Abstract: Copper is an indispensable raw material for modern industry,but China′s copper resources have a high degree of dependence on foreign countries and are typical "stuck neck" resources. Copper is mainly prepared by fire smelting copper concentrate,and the slag amount is large in the smelting process,and the copper content of the slag is as high as 0. 5%~5%, which is much higher than the recoverable grade of copper ore in China (0. 2%). Therefore,it is of great significance to study the process of recovering copper from depleted copper slag to improve China′s resource security capacity. Based on the occurrence state of copper/ copper sulfonium in slag and the main forms of copper loss,the technical process of recovering copper from depleted copper slag at this stage is reviewed,including fire dilution,flotation method,wet treatment,etc. ,and the future research focus is prospected. At present,the electric furnace has a large amount of dilution treatment and mature technology, but it usually uses coal as a reducing agent,because its density is less than copper slag,most of the floating slag layer surface combustion during the reaction,the reaction is insufficient,and it is not conducive to atmospheric environmental protection. In addition,metal iron rods are often used in industry to reduce the nodulation of magnetite at the bottom of the furnace,but its density is greater than that of copper/ copper sulfonium,and the sedimentation rate in the slag liquid is fast,and the reduction of the slag layer is incomplete. Therefore,the development of environmentally friendly and efficient reducing agents has gradually become the focus of research on the dilution of thermal electric furnaces. Flotation method is a common means of treating natural copper ore,but copper slag has high hardness,complex associated relationship,uneven particle size distribution,many fine particles and other flotation difficulties,and the problem of inactivation of collector caused by high temperature flotation of copper slag also needs to be solved. In the treatment of low-grade copper slag,wet leaching is a common method,but the environmental protection problems of chemical reagents and waste liquid are difficult to solve. Biological leaching has the advantages of stable properties,no pollution to the environment and low metal content after leaching,but its leaching cycle is long and the efficiency is low. According to the current difficulties of the depletion process,the development and optimization of the future depletion process are prospected,such as increasing the accumulation of ferric tetroxide in the field to improve the sedimentation environment of copper/ copper sulfonium,developing environmentally friendly and efficient fire depleted reducing agent, exploring the mechanism of action of reducing agent on different copper slag types,and developing new agents for copper slag flotation with high temperature resistance.

Key words: copper slag,copper content of slag,reduction and dilution,reducing agent,matte铜渣　渣含铜　还原贫化　还原剂　冰铜