高磷鲕状赤铁矿深度还原过程中磷的迁移行为

Migration Behavior of Phosphorus in Coal-based Reduction of a High Phosphorus Oolitic Hematite Ore

湖北某高磷鲕状赤铁矿石铁品位为42.21%、磷含量为1.31%;铁主要以赤铁矿形式存在,磷主要以磷灰石形式存在。为考察深度还原过程中磷的迁移行为,对该矿石进行了深度还原—弱磁选试验。结果表明:升高还原温度、延长还原时间或增大碳氧摩尔比均有利于磷向金属铁相富集。在还原温度1 548 K、碳氧摩尔比2.5和还原时间60 min的条件下进行还原,获得的还原产品磨细至-0.074 mm占84%,在磁场强度为107 k A/m的条件下弱磁选后,可得到磷品位2.49%、回收率77.07%的高磷金属相。金属相SEM及EDS能谱分析结果表明:金属相中部分区域的磷以P-Fe固溶体的形式存在,部分区域的磷以Fe_xP和P-Fe固溶体的形式共存。

A high phosphorus oolitic hematite ore from Hubei province contains 42. 21% total iron and 1. 31% phosphorus.Iron and phosphorus are mainly existed in form of hematite and apatite,respectively.In order to investigate the migration behavior of phosphorus in reduction process of the ore,coal-based reduction followed by low intensity magnetic separation was employed.The results indicated that increase reduction temperature,C and O molar ratio and reduction time were favorable for the migration of phosphorus in the metallic iron phase.The reduction products obtained at 1 548 K for 60 min with C and O molar ratio of 2. 5,high phosphorus metallic phase containing 2. 49% phosphorus with recovery of 77. 07% was produced after ground the reduction products to 84% passing 0. 074 mm and magnetic separation with magnetic field intensity of 107 k A/m.The SEM-EDS analysis results showed that some phosphorus distributed in metallic phase as Fe-P solid solution but others coexisted in the form of both Fe_xP compound and Fe-P solid solution.