Extraction of molybdenum and nickel from carbonaceous shale by oxidation roasting, sulphation roasting and water leaching

The extraction of molybdenum and nickel from a carbonaceous shale ore was investigated by oxidation roasting, followed by sulphation roasting and water leaching. The results indicated that this process was an efficient method for the extraction of molybdenum and nickel from the ore. Sulphation roasting promotes the reaction of sulphuric acid with molybdenum and nickel oxides and also decomposes the molybdenum-bearing mineral phase powellite in the roasted Ni–Mo ore. Under the optimum experimental conditions (sulphation roasting at 240 °C for 1 h; 32 ml sulphuric acid/100 g roasted Ni–Mo ore; water leaching for 2 h. at 98 °C with a liquid-to-solid ratio of 2:1), the water leach extracted 92.1% Mo and 83.5% Ni.