| 摘要 |
PURPOSE:To produce a stable pasty slurry of hydrated silica, by filtering a suspension of hydrated silica, washing the cake with water, stirring and slurrying the obtained filter cake of hydrated silica, dehydrating the slurry by filtering under pressure, and again stirring the obtained cake to form a slurry. CONSTITUTION:An aqueous solution of sodium silicate is neutralized with a mineral acid (e.g. sulfuric acid), and the obtained suspension of fine hydrated silica is filtered with a filter press, etc., and washed with hot water to remove the impurities. The produced filter cake of hydrated silica is stirred e.g. with a reciprocating stirrer to obtain a slurry, which is dehydrated by filtering under pressure, and stirred again to obtain a slurry. The stirring of the filter cake of hydrated silica destructs the agglomerated structure of the cake to convert the included water to the attached water of the hydrated silica particles. The attached water can be removed by the filtration under pressure to lower the water-content of the cake. The slurry obtained finally is a stable paste which can be stored or transported without causing the separation of water.
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