含钛铌铁精矿含碳球团熔分过程试验研究

为了实现我国白云鄂博地区含钛铌铁精矿资源的高效利用，以含钛铌铁精矿为原料，采用预还原-熔分的加热制度，研究熔分温度、熔分时间和碱度对含钛铌铁精矿含碳球团熔分行为以及渣系性质的影响.进一步采用X射线衍射、扫描电子显微镜等手段表征含碳球团在熔分过程中的微观结构及物相变化.实验结果表明:金属化率86.31 %的预还原含钛铌铁精矿含碳球团在1 400 ℃下熔分12 min后可实现渣铁有效分离，获得珠铁和富铌渣.随碱度升高，渣的熔点升高，渣的流动性指数降低，碱度为1.0时，球团的熔分效果较优；随熔分时间增加，含钛铌铁精矿含碳球团中的Ca₂Ti₂O₆相减少，Ca（Ti_0.4Fe_0.3Nb_0.3）O₃相增加，钙钛铌共生物的尺寸增加，呈十字树枝状. 

Experimental study on the melting-separation of carbon composite pellets in Ti-Nb-bearing Fe concentrate

Effects of the melting-separation temperature, melting-separation time and slag basicity on the melting-separation behavior of carbon composite pellets in Ti-Nb-bearing Fe concentrate and the properties of slag were studied by preproduction-melting-separation experiment in order to realize efficient utilization of Ti-Nb-bearing Fe concentrate in Bayan Obo Area, Inner Mongolia, with Ti-Nb-bearing Fe concentrate being the raw material. Moreover, the microstructure and phase transformation of pellets were characterized by XRD and SEM during melting-separation process. Results showed that complete slag-metal separation of reduced pellets whose metallization rate was 86.31 % could be realized after the melting-separation lasted 12 min at 1 400 ℃. Besides, iron nuggets and Nb-enriched slag were also obtained. The melting point of slag increased and the fluidity index of slag decreased with the increase of basicity. The best melting-separation effect could be achieved when slag basicity was 1.0. With the increase of melting-separation time, Ca₂Ti₂O₆ transformed gradually to Ca(Ti_0.4Fe_0.3Nb_0.3)O₃ and the size of Ca(Ti_0.4Fe_0.3Nb_0.3)O₃ increased.