Recycle of ceria-based glass polishing powder was investigated. A waste polishing powder was treated in a 4 mol kg-1 NaOH solution with a waste/NaOH weight ratio of 1 at 60 °C, and SiO2 and Al2O3 impurities were dissolved into the solution and removed from the polishing powder. A solution which containing the impurities was heated to 100 °C, and hydroxysodalite (Na8(AlSiO4)6(OH)24H2O) was precipitate. Thus the glass polishing powder can be regenerated and hydroxysodalite was obtained as a by-product, and excess NaOH solution was reused. However addition of Si source, such as sodium silicate was required to control the leaching and precipitation process.
ASJC Scopus subject areas
- Chemical Engineering(all)