铜冶炼烟尘中有价金属回收研究现状

Research status of the recovery of valuable metals in copper smelting dust

铜火法冶炼过程中产生大量的烟尘,含有砷和多种有价金属,对环境有潜在的污染风险,但也是重要的二次资源。烟尘资源化处理方法主要有湿法、火法和联合法。火法工艺通过氧化焙烧(熔炼)或者还原焙烧(熔炼)实现杂质元素与有价金属选择性分离的目的,具有工艺流程短、处理量大以及投资成本较低等优势,但存在金属回收率低、综合能耗高、产生的无价值残留物多、环境污染严重等问题。湿法工艺包括酸浸法、碱浸法和水浸法,酸浸法工艺成熟,工业上应用较多,但酸浸过程也会产生大量废渣,需要进行后续处理。联合法工艺主要包括湿法-火法联合工艺和选冶联合工艺,其对于处理元素组成相对复杂、物质形态多样的烟尘优势较为明显,脱砷效果好,并可以综合回收烟尘中铜、锌、镉、铅、铋、锑、铟等有价金属,但存在处理流程长、投资成本较大等问题。

The large volumes of offgas dust generated from copper pyrometallurgical processes contains arsenic and multiple valuable metals,a potential environmental hazard but important secondary resources at the same time.The approaches of recovering resources from the smelter dust are mainly:hydrometallurgical,pyrometallurgical,and combination.In the pyrometallurgical approach,impurity elements and metal values are selectively separated through oxidizing roasting(smelting) or reducing roasting(smelting).Such processes are short,capable of treating large quantities of dust,and low in capital costs,but at the same time have several disadvantages:low metal recovery,high overall energy consumption rate,large quantities of waste,and heavy environmental impact.The hydrometallurgical processes include acid leaching,alkaline leaching,and water leaching.Comparatively acid leaching is more developed,and numerous in industrial applications.However,acid leaching also generates large amounts of residue which requires treatment.The combined processes are mainly a combination of hydro and pyro metallurgical process or of mineral processing and metallurgical treatment.Such a combined approach has salient advantages when treating smelter dusts of complex composition in terms of elements and substances.These processes have good arsenic removal performance,and allow the recovery of multiple metal values including copper,zinc,cadmium,lead,bismuth,antimony,indium,but is also long in process flow and high in capital costs.