A new process of acidic hydrolysis of residual chlorosilane liquid for the preparation of silica and hydrochloric acid

作者：Cai, Jixiang; Huang, Bing^*; Ma, Qikun; Zhang, Wenwen

来源：Korean Journal of Chemical Engineering, 2017, 34(6): 1793-1800.

DOI：10.1007/s11814-017-0093-2

• Chlorosilane Residual Liquid
• Silica
• Hydrochloric Acid
• Acidic Hydrolysis Process
• Polysilicon

We propose a novel process for the preparation of silica and concentrated hydrochloric acid using chlorosilane residual liquid originating from the polysilicon production process. The process was designed and optimized after conducting pilot plant tests. The effects of circulating acid concentration, flow rate, chlorosilane residual liquid treatment load and other factors on silica products were studied. The results showed that the circulating acid flowrate can effectively control the formation of gel, and the amount of chlorosilane residual liquid has significant influence on the hydrolysis efficiency and operation of the hydrolysis tower. The prepared silica was characterized using XRD, XRF, FTIR, SEM, DLS, TG-MS and N-2 adsorption/desorption experiments. The results indicated that silica consisted of amorphous particles, which were spherical, had surface hydroxyl, and showed heterogeneous distribution. The average particle size was 50-80 mu m and had high specific surface area (565.049m(2)g(-1)), large pore volume (0.449 cm(3)g(-1)), and a narrow pore size distribution (3.419 nm). The new technology provides a simple, efficient and environmentally friendly way for treating chlorosilane residual liquid, as well as a cost-effective method for the preparation of silica.

• 出版日期2017-6
• 单位昆明冶金研究院; 昆明理工大学