Water → Sodium orthosilicate

Participants

Reaction Steps

300 ml of sodium water glass was mixed with 2700 ml of de-ionized water to form an aqueous solution of sodium silicate, which was passed through a cationic exchange resin column, thereby forming silicic acid. 5 wt % aqueous KOH was added gradually at a temperature below 80° C. (preferably, 70-80° C.) until the pH value of the aqueous solution was greater than 10 so that the silicic acid was alkalized and underwent polycondensation. The reaction product was cooled to 40° C., and was added with 300 ml of 10 wt % sodium aluminate aqueous solution. After 40 minutes, the reaction product was passed through a cationic exchange resin column to obtain a clear silica sol A.

Provenance & Evidence