Cu-co-fe Alloy Dissolution And Separation

A technological process of preparing Co₃O₄ from Cu—Co—Fe alloy powder wasinvestigated. The alloy was obtained by reducing the mine rich of copper and cobaltand the whole extracting processs was carried out by the following steps: roastingslag process,leaching of sulfuric acid,removing iron by the method of ferric alum,purging calcium and magnesium by villiaumite,precipitating by ethane diacid andcalcining. The leaching rates of cobalt from alloy powder was about 95.67％in thisprocesses, which were convenient,pollution—free.The effects of roasting time,temperature and amounts of adding CaCO₃ wereinvestigated and optimized during the slagging process. The original alloy powderwas calcined for 10 hours at 1300℃with adding 10％CaCO₃. The content of cobaltin the alloy increased to 37.83％from 31.07％, and the loss of cobalt in slag was lessthan 1.5％while the leaching rates of cobalt were more than 95％in the optimalcondition. The nature of different kinds of acids,leaching time,leachingtemperatures,concentrations,particle sizes,oxidants and stirring speed were studiedduring the leaching process, and the optical process was gotten as follows: the alloypowder under 100 mesh were leached by H₂SO₄ for 6 hours at the temperature of80℃. The leaching rate of cobalt was 95.67％and iron was 96.63％, while more than99％of copper remained in the leaching slag, which could be electrolyzed to get metalcopper. Besides sulfuric acid leaching, many other methods were tried includingelectrolyzing original alloy powder or alloy block in sulfuric acid or ammonia.Electrolyzing alloy block in sulfuric acid was better, but still worse than sulfuric acidleaching of the alloy powder after roasting.During the processes of iron removing, reaction temperature,end pH,reactiontime were researched.The ferric alum reaction was kept for 1 hour after the Fe²⁺ wasoxidized into Fe³⁺ by H₂O₂ and the pH was adjusted to 1.6 by adding Na₂CO₃ at90℃, then the pH was adjusted to 3.5 by NaOH and kept for 5 hours. The solutionwas filtrated after depositing for 15 minutes. The removing rates of iron reached99.97％and cobalt loss was less than 0.65％. The depositing process of cobalt wascarried out by the following steps: first, the solution pH was adjusted to 1.0 by H₂SO₄;second, the solution was shifted into 45g/L ethane acid solution and the pH wasadjusted to 2.2 by adding NaOH; third, the reaction was kept for 2 hours at 55℃.After the last step, the recovery of cobalt precipitating reached 99.92％and the purity arrived 99.91％. The cobalt oxalate was transited into Co₃O₄ by calcineing for 5 hoursat 650℃, and the CO₃O₄ can meet the GB6518—86.The significant features in the whole technological process were the followingsteps: firstly, the alloys were roasted using pyrometallurgical refining; secondly, thebroken alloys were leached by sulfuric acid with leaching rates of more than 95％.The both steps depended on each other, not only avoiding the pollutions fromhydrochloric acid or/and nitric acid leaching but also getting high leaching rates ofcobalt compared with traditional methods.