Study On Modification Of Copper Slag And Recovery Of Copper And Iron

Resource shortage and environmental pollution are the important factors that restrict the development of our country.China is currently the largest producer and consumer of copper and iron in the world,and the external dependencies of copper and iron resources were over 70% and 50%,respectively.Therefore,the recycling of tailings,smelting slags and other large industrial solid wastes which contain valuable metal components,can effectively supplement the metal mineral resources,increase insurance protection of the domestic resources,and reduce environmental pollution.Based on the problems existing in the copper converter slag processing and improving the recovery of valuable metals such as copper and iron,a new technology of “modified roasting-magnetic separation-flotation-leaching” was put forward.The process conditions were investigated through experime nts,and the feasibility of the process was analyzed theoretically.(1)By means of partial reflection microscope analysis,multi-element analysis,XRD analysis,SEM-EDS analysis,XPS analysis and other methods,the technological mineralogy of a copper co nverter slag and its modified slag was studied.The results showed that a fundamental change of valuable metals existence form occurd in the copper slag before and after its modification.Metellic copper and oxide were changed into copper sulfides,and fayalite into magnetite.(2)The thermodynamic analysis of the process,especially the modified roasting and acid leaching process,was used to support the new process theoretically.The theoretical analysis showed that the copper component and iron component could be enriched to the copper sulfides and magnetite separately by the modified roasting,and the separation of sodium silicate and magnetite could be achieved through sulfuric acid leaching.(3)The process conditions were discussed through experiments,and the copper flotation closed circuit experiments were carried out under the optimized conditions.The results showed that the copper grade of 36.4% and recovery of 72.9% were obtained,and plus the copper recovery of 24.77% in the leaching,the total recovery of copper was up to 97.67%,meanwhile iron grade of 60.31% and recovery of 55.81% were obtained also.