碳酸钠在高磷鲕状赤铁矿直接还原中的作用

为了研究碳酸钠对尼日利亚某高磷鲕状赤铁矿直接还原焙烧-磁选脱磷效果的影响，采用X射线衍射(XRD)和扫描电镜(SEM)研究了添加碳酸钠后直接还原焙烧的产物.结果表明，还原焙烧过程中添加碳酸钠后可以实现脱磷:碳酸钠的加入抑制了铁橄榄石的生成，阻断了磷进入金属铁的过程；使得鲕粒结构破坏，促进金属铁颗粒的聚集长大，有利于金属铁颗粒与脉石的解离；原矿中含磷矿物在焙烧过程中与碳酸钠反应生成可溶性的Na3PO4，在磨矿磁选过程中溶于水，使直接还原铁中磷的含量降低.

Dephosphorization Effect of Sodium Carbonate in the Process of Direct Reduction Roasting of High Phosphorous Oolitic Hematite

In order to investigate the effects of sodium carbonate on magnetic concentration and dephosphorization in direct reduction roasting process of a high phosphorous oolitic hematite from Nigeria， the products of direct reduction roasting were analyzed by X ray diffraction(XRD) and scanning electron microscopy(SEM) after sodium carbonate was added. The results showed that the dephosphorization can be realized in the reduction roasting process after the sodium carbonate was added:sodium carbonate added inhibits the formation of fayalite and interdicts the process of the phosphorus entering metallic iron; the oolitic structure is destroyed， promoting aggregation and growth of metallic iron particles and the liberation of metallic iron particles from gangue; phosphorus bearing minerals in the raw ore can react with sodium carbonate in the process of roasting， so that soluble complex sodium phosphate is generated， which is soluble in water in the process of grinding and magnetic separation and lower phosphorus content of direct reduction iron.