Study for recycling of ceria-based glass polishing powder II-recovery of hydroxysodalite from the alkali waste solution containing SiO2 and Al2O3

The recovery of SiO2 and Al2O3 from the alkali waste solution of the glass polishing powder-recycling process was investigated. The effects of seed cr ystal, stirring speed, and temperature were also studied. Hydroxysodalite w as obtained from the waste solution by heating to 80-100 degreesC. Addition of seed crystal shortened the reaction time and made easy the recovery of hydroxysodalite. The hydroxysodalite deposition process was rate-determined by the chemical reaction step, and increased temperature was also effectiv e in shortening a reaction time.