Silica Gel is a highly active adsorption material, usually with sodium silicate and sulfuric acid reaction, and after aging, acid bulbs and a series of post-processing in the system. Silica gel according to the size of the aperture is divided into: wide pore granular silica gel, coarse silica gel, Silica Gel Type B, Narrow Pore Granular Silica Gel . Because the different pore structure, adsorption properties so they have their own characteristics. Wide pore silica gel in the case of high relative humidity had a higher adsorption capacity, pore silica gel in the case of low relative humidity higher than coarse silica gel adsorption, and B-type silica pore structure between the coarse and fine hole between the amount of adsorption between the coarse pore between. Macroporous silica gel generally used as a catalyst carrier, matting agents, toothpaste abrasive. Should be selected according to different uses of different varieties.