Study On Increasing Indium Leaching Rate In Indium Ash

Indium,as one of the most important new materials in high-tech fields in today's era,is widely used in the fields of national defense,aerospace,nuclear industry,information industry,electronic industry and medical and health care,and has an important strategic resource position.In the smelting process of lead,zinc,aluminum and other metals,most indium enters the waste residue and is discarded,or it is lost in the waste water,resulting in significant resource loss and environmental pollution.Therefore,it is of great significance to study and analyze the recovery and utilization of indium in the smelting process of zinc,lead,aluminum and other metals for improving the economic benefits of enterprises and protecting the ecological environment.Taking copper soot produced in zinc smelting process of Zhuzhou Smelting Co.as raw material,through research and analysis,in the process of recovering indium,it is mainly because the leaching rate of indium in copper soot is low,which affects the recovery of indium.Through XRD analysis of raw materials and mineralogical analysis of indium process,it can be known that indium exists mainly in indium oxide?In₂O₃?and indium sulfide?In₂S₃?in copper soot.the reaction thermodynamics of indium sulfide and metal oxides in raw materials are analyzed and calculated.the potentials and ph values of various equilibrium reactions of indium and indium sulfides at different temperatures are analyzed from the thermodynamic point of view,and the potential-ph diagrams of In-H₂O system and In-S-H₂O system at different temperatures are drawn according to the calculation results,so as to understand the dissolution stable areas and advantageous areas of each component and provide theoretical guidance for experiments.According to the technological method of sulfuric acid leaching indium from copper soot by Zhuzhou Smelting Co.,the factors influencing indium leaching rate are studied and analyzed,characterized by the leaching rate of indium.through single factor analysis experiments,the optimal parameters of sulfuric acid leaching indium from copper soot are obtained as follows:sulfuric acid concentration 300g/L,liquid-solid ratio?mL/g?6:1,leaching reaction temperature 90?,leaching reaction time 5 hours,potassium permanganate addition 0.3%?0.06g?.under the optimal technological parameters,the leaching rate of indium is 65.73%.According to experimental theory and thermodynamic calculation analysis,based on the experiment of sulfuric acid leaching indium from copper soot,the aging leaching process of concentrated sulfuric acid was explored to improve the leaching rate of indium.Through experiments,it was found that the optimum technological parameters of the experiment of curing and leaching indium in copper soot with concentrated sulfuric acid were as follows:the dosage of concentrated sulfuric acid?30mL?,the liquid-solid ratio?mL/g?was 1.5:1,the curing time of concentrated sulfuric acid was 2hours,the leaching reaction time was 2 hours,the leaching reaction temperature was90?,the amount of potassium permanganate was 0.3%?0.06g?,a proper amount of water was added to the system during the leaching process,and the liquid-solid ratio?mL/g?of the initial leaching state was 6:1.when the initial acid concentration was kept at 300g/L,the leaching effect of indium was the best,and the leaching rate of indium reached 88%.The analysis and detection of indium-containing leachate show that in the experiment of aging and leaching indium from copper soot with concentrated sulfuric acid,a large number of impurities in copper soot will enter the solution,and the impurity composition in the leachate will not change much,but the impurity concentration will change.In this paper,iron powder was used to purify indium leaching solution,and it was verified whether the process of aging concentrated sulfuric acid to leach indium from copper soot had negative impacts on subsequent purification processes,and whether it could effectively improve the final recovery rate of indium.From the purification experiment results,it can be seen that the purification and retention rate of in can reach 99.03%by adopting the new process?concentrated sulfuric acid aging and leaching process?.Compared with conventional sulfuric acid leaching,the concentrated sulfuric acid aging leaching process proposed in this study can effectively improve the leaching rate of indium,and has a positive effect on the leaching process.Subsequent purification,extraction and other processes can be carried out to change related process parameters,which can meet the production requirements of enterprises and achieve the purpose of improving indium recovery rate.