Abstract
Oolitic hematite is an iron ore resource with rich reserves, complex composition, low grade, fine disseminated particle sizes, and a unique oolitic structure. In this study, a microwave-assisted suspension magnetization roasting technology was proposed to recover and utilize the ore. The results showed that under the conditions of microwave pretreatment temperature of 1050 °C for 2 min, a magnetic concentrate with an iron grade of 58.72% at a recovery of 89.32% was obtained by microwave suspension magnetization roasting and magnetic separation. Moreover, compared with the no microwave pretreatment case, the iron grade and recovery increased by 3.17% and 1.58%, respectively. Microwave pretreatment increased the saturation magnetization of the roasted products from 24.974 to 39.236 (A·m2)/kg and the saturation susceptibility from 0.179×10−3 m3/kg to 0.283×10−3 m3/kg. Microcracks were formed between the iron and gangue minerals, and they gradually extended to the core of oolite with the increase in the pretreatment time. The reducing gas diffused from outside to inside along the microcracks, which promoted the selective transformation of the weak magnetic hematite into the strong magnetic magnetite.
摘要
鲕状赤铁矿是一种储量丰富、成分复杂、品位低、粒度细、鲕状构造独特的铁矿资源。本文提 出了微波辅助悬浮磁化焙烧回收利用该矿石的工艺。结果表明, 在微波预处理温度1050 °C、时间 2 min 的条件下, 微波预处理的效果较好; 预处理产品采用微波悬浮磁化焙烧-磁选工艺, 获得铁品位 58.72%, 回收率89.32% 的磁精矿。与无微波预处理相比, 铁品位和回收率分别提高了3.17% 和 1.58%。微波预处理使磁化焙烧产品的饱和磁化强度由24.974 (A·m2)/kg 提高到39.236 (A·m2)/kg, 饱和 磁化率由0.179×10−3 m3/kg 提高至0.283×10−3 m3/kg。随着预处理时间的延长, 铁矿物与脉石矿物之间形 成微裂纹, 并逐渐扩展到鲕粒核心。还原气体沿微裂纹由外向内扩散, 促进了弱磁性赤铁矿向强磁性 磁铁矿选择性转化。
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TANG Hui-qing, QIN Yan-qi, QI Teng-fei, et al. Application of wood char in processing oolitic high-phosphorus hematite for phosphorus removal [J]. Journal of Iron and Steel Research, International, 2016, 23(2): 109–115. DOI: https://doi.org/10.1016/S1006-706X(16)30021-8.
OMRAN M, FABRITIUS T, MATTILA R. Thermally assisted liberation of high phosphorus oolitic iron ore: A comparison between microwave and conventional furnaces [J]. Powder Technology, 2015, 269: 7–14. DOI: https://doi.org/10.1016/j.powtec.2014.08.073.
IONKOV K, GAYDARDZHIEV S, CORREA D A A, et al. Amenability for processing of oolitic iron ore concentrate for phosphorus removal [J]. Minerals Engineering, 2013, 46–47: 119–127. DOI: https://doi.org/10.1016/j.mineng.2013.03.028.
ZHOU Wen-tao, HAN Yue-xin, SUN Yong-sheng, et al. Research status and prospect of iron increase and aluminum reduction in high alumina oolitic hematite [J]. Metal Mine, 2018(9): 9–14. DOI: https://doi.org/10.19614/j.cnki.jsks.201809002. (in Chinese)
ZHOU Wen-tao, HAN Yue-xin, SUN Yong-sheng, et al. Review of research on iron extraction and phosphorus reduction of high phosphorus oolitic hematite [J]. Metal Mines, 2019(2): 10–11. DOI: https://doi.org/10.19614/j.cnki.jsks.201902002. (in Chinese)
ZHANG Yuan-bo, ZHAO Yi, YOU Zhi-xiong, et al. Manganese extraction from high-iron-content manganese oxide ores by selective reduction roasting-acid leaching process using black charcoal as reductant [J]. Journal of Central South University, 2015, 22(7): 2515–2520. DOI: https://doi.org/10.1007/s11771-015-2780-7.
LUO Li-qun, HUANG Hong, YU Yong-fu. Characterization and technology of fast reducing roasting for fine iron materials [J]. Journal of Central South University, 2012, 19(8): 2272–2278. DOI: https://doi.org/10.1007/s11771-012-1271-3.
OMRAN M, FABRITIUS T, ELMAHDY A M, et al. Effect of microwave pre-treatment on the magnetic properties of iron ore and its implications on magnetic separation [J]. Separation and Purification Technology, 2014, 136: 223–232. DOI: https://doi.org/10.1016/j.seppur.2014.09.011.
