Wu Fenghui, Chen Bangjin, Qu Guangfei, Liu Shan, Zhao Chenyang, Ren Yuanchaun, Liu Xinxin
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Yunnan, Kunming, 650500, China; National Regional Engineering Research Center-NCW, Yunnan, Kunming, 650500, China.
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Yunnan, Kunming, 650500, China; National Regional Engineering Research Center-NCW, Yunnan, Kunming, 650500, China.
J Environ Manage. 2022 Mar 3;311:114827. doi: 10.1016/j.jenvman.2022.114827.
Phosphogypsum is one of the typical by-products of phosphorus chemical industry. As a strategic industry related to the national livelihood of China, phosphorus chemical industry has accumulated and produced a significant amount of phosphogypsum. In general, phosphogypsum contains approximately 80%-95% calcium sulfate dihydrate, and less than 5% toxic and harmful elements. In this paper, toxic and hazardous components in phosphogypsum were efficiently solidified and stabilized by highly targeted solidification and stabilization technology. Calcium carbide slag or lime was used as an alkali-base neutralizer of phosphogypsum, and polymeric ferric sulfate or polymeric aluminum chloride as a directional solidification stabilizer to analyze the leaching toxicity of the mixed powder in 1, 3, 5 and 15 days. The experimental results demonstrate excellent solidification and stabilization effect with the leaching pH of 6-9, the leaching concentration of P, F and heavy metals of less than 0.5 mg/L, 10 mg/L and 0.1 mg/L, respectively, which meets the requirements of relevant international standards. Mechanistic analysis indicates that the solidification and stabilization of toxic and hazardous substances in phosphogypsum is perfectly achieved owing to the generation, adsorption and encapsulation of insoluble substances. This technology can reduce the costs and difficulty in the phosphogypsum treatment, and has extensive application potentials.
磷石膏是磷化工行业典型的副产品之一。作为关系到国计民生的战略性产业，磷化工行业积累并产生了大量的磷石膏。一般来说，磷石膏含有约80%-95%的二水硫酸钙，有毒有害元素含量低于5%。本文采用高针对性的固化稳定化技术，对磷石膏中的有毒有害成分进行了有效固化稳定化处理。以电石渣或石灰作为磷石膏的碱式中和剂，以聚合硫酸铁或聚合氯化铝作为定向固化稳定剂，分析了混合粉末在1天、3天、5天和15天的浸出毒性。实验结果表明，固化稳定化效果良好，浸出液pH值为6-9，磷、氟和重金属的浸出浓度分别小于0.5mg/L、10mg/L和0.1mg/L，符合相关国际标准要求。机理分析表明，由于不溶物的生成、吸附和包裹作用，磷石膏中有毒有害物质的固化稳定化得以完美实现。该技术可降低磷石膏处理成本和难度，具有广泛的应用潜力。
