PRODUCTION OF HIGH-PURITY SILICA FROM INDUSTRIAL SODIUM SILICATE BY ION EXCHANGE PROCESS

摘要

PURPOSE:To obtain simply and inexpensively high-purity silica, by dissolving industrial sodium silicate in pure water, adjusting the solution to acidic pH, and subjecting the solution to combined treatment of H-type strongly acidic cation exchange resin treatment and OH type weakly acidic anion exchange resin treatment. CONSTITUTION:Industrial sodium silicate is dissolved in pure water, an acid is added to the solution, the solution is adjusted to 3.5-2pH, the prepared solution is treated with H-type strongly acidic cation exchange resin (e.g., Amberlite IR-120) at 0.3-1ml/min/cm2 flow velocity at =310mg resin based on 1ml treatment amount resin. The prepared solution is treated with OH-type weakly acidic anion exchange resin (e.g., Amberlite-4B) at 0.3-1ml/min/cm2 flow velocity at =310mg based on 1ml treatment amount resin. Then, the prepared eluate is concentrated to dryness and calcined to give the aimed high- purity silica. The prepared high-purity silica is preferably used as optical quartz glass, etc.