高磷铁矿石直接还原—磁选研究进展

Research Progress of Direct Reduction—Magnetic Separation of High Phosphorus Iron Ore

针对高磷铁矿石性质复杂,铁回收困难的问题,研究人员提出的直接还原—磁选工艺处理高磷铁矿石具有良好的提铁效果。归纳了各类高磷铁矿石性质,从高磷铁矿石直接还原—脱磷工艺和直接还原—富磷工艺两种路线总结了近年来的成果,并阐明了两种工艺的机理。根据高磷铁矿石是否为鲕状构造,将高磷铁矿石分为高磷鲕状铁矿石和其它高磷铁矿石。采用直接还原—脱磷工艺处理各类高磷铁矿石能获得炼钢要求的直接还原铁,寻找低成本脱磷剂、研究反应进程的控制以及查明脱磷剂用量大的原因是未来的重要方向。采用直接还原—富磷工艺可获得磷含量大于1.5%,磷回收率在60%~70%的高磷直接还原铁,调整焙烧条件进一步提高磷回收率以及查明磷在铁相中存在形式是今后的研究重点。采用直接还原—脱磷工艺处理高磷铁矿石已成功进行了工业试验,为实现该类矿石的开发利用,要从研发新的还原装备、研究还原气氛的精准控制技术、气体成分在线监测仪器以及降低生产能耗等方面进行深入研究。

view of the complex nature of high-phosphorus iron ore and the difficulty of iron recovery,the researchers proposed that the direct reduction-magnetic separation process for treating high-phosphorus iron ore has a good effect for iron recovery.The properties of various kinds of high-phosphorous iron ores were compared,and the achievements in recent years were summarized from the direct reduction-dephosphorization process and the reduction-phosphorus enrichment process of high-phosphorous iron ore,and the mechanisms of the two processes were analyzed.According to whether the high-phosphorus iron ore is an oolitic structure,the high-phosphorus iron ore is divided into high-phosphorus oolitic iron ore and other high-phosphorus iron ore.Direct reducion iron required for steelmaking can be obtained by treating all kinds of high-phosphorous iron ore with direct reduction-dephosphorization process.However,the cost of dephosphorization agent is high,and it is necessary to develop a cheaper dephosphorization agent,and to study the control of the reaction process and find out the reason for the large amount of dephosphorization agent is an important direction in the future.High-phosphorus direct reduced iron with phosphorus content of more than 1.5%and phosphorus recovery of 60%~70%can be obtained by direct reduction-phosphorus enrichment process.Adjusting the roasting conditions to further improve the phosphorus recovery and to find out the form of phosphorus in the iron phase is the focus of future research.The direct reduction-dephosphorization process has been successfully used in industrial trials to treat high-phosphorus iron ore.In order to realize the development and utilization of this type of ore,it is necessary to conduct in-depth research in the aspects of researching and developing new reduction equipment,studying precise control technology of reducing atmosphere and online monitoring equipment for gas composition,and reducing energy consumption.