回收超细硅粉制备高浓度硅溶胶的研究

摘要

以有机硅单体生产中回收的单质硅粉(约500～2000目)为原料,采取分步加入碱液法和调节控制溶液的pH值等新措施,利用超细硅粉制得了浓度在30%以上(未浓缩)的二氧化硅溶胶,并对其进行了性能检测.对在新方法下获得性能较好硅溶胶的原因及反应体系pH值下降等问题进行了分析.研究结果对拓宽单质硅水解法制备硅溶胶原料的来源、资源回收利用具有积极意义.%A new manufacturing process was been investigated of silica sol with concentration above 30% (Not concentrate), using Ultra-fine silica fume as raw material in this paper. The experimental results indicated that high concentration silica sol could easily be obtained by adding alkali liquid for several steps and controlling the pH value of reaction liquid. The performances of silica sol had been tested in accordance with the national standard. The mechanism of formation of high concentration silica sol and the cause of decreasing pH value of reaction liquid after reaction between silicon and water has been discussed. The research results were beneficial to expand the source of raw materials for silica sol by dissolving silicon powder and recycling industrial wastes.