Recovery of iron and nickel from nickel laterite ore by direct reduction roasting and magnetic separation

By adding a flux and using a direct reduction roasting and magnetic separation method,iron and nickel enrichment from refractory low-grade nickel laterite ore,in which nickel is mainly contained in silicates,was studied.Better technical indicators were obtained by adding the flux.The optimal conditions are coal as the reducer with a dosage of 15%,KD-2 as the flux with a dosage of 20%,and roasting at 1200℃ for 40min.A concentrate of the Ni content of 10.83% and the Fe content of 52.87%,with the Ni recovery of 82.15% and the Fe recovery of 54.59%,was produced under the optimal conditions.The action mechanisms of KD-2 and coal were also investigated by XRD and TEM.The results show that KD-2 can react with quartz and silicates containing Ni,leading to releasing Ni from the quartz and silicates.An overdosage of coal in the reduction roasting process can result in the formation of pure iron,in company with a decrease in nickel recovery.