氰化尾渣无害化处置及资源综合回收研究和工业应用

Harmless treatment of cyanide tailing and recycle research and industrial application of resources

研究以某冶炼厂的氰化尾渣为原料,采用了炭浸+酸化吹脱-中和-二氧化硫(冶炼烟气)空气法+XJD除重金属组合的新工艺,建成了一套氰化尾渣无害化处理及资源综合回收系统,以期实现无害处理和资源的综合利用。研究结果表明:最佳工艺参数为矿浆浓度30%,炭浸2 h,采用硝酸-硫酸混酸酸化,pH值1.5~2.0,酸化曝气时间30 min,酸化吹脱后,加碱中和,控制中和pH值8.5,通二氧化硫-空气反应30 min;该工艺已工业应用2年,效果良好,处理后的氰化尾渣符合《黄金行业氰渣污染物控制技术规范》(HJ 943—2018)要求,满足《国家危险废物名录(2021年版)》中对于氰化尾渣的豁免条件,无害化后处置过程按一般固废处理。该工艺应用对氰化尾渣中氰化物和贵金属进行综合回收,产生了一定的经济效益和社会效益。

A new process combining carbon leaching,acidification stripping,neutralization,sulfur dioxide(smelting flue gas)air method,and XJD heavy metal removal was studied using cyanide tailings from a certain smelter as raw materials.A harmless treatment and comprehensive resource recovery system for cyanide tailings was established to achieve harmless treatment and comprehensive utilization of resources.The results showed the optimum process parameters were as follows:pulp concentration 30%,carbon leaching for 2 h,acidification with nitric acid-sulfuric acid mixture,pH=1.5~2.0,acidizing and aeration for 30 min,after acid stripping,adding alkali for neutralization,controlling neutralization pH at 8.5,reacting with sulfur dioxide in air for 30 min;the process had been applied industrially for two years,which had got good effect,the process of cyanide tailing conformed to the standard Technical Specification for Pollution Control of Cyanide Leaching Residue in Gold Industry(HJ 943-2018),met the exemption conditions for cyanide tailing in the National Hazardous Waste List(2021 Edition),and the harmless post-disposal process is treated as general solid waste.The process is applied for comprehensively recycling cyanide and precious metal from cyanide tailing,with certain economic and social benefits.