3·4SiO2·H2O