Process Research On Recovering Cobalt From Cobalt Slag

A process for recovery cobalt from cobalt residue of removing cobalt with Autimonic oxide from a zinc hydrometallurgy factory was investigated.At present,the process of recovering cobalt from cobalt residue mainly adopts the technology of sulfuric acid leaching,impurity removal,depositing cobalt,but the process is not close to the main process of zinc hydrometallurgy and complicate.At the base of the review of the extraction methods of cobalt from cobalt residue,the selectively sulfuric acid leaching of zinc-sulfuric acid leaching of the rich cobalt residues-potassium permanganate oxidation precipitation of cobalt process is proposed.The optimum parameters were obtained after research in the experiments,which can provide a new technique for practical industrial application.In this thesis,the selective leaching of cobalt residue with sulfuric acid as the leaching agent was used to obtain rich cobalt residue,the cobalt oxidation-precipitation were carrid out by using the Potassium Permanganate as oxidant on leaching solution obtainted by acid leaching from rich cobalt residue.The recovery and utilization of cobalt is achieved in this process.The main experiment results are as follows:(1)The effects of restrainer dosage,sulfuric acid dosage,flow rate of feeding acid,leaching time,leaching temperature,liquid-solid ratio were researched.The optimum terms of selective acid leaching of zinc were gained as follows,restrainer dosage is 10%,sulfuric acid dosage is 70%,flow rate of feeding acid is 2.OmL·min-1,leaching time is 30min,leaching temperature is 50?,liquid-solid ratio is 6:1,The verification experiments of selective acid leaching of zinc were studied under those conditions above and the results showed that the leaching ratio of zinc and cobalt are 82.37%and 11.21%respectively,the zinc and cobalt content of leaching residue are 19.90%and 11.73%,Cobalt is preliminary enriched.(2)The leaching solution of Zn2+ and Co2+ containing 14.29g/L and 8.79g/L was obtained by the acid leaching of rich cobalt residue.Using this solution as material,experiments of oxidizing precipitation separate cobalt and zinc was carried.The effects of the amount of KMnO4,reaction time,the terminal pH,reaction temperature were researched.The optimum terms of oxidizing precipitation separate cobalt and zinc were gained as follows,the amount of KMnO4 is theoretical quantity,reaction time is 75min,the terminal pH is 3.4?3.6,reaction temperature is 80?.The verification experiments of oxidizing precipitation separate cobalt and zinc were studied under those conditions above and the results showed that the precipitation ratio of zinc and cobalt are 1.68%and 99.96%respectively,zinc and cobalt content of precipitation residue are 0.11%and 41.36%respectively.