Selective extraction of Mo from a Ni-Mo ore using pressure alkaline leaching

Pressure alkaline leaching of a Ni-Mo ore for selective extraction of Mo was investigated. Thermodynamic analysis of Mo-S-H2O and Ni-S-I-H2O indicated that pressure alkaline leaching of Ni-Mo ore is technically feasible for selective extraction of Mo. The effects of NaOH concentration, temperature, leaching duration, liquid/solid ratio and particle size on the leaching of Mo and Ni were studied. The results showed that Mo extraction was improved significantly by NaOH concentration, temperature or leaching duration, but not by liquid/solid ratio or particle size. The optimum parameters were: NaOH concentration of 100 g/L, temperature of 120 degrees C, leaching duration of 5 h, liquid/solid ratio of 3 mL/g and particle size of 74-98 mu m. Under these conditions, about 95.7% of Mo and 13% of Ni could be extracted. (C) 2015 Elsevier B.V. All rights reserved.