Extraction of Nickel from Magnesia–Nickel Silicate Ore

In this study, magnesia–nickel silicate ore was investigated, which contained 0.83% Ni and antigorite, chlorite, magnetite (Fe 3 O 4 ), quartz, and mica as the main minerals. Chloride roasting and magnetic separation were used to treat the ore. The addition of red mud enhanced the transformation of nickel silicate to a strongly magnetic mineral mainly comprising metallic Ni and that of hematite to Fe 3 O 4 and metallic Fe. Test results showed that a Ni concentrate with a Ni content of 11.41% and Ni recovery of 92.77% was achieved under the following optimal conditions: roasting temperature: 1373.15 K; roasting time: 120 min; CaCl 2 dosage: 20%; coke dosage: 14%; red mud dosage: 30%; magnetic field intensity = 0.14 T; and grinding fineness: 90%