| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a makatite type sodium silicate having a high calcium ion exchange capacity in high yield with a high productoivity. SOLUTION: A seed crystal of makatite and a water-miscible or a water-soluble nonionic or anionic organic crystallizing agent are added to an aqueous solution or dispersion of sodium silicate and the resultant mixed composition is then heated to produce a makatite type sodium silicate. A water-miscible organic solvent, especially an organic solvent having >=60 deg.C boiling point is used as the organic crystallizing agent and a polyhydric alcohol or its ether derivative, a nonionic surfactant or an anionic surfactant, a nonionic water-soluble polymer or an anionic water-soluble polymer can be used as the preferred one.
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