鄂西高磷鲕状赤铁矿直接还原焙烧同步脱磷机理

Dephosphorization mechanism in a roasting process for direct reduction of high-phosphorus oolitic hematite in west Hubei Province,China

采用XRD和SEM分析方法研究了鄂西高磷鲕状赤铁矿添加脱磷剂后直接还原焙烧的产物及磁选后的最终产品.结果表明,还原焙烧过程中添加的脱磷剂除具有脱磷效果外,对铁的还原也有促进作用.脱磷剂可以使部分磷转化为易去除的可溶性磷酸盐,同时破坏鲕粒结构,使细磨-磁选后铁相易与脉石矿物分离从而达到脱磷效果,并且可以提高产品中铁的品位和回收率.

Direct reduction-roasted products and final products after magnetic separation, which are reduced from high-phosphorus oolitic hematite in west Hubei Province of China by adding a dephosphorization agent, were investigated by XRD and SEM. The results show that the dephosphorization agent added in the reduction-roasting process can remove phosphorus and promote iron reduction. The dephosphorization agent not only transforms partial phosphorus ores into easy removed solvable phosphate but also breaks the oolitic structure, leading to an easy separation of iron from gangue after fine grinding and magnetic separation in order to remove phosphorus. The grade and recovery of iron also improve due to adding the dephosphorization agent.