赤铁矿属于六方晶系,a轴、c轴长度不等,存在着各向异性的特点。因此在赤铁矿→磁铁矿的还原阶段,其还原速度和还原膨胀存在着各向异性。特别是赤铁矿中固溶有其它元素时会造成赤铁矿晶胞发生畸变,内应力增大,各向异性增大。在还原时a、c方向的还原速度和膨胀速度的各向异性增大,因而导致了球团矿的膨胀和粉化。 Hematite belongs to the hexagonal system, a-axis, c-axis length ranging from the existence of anisotropic characteristics. Therefore, in the reduction phase of hematite → magnetite, there is anisotropy in its reduction rate and reduction and expansion. In particular, when hematite is dissolved in other elements, hematite cells will be distorted, the internal stress will increase, and the anisotropy will increase. At the time of reduction, the anisotropy of a and c in the direction of reduction and expansion rate increases, resulting in the expansion and pulverization of pellets.