Study On The Treatment Process Of High Cobalt Slag In Zinc Hydrometallurgy

The raw materials are high cobalt residue obtained by cementation in the purification residue leachate,it contains a large amount of valuable metals,due to the complex composition,the rotary kiln is often sent to recover only zinc,which causes waste of resources such as cobalt and nickel in the residue.Aiming at improving the deficiencies of the existing processes,a dilute sulfuric acid leaching-second-stage high cobalt residue neutralization-hydrogen peroxide de-iron-zinc powder replacement cadmium-new active vulcanizing agent except nickel-sodium persulfate is determined which combines a hydrometallurgical process for the selective oxidation of manganese-sodium persulfate oxide cobalt.Through experimental research,the better experimental results are obtained,which lays a foundation for the subsequent industrial application,the main experimental results are as follows:(1)The optimum conditions for dilute sulfuric acid leaching are as follows:liquid-solid ratio is 10:1,the concentration of dilute sulfuric acid is 150 g/L,the time of leaching is 120 minates,leaching temperature is 85?.Under these superior conditions,the leaching rate of cobalt was 96.14%.,and the leaching rates of zinc,nickel,cadmium,iron and manganese are all greater than 99%.The acidic leachate was added to the raw material to control the pH at 5.0 with the temperature of 85?(2)The optimum process conditions for the oxidation of iron oxyhydroxide are as follows:the theoretical amount of hydrogen peroxide is 1.0 times,the oxidation temperature is 80?,and the oxidation time is 15 min.After the reaction is completed,the CaCO3 adjusts the pH at 4.0-4.5,the precipitation rate of iron is greater than 99.98%(3)For the process of removing manganese,the preferred process conditions for the oxidation of manganese sulphate by sodium sulphate are:initial acidity of 3 g/L,sodium persulfate addition of 2.0 times the theoretical amount,oxidation time of one hour,and oxidation temperature of 85?.Under this optimal condition,the Mn decreased from the initial 897.3 mg/L to 0.13 mg/L,the precipitation rate was over 99.98%,and the precipitation rate of Co was less than 0.13%.(4)The preferred process conditions for the oxidation of cobalt over sodium sulfate are:sodium persulfate addition of 2.2 times the molar amount of cobalt,the amount of flocculant CH-2813 is 0.8 mg/L,the oxidation time is 120 minates,the oxidation temperature is 85?.Under this optimal condition,the precipitation rate of Co is above 99.99%.The cobalt content in the cobalt residue was 49.62%,the zinc content was 24.11%.The method is used to treat the purified residue produced in zinc hydrometallurgy,and the process is simple and easy.The cobalt,nickel,cadmium,iron and manganese in the high cobalt residue can be obtained by the corresponding experimental conditions obtained in the present study.At last,the solution is returned to the zinc hydrometallurgy system to recover zinc.