Process flowsheet development for beneficiation of nickel ore

Nickel sulphide ore subjected to this investigation was taken from the Marmara district of Turkey, where widespread chromite mineralization can be observed. Some amounts of magnetite and chromite exist in the ore together with sulphide and oxide type nickel minerals. The ore sample contains 1.32% Ni, 10.79% SiO2, 78.39% Fe2O3, 1.3g/t Ag, and 1.0g/t Au. The ore sample is constituted of about 70% magnetite, 15% sulphide minerals, and 5% chromite and iron oxides, as well as 10% gangue minerals. Nickel mineralization in the ore such as pentlandite, violarite, millerite awaruite, and asbolanewas determined. Due to the complex structure of mineralization, a combination of gravity-separation and flotation methods was applied for the concentration of nickel sulphide and oxide ores. A nickel concentrate containing 12.32% Ni was produced with 89.7% recovery and final tailings with 0.088% Ni can be disposed with 4.9% of metal loss. A process flowsheet was developed according to the optimum test results. The importance of this research is that it is the first example of developing a flowsheet for the beneficiation of sulphide and oxide type nickel mineralization observed together in chromite ore deposits.