三氯氢硅生产废水资源化回收工艺探索

Process Exploration of Resource Recovery of Trichlorohydrosilicon Production Wastewater

三氯氢硅生产过程中产生一股酸性废水,其酸度约为2%,直接中和处理不仅成本高,且形成的高盐废水仍需进一步处理。本研究探索基于酸资源回收、水资源回用的“扩散渗析+特种耐酸膜回收+清液中和回用”的工艺,可有效降低企业的经营成本。研究表明:扩散渗析可将废水酸浓度由2%浓缩至8%,作为盐酸解析单元的原料;扩散渗析产生的淡水酸浓度约为0.5%,经特种耐酸膜装置进一步浓缩后,浓度提高至2%,返回扩散渗析进水单元和原水混合;特种耐膜装置产生的清液酸浓度<0.05%,通过中和后,TDS(Total Dissolved Solids)不高于500 mg·L^(-1),可作为循环水补水。

The production process of trichlorohydrosilicon produces a stream of acidic wastewater with an acidity of about 2%,which is not only costly to treat by direct neutralisation,but also requires further treatment of the high-salt wastewater formed.The study explores the process of‘Diffusion Dialysis+Special Acid Resistant Membrane Recovery+Clear Liquid Neutralisation and Reuse’based on the recovery of acid resources and reuse of water resources,which can effectively reduce the operating costs of enterprises.Research shows that:diffusion dialysis can concentrate the acid concentration of wastewater from 2%to 8%,as the raw material of hydrochloric acid resolution unit;the acid concentration of fresh water produced by diffusion dialysis is about 0.5%,and the concentration is increased to 2%by further concentration of special acid-resistant membrane device,which is returned to diffusion dialysis influent unit and mixed with the raw water;the acid concentration of the clear liquid produced by the special acid-resistant membrane device is less than 0.05%.After neutralisation,the TDS(Total Dissolved Solids)is not higher than 500 mg·L^(-1),which can be used as circulating water make-up water.