高磷鲕状赤铁矿直接还原同步脱磷新脱磷剂

为开发高磷鲕状赤铁矿,采用直接还原焙烧的方法对含TFe品位为43.58%,磷含量0.83%的鄂西某宁乡式高磷鮞状赤铁矿进行系统研究。通过X线衍射仪(XRD)和扫描电镜(SEM)对提铁降磷机理进行研究。研究结果表明:在配合使用NCP和新脱磷剂TS2种脱磷剂的条件下,可以获得TFe品位为91.35%、铁回收率为85.12%、磷含量为0.081%的直接还原铁粉。原矿加入脱磷剂焙烧后,含磷矿物的物相并没有发生变化,仍以氟磷石的形式存在,通过细磨磁选实现提铁降磷。加入的脱磷剂有助于破坏鲕状结构,使金属铁颗粒与脉石颗粒的接触面变得平滑、清晰,改善高金属铁和脉石的解离条件,同时脱磷剂还能促进中间产物铁橄榄石的还原。

New dephosphorizing agent for phosphorus removal from high-phosphorus oolitic hematite ore in direct reduction roasting

In order to exploit high-phosphorus oolitic hematite,Phosphorus removal in direct reduction roasting of the Ningxiang type high phosphorus oolitic hematite with iron content about 43.58%,phosphorus content about 0.83% was studied.XRD and SEM were used to analyze the mechanism of direct reduction roasting and phosphorus removal.The results show that the direct reduction iron powder with an iron grade 91.35%,85.12% in recovery,phosphorus content about 0.081% is obtained under the condition that dephosphorizing agent NCP and new dephosphorizing agent TS is used together.It is found that phosphate phase has not changed,still existing in the form of apatite after direct reduction rosting,and phosphorus removal is achieved by finely ground and magnetic separation.The addition of dephosphorizing agent can make boundary of the gangue particles and metallic iron particles become smooth and clear,which is good to the dissociation of metallic iron particles and gangue,while dephosphorizing agent can also promote the reduction of fayalite.