Enrichment of Niobium by Selective Reduction of Niobium-Bearing Iron Ore:An Orthogonal Experimental Study

A novel technique has been successfully developed to enrich Nb by selective reduction of Nb-containing iron-ore powder, with H₂ as the reduction agent in argon atmosphere.The influence of the hydrogen flow rate, reduction temperature and reduction time on the removal of the impurities, including, but not limited to the Fe, S, P, Al and Si oxides (or weight loss rate) from the Nb-bearing iron ore, was experimentally investigated via orthogonal design. The preliminary results show that the newly-developed hydrogen selective reduction is feasible for the enrichment of Nb under the optimized conditions, including a reduction temperature of 950℃, a reduction time for 3 h and a hydrogen flow rate of 90 L/h.We suggest that the new technique be of some technological interest in extraction of metal Nb from the Nb-containing multi-metallic minerals.