关键词: 铁矿石, 磁化焙烧, 弱磁选, 阶磨阶选

Abstract: The TFe grade of Gushan iron ore in Masteel is 37.68%.The main iron-containing mineral is hematite,and gangue composition is mainly composed of SiO₂ and Al₂O₃.The content of harmful element P is high.It is difficult to obtain good technical and economic indexes by using traditional beneficiation technology,while the magnetization roasting for refractory iron ore is an effective pretreatment method.Therefore,an experimental study on magnetization roasting-low intensity magnetic separation was carried out for Gushan iron ore,and the effects of roasting feeding fineness,roasting temperature,reducing gas concentration and roasting time on magnetization roasting effect were explored.The results showed that under the conditions of -0.074 mm accounting for 50%,roasting temperature of 500 ℃,CO gas concentration of 40%,roasting time of 20 min,gas flow rate of 500 mL/min,the roasted products were obtained by grinding-magnetic separation-regrinding-magnetic separation-tertiary grinding-magnetic separation.Iron concentrate with iron grade of 63.98%,iron recovery rate of 83.32% and P content of 0.15% was obtained,and the product index was better than the existing process.The research results can provide a new idea for the efficient utilization of Gushan iron ore in Masteel.

Key words: iron ores,magnetization roasting,low intensity magnetic separation,stage grinding and stage magnetic separation