高磷鲕状赤铁矿磷的存在形态及脱磷机理

 针对高磷鲕状赤铁矿石矿物结构复杂导致的脱磷困难现状,为实现深度脱磷的目的,探索矿物还原过程中磷的形态及微观脱磷过程。以铁品位为44.78%、磷的质量分数为0.92%的高磷鲕状赤铁矿为研究对象,根据其面扫描电镜及矿相结构图可知,矿物之间嵌布紧密、逐层形成鲕状结构,石英、鲕绿泥石与赤铁矿等互相包裹,磷元素集中分布在鲕粒内部的氟磷灰石中。通过对焙烧产物做扫描电镜(SEM)及能谱分析(EDS),对高磷鲕状赤铁矿脱磷机理进行研究。研究结果表明,当YM-1脱磷剂质量分数为16%,还原过程中鲕状结构被破坏,金属铁逐渐从鲕粒中析出聚集,脉石与铁颗粒分离明显,磷化为不同形态被脱除。磁选后尾矿、铁分离完全,磷元素几乎全部进入尾矿,添加复合脱磷剂YM-1焙烧磁选后铁精矿的铁品位为90.16%,铁回收率为91.25%,磷质量分数为0.056%,脱磷率为93.91%。铁精粉各项指标满足工业冶炼要求。

Existing forms of phosphorus in high phosphorus oolitic hematite and its dephosphorization mechanism

Based on difficulty in dephosphorization caused by the complex mineral structure of high phosphorus oolitic hematite, the morphology and micro dephosphorization process of phosphorus in the mineral reduction process were studied to achieve the purpose of deep dephosphorization. The high phosphorus oolitic hematite with the iron grade of 44.78% and the phosphorus mass percent of 0.92% was used in the experiment. From the surface scanning electron microscope and mineral phase structure diagram, it is known that the minerals were inlaid and formed oolitic structure layer by layer, with quartz, oolitic mud and hematite wrapping together, and phosphorus was concentrated and distributed in the fluorapatite inside the oolitic. The dephosphorization mechanism of high phosphorus oolitic hematite was studied based on the scanning electron microscope (SEM) and energy spectrum analysis (EDS). The results show that the oolitic structure is destroyed during the reduction process when the content of YM-1 dephosphorization agent is 16%, resulting in the gradually precipitated and aggregated from the oolitic of iron, separating of gangue from iron particles, and phosphorus removed in different forms. After magnetic separation, the tailings and iron are completely separated, and almost all phosphorus elements were found in the tailings. After adding composite dephosphorization agent YM-1 for calcined magnetic separation, the iron grade of the iron concentrate is 90.16%, the iron recovery is 91.25%, the mass percent of phosphorus is 0.056%, and the dephosphorization rate is 93.91%. The indexes of iron concentrate powder meet the requirements of industrial smelting.