Roasting characteristics of specularite pellets with modified humic acid based (MHA) binder under different oxygen atmospheres
Roasting characteristics of specularite pellets with modified humic acid based (MHA) binder under different oxygen atmospheres
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DOI：
10.1016/j.powtec.2014.04.053
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发表时间：
2014-07
影响因子：
5.2
通讯作者：
Yuanbo Zhang;Zhou Youlian;Liu Bingbing;Guanghui Li;T. Jiang
中科院分区：
文献类型：
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作者：
Yuanbo Zhang;Zhou Youlian;Liu Bingbing;Guanghui Li;T. Jiang
在镜铁精矿造球过程中，MHA（改性腐植酸基）粘结剂是膨润土的有效替代物。研究了不同氧气氛下以MHA为粘结剂的镜铁矿球团的焙烧行为。通过TG-DSC、TG-FTIR和MRU气体分析初步确定了MHA粘合剂的热行为。还原性气体产物（如CO和H2）由于在空气中加热的MHA粘结剂中的有机物的热解而影响具有MHA粘结剂的镜铁矿球团的氧化和固结。含MHA粘结剂的镜铁矿球团在N2和10%氧气气氛下焙烧时的主相组成为赤铁矿和磁铁矿，而在20%氧气气氛下焙烧时的主相组成仅为赤铁矿。光学显微镜和扫描电子显微镜的观察结果进一步表明，焙烧气氛中氧含量对以MHA为粘结剂的镜铁矿球团矿的显微结构特征有显著影响。
MHA (modified humic acid based) binder has been found as an effective substitution for bentonite in the pelletization of specularite concentrates. This study aimed to clarify the roasting behavior of specularite pellets with MHA binder under different oxygen atmospheres. The thermal behavior of the MHA binder was initially determined by TG-DSC, TG-FTIR and MRU gas analysis. The reducing gaseous products, such as CO and H2, affected the oxidation and consolidation of the specularite pellets with MHA binder due to the pyrolysis of organic matter in the MHA binder heated in air. The primary phase compositions of the specularite pellets with MHA binder roasted in N2and 10% oxygen atmospheres were composed of hematite and magnetite, whereas there was only hematite in the pellet roasted in a 20% oxygen atmosphere. The images by optical microscopy and SEM further indicated that the oxygen content of the roasting atmosphere markedly influenced the microstructure feature of the specularite pellets with MHA binder.