磁铁矿粉粒度对球团矿预热焙烧性能的影响

 研究了3种不同粒度的超细磁铁精矿粉，粒度小于0.044 mm的矿粉质量分数在89%以上。试验研究了其制备的球团矿的焙烧性能。试验结果表明，铁精矿粉粒度越细，球团矿在最佳焙烧制度下获得的抗压强度也越高，但适宜的预热温度也越低，而所需预热及焙烧时间也越长。在对生球孔隙率测试研究的基础上发现，精矿粒度越细，生球孔隙率越小，氧化变得越困难，需要较长的预热时间，而预热温度太高，表层易形成致密层，导致球团矿强度下降；在对适宜的焙烧制度下焙烧的球团矿的FeO含量测定结果表明，对于焙烧球团矿，随矿粉粒度的变细，其FeO含量则越高，表明氧化条件变差，需较长的焙烧时间。

Effect of Particle Size Distribution of Magnetite Concentrate on Preheating and Roasting Parameters of Pellet

The researches were carried out on three kinds of super-fine magnetite concentrate with nearly 89% of the material being less than 0.044 mm. The results show that the compression strength of roasted pellets increase with the increasing of proportion for minus 0.044 mm, but pellets must be roasted with lower preheating temperature and longer preheating and roasting time. The research work on the changes of porosity of green pellets indicates that the finer the iron concentrate become, the lower porosity pellet get, so the pellet must be roasted at lower preheating temperature to avoid the formation of crusted layer, which deteriorates the compression strength of pellet. The pellet also must be roasted at longer preheating time to compensate the slower oxidization process because of lower porosity of pellet. The research work on the FeO content of pellet indicates that the finer the iron concentrate become, the lower FeO content of pellet attain, so the pellet must be roasted at longer roasting time to guarantee the effective oxidization process.