非洲某高磷铁矿氧化焙烧-气基还原-磁选

Oxidation Roasting,Gas-based Reduction Followed by Magnetic Separation of a High Phosphorus Iron Ore in Africa

这是一篇冶金工程领域的论文。针对高磷铁矿石气基还原存在球强度低以及还原温度高的问题,提出了氧化焙烧-气基还原-磁选新工艺。考查了氧化温度以及脱磷剂种类对氧化球抗压强度的影响,并找出了符合竖炉强度要求的氧化焙烧条件,在此基础上,研究了还原温度、还原气体总流量、还原气体组成以及还原时间对提铁降磷的影响。结果表明,在Na^(2)CO_(3)用量10%,氧化温度1200℃,氧化时间60 min,还原温度950℃,H_(2)与CO的流量分别为3.75 L/min以及1.25 L/min,还原时间180 min的条件下,可获得铁品位91.15%、铁回收率93.07%和磷含量0.14%的粉末还原铁。扫描电镜结果表明,粉末还原铁中的磷以机械夹杂的形式存在,磷是通过磨矿-磁选除去。

This is an article in the field of metallurgical engineering.In view of the problems of low compressive strength and high reduction temperature in the gas-base reduction of a high-phosphorus iron ore,a new process of oxidation roasting,gas-based reduction followed by magnetic separation was proposed.The effect of oxidation temperature and the types and dosages of dephosphorization on the compressive strength of the oxidized pellets were investigated,and the conditions of oxidation roasting that met the strength requirements of the shaft furnace were found.On this basis,the effects of reducing temperature,total reducing gas flow rate,reducing gas composition and reducing time on iron recovery and dephosphorization were studied.The results showed that under the conditions of 10%Na_(2)CO_(3)dosage,oxidation temperature 1200℃,oxidation time 60 min,reduction temperature 950℃,flow rates of H_(2)and CO were 3.75 L/min and 1.25 L/min,respectively,and reduction time 180 min,Iron grade,iron recovery and phosphorus content were 91.15%,93.07%and 0.14%,respectively.The SEM results show that the phosphorus in the powdered reduced iron exists in the form of mechanical inclusions,and the phosphorus is removed by grinding-magnetic separation.