某高磷鲕状赤铁矿磷赋存状态及还原焙烧脱磷研究

采用浸出、电渗析等试验方法研究了尼日利亚高磷鲕状赤铁矿中磷的赋存状态并采用XRD和SEM分析添加脱磷剂Na2CO3直接还原焙烧产物的特性.结果表明，含磷矿物主要是呈微细粒包裹体嵌布在铁矿物鲕粒的裂隙或孔洞中的纤磷钙铝石(CaAl3(OH)6(HPO4)(PO4))、蓝磷铝铁矿(FeAl2(PO4)2OH·6H2O)以及均匀分散在铁矿物中的磷.通过添加脱磷剂Na2CO3的还原焙烧磁选可实现高效铁磷分离.磷通过两种方式去除:一部分含磷矿物与金属铁分离，存在于脉石矿物中，通过磨矿磁选可以有效去除，一部分含磷矿物与Na2CO3反应生成溶于水的磷矿物，最终使得还原铁产品中的磷含量降低.

Phosphorus Occurrence State and Phosphorus Removal Research of a High Phosphorous Oolitic Hematite by Direct Reduction Roasting Method

The phosphorus occurrence states of high phosphorous oolitic hematite in Nigeria were studied by soak leaching and electrodialysis test. The characteristics of roasted products in the beneficiation by direct reduction roasting with dephosphorization agent Na2CO3 was also analyzed using the XRD and SEM. It showed that phosphorus bearing minerals mainly existed as crandallite (CaAl3(OH)6(HPO4)(PO4)) and vauxite (FeAl2(PO4)2OH·6H2O)， which embedded in the fissures and holes of oolitic iron ore particles， or existed as the form of isomorphism interfusing in the ore mechanically. Separation of phosphorus and iron can be realized by direct reduction roasting (adding dephosphorizing agent Na2CO3) and magnetic separation. Phosphorus can be removed in two ways: part of the phosphorus was separated with iron and existed in the gangue mineral，which could be removed by grinding and magnetic separation. The other part of the phosphorus bearing minerals was transferred into the soluble phosphorus by reacting with the dephosphorization agent Na2CO3. Then the phosphorus content of the reduced iron products was reduced.