Studies On The Separation Of Molybdenum And Nickel From High Carbon Ni-Mo Ore

As a non-ferrous metal,molybdenum and nickel,used in a wide range,were limited resources.So the development and utilization of its lean and mixed ore is very necessary.There is one kind of molybdenum and nickel complex multi-metal mineral resource which has not been fully utilized because of its unique composition and physical and chemical properties.Traditional beneficiations or pyrometallurgical processes can hardly separate and extract molybdenum and nickel from that ore.Studies on hydrometallurgical process for that ore are also finite.Based on that,this paper mostly researched on the leaching and extraction process by experiments and found that the hydrometallurgical treatments for such ores were technically feasible.By theoretical analysis and experimental exploration,a complete hydrometallurgical process flow sheet was determined ultimately:direct leaching by nitric acid—impurity removal from leaching solution—precipitation of nickel sulphide—precipitation of magnesium carbonates—alkaline leaching of acid-leach residue and purifying residue—precipitation of calcium molybdate.The practical process parameters were found in experiments.Direct leaching using nitric acid was adopted and investigated.Under optimum conditions:liquid-solid ratio of 3,35%HNO3 and 10%H₂SO₄,70℃and 1.5h reaction, the leaching efficiency of Mo,Ni and Mg was 50%,97%and 85%respectively.In the following process,the total leaching rate of Mo could reach up to 90%by alkaline leaching of acid-leach residue.As the main impurities in the leaching solution,93% ferric could be removed by jarosite process.Special grade nickel sulfide concentrates could be gained by adding Na₂S to the purified solution and adjusting the pH value by NaOH.After that,dolomites could be obtained by adding Na₂CO₃.Then,confected by the remanent solution,the mixed lixivium containing 10%NaOH and 5%Na₂CO₃ was used to leach the acid-leach residue and purifying residue.It could make the molybdenum transferred from the residue to the solution.Then the secondary calcium molybdates could be obtained by adding CaCl₂ and adjusting the pH value by hydrochloric acid.In conclusion,according to that process,the recovery rate of Mo,Ni and Mg from the leaching solution was 80%,90%and 89%respectively,and secondary calcium molybdates,special grade nickel sulfide concentrates and dolomites could be obtained.The tests proved that the process was technically reliable and economically reasonable.It could effectively recover the valuable metals from the high carbon Ni-Mo ore.So it had an important reference value in the development and utilization of those molybdenum and nickel resources.