Studies on Reduction Characteristics of Limonite and Effect of Sodium Sulphate on The Selective Reduction to Nickel

The selective reduction process is the process to separate nickel and iron on limonite with the combination of magnetic separation. This process uses sodium sulphate as the additive and graphite as the reductant. The stoichiometry of reductant and the concentration of additive are the key for this process on the selective reduction to the nickel grade, recovery, and grain size of iron–nickel which has been investigated in the variation of graphite stoichiometry and Na₂SO₄. The samples were analysed by X-Ray diffraction, fluorescence, and the grain size was measured with an optical microscope. The optimum graphite stoichiometry and Na₂SO₄ dosage are in the 0.125 st and 10% Na₂SO_4, which produced a concentrate with nickel grade and recovery of 4.54 weight% and 89.12%. The grain size is being smaller than high level of stoichiometry, and Na₂SO₄ due to the amount of carbon and Na₂SO₄ excess in the process with the size 60.63 μ m.