低铁高硅赤铁精矿对氧化球团性能的影响

为合理利用国内低铁高硅铁精矿、降低球团生产成本,研究了低铁高硅赤铁精矿对生球、预热球和焙烧球团性能的影响。结果表明,典型的低铁高硅赤铁精矿A较磁铁精矿有更好的润磨性能。赤铁精矿A的亲水性较磁铁精矿强,在保持生球水分不变且赤铁精矿配比较高的条件下(>10%),生球水分不足,生球质量随着赤铁矿配比的提高而变差。随着赤铁精矿A的配比由0提高到50%,预热球强度由588降低到196 N/个,焙烧球团抗压强度由3 425降低到1 368 N/个,赤铁精矿A配比不宜高于30%,适当提高焙烧温度有利于球团抗压强度的提高。配加低铁高硅赤铁精矿A的球团还原膨胀性能和还原性能均有一定程度改善。

Effect of low iron and high silicon hematite concentrate ratio on properties of oxidized pellets

In order to make rational use of the domestic low iron and high silicon iron concentrate and reduce the pellet production cost,the effect of low iron and high silicon hematite concentrate on the properties of green pellet,preheating pellet and roasted pellet was studied. The results showed that the typical low iron and high silicon hematite concentrate A had better wet grinding performance than that of magnetite concentrates. And the hydrophilicity of hematite concentrate A was stronger than that of magnetite concentrate. Under the condition that the water content of raw pellets was unchanged and the ratio of hematite concentrate to magnetite concentrate was high (>10%),the water content of raw pellets was insufficient,and the strength of green pellets decreased with the increase of hematite ratios. As the ratios of hematite concentrate A increased from 0 to 50%,the strength of the preheated and roasted pellets decreased from 588 to 196 N/pellet and 3 425 to 1 368 N/pellet,respectively. These results indicated that the feasible ratio of hematite concentrate A was lower than 30%. Moreover,an appropriate level to improve the roasting temperature could improve the compressive strength of roasted pellets. The results also indicated that the reduction swelling and reducibility of pellets had some improvement with the addition of a certain amount of hematite concentrate A.