煤基直接还原—磁选超微细贫赤铁矿新工艺

Beneficiation of super microfine low-grade hematite ore by coal-based direct reduction-magnetic concentration process

针对某种超微细粒贫赤铁矿难选的特点,开发了煤基直接还原—磁选新工艺,制备出高品位铁精矿。采用预热团块煤基直接还原工艺制取高金属化率的直接还原团块,经磨矿—磁选,得到高品位高金属化率的铁精矿,从而为开发利用微细粒嵌布复杂低品位铁矿提供了理论依据。通过对还原温度、还原时间及C与Fe质量比等条件的优化,得到金属化率93.72%的还原矿,经三段磨矿—三段磁选得到Fetot为69.54%,金属化率为98.01%,且有害杂质含量少的铁精矿。该工艺所得的高金属化率的铁精矿可直接作为转炉炼钢的原料。

Coal-based direct reduction-magnetic concentration, a new process on up-grading of super microfine refractory hematite was developed. With adoption of the coal-based direct reduction and milling-magnetic separation, the concentrate with high grade and metallization degree was produced. This work provides a theory basis for utilization of low grade iron ore. Under the optimize conditions of reduction temperatures, duration and C/Fe mass ratio, the reduced ore with 93.72% metallization degree is produced. After three stages grinding-magnetic separation, the concentrate with 69.54% Fetot, 98.01% metallization degree and low content of impurities are obtained. The iron concentrate with high metallization degree produced by this process is a superior burden for making steel in converters.