| 摘要 |
PURPOSE:To simply produce silica gel for liq. chromatography at a low cost by reacting an aqueous soln. of an alkali metallic silicate with an aqueous soln. of a mineral acid to form active silicic acid, making the silicic acid gel by stirring and carrying out spray drying. CONSTITUTION:An aqueous soln. of an alkali metallic silicate such as sodium silicate is reacted with an aqueous soln. of a mineral acid such as sulfuric acid to form active silicic acid of 3.0-4.0pH contg. 6.5-11.5wt% SiO2. The silicic acid is made to gel by stirring with a paddle type stirring blade or the like and a prepd. silica hydrogel slurry is reacted with an aqueous soln. of ammonia at about 8.0-9.0pH and about 60-90 deg.C. After the reaction is finished, the reaction product is well filtered and washed. The resulting hydrogel is wet-ground with a ball mill or the like and spray-dried by a two-way nozzle system. Thus, fine spherical silica gel having a smooth surface, contg. no deformed particles and showing high performance as a filler for liq. chromatography is obtd.
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