鲕状赤铁矿高温快速还原试验研究

Study on Dephosphorization Behavior for Oolitic Hematite by High Temperature Reduction

摘要: 采用内配碳球团高温快速还原-磁选工艺处理国内某高磷鲕状赤铁矿，系统研究了C/Fe比、还原温度、还原时间、二元碱度、添加剂配比对还原过程中金属化率、脱磷及磁选等指标的影响，并对其提铁脱磷行为进行探讨。研究表明，在适宜的条件下还原-磁选，可获得铁品位94.06%、铁回收率91.37%的铁精矿，总脱磷率由自然碱度、无添加剂条件下的35.49%提高到91.79%，铁精矿的磷含量由2.03%降低到0.25%。部分磷被还原成气态挥发，大部分磷被还原后与金属铁结合，磁选难以脱除；提高碱度，形成高熔点物质可抑制一部分磷与铁反应，加入钠盐添加剂可提高精矿铁品位并抑制磷灰石的还原。

Abstract: Based on the characteristics of high phosphorus oolitic hematite, the studies were done by short time reduction at high temperature and magnetic separation for carbon-bearing pellets. The effects of C/Fe ratio, reduction temperature, reduction time, binary basicity, and additives on the concentrate indexes on metallization ratio and dephosphorization behavior were studied. The results show that the iron concentrate, assaying 94.06% Fe and 0.25% P with iron recovery of 91.37% and dephosphorization of 91.89%, was conducted under the optimum conditions. The iron concentrate, assaying 2.03% P with dephosphorization of 35.49%%, was conducted under natural basicity and no additives. During the reduction roasting, some phosphorus was volatilized in the form of P gas. For the pellets without adding additives, most phosphorus formed phosphorus iron compounds with metallic iron, which was difficult to remove. When the additives were employed and the basicity was increased, most phosphorus was absorbed in the high melting substances, and removed by magnetic separation.