Aactivated clay is the product of bentonite modified by inorganic acid, which has greater adsorption and activity compared with bentonite and is widely applied to petroleum industry, chemical industry, metallurgy, food industry, etc. While the activated clay quality cannot be guaranteed because the montmorillonite content of bentonite mines declines with the developing time being, In order to ensure the high quality of activated clay, the low grade bentonite should be purified. In this paper, the purificati...