Experimental Study On Corrosion Leaching Of Reduced Smelting Co-Ni-Cu-Fe Alloy Powder

In recent years,with the rapid widespread of modern electronic communication equipment and the vigorous flourish of electric vehicle industry,Lithium-ion battery consumption and scrap quantity is increased significantly.One of the urgent problems to be solved at present is recovery Co,Ni,Cu from waste lithium-ion battery by using advanced technology.Driven by the State-Owned Enterprise Electric Vehicle Industry Alliance,Changsha Research Institute of Mining and Metallurgy Co.,Ltd.researched and developed the new process of "waste lithium-ion battery free dismantling Reduction Smelting—Corrosion Leaching—Separation Recovering".In this paper,the theoretical analysis of the thermodynamic conditions for the leaching reaction of the alloy powder produced by the Reduction Smelting—Atomization Comminuting process was carried out,and the leaching process test and the kinetic mechanism were studied.Through the thermodynamics analysis of potential-pH diagram of corrosion process solution,the following conclusions are obtained:1)In Co-Ni-Cu-Fe alloy powder raw material,Co,Cu,Fe mainly exist in the form of solid solution and alloy.The Co chemical phase is mainly metal Co,the Cu,Ni,Fe wraped each other and formed Co-Cu-Fe solid solution,Cu-Co alloy and Cu-Co-Ni-Fe alloy.2)The content of Fe in the alloy powder is an important factor to influence the leaching effect?leaching rate?of corrosion.The leaching rate of Co,Ni,Cu decrease with the increase of Fe content in the alloy powder,and the leached slag increase with the increase of Fe content.When the Fe content is 45%in the alloy powder,the best technology of corrosion leaching is:granularity-0.074mm?+0.043mm,acid excess coefficient 1.4,liquid-solid ratio 8:1,leaching temperature 85 ?,oxygen flow 0.20m³/h,speed of agitator 1500r/min,reaction 8h.Under those conditions,the leaching rate of Co,Ni,Cu are 98.12%,97.99%,97.81%,the leaching rate of Fe is about 10%,the good results of separating the valuable metals and Fe were achieved.3)In sulfuric acid system,the speed of Co-Ni-Cu-Fe alloy corrosion leaching effect is controlled by interfacial chemical reaction.The reaction activation energy is 33.34KJ·mol^-1,the corrosion leaching rate equation is KCo=9.06exp?-4.01×10³/T?.