Abstract: Taking BET and pore volume of water-resistant silica gel as investigation indexes,influences of the factors,such as mass fraction of aluminum sulfate solution and amount-of-substance ratio of sulfuric acid to aluminum sulfate etc.,on experiment results in preparation process were studied by orthogonal design and variance analysis.Results showed that the mass fraction of aluminum sulfate and amount-of-substance ratio of sulfuric acid to aluminum sulfate were the most significant influencing factors,and the optimal process parameters were as follows:the mass fraction of aluminum sulfate was 6%,the amount-of-substance ratio of sulfuric acid to aluminum sulfate in raw material was 2∶1,the amount-of-substance ratio of sulfuric acid to aluminum sulfate in the acid soaking process was 6∶1,the mass fraction of ammonia in the alkali soaking process was 0.1%,and aging time was 1.5 h.Thus the adsorption separation material,whose BET no less than 300 m²/g and pore volume no less than 0.7 mL/g,with good water resistance can be obtained.

Key words: water-resistant silica gel, process optimization, surface area, pore volume