| 摘要 |
PURPOSE:To obtain silica sol in a high concentration with a low alkali and low alumina contents, by mixing fine silica powder with an aqueous medium at a limited pH using ultrasonic waves. CONSTITUTION:Silica powder having 5-200mmu primary particle diameter is mixed with an aqueous medium at <=5pH while giving ultrasonic vibration to the aqueous medium to disperse the silica powder in the aqueous medium and form an aqueous sol. According to this method, an alkali assistant or another additive is not used, and the use of pure water as the aqueous medium provides the aimed silica sol having the retained high purity of the raw material silica powder. The frequency of the ultrasonic waves to be used is preferably about 10-100kHz.
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