Copper Electrowinning Preparation And Properties Of New Lead-based Alloy Anodes

Recently, the hydro metallurgy processes for smelting copper by soakâ†'extractionâ†'back extractionâ†'smelting meltal developmnented fust at home and abroad. Hence the anode for electrowining copper is studied by smelting research workers widely. Now,Pb-Ca-Sn anode is widespresd used in electrowining copper industry which with the high content of Ca and Sn, it may cause higher oxygen evolution potential,bad corrosion stability and lower current efficiency. In order to improve the corrosion stability, current efficiency, electrochemical performance and mechanical capacity of anodes, we had preparation Pb-Cu-Ca-Sn and Pb-Cu-Ca-Sn-Ce alloys in this experiment.The results of metallographic analysis and microcosmic hardenss testing shows that 1% Cu or 1% Ca could lead liquation, and Sn had expedited Cu and Ca dispersed in lead alloy.Ce also could expedited Cu and Ca dispersed in lead alloy,and that Ce had refined grain,advanced hardenss of lead alloy.The purpose of refined grain by copper would be better when RE had been appended into lead alloy. The hardness of Casting and rolling Pb-Sn-Cu-Ca alloy were10.33-12.09HB and 10.55～12.37 HB. The hardness of Casting and rolling Pb-Sn-Cu-Ca-Ce alloy were 11.7～13.69 (HV) and 11.32-13.9 (HV). The hardness of Casting and rolling Pb-Ca-Sn alloy were 9.26HB and 8.95 HB. Rolling had different influence to alloys.Rolling made the Pb-Sn-Cu-Ca and Pb-Sn-Ca alloys had recrystallized, so that the hardness of alloys has been reduced.When the alloys contained Cu(≤0.3%) and Ce,Rolling had hardening effect to lead alloys.The accelerated corrosion experiments was studied in CuSO4-H2SO4 system with 45℃,the current 1000/m2.The results shows that:the corrosion resistance of intermediate alloy which contain only Cu or Ca was the worst, and Pb-0.06%Ca-0.1%Cu-0.6%Sn-Ce alloy is the best (the corrosion rate was 3.3745g m-2h-1,lower 0.6505g m-2h-1 compared to rolling Pb-0.06%Ca-0.6%Sn alloy). The corrosion rate of casting alloys had a linear increasing with the copper increased.Ce had increased the corrosion resistance of casting alloys. Rolling had increased the corrosion resistance of Pb-0.06%Ca-Cu-0.6%Sn alloys, howere it made the corrosion rate of Pb-0.06%Ca-0.6%Sn and Pb-0.1%Cu-0.06%Ca-0.6%Sn-Ce had increased. The anodic polarization,Cyclic voltammograms and Ac impedance was studied at 45℃,in the solution of 45g/LCu2+,180g/L H2SO4.The conclusion of these testing as follows:the active of lead alloy climb up and then decline with increased the content of copper. Corrosion rate had increased slightly with increased the content of copper. Ce and Copper had synergetic effect in enhance electrochemical performance of lead alloy.The results of deposition experiment showed that:copper lead the voltage reduced by O.Olv. But the change of copper had no noticeable effect in voltage. The current efficiency had been increased with the content of copper.Re also had noticeable effect current efficiency...