HAN Yue-xin, Gao Peng, LI Yan-jun, et al. Suspension magnetization roasting high efficiency separation technology for complex refractory iron ore [J]. Metal Mines, 2016(12): 2–8. DOI: https://doi.org/10.13228/j.boyuan.issn1001-0963.20180329. (in Chinese)
QIAN Gong-ming, ZHANG Bo, LI Man-man, et al. Effect of microwave pretreatment condition on the grinding efficiency of oolitic hematite from western Hubei Province [J]. Journal of Wuhan University of Science and Technology, 2016, 39(1): 1–6. (in Chinese)
OMRAN M, FABRITIUS T, ELMAHDY A M, et al. Improvement of phosphorus removal from iron ore using combined microwave pretreatment and ultrasonic treatment [J]. Separation and Purification Technology, 2015, 156: 724–737. DOI: https://doi.org/10.1016/j.seppur.2015.10.071.
SHI Chang-liang, WANG Sheng-nan, ZHAO Ji-fen, et al. Experimental study on dry magnetic separation of siderite enhanced by microwave roasting [J]. Mineral Protection and Utilization, 2017(3): 65–67, 74. DOI: https://doi.org/10.13779/j.cnki.issn1001-0076.2017.03.012. (in Chinese)
ZHOU Wen-tao, SUN Yong-sheng, HAN Yue-xin, et al. Recycling iron from oolitic hematite via microwave fluidization roasting and magnetic separation [J]. Minerals Engineering, 2021, 164: 106851. DOI: https://doi.org/10.1016/j.mineng.2021.106851.
ZHOU Wen-tao, HAN Yue-xin, SUN Yong-sheng, et al. Strengthening iron enrichment and dephosphorization of high-phosphorus oolitic hematite using high-temperature pretreatment [J]. International Journal of Minerals, Metallurgy and Materials, 2020, 27(4): 443–453. DOI: https://doi.org/10.1007/s12613-019-1897-3.
WANG Xun, LIU Jie, ZHU Yi-min, et al. The application and mechanism of high-efficiency depressant Na2ATP on the selective separation of cassiterite from fluorite by direct flotation [J]. Minerals Engineering, 2021, 169: 106963. DOI: https://doi.org/10.1016/j.mineng.2021.106963.
XIE Rui-qi, ZHU Yi-min, LIU Jie, et al. Differential collecting performance of a new complex of decyloxypropyl-amine and α-bromododecanoic acid on flotation of spodumene and feldspar [J]. Minerals Engineering, 2020, 153: 106377. DOI: https://doi.org/10.1016/j.mineng.2020.106377.
TANG Zhi-dong, ZHANG Qi, SUN Yong-sheng, et al. Pilot-scale extraction of iron from flotation tailings via suspension magnetization roasting in a mixture of CO and H2 followed by magnetic separation [J]. Resources, Conservation and Recycling, 2021, 172: 105680. DOI: https://doi.org/10.1016/j.resconrec.2021.105680.
HAN Zong-ying, WU Ya-yun, YU Hao, et al. Location-dependent effect of nickel on hydrogen dissociation and diffusion on Mg (0001) surface: Insights into hydrogen storage material design [J]. Journal of Magnesium and Alloys, 2021. DOI:https://doi.org/10.1016/j.jma.2021.03.002.
HAN Zong-ying, YU Hao, LI Chang-lun, et al. Mulchassisted ambient-air synthesis of oxygen-rich activated carbon for hydrogen storage: A combined experimental and theoretical case study [J]. Applied Surface Science, 2021, 544: 148963. DOI: https://doi.org/10.1016/j.apsusc.2021.148963.
YU Jian-wen, HAN Yue-xin, LI Yan-jun, et al. Recent advances in magnetization roasting of refractory iron ores: A technological review in the past decade [J]. Mineral Processing and Extractive Metallurgy Review, 2020, 41(5): 349–359. DOI: https://doi.org/10.1080/08827508.2019.1634565.
YUAN Shuai, ZHOU Wen-tao, HAN Yue-xin, et al. Efficient enrichment of low-grade refractory rhodochrosite by preconcentration-neutral suspension roasting-magnetic separation process [J]. Powder Technology, 2020, 361: 529–539. DOI: https://doi.org/10.1016/j.powtec.2019.11.082.
Funding
Projects(51874071, 51734005, 52104257) supported by the National Natural Science Foundation of China; Project(161045) supported by the Fok Ying Tung Education Foundation for Yong Teachers in the Higher Education Institutions of China
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ZHOU Wen-tao provided the concept and edited the draft of manuscript. SUN Yong-sheng conducted the data curation and formal analysis. HAN Yue-xin, GAO Peng and LI Yan-jun conducted the supervision and edited the draft of manuscript. All authors replied to reviewers’ comments and revised the final version.
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The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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Zhou, Wt., Sun, Ys., Han, Yx. et al. Mechanism of microwave assisted suspension magnetization roasting of oolitic hematite ore. J. Cent. South Univ. 29, 420–432 (2022). https://doi.org/10.1007/s11771-022-4937-5
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DOI: https://doi.org/10.1007/s11771-022-4937-5
Key words
- oolitic hematite
- microwave
- suspension magnetization roasting
- phase and magnetic transformation
- microstructure evolution