Study On Recovery Of Bismuth From Bismuth Chloride Solution By Diaphragm Electrodeposition

Chlorine harm and high power consumption are all the time since a difficult problem in bismuth of hydrochloric acid chloride solution by electrodeposition recycling bismuth. This paper put forward recovery bismuth from bismuth of hydrochloric acid chloride solution by diaphragm electrodeposition, avoid chlorine was produced, at the same time also reduces power consumption, in the theory and the application value of production bismuth has important significance.In12hours, direct electrodeposition average current efficiency of bismuth of hydrochloric acid chloride solution was63.5%, chlorine is difficult to collect and use in the anode, The chlorine caused great harm to the electrodeposition. This paper present electrolytic cell is divided into the anode chamber and a cathode chamber by used RF-COOH/RF-SO3H exchange membrane, respectively put in NaOH and bismuth of hydrochloric acid chloride solution, at the diaphragm electrodeposition after generation the formation of sodium chlorate and high purity bismuth.In the diaphragm electrodeposition test, the experiment through single component change to be investigate the effect of current density, temperature,[HC1],[NaOH],[Bi3+] in the electrodeposition, each single factor variation on the influence law of diaphragm electrodeposition. After diaphragm electrodeposition the actual bismuth of hydrochloric acid chloride solution, The experiments results have shown that the optimum conditions of diaphragm electrodeposition were as follows:current density150A/m2, temperature45-55℃,3.5mol/LHC1,[TBP]<0.4g/L110g/LBi3+,Bi/Sb>50,Bi/As>100,80g/LNaCl and15g/LNaOH, The current efficiency and the cathode bismuth purity were98.8%and99.5%, the cell voltage is lower than2.1V. The RF-COOH/RF-SO3H exchange membrane was found that life short-lived in the diaphragm electrodeposition test, the study found that in addition to composite ion-exchange membrane quality itself and the installation of the operating problems, when [HCl]>3mol/L or [HCl]≥5.5mol/L,[Bi3+]≤65g/L,[NaOH]≤2g/L,[TBP]≥0.6g/L, than diaphragm electrodeposition will make the omposite ion-exchange membrane was damaged phenomenon.After the end of diaphragm electrodeposition test, reutilization the electrodeposition waste solution. At the circumstances40℃,8mol/LNaOH solution isolated sodium chlorate, after used sodium chlorate and bismuth of hydrochloric acid chloride waste solution to return of leaching bismuth ore, after isolated sodium chlorate solution ware return of anode electric effusion, then again was diaphragm electrodeposition, realize closed cycle of the entire process.