熔融法还原中低品位磷矿的工艺及动力学

Process Parameters and Kinetics of Smelting Reduction Technology for Low-Grade Phosphate Ore Reduction

利用实验室高温电炉研究了中低品位磷矿熔融还原的工艺条件及动力学,考察了反应温度、反应时间、石墨粉用量、磷矿碱度对P2O5还原率的影响。结果表明P2O5还原率随反应温度、反应时间、石墨粉用量的增加而增加,随磷矿碱度的增加而先增加后降低最后趋于平衡,在碱度B=0.9时达到最大值,因此该反应较适宜的反应条件是反应温度1550℃、B=0.9、石墨粉用量应为理论用量的2倍、反应时间60 min,P2O5的还原率达到98.9%。同时由不同碱度,不同温度下,P2O5还原率随时间变化的关系表明熔融法还原中低品位磷矿是一级反应,且在B=0.9时表观活化能为225.106 kJ·mol-1。

Low-grade phosphate ore reduction by smelting reduction technology was investigated in a laboratory trial furnace. The effects of reaction temperature, reaction time, carbon consumption, phosphate ore basicity on the P205 reduction ratio were studied. The results show that the P205 reduction ratio increases with the increase of reaction temperature, reaction time and carbon consumption, while it increases and then decreases, and later becomes stable with the increase of phosphate ore basicity. The reduction ratio reaches maximum with basicity of 0.9. The P205 reduction ratio reaches to 98.9% under the optimal conditions： reaction temperature 1550℃, reaction time 60 min, two times of theoretical value of carbon consumption and 0.9 basicity. The relationship between P205 reduction ratio and time under different basicity and temperature shows that the smelting reduction reaction is a first-order reaction and its apparent activation energy is 225.106 kJ.mog^-1.