(1. 中南大学 冶金与环境学院，长沙 410083； 2. 中南大学 国家重金属污染防治工程技术研究中心，长沙 410083)
摘 要: 以模拟含砷废渣为研究对象，考察机械活化铁锰稳定剂对砷稳定效果的影响，确定了最优参数：稳定剂种类为Fe-MnO2、稳定剂铁锰摩尔比为0.4:0.6、稳定剂用量为8%、球磨时间为1 h。在此最佳条件下，可将砷酸铁渣中As的浸出毒性由51.45 mg/L降至2.36 mg/L，优于国家危险废物鉴别标准浸出毒性鉴别(GB 5085—2007)。借助X射线衍射、粒度和比表面分析、扫描电镜等，从球磨过程中铁锰反应机制、铁锰复合稳定剂腐蚀过程特征以及砷吸附后的铁锰复合稳定剂形貌结构变化等方面，研究铁锰复合稳定剂稳定含砷废渣的机理。在机械力化学和MnO2复合作用下，促进零价铁粉表面的腐蚀过程，生成了大量高效吸附砷的水铁矿类物质，实现砷的高效稳定。
关键字: 含砷废渣；机械力；稳定化；浸出毒性
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China; 2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China）
Abstract:The simulated arsenic bearing solid waste was prepared, and the parameters of stabilizer, mole ratio of Fe and Mn, dosage of stabilizer and ball-milling time for the stabilization effect were optimized. The results show that the extraction toxicity of arsenic decreases from 51.45 mg/L to 2.36 mg/L under the optimized conditions of stabilizer of Fe-MnO2, mole ratio of Fe and Mn of 0.4:0.6, stabilizer dosage of 8% and ball-milling of 1 h, which is lower than that of identification standards for hazardous wastes-identification for extraction toxicity (GB 5085—2007), and the stabilization of arsenic is accomplished. Stabilization mechanism of arsenic bearing solid waste with Fe-MnO2 activated by mechanochemical process was investigated with XRD, SEM-EDS, particle size and specific surface analysis. Because of the synergistic action of mechanochemical process and MnO2, the surface corrosion process of zero-valent iron powder is accelerated and large amount of ferrihydrite material absorbing arsenic effectively forms. Therefore, highly effective stabilization of arsenic is achieved.
Key words: arsenic bearing solid waste; stabilization; mechanochemical process; extraction toxicity
