巴润精矿配比对球团矿强度的影响

 为了充分发挥巴润铁精矿(白云鄂博西矿)含铁品位高、粒度分布集中、成球性能优异的特点,同时抑制其K₂O、Na₂O和F含量较高的弱点,研究了如何通过其与有害元素含量较低的区内矿合理搭配,在保证氧化球团成品矿强度的基础上,提高巴润矿的利用率。研究过程中,采用FactSage7.3热力学软件计算、氧化焙烧、抗压强度检测、化学成分检测、矿相分析、SEM-EDS分析等试验研究手段,对不同巴润铁精矿配比下成品球强度的影响因素进行了分析。研究结果表明,区内铁精矿比巴润铁精矿的粒度范围宽,两者平均粒度分别为53.21 μm和32.01 μm;区内矿铁精矿小于0.043 mm(<300目)的矿粉颗粒比例为78.65%,而巴润铁精矿粉所占比例为84.70%。巴润矿配比为40%的成品球的强度最高,为4 602.2 N/P。热力学计算表明,随着巴润矿配比增加,成品球中渣相量增加;氧化焙烧冷却过程中,40%巴润矿配比的成品球渣相析出物以辉石和石英为主,而100%巴润铁精矿成品球渣相析出物则以钙铁橄榄石为主。矿相结构上,随着巴润铁精矿配比增加,赤铁矿连晶效果下降,但40%配比时渣相分布均匀,起到了较好的黏结相的作用。100%巴润矿成品球中由于MgO质量分数达到1.05%,所形成的含镁磁铁矿颗粒连晶作用较差,这是造成其抗压强度较低的原因之一。

Effect of Barun concentrate ratio on strength of finished pellets

In order to give full play to the characteristics of Barun iron concentrate with high iron grade, concentrated particle size distribution and excellent pellet-forming performance, while suppress the weakness of high content of K₂O, Na₂O and F, how to improve the utilization rate of Barun ore on the basis of ensuring the strength of finished oxidized pellets by reasonably matching it with the ore in the region with low content of harmful elements was studied. In the research process, the influencing factors on strength of finished ball under different ratios of Barun iron concentrate were analyzed by FactSage7.3 thermodynamic software calculation, oxidation roasting, compressive strength detection, chemical composition detection, mineral phase analysis, SEM-EDS analysis and other experimental research methods. The results show that the iron concentrate in the area has a wider particle size range than the Barun iron concentrate, with the average particle size of 53.21 μm and 32.01 μm, respectively. The mineral powder particles smaller than 0.043 mm(<300 mesh) of iron concentrate in the area is accounting for 78.65%, while the mineral powder particles of Barun iron concentrate is accounting for 84.70%. The strength of finished ball with 40% ratio of Barun iron concentrate is the highest, which is 4 602.2 N /P. Thermodynamic calculation shows that with the increase of Barun iron concentrate ratio, the slag phase in the finished ball increases. In the process of oxidizing roasting and cooling, pyroxene and quartz are the main precipitates of finished ball slag phase for 40% Barun iron concentrate, while calcium iron olivine is the main precipitates of 100% Barun iron concentrate. In terms of mineral phase structure, with the increase of Barun iron concentrate ratio, the hematite intercrystal effect decreases, but the slag phase distribution is uniform at 40% ratio, which plays a good role of bonding phase. One of the reasons for low compressive strength of magnesium-bearing magnetite particles formed by MgO content of 1.05% in 100% Barun finished ball is its poor intercrystal.