气基预还原处理高铝铁矿石

使用气基预还原的方法对一种全铁质量分数为3082%，Al2O3质量分数为2332%的高铝铁矿石进行铝铁分离研究.研究结果表明:1#球团于900℃、还原气氛为70%CO(体积分数)+30%H2、还原时间为77min时得到最高还原率7713%；2#球团于950℃、还原气氛为70%CO+30%H2、还原时间为80min时得到最高还原率822%；另外，2#球团在900℃以上还原时所能达到的最高还原率很接近；综合考虑，两种球团的最佳预还原温度为900℃；配加消石灰后，可以破坏原矿中铁、铝、硅之间的嵌布关系.X射线衍射分析结果表明，在还原过程中，出现了难还原的Fe2SiO4相和FeAl2O4相，这是导致还原难以进行的原因.

Treatment of High-Aluminium Content Iron Ore by Gas-Based Prereduction

An approach of gas-based prereduction was introduced to treat a high-aluminium content iron ore with total iron of 30.82% (mass fraction) and Al2O3 of 23.32% for Al-Fe separation. The results showed that the maximum reduction rate of 1^# pellets reached 77.13% by reduction for 77 minutes in the reduction atmosphere of 70%CO and 30%H2 in volume fraction at 900 °C. The maximum reduction rate of 2^# pellets reached 82.2% by reduction for 80 minutes with 70%CO and 30%H2 in volume fraction at 950 °C. The maximum reduction rates achieved for 2^# pellets at the temperatures above 900 °C were very close, so the optimal prereduction temperature of two kinds of pellets was 900 °C by taking all the factors into consideration. The additive of slaked lime undermined the existential relationship among ferreous, aluminiferous and silaceous minerals. X-ray diffraction results indicated that the phases Fe2SiO4 and FeAl2O4 which were difficult to deoxidize appeared in the process of reduction and made the reduction process difficult to carry on.