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过程工程学报 ›› 2022, Vol. 22 ›› Issue (11): 1528-1537.DOI: 10.12034/j.issn.1009-606X.221362

• 研究论文 • 上一篇    下一篇

铜尾矿浮选明矾石精矿中有价元素直接碱浸动力学及过程强化

刘玲*， 金思强， 董彬欣   

  1. 安徽工业大学能源与环境学院，安徽 马鞍山 243002
  • 收稿日期:2021-11-12 修回日期:2022-01-27 出版日期:2022-11-28 发布日期:2022-11-28
  • 通讯作者: 刘玲 liuling85@ahut.edu.cn
  • 作者简介:刘玲(1985-)，女，河北省宁晋县人，博士研究生，讲师，环境工程专业，E-mail: liuling85@ahut.edu.cn.
  • 基金资助:
    多元伴生资源中镓活化重构与高效电解提取基础

Kinetics and intensified leaching of valuable elements in KOH solution in alunite concentrate from copper tailings

Ling LIU*,  Siqiang JIN,  Binxin DONG   

  1. School of Energy and Environment, Anhui University of Technology, Ma'anshan, Anhui 243002, China
  • Received:2021-11-12 Revised:2022-01-27 Online:2022-11-28 Published:2022-11-28
  • Contact: Ling Liu liuling85@ahut.edu.cn

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摘要： 作为一种多元素矿物，紫金山铜尾矿浮选明矾石精矿有望成为铝、钾和镓等元素的替代资源。相对于传统工艺，KOH溶液直接浸出明矾石精矿可以避免高能耗的热分解过程，同时降低杂质离子的干扰。本工作研究了铜尾矿浮选明矾石精矿在KOH溶液中的直接浸出行为特性，重点研究了不同碱浓度和温度下精矿中多元素浸出率随时间的变化规律，并结合动力学分析阐明了精矿直接碱浸反应的控制步骤；在此基础上，引入机械活化促进精矿中有价元素的高效浸出。结果表明，在实验条件下精矿直接碱浸过程中仅发生明矾石相的分解；提高KOH浓度和浸出温度可使元素浸出速率快速增加；根据经典的液-固反应收缩核模型的动力学理论，分析发现浸出反应符合化学反应步骤控制。机械活化使精矿粒径降低、比表面积增加、非晶化程度提高，从而使精矿的反应活性增强，使铝、钾和镓的浸出速率提高。

关键词: 明矾石精矿, 浸出动力学, KOH, 机械活化

Abstract: Alunite concentrate can be obtained from Zijinshan copper tailings by flotation process, which contains a large amount of potassium alunite accompanied by kaoline and quartz. It is a potential source for the recovery of aluminum, potassium and gallium. Therefore, alunite flotation concentrate extracted from copper tailings is considered for the recovery of aluminum, potassium and gallium in this work. Compared with the traditional process, direct leaching of alunite concentrate in KOH solution has the advantages of avoiding the thermal decomposition process with high energy consumption and reducing the interference of impurity ions. The direct leaching behavior of alunite concentrate in KOH solution is researched. The variation of element leaching ratio with time under different KOH concentration (4~8 mol/L) and leaching temperature (60~90℃) is investigated emphatically. The control step of the direct leaching of alunite concentrate in KOH solution is investigated on the research of kinetic analysis. Based on the above studies, mechanical activation is introduced to promote efficient leaching of valuable elements from the concentrate. The results show that only the alunite phase decomposes during the alkaline leaching under experimental conditions. The increase of KOH concentration and leaching temperature is beneficial to the rapid leaching of elements. According to the kinetic theory of the shrinkage core model of liquid-solid reaction, it is found that the leaching reaction is controlled by chemical reaction step. The apparent activation energy of the reaction is 79.5 kJ/mol, and the order of chemical reaction of KOH is 2.31. According to the laser particle scanning analyzer, XRD and FTIR analysis, it is found that the mechanical activation reduces the particle size, increases the specific surface area and improves the degree of amorphous of the alunite ore. The reactivity of the concentrate is thus enhanced, and the leaching experiment shows that the leaching ratio of aluminum, potassium and gallium are increased for the ore after mechanical activation.

Key words: Alunite, Leaching kinetics, KOH, Mechanical activation