Active clay (mainly bentonite) as raw materials, the role of active clay, inorganic acidification treatment, and then by water rinsing, drying made of adsorbent, the appearance of milky powder, active clay, odorless, active clay, adsorption performance is very strong, can absorb colored substances. Easy to absorb moisture in the air, placed too long will reduce the adsorption performance. However, when heated to more than 300 degrees Celsius, the crystal water begins to lose, which changes the structure and affects the fading effect. Active clay is insoluble in water, solvents and various oils, almost soluble in hot caustic soda and hydrochloric acid, the relative density of 2.3 ~ 2.5, in water and oil swelling small.