高铝高硫低品位铁矿粉还原熔分制备珠铁

 基于转底炉珠铁工艺，以一种高铝高硫低品位铁矿粉和无烟煤为原料，在实验室条件下进行了还原熔分试验研究，考察了温度、配碳量、碱度和添加剂对高铝铁矿含碳球团还原熔分行为的影响，并分析了碱度和添加剂对珠铁中硫质量分数的影响。试验结果表明，温度为1 350～1 450 ℃时，空白球团熔分效果较差，金属铁渗碳量较低；提高配碳量，金属铁渗碳量略有增加，但熔分效果仍较差；碱度增加会促进球团还原，1 450 ℃时，碱度为0.6、0.8、1.0、1.2的球团可以实现渣铁良好分离，珠铁中硫质量分数逐渐降低，碱度为1.2时降低较明显；Na2CO3配比增加，球团熔分也会逐渐变差，1 450 ℃时球团基本均可以熔分，珠铁中的硫质量分数逐渐降低，但脱硫效果不明显；当碱度为1.2、Na2CO3配加为8%、CaF2配加为4%时，球团可以在1 450 ℃下良好熔分，脱硫效果显著，珠铁中硫质量分数为0.085%，脱硫率达到96.5%，所得珠铁基本满足炼钢要求。

Preparation of iron nugget using low grade iron ore of high alumina and sulphur

The iron nugget process using low grade iron ore of high alumina and sulphur as raw material was performed at laboratory scale. The effect of reduction temperature， carbon content， basicity and additives on the reduction and melting behavior of the high alumina ore/coal composite pellet was investigated. The sulphur content of the iron nugget was also analyzed. The standard pellet (without any additives) had bad melting separation and the carburization degree of the reduced iron was low. The increasing of carbon content could improve the melting separation a little. The reduction rate of the pellet would be improved with the increasing of basicity and the pellet could melt better at 1 450 ℃. The sulphur content of the iron nugget gradually decreased as the basicity increased from 0.6 to 1.2 and was obviously low when the basicity was 1.2. The pellet would also melt worse with the Na2CO3 content in the pellet increased and could melt to some extent at 1 450 ℃. The sulphur content of the iron nugget would also gradually decrease. However， the effect of Na2CO3 on the sulphur content of the iron nugget was not much. The sulphur content of the iron nugget was 0.085% and the desulphurization rate was 96.5% with basicity of 1.2， 8% Na2CO3 and 4% CaF2 reduced at 1 450 ℃. The obtained iron nugget could meet the requirement of steel making to some extent.