添加赤铁矿对氧化球团性能的影响

Effects of adding hematite on the properties of oxidized pellets

由于环境保护以及高铁品位冶炼生产的需要,提高球团矿配比已经成为高炉冶炼的趋势。选取澳矿(赤铁矿)作为研究对象,探究不同配比(5%、10%、15%)赤铁矿的加入对生球性能、焙烧球抗压强度和冶金性能的影响。结果表明:随着赤铁矿配比的提高,生球落下强度变化不明显,抗压强度上升1.58 N/P;焙烧球中Fe2O3连晶变差,焙烧球强度下降,由未加赤铁矿的2761 N/P降低到含15%赤铁矿的2587 N/P,延长焙烧时间能够增强含赤铁矿球团抗压强度;球团的还原膨胀率由10.42%提高到13.47%、还原性由60.20%提高到62.60%;球团的软熔层变化不大,熔融层变宽,滴落层变窄,透气性指数由869.15 kPa·℃降低到182.71 kPa·℃。在球团矿生产过程中,可以采用一部分赤铁矿来代替磁铁矿。

Due to the need of environment protection,and smelting and production of high grade iron,high proportion pellets has become more and more adopted in blast furnace smelting.The Australian ore(hematite)is selected as the research object to explore the effects of hematite in different proportions(5%,10%,15%)on pellet properties,compressive strength of calcined pellets and metallurgical properties.The results show that with the increase of hematite proportion,the change of the falling strength of green pellets is not evident,and the compressive strength rises by 1.58 N/P.The continuous crystal region of Fe2O3 in the pellets is lessened,and the strength of the roasted pellets decreases from 2761 N/P without hematite to 2587 N/P containing 15%hematite.The strength of hematite-bearing pellets can be enhanced by extending the roasting time.The reduction expansion rate of pellets increases from 10.42%to 13.47%,and the reducibility increases from 60.2%to 62.6%.The soft melt layer of pellet changed little,the melt layer widens and the droplet layer narrows,and the permeability index decreases from 869.15 kPa·℃to 182.71 kPa·℃.In the pellet production process,a certain amount of the hematite can be used to replace the magnetite.