组合脱磷剂对高磷铁矿还原焙烧-磁选的影响

针对高磷铁矿还原焙烧降磷过程中脱磷剂成本高、用量大等难题，为更好地开发利用高磷铁矿，采用还原焙烧-磁选工艺，研究了组合脱磷剂对高磷铁矿提铁降磷的影响.通过X射线衍射(XRD)和扫描电子显微镜-能谱仪(SEM-EDS)揭示提铁降磷机理.结果表明:加入13%碳酸钙和2%碳酸钠作为组合脱磷剂能代替传统脱磷剂，并获得了良好的脱磷效果.当原矿铁品位55.58%，含磷0.57%时，在推荐的试验条件下，可获得铁品位93.25%，铁回收率90.75%、磷质量分数0.09%以及磷的去除率高达91.46%的粉状还原铁.加入的组合脱磷剂不仅促使铁氧化物中的磷组元向磷酸钙发生转变，使金属铁颗粒与磷酸钙界限明显，而且还能防止难以还原的铝尖晶石和铁橄榄石的生成，最终实现了磷的深度脱除和铁的有效回收.

Effects of Combined Dephosphorization Agents on Reduction Roasting-Magnetic Separation of High Phosphorus Iron Ore

In view of the problems such as high cost and large amount of dephosphorization agents in the process of dephosphorization by reduction roasting of high phosphorus iron ore， to better develop and utilize high phosphorus iron ore， the effect of combined dephosphorization agents on iron improvement and dephosphorization of high phosphorus iron ore was studied via reduction roasting-magnetic separation process. X-ray diffraction(XRD)and scanning electron microscope-energy dispersive spectroscopy(SEM-EDS)were used to reveal the mechanism of dephosphorization. The results showed that adding 13% CaCO₃ and 2% Na₂CO₃ as a combined dephosphorization agent can replace the traditional dephosphorization agent， and good dephosphorization effect is obtained. Under the recommended experimental conditions， powdery reduced iron with iron grade of 93.25%， iron recovery of 90.75%， phosphorus content of 0.09%， and dephosphorization of 91.46%can be obtained when iron grade is 55.58% and phosphorus content of raw ore is 0.57%. The added combined dephosphorization agent not only promotes the transformation of phosphorus components in the iron oxides into calcium phosphate， and makes the boundary between metallic iron particles and calcium phosphate distinct， but also prevents the formation of hercynite and fayalite， which is difficult to reduce. Finally， the deep removal of phosphorus and the effective recovery of iron are realized.