鲕状赤铁矿深度还原过程中温度对磷分布规律的影响

Effect of Temperature on Phosphorus Distribution During Coalbased Reduction of Oolitic Iron Ore

针对鲕状赤铁矿石深度还原过程中有害元素磷在金属相中富集的问题,对深度还原过程中磷富集过程进行了研究.在配碳系数为2.0,还原时间80 min,还原温度分别为1 200,1 225,1 250和1 275℃条件下,分析了磷元素在还原物料中的分布规律及还原过程中磷元素的迁移路径.试验结果表明:在1 225℃以下时,磷元素含量由渣相内部到相界面逐渐升高,由相界面到金属相内部逐渐降低;1 250℃以上时,磷含量由渣相到金属相内部逐渐升高.此外,还原过程中磷元素的走向为:磷元素最初主要存在于磷酸盐中,反应开始后磷酸盐与C反应,磷元素被还原为单质磷溶入铁,并在金属相中富集.

As harmful element phosphorus concentrated in iron particles during reduction of oolitic iron ore,the reaction process of phosphorus migration was investigated. During the reaction process,reaction time is 80 min and reaction temperature are 1 200,1 225,1 250 and 1 275 ℃,respectively. Phosphorus distribution are analyzed in slag phase and metal phase and phosphorus migration route is also discussed. The results showbelow1 225 ℃ phosphorus content gradually increases from slag phase to phase interface,but decreases from phase interface to inner metal phase,and phosphorus content increases from phase interface to inner metal phase while temperature increases above 1 250 ℃. Phosphorus migration route is also confirmed eventually.Firstly phosphorus exists in phosphate,phosphate reacts with carbon when the reaction begins,and then simple substance phosphorus is created and migrates into metal phase.