某高磷鲕状铁矿石气基直接还原-磁选提铁降磷研究

以国外某高磷鲕状铁矿石为原料, 研究了气基直接还原-磁选生产粉末还原铁工艺。考察了CaCO₃用量、还原温度、还原气体组成、还原气体总流量以及还原时间对提铁降磷的影响。结果表明, 该矿石通过气基直接还原提铁降磷是可行的, 在CaCO₃用量25%、还原温度1 200 ℃、还原时间90 min、H₂与CO流量比3∶1、还原气体总流量5 L/min条件下, 可获得铁品位、铁回收率以及磷含量分别为93.24%、92.83%以及0.085%的粉状还原铁。

High-Phosphorus Oolitic Iron Ore Processed with Gas-based Direct Reduction and Magnetic Separation for Iron Increasing and Phosphorus Reduction

With a foreign high-phosphorus oolitic iron ore as raw material, a process of gas-based direct reduction followed by magnetic separation was adopted in the study for producing powdered reduced iron. The effects of CaCO₃ dosage, reduction temperature, reducing gas compositions, total reducing gas flow, and reduction time on iron increasing and phosphorus reduction were investigated. The results show that it is feasible to reach the purpose of iron increasing and phosphorus reduction by using the process of gas-based direct reduction. It is shown that after the reduction process at 1 200 ℃ for 90 min, with the addition of CaCO₃ at an amount of 25%, the flow ratio of H₂ to CO at 3∶1 and the total flow of reducing gas at 5 L/min, a kind of reduced iron powder grading 93.24% Fe at 92.83% recovery, with phosphorus content of 0.085%, can be obtained.