稻壳制备超细二氧化硅新工艺

Study on the New Preparation Technology of Ultrafine Silica from Rice Husk

研究以稻壳为原料,经过预处理、燃烧、后处理、粉碎过程,制备超细二氧化硅新工艺。过程可回收稻壳燃烧热能,治理稻壳灰造成的污染。通过单因素实验与正交实验,确定过程的最佳工艺条件为:盐酸浓度为1.3mol/L,酸浸泡时间为24 h,燃烧温度为650℃,燃烧时间为5 h,后处理剂体积分数为25%。此条件下可制备得到白度为90.5,二氧化硅含量为98.62%,平均粒径为0.96μm的优质超细二氧化硅。

This paper introduced a new method of preparing uhrafine silica from the rice husk with the process of pretreatment, combustion, post-treatment and grinding. The process could recover heat energy from combustion of rice husk and control the pollution from rice husk ash. By one-factor experiment and orthogonal experiment, the optimal reaction conditions were determined ： the concentration of hydrochloric acid was 1.3 mol/L, immersion time was 24 hours, combustion temperature was 650℃, combustion time was 5 hours, and post-treatment agent ＇ s volume fraction was 25%. Under these conditions, ultrafine silica could be prepared. The whiteness of product was 90.5%, the content of SiO2 reached 98.60%, and the average size of particle was 0.96μm.