高磷鲕状铁矿直接还原-磁选提铁降磷扩大试验研究  

Pilot study of high-phosphorus oolitic iron ore for iron recovery and dephosphorization by direct reduction–magnetic separation

作　　者：吴世超 孙体昌[1] 寇珏[1] 李小辉 WU Shi-chao;SUN Ti-chang;KOU Jue;LI Xiao-hui(School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083

出　　处：《工程科学学报》2022年第5期849-856,共8页Chinese Journal of Engineering

基　　金：国家重点研发计划资助项目(2021YFC2902404);国家自然科学基金资助项目(51874017)。

摘　　要：为给回转窑工业试验提供参数,以小型试验最佳结果为基础,进行了高磷鲕状铁矿煤基直接还原-磁选提铁降磷扩大试验.结果表明,在最佳的条件下可获得铁品位94.17%、铁回收率77.47%以及磷质量分数0.08%的粉末还原铁,推荐的回转窑工业试验初始条件为:石灰石用量(质量分数)28%、无烟煤用量(质量分数)16%、还原温度1300℃,还原时间3 h.采用XRD以及SEM-EDS研究了无烟煤的作用机理,发现无烟煤用量增加,促进了浮氏体、镁铁尖晶石的还原以及铁颗粒长大,从而提高了铁的回收效果,但过多的无烟煤通过增强还原气氛及其带入的灰分消耗了石灰石,使铁矿物中的磷以及磷灰石还原成单质磷并与铁颗粒形成铁磷合金.With the development of the steel industry,the use of high-grade and easy-to-handle iron ore is gradually decreasing.At present,the effective utilization of low-grade and refractory iron ore,particularly high-phosphorus oolitic iron ore,has gradually become a research hotspot and a worldwide problem.This type of ore is mainly distributed in the USA,France,Germany,Russia,and China and often has an oolitic structure,where the intercalation relationship between iron minerals and gangue minerals is complicated and the phosphorus content is high.Therefore,this type of ore has not yet been developed and utilized.Studies have shown that the use of coalbased direct reduction –magnetic separation to process high-phosphorus oolitic iron ore is one of the methods to achieve efficient utilization of its iron resources.Researchers have conducted in-depth studies on process optimization,dephosphorization mechanism,and iron and phosphorus reduction kinetics.To determine the parameters for the industrial test of the rotary kiln,based on the best result of the small-scale test,a pilot-scale experiment on iron recovery and dephosphorization from high-phosphorus oolitic iron ore was conducted using coal-based direct reduction,followed by magnetic separation.Results showed that under the optimum conditions,the grade and recovery of iron and phosphorus contents in the powdered reduced iron concentrate were 94.17%,77.47%,and 0.08%,respectively.Limestone dosage of 28%,anthracite dosage of 16%,reduction temperature of 1300 °C and reduction time of 3 h were recommended as the initial conditions for the industrial test of the rotary kiln.The mechanisms of anthracite were investigated by X-ray diffraction and scanning electron microscopy –energy-dispersive X-ray spectroscopy.The results showed that with the increase in anthracite dosage,the reduction of wustite and pleonaste and the growth of iron particles are promoted,thereby improving the recovery effect of iron.However,a high anthracite dosage enhanced the reducing atmosphere and

关 键 词：高磷鲕状铁矿 煤基直接还原 磁选 提铁降磷 扩大试验 

分 类 号：TD925[矿业工程—选矿]