Study On Removal Of Selenium, Tellurium And Copper From Nickelic Copper Anodic Slime

As for the high Ni copper anodic slime raw material, to begin with, this paper make use of XRD, XRF and chemical analysis to preliminary master the material content and elements; and then, in view of selenium, tellurium, copper elements interfere with the process of extraction of precious metals such as gold and silver largely in anodic slime, we take the thermodynamic analysis of the mechanism of removal; on this basis, the anodic slime materials were taken alkaline roasting-alkaline leaching to get rid of selenium-acid leaching to remove copper and tellurium on the experimental study; on the basis of experimental study, the slag phase which come from the process of roasting, alkaline leaching, acid leaching analyzed by XRD, and combined with the removal of the test results, and with them analyzed and verified selenium, tellurium, copper removal mechanism. The main results are as follows:By adding alkali to oxidation roasting-alkaline leaching to remove selenium-acid leaching to get rid of copper and tellurium, the optimum conditions are as follows:The optimum conditions of oxidation roasting:roasting temperature500℃, the addition of Na2CO3or NaOH are equivalent to10%the amount of anodic slime, roasting time0.5h, the optimum conditions of alkaline leaching to remove selenium:the concentration of NaOH20g/L, alkaline leaching time1.0h, alkaline leaching temperature80℃, ratio of solid to liquid5:1; the optimum acid leaching conditions to remove copper and tellurium:sulfuric acid concentration5%, leaching temperature70℃, acid leaching time1.0h, ratio of liquid to solid20:1.Under this optimum condition, using Na2CO3roasting, the rate in the process of removal selenium on alkaline leaching is95.59%, the content of selenium in solid phase decreased from3.93%to0.25%; the rate in the process of removal copper and tellurium on acid leaching are96.35%and99.93%. Using NaOH roasting, the rate in the process of removal selenium on alkaline leaching is95.50%, the content of selenium in solid phase decreased from3.93%to0.23%; the rate in the process of removal copper and tellurium on acid leaching are96.87%and98.96%.In the process of adding alkali to oxidation roasting, selenides in anodic slime were converted into sodium selenite, tellurides were converted in form of Te6+; calcine in alkaline leaching process, sodium selenite was dissolved in alkaline solution, While Te6+into TeO32-with free Cu2+form copper tellurite, copper tellurite was little dissolved, so the alkaline leaching can achieve removal of selenium preferentially, the leaching residues which contains copper tellurite, dissolved in sulfuric acid solution, and the residual selenium will further leaching.Experimental results show that, By the means of adding alkali to oxidation roasting-alkaline leaching to remove selenium-acid leaching to get rid of copper and tellurium to deal with copper anodic slime, either using Na2CO3or NaOH, can achieve effective removal of selenium, tellurium, copper, and can obtain the prefractionation between copper and selenium and tellurium.