Comprehensive Utilization Of Indium And Cadmium In High-iron Sphalerite

Marmatite is a typical kind of zinc ores with rich iron and indium,besides copper,cadium and silver etc..It is the important problem that how to extract metals from Marmatite efficiently and cleaningly.Hydrometallurgy of marmatite produces a large amount of leaching residues and the recovery rate of indium is lower(In<60%).Process of"Reduction Smelting-Atmospheric Distillation-Comprehensive Recovery" has been proved to be efficient comprehensive extraction utilization of indium,zinc and cadmium.But there are still some key technology problems:Lose of In is still too much in residues of water-quenched slag and Cu-containing pig iron,the directly recovery rate is lower.The zinc with cadmium is hard to handle in smelting process,this results waste of cadmium resources,simple product of In and lower additional value.In this paper,the new process of comprehensive utilization of zinc,In,Cd was studied.Firstly,the distribution of elements was studied in the smelting reduction process of high marmatite;Secondly,ab initio molecular dynamics simulation was carried out to study the feasibility of simelting of mixed Pb and Zn in reduction process,and also do experimental study on smelting reduction smelting of zinc and lead;Then process of vacuum distillation was proposed to handle the Zn with high Cd which produced form atmospheric distillation;Last,the experimental research of purification of indium was studied.The specific research work is as follows:(1)The distribution behavior of zinc,indium,cadmium,copper,iron,silver,lead,and tin in the process of high temperature reduction volatilization of Marmatite were analyzed as follows:?The direct yield of zinc was 83.86%,the direct yield of indium was about 64.45%,the direct yield of tin was about 13.55%,and the yield of silver was about 32%;?The indium which lossed in the process of melting slag containing copper pig iron in water quenching was14.87%,80.93%of cadmium was enriched in high cadmium zinc;?11.62%of copper was into the water-quenched slag,63.85%enriched in copper containing pig iron;60%of iron was into the copper containing pig iron,and the 11%into the water quenching slag;The 83.62%of lead in zinc calcine was in the crude zinc.(2)In consideration of the huge loss of indium in Cu-containing pig iron and water-quenched slag during reduction smelting,the enhancement of indium concentration in Pb-Zn smelting process was proposed.Ab initio molecular dynamics(AIMD)was first employed to study the feasibility of indium richness with lead addition during reduction smelting hence the interaction between Zn,In and Pb was determined.Then the influence of lead content in the distribution of indium in the product during reduction smelting was explored by experimental study of Zn-Pb smelting.The results show that:1)Firstly,the total energy of PbnInn?PbnZnn?ZnnInn(n=2-10)with different n clusters was studied.The ability combining between atoms of binary clusters is Pb-In>Pb-Zn>Zn-In.Then,the molecular dynamics simulation of Zn12In6Pb-2 clusters(In:Pb=3:1),Zn14In2Pb4(In:Pb=l:2)clusters,Zn,2In2Pb6(In:Pb=1:3)clusters and Zn15lnPb4(In:Pb=1:4)clusters were carried out.The simulation results showed that Zn atoms in clusters were unstable,after the dynamic simulationthe Zn atoms in the Zn-In-pb ternary alloy clusters were separated from the cluster body;The binding force of In-Pb was the best in Zn12In2Pb6 and the binding force of In-Pb was the weakest in Zn15InPb4.Finally,ab initio molecular dynamics simulation of Zn106In11Pb11 ternary alloy:The interaction between In-Pb is stronger than Zn-In and Zn-Pb.2)Utilization of reaction between Pb and In,mixed Pb and Zn smelting was carried out:Changing ratio between lead and zinc(In:Pb-3:1,1:2,1:3,1:4)showed the enrichment of indium in crude zinc can increased the concentration of indium in crude zinc.At the same time,reducing the loss of indium in the process of reducing smelting slag,and the content of lead in enrichment and reduction smelting was 0.18?0.2%(In:Pb?1:3)indium can be well enriched in zinc melt.3)The experimental datas of In:Pb ratio 1:3 showed:?The increase of lead content in furnace can reduce the content of indium in copper containing pig iron,from 573.28g/t to 100g/t,greatly increasing the recovery of indium.?The indium content in crude zinc increases from 1073.7g/t to 1442.3g/t by 25.19%.Indium recovery rate increased to 95%,an increase of 18.46%;The content of iron in crude zinc decreased to below 0.2%.(3)Faced to the zinc with high Cd produced in the process of pyrometallurgy,The idea of vacuum distillation-multistage condensantion of zinc with high Cd was put forward.It showed:It is beneficial for the vacuum distillation separation and purification of zinc cadmium alloy to keep the long time heat preservation.In higher the number of condensing disks,the more purified cadmium can be obtained,and the separation was more efficiency the 4N refined Cd can be obtained form Zn-Cd alloy in the condition of 30Pa,673K,30min by three times vacuum distillation.(4)Experimental study on the purification of indium showed:Most of the impurities in the indium were enriched in the ingot during the melting process;The impurity elements in the molten zone can be fully condensed byreduced the melting speed and increased the number of zone melting,so that the purity effects were improved..Under the condition of melting rate of 1mm/min,After 10 times of zone melting,High purity indium of 99.9991%was obtained.The process of high temperature smelting reduction of Marmatite was completed in the paper,through the research working of enrichment of In,vacuum distillation of znic with high Cd,purification of In in zone melting,the comprehensive utilization of In,Cd in marmatite was realized.