Tian Y.,Kunming University of Science and Technology |
Tian Y.,National Engineering Laboratory for Vacuum Metallurgy |
Tian Y.,State Key Laboratory Breeding Base Of Complex Non Ferrous Metal Rsrc Clear Utilization In Yunnan Prov |
Qu T.,Kunming University of Science and Technology |
And 17 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2012
We addressed the extraction of magnesium metal from nickel laterite by carbothermic reduction in vacuum. The Gibbs free energy and critical temperature in the nickel laterite de-oxidation by carbon were calculated in thermodynamics. The calculated results show that low pressure significantly lowers the curve of Gibbs free energy and temperature, and that the magnesium carbothermic reduction occurs at the critical temperature ranging from 1200°C to 1350°C, coinciding with magnesia silicothermic reduction. The contents in the slag were analyzed. The results show that the Mg removal rate was over 99.96%, the direct recovery rate of Ni was 99.67%, and that the recovery rates of Fe and Si were 83.98% and 85.32%, respectively. Mg metal, 95.59% pure, dominated in the condensate. X-ray diffraction results show that small amount of magnesia existed in the slag possibly because of the reverse reaction: Mg(g)+CO(g)=Mg(s)+C(s). Source