球团矿抗压强度对其冶金性能的影响

Effect of compression strength of pellets on metallurgical properties

对一种细粒度磁铁精矿粉制备的生球团,通过调整其预热及焙烧工艺参数,生产出不同抗压强度的球团矿,并对其孔隙率以及还原度和还原膨胀率进行了测定。试验结果表明,随着球团矿抗压强度的提高,其孔隙率呈下降趋势,其900℃还原度也呈下降趋势,而还原膨胀率变化不大。对不同抗压强度球团矿的矿相进行了测定,结果表明,预热时间的延长,使球团初期的预热氧化过程更加完全,Fe2O3微晶键更好地发育和长大,而焙烧温度的升高,则可以促进后期Fe2O3的再结晶和长大,提高晶键互连程度,晶粒紧密连接成片,孔隙率下降,使焙烧球团具有较高的抗压强度,但结构致密,变得难以还原。

The pellets of different compression strength were produced with a green pellet,which made up with mag-netite concentrate,by adjusting preheating and roasting parameters,the porosity,reducibility and reduction swelling index were then determined.The results showed that the porosity and reduction index（RI）at 900 ℃ decreased with the increase of compression strength,but no remarkable changes were observed for reduction swelling index（RSI）. The researches were also carried out by analyzing the mineral phase of the pellets of different compression strength. The results indicated that preheating oxidization process were finished fully and Fe2 O3 micro-particles were devel-oped completely along with the prolongation of preheating time.While Fe2 O3 re-crystallization and grain growth were promoted and Fe2 O3 micro-particles are connected closely with the increase of roasting temperature,which re-sulted in the increase of compression strength and decrease of porosity and reduction index.