含砷烟尘的处理及利用研究现状

Research Status on Treatment and Utilization of Arsenic Containing Dust

含砷金属矿物在火法冶炼过程中会产生大量含砷或砷化物的烟尘,这些烟尘因砷含量高而被列为危险固废,但同时仍富含铅、锌、锡、铋、锑、铟、银等有价金属,因此,对其的无害化、资源化处理越来越受到重视,已成为重有色冶炼工业可持续发展必须解决的关键问题之一.本文评述了国内外对于含砷烟尘的处理和利用技术.目前含砷烟尘的处理方法有湿化学法、火法和联合法.湿化学法主要通过氧化浸出、结晶、沉淀等将烟尘中大部分砷转化为三氧化二砷产品,或以稳定砷酸盐沉淀的形式固化堆存;火法技术主要是通过对含砷烟尘进行高温处理,含砷物质经挥发、冷凝制得三氧化二砷或粗砷产品;联合法则通过湿法浸出、分离并回收部分有价金属元素,再采用选矿或火法熔炼方法回收浸出渣中剩余的有价金属,整个过程中砷以砷铁渣或砷钙渣形式堆存处理.在此基础上,提出了未来含砷烟尘无害化处理和资源综合回收利用技术的发展方向,并针对炼铜过程产生的一次含砷烟尘提出了真空还原预脱砷、低温硫化深度脱砷及回收有价金属的思路.

A large amount of dust containing arsenic have been generated in pyrometallurgical process of nonferrous minerals and classified as dangerous solid waste due to high arsenic content. However,much rich valuable component exist beside arsenic,such as lead,zinc,tin,antimony,bismuth,indium,silver,etc. Therefore,its harmless and resource-recycling treatment is receiving more and more attention,which has become one of the key issues that must be solved in the sustainable development of heavy nonferrous smelting industry. This paper gives a general review of the treatment and utilization technology of arsenic containing dust at home and abroad.At present,the treatment methods of arsenic containing dust include wet chemical method,pyrometallurgical method and combined method. The wet chemical method mainly converts most arsenic in dust into arsenic trioxideproducts by oxidation leaching,crystallization and precipitation,or solidifies and stores them in the form of stable arsenate precipitation;The pyrometallurgical method is mainly to prepare arsenic trioxide or crude arsenic products by high temperature treatment of arsenic containingdust and volatilization and condensation of arsenic containing substances;The combined method leaches,separates and recovers some valuable metal elements by wet method,and then recovers the remaining valuable metals from leaching residue by mineral processing or pyrometallurgical smelting,during the whole process,arsenic is stored in the form of arsenic-iron slag or arsenic-calcium slag. On this basis,the development direction of technology for harmless treatment and comprehensive recovery of primary arsenic containing dust in the future is put forward,and the ideas of vacuum reduction pre-arsenic removal,low temperature sulfide deep arsenic removal and recovery of valuable metals for arsenic containing dust produced in copper smelting process are suggested.