Effect mechanism of aluminum occurrence and content on the induration characteristics of iron ore pellets
Effect mechanism of aluminum occurrence and content on the induration characteristics of iron ore pellets
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DOI：
10.1007/s12613-023-2725-3
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发表时间：
2023-12
期刊：
影响因子：
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通讯作者：
Hongyu Tian;De‐qing Zhu;Jian Pan;Cong-cong Yang;Wei-qun Huang;Mansheng Chu
中科院分区：
文献类型：
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作者：
Hongyu Tian;De‐qing Zhu;Jian Pan;Cong-cong Yang;Wei-qun Huang;Mansheng Chu
随着高品位铁矿石贫化的加剧，铁精矿中铝含量的增加已不可避免，这对球团生产是不利的。因此，必须明确铝对球团矿质量的影响机理。通过添加相应的含铝添加剂，包括氧化铝、铝针铁矿、三水铝石和高岭石，研究了铝的赋存状态和含量对赤铁矿（H）和磁铁矿（M）球团硬结的影响。通过系统的矿物学分析，结合不同铝赋存状态的热力学性质和固结行为的定量表征，确定了相关机理。结果表明，不同含铝矿物中的氧化铝对球团的硬结特性有不利影响，特别是当铝含量大于2.0wt%时。三水铝石和高岭石的热分解容易产生内应力和细小裂纹，阻碍了Fe2O3颗粒之间的微晶结合和再结晶。不同铝赋存状态的球团矿焙烧过程中，由于赤铁矿颗粒间形成液相键，对球团矿硬结特性的不利影响可得到不同程度的缓解。高岭石比其他三种铝矿点更有利于球团的固结，因为高岭石形成了更多的液相，从而改善了球团的固结。研究结果可进一步了解铁精矿中铝的赋存状态和含量对后续加工的影响，为高铝铁精矿球团的利用提供指导。
With the intensified depletion of high-grade iron ores, the increased aluminum content in iron ore concentrates has become unavoidable, which is detrimental to the pelletization process. Therefore, the effect mechanism of aluminum on pellet quality must be identified. In this study, the influence of aluminum occurrence and content on the induration of hematite (H) and magnetite (M) pellets was investigated through the addition of corresponding Al-containing additives, including alumina, alumogoethite, gibbsite, and kaolinite. Systematic mineralogical analysis, combined with the thermodynamic properties of different aluminum occurrences and the quantitative characterization of consolidation behaviors, were conducted to determine the related mechanism. The results showed that the alumina from various aluminum occurrences adversely affected the induration characteristics of pellets, especially at an aluminum content of more than 2.0wt%. The thermal decomposition of gibbsite and kaolinite tends to generate internal stress and fine cracks, which hinder the respective microcrystalline bonding and recrystallization between Fe2O3particles. The adverse effect on the induration characteristics of fired pellets with different aluminum occurrences can be relieved to varying degrees through the formation of liquid phase bonds between the hematite particles. Kaolinite is more beneficial to the induration process than the other three aluminum occurrences because of the formation of more liquid phase, which improves pellet consolidation. The research results can further provide insights into the effect of aluminum occurrence and content in iron ore concentrates on downstream processing and serve as a guide for the utilization of high-alumina iron ore concentrates in pelletization.