还原温度对直接还原镍铁颗粒长大特性的影响

摘要

The effect of reduction temperature on the grain size of ferronickel in directly reducing laterite with rotary kiln was studied. The results show that the optimal reduction temperature is 1 360℃ when c/o ratio of briquette is 2, the reduction time is 3 h and the Cao/ore ratio of briquette is 7%. Based on the reducing conditions, the grain size of more than 80% ferronickel particles is greater than 1 mm. When the temperature is low, the slag viscosity is large, which lead to the bad transfer of mass and heat, so the grain of ferronickel is hard to grow up, and the recovery rate of ferronickel is decreased. When the temperature is too high, the reducing atmosphere is lower in the reaction system, so the grade and recovery rate of ferronickel become lower. Hence, the optimal reduction temperature is 1 360℃ considering the quality of ferronickel and saving energy.%实验考察了还原温度对红土镍矿回转窑直接还原生产粒状镍铁工艺中镍铁颗粒团聚长大的影响。试验结果表明，还原时间3 h、球团配碳比Xc/Xo为2、球团氧化钙配比7%，还原温度约1360℃，此时还原产品镍铁颗粒粒径80%以上大于1 mm。温度偏低时，渣相粘度过大，不利于传质传热的进行，不利于镍铁颗粒团聚长大，降低了镍铁回收率；当温度过高时，还原体系中还原气氛相对更弱，导致镍铁颗粒中镍铁品位以及镍铁回收率有小幅下降趋势。综合考虑镍铁颗粒的产品质量和节能降耗等，选择熔炼温度为1360℃。