包头含铌铁精矿选择性还原试验

Selective reduction of Baotou Nb-bearing iron ore concentrate

采用兰炭为还原剂,利用罐式选择性还原的方法处理铌铁精矿,研究不同还原条件时金属化率的变化规律,利用扫描电镜观察铌的赋存形式,利用电炉熔分脱铁的方法处理还原后的铌铁精矿,考察铌氧化物的富集程度。研究结果表明,当温度为940~970℃时,还原2.5 h时铌铁精矿中铁氧化物金属化率可达85%以上,在还原过程中,铌氧化物不被还原成金属铌;铌主要以含钛、铁硅酸盐形式存在于还原后团块中;熔分获得金属铁和富铌渣,富铌渣中铌氧化物是原矿的1.55倍。

The treatment of Nb-bearing iron ore concentrate by the method of selective reduction in tank and using semicoke 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 niobiumenriched slag,for the latter,the concentration of niobium oxide in niobium-enriched slag was 1.55 times that in crude minerals.