摘要：

采用磁混凝技术，以宁夏某煤化工企业煤制油气化过程中产生的黑水为研究对象，以SiO₂和悬浮物去除率为评价指标，系统分析了影响磁混凝技术去除污染物效果的关键因素，主要涉及磁粉（Fe₃O₄）粒径和投加量，除硅剂（MgO）、混凝剂（聚合硫酸铁PFS）和絮凝剂（阴离子型聚丙烯酰胺APAM）投加量，药剂投加顺序以及废水初始pH。试验结果表明，磁混凝技术处理煤化工气化废水的最佳条件为磁粉粒径200目、磁粉投加质量浓度200 mg/L、除硅剂投加质量浓度200 mg/L、混凝剂投加质量浓度150 mg/L、絮凝剂投加质量浓度1.5 mg/L、废水初始pH 9.0，药剂最佳投加顺序为Fe₃O₄+MgO+PFS+APAM。在此优化条件下，气化废水中SiO₂去除率可达96.38%，悬浮物去除率可达98.29%。这一结果表明磁混凝技术在处理煤化工企业高污染废水方面具有显著优势。

关键词: 磁混凝技术, 煤化工, 气化废水, 除硅剂

Abstract:

Using magnetic coagulation technology, this study investigated the treatment of black water generated during the coal gasification process in a coal-to-liquids plant in Ningxia. The removal rates of SiO₂ and suspended solids(SS) were employed as evaluation indicators. The key factors affecting the pollutant removal efficiency of magnetic coagulation technology were systematically analyzed, including the particle size and dosage of magnetic powder(Fe₃O₄), the dosages of silica removal agent(MgO), coagulant(polyferric sulfate, PFS), and flocculant(anionic polyacrylamide, APAM), the sequence of chemical dosing, and the initial pH of wastewater. Experimental results revealed that the optimal conditions for treating coal gasification wastewater using magnetic coagulation technology were as follows: Magnetic powder particle size of 200 mesh, magnetic powder dosage of 200 mg/L, silica removal agent dosage of 200 mg/L, coagulant dosage of 150 mg/L, flocculant dosage of 1.5 mg/L, and initial wastewater pH of 9.0. The optimal order for adding chemical agents was Fe₃O₄+MgO+PFS+APAM. Under these optimized conditions, the removal rate of SiO₂ reached 96.38%, and the removal rate of suspended solids reached 98.29%. These results demonstrated the significant advantages of magnetic coagulation technology in treating highly polluted wastewater from coal chemical industries.

Key words: magnetic coagulation technology, coal chemical industry, gasification wastewater, desilication agent

中图分类号: 

• X703.1