| 摘要 |
PURPOSE:To obtain high purity alkali metal silicate having an impurity content of lower than a specific level, and suitable for inorganic binder of electronic parts, medicine, etc., by using a crystalline alkali metal silicate as the alkali source and a high-purity synthetic silica as the silica source. CONSTITUTION:A high-purity alkali metal silicate containing <=50ppm of impurities in terms of the sum of impurity elements (Ca+Al+Fe+Ti+Zr) based on the solid component of the alkali metal silicate (M2O+SiO2) (M is Na or K). The high-purity alkali metal silicate can be prepared by dissolving crystalline alkali metal silicate, and dissolving high-purity silica in the aqueous solution of alkali metal silicate. The use of crystalline alkali metal silicate is essential. The crystalline alkali metal silicate is e.g. alkali metal metasilicate, alkali metal orthosilicate or alkali metal sesquisilicate, or their mixture.
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