关键词:  , 废砂浆, 粗孔块状硅胶, 硅, 碳化硅

Abstract: A preparation technology of massive macroporous silica gel with silicon powder as silicon source in drained slurry generated by cutting silicon crystal was introduced.This technology could also reclaim silicon carbide (SiC) abrasive and the PEG cutting fluid from the drained slurry at the same time.Basic principle and technological process were described in detail and the process conditions were optimized as follows:Hydrolysis process conditions:the mass ratio of mixed particles of silicon and silicon carbide in drained slurry to NaOH was 3.38∶1,the initial reaction temperature was 80 ℃and reaction time was 85 min,then raising temperature to 95 ℃ and the reaction will continue for 150 min,at last,the conversion rate of hydrolysis reaction could reach 100%;Preparation of silica gel from sodium silicate:gel reaction temperature was 40 ℃ and the pH was 10,silica gel aging reaction carried on for 10 h at 45 ℃,the pore volume of silica gel need to be enlarged by dilute ammonia solution of 0.04%（mass fraction）,then massive silica gel with surface area and pore volume of 405 m²/g and 1.422 6 mL/g,respectively could be obtained.Based on this process research,the recovery of drained slurry generated by cutting silicon crystal can also produce massive macroporous silica gel and recovery process of drained slurry can be more economical and reasonable by the new recovery method.

Key words: drained slurry, massive macroporous silica gel, silicon, silicon carbide