PMC矿粒度及球团预热、焙烧工艺参数的选择

 为了促进PMC矿粉的高效利用,研究了PMC矿粉粒度和预热、焙烧温度对球团矿抗压强度、还原度、低温还原粉化、膨胀率、转鼓强度、孔隙率和熔滴性能的影响。结果表明,随着预热、焙烧温度的升高,改善了球团矿的抗压强度、还原度、转鼓强度和软熔滴落性能,低温还原粉化率变化幅度较小。随着焙烧温度的升高,膨胀率先升高后降低,孔隙率降低。随着预热温度的升高,1号球团矿 (PMC 0.074 mm)的膨胀率下降,2号球团矿(PMC 0.045 mm)的膨胀率小幅度升高;随预热温度的升高,两种PMC球团矿孔隙率先降低然后升高,在预热温度为950 ℃时,孔隙率最低。根据上述研究结果,通过加权灰色关联度法确定了PMC矿球团生产最佳工艺参数,粒度为0.074 mm,预热温度为925 ℃,焙烧温度为1 300 ℃。

Selection of PMC ore size,preheating and roasting process parameters for pelletizing

In order to promote the efficient utilization of PMC ore powder, the effects of particle size, preheating, and roasting temperature of PMC ore powder on the compressive strength, reduction index, reduction degradation index, swelling rate, drum strength, porosity, and softening-melting properties of pellets were studied. The results indicate that, with the increase of preheating and roasting temperature, the compressive strength, reduction index, drum strength and softening-melting properties of pellets are improved, and the change of reduction degradation index is small; with the increase of roasting temperature, the swelling rate increases first and then decreases, and the porosity decreases; with the increase of preheating temperature, the swelling rate of No.1 pellets decreases, while the swelling rate of No.2 pellets increases slightly; with the increase of preheating temperature, the porosity of two kinds of PMC pellets first decreases and then increases, and the porosity is the lowest when preheating temperature is 950 ℃. According to the above research results, the best process parameters are determined by the weighted grey correlation method: the particle size of No.1 PMC, the preheating temperature is 925 ℃, and the roasting temperature is 1 300 ℃.