Experimental Study on Reduction-Magnetic Separation Process of Low-grade Nickel Laterite Ore

摘要

The reduction and magnetic separation of low-grade nickel laterite was studied at varing temperatures between 1325-1400℃ and a weak magnetic field of 100 mT in order to acquire high grade concentrations. The influence of reduction temperature, percentage of CaO, and atomic ratio of C/O (carbon/oxygen) were investigated. According to the gas analysis, the reaction process was divided into two stages: the direct reduction had a greater advantage than the indirect reduction in the earlier stage when the temperature was low, and the direct reduction and the indirect reduction reacted together in the later stage when the temperature was high. The result indicated that reduction temperature of 1375℃, percentage of CaO of 12% and atomic ratio of C/O of 1.2, the grade of fine ore was improved up to 5.71%. At the same time, the recovery rate of nickel reached up to 96.35%.