配加蒙古精矿对球团矿性能的影响

对蒙古精矿在包钢624 m2带式球团的合理利用进行了全面研究。研究表明，随着蒙古精矿配比增加，球团矿品位提高，还原膨胀率增加，当配比小于20%时，还原膨胀率小于20.0%，主要是由于还原后球团矿矿物组成中析出大量金属铁，在浮氏体(FexO)转变为铁的阶段，铁晶粒自浮士体表面向外长出晶须，晶须的生长让晶粒产生位移或晶粒开裂，导致球团结构疏松发生膨胀。通过添加适量矽石，可显著降低球团还原膨胀率，当配加30%～50%的蒙古精矿时，可通过添加1.0%～2.0%的矽石，将球团还原膨胀率降低至20%以内，球团矿质量满足高炉冶炼生产要求。

Effects of adding Mongolian concentrate on pellets properties

The rational utilization of Mongolian concentrate in the 624 m2 belt pellets of Baotou Steel is comprehensively investigated. The results showed that with the increase of the proportion of Mongolian concentrate, the grade of pellets improved, and the reduction expansion rate increased. When the ratio was less than 20%, the reduction expansion rate was less than 20.0%, mainly due to the precipitation of a large amount of metal iron in the pellet mineral composition after reduction. In the phase transformation of ferrite (FexO) to iron, iron whiskers growed outward from the surface of the float. The growth of iron whiskers caused the displacement or cracking of the grains, leading to the expansion of the pellet structure. The reduction expansion rate of pellets can be significantly reduced by adding an appropriate amount of silica. By adding an appropriate amount of silica, the reduction ratio of the pellets can be significantly reduced. When adding 30% to 50% of Mongolian concentrate, the reduction expansion rate of pellets can be reduced within 20% by adding 1.0% to 2.0% of silica. The quality of pellets met the requirements of blast furnace smelting production.