| 摘要 |
PURPOSE:To readily produce the titled silica gel at a low cost, by reacting an aqueous solution of an alkali metal silicate with an aqueous solution of a mineral acid, gelatinizing the resultant aqueous solution of silicic acid, treating the aqueous solution with an aqueous solution of ammonia, filtering and washing the filtrate with water, wet pulverizing the resultant hydrogel, spray-drying the pulverized hydrogel, treating the spray-dried hydrogel with a mineral acid and drying the treated hydrogel. CONSTITUTION:An aqueous solution of an alkali metal silicate is reacted with an aqueous solution of a mineral acid to give an aqueous solution of active silicic acid at 3.0-4.0pH in 6.5-11.5wt% SiO2 concentration, which is then gelatinized while stirring. An aqueous solution of ammonia is then added to react with the formed silica hydrogel slurry and the reaction slurry is filtered and washed with water to give hydrogel, which is wet pulverized. The pulverized hydrogel is further spray-dried, treated with an aqueous solution of a mineral acid, washed with water and dried. According to this method, the aimed silica gel, having high performance and smooth surfaces without containing deformed particles and useful as a packing for liquid chromatography is obtained at a low cost by a simple method without using an organic solvent or organic material and further requiring troublesome operation. |
