高铁低硅赤泥钠化还原的物相转变及铁分离特性

硅酸盐通报 ›› 2024, Vol. 43 ›› Issue (1): 209-218.

高铁低硅赤泥钠化还原的物相转变及铁分离特性

郑富强¹, 戴妍妮², 胡兵¹, 刘臣¹, 欧阳思雯², 胡佩伟^{2, 3}

1.中冶长天国际工程有限责任公司, 长沙 410205;
2.武汉科技大学资源与环境工程学院, 武汉 430081;
3.冶金矿产资源高效利用与造块湖北省重点实验室, 武汉 430081

收稿日期:2023-09-01 修订日期:2023-10-31 出版日期:2024-01-15 发布日期:2024-01-16
通信作者: 胡佩伟,博士,副教授。E-mail:pwhu@wust.edu.cn
作者简介:郑富强(1988—),男,博士,高级工程师。主要从事硅酸盐固废综合利用的研究。E-mail:f.q.zheng@csu.edu.cn
基金资助:
2022年长沙市“小荷”青年人才创新项目;湖南省自然科学基金(2019JJ51007)

Phase Transformation and Iron Separation Characteristics of High Iron and Low Silicon Red Mud Using Sodium Reduction

ZHENG Fuqiang¹, DAI Yanni², HU Bing¹, LIU Chen¹, OUYANG Siwen², HU Peiwei^2,3

1. Zhongye Changtian International Engineering Co., Ltd., Changsha 410205, China;
2. College of Resources and Environment Engineering, Wuhan University of Science and Technology, Wuhan 430081, China;
3. Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan 430081, China

Received:2023-09-01 Revised:2023-10-31 Online:2024-01-15 Published:2024-01-16

摘要/Abstract

摘要： 高温焙烧赤泥可实现铁、铝、硅等元素的形态转化,使其易于分离回收,但高铁低硅赤泥的钠化还原焙烧反应差异性及机制研究却少有报道。本文采用X射线衍射分析,考察了还原温度、碳酸钠用量、还原时间等对高铁低硅赤泥还原焙烧的矿相转化及微结构影响,分析了反应后的铁磁化分离差异性。结果表明:还原焙烧中钠与铝、硅元素结合形成铝钠硅酸盐,有效破坏了铁、铝元素的紧密结构;赤铁矿、铝针铁矿大部分转为磁铁矿和浮氏体,促进了铁氧化物还原;低熔点含钠固溶体降低了金属铁质点迁移阻力,加速了铁晶粒的长大。基于铁铝结构崩解及粗晶粒金属铁的生成,焙烧产物经磨矿-磁选后,获得了全铁含量为90.41%、Fe回收率为93.08%的铁回收指标。

关键词: 高铁低硅赤泥, 还原焙烧, 碳酸钠, 物相转变, 铁分离

Abstract: The high-temperature roasting of red mud can realize the form transformation of iron, aluminum and silicon, making it easy to separate and recover. However, there are few reports about the difference and mechanism of sodium reduction roasting reaction of high iron and low silicon red mud. The effects of reduction temperature, Na₂CO₃ addition and reduction time on the phase transformation and microstructure of high iron and low silicon red mud were investigated by X-ray diffraction analysis, and the difference of iron magnetic separation after reduction reaction was also analyzed. The results show that sodium combines with aluminum and silicon elements to form sodium aluminosilicate during reduction roasting, which effectively destroys the compact structure of Fe and Al elements. Hematite and goethite are converted into magnetite and wustite mostly, which promotes the reduction of iron oxides. The low melting point sodium-containing solid solution reduces the migration resistance and accelerates the growth of metal iron grains. Based on the disintegration of the Fe-Al structure and the formation of coarse-grained metal iron, the roasted product is subjected to grinding-magnetic separation, and iron recovery indicator with the TFe content 90.41% and Fe recovery rate 93.08% is obtained.

Key words: high iron and low silicon red mud, reduction roasting, sodium carbonate, phase transformation, iron separation

中图分类号:

TF09

郑富强, 戴妍妮, 胡兵, 刘臣, 欧阳思雯, 胡佩伟. 高铁低硅赤泥钠化还原的物相转变及铁分离特性[J]. 硅酸盐通报, 2024, 43(1): 209-218.

ZHENG Fuqiang, DAI Yanni, HU Bing, LIU Chen, OUYANG Siwen, HU Peiwei. Phase Transformation and Iron Separation Characteristics of High Iron and Low Silicon Red Mud Using Sodium Reduction[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(1): 209-218.

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