Selective reduction of Baotou Nb-bearing iron ore concentrate
LIU Yu-bao1,2,WANG Jing-song1,ZHANG Xian-heng2,ZHAO Er-xiong2,XUE Qing-guo1,SHE Xue-feng1
(1. State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijng 100083,China 2. State Key Laborotory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization,Baotou Research Institute of Rare Earths,Baotou 014030,Nei Mongol,China)
Abstract:The treatment of Nb-bearing iron ore concentrate by the method of selective reduction in tank and using semi-coke as the reductant was discussed, the change law of the metallization rate under different reduction conditions was studied. The occurrence of niobium was observed by scanning electron microscope. The enrichment degree of niobium oxide was investigated after the reduction of Nb-bearing iron ore concentrate by means of melt-separation and deferrization. Main results show that holding in the temperature from 940 to 970 ℃ for 2.5 h, the metallization rate of the iron oxide in the Nb-bearing iron ore concentrate reached more than 85%. Niobium oxide was not transformed to niobium metal in the reduction. Niobium which was mainly in the form of titanium and iron silicate was distributed in the reduced agglomerate. By the way of melt-separation and deferrization, the study obtained iron metal and niobium-enriched slag, for the latter, the concentration of niobium oxide in niobium-enriched slag was 1.55 times that in crude minerals.