提出了以硅切割废砂浆中的硅粉为硅源,制备粗孔块状硅胶,同时回收硅切割废砂浆中的碳化硅磨料和聚乙二醇切削液的工艺.重点阐述了基本原理和工艺流程,并对工艺条件进行了优化.水解反应工艺条件:硅、碳化硅混合颗粒和氢氧化钠的质量比为3.38∶1,在80℃下反应85 min,然后将温度提高到95℃继续反应150 min,最终的硅粉水解率达到100%.多硅酸钠制备硅胶工艺条件:凝胶反应在pH=10、温度为40℃条件下进行,硅凝胶在45℃老化10 h,并用质量分数为0.04%的稀氨水扩容,可得到比表面积为405 m2/g、孔容为1.422 6 mL/g的粗孔块状硅胶.该工艺实现了硅切割废砂浆回收联产粗孔块状硅胶,使硅切割废砂浆的回收更加经济合理.%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.
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