多元伴生资源中镓活化重构与高效电解提取基础

The transformation of soluble Ga structure and the extraction of Ga from solution with low Ga concentration are the common issues facing Ga recovery. The research focuses on Ga recovery from alunite, and the followings are going to be studied: the mechanism of Ga activation reconstruction to promote the preconcentration of Ga and the separation of impurities; the intensified Ga electrowinning technique from solution with low Ga concentration and impurities. In order to adjust the soluble structure transformation of Ga, the occurrence states of Ga in alunite and the migration and transformation of Ga during calcinations will be researched by mineral structure characterization technology and physical and chemical separation method. Furthermore, to promote Ga dissolution and impurity separation, the soluble Ga structure transformation is accelerated by the application of mechanical activation. The influence mechanism of mechanical activation on the change of Ga structure will be verified by the study of lattice distortion and the thermal decomposition behavior of alunite. Ga electrodeposition from solution with low Ga concentration is intensified by the use of porous three-dimensional electrode, and the influence mechanism of porous three-dimensional electrode on Ga electrodeposition will be illustrated by the execution of the reaction, diffusion and nucleation dynamic study. Combining the analysis of the transformation of impurities during active pretreatment, the optimization method for Ga electrodeposition in the presence of impurities is looking forward to be found out by the study of the impacting mechanism of impurities on Ga electrodeposition and the dynamic regulation means. The project expects to achieve the goal of efficient recovery of Ga through the research of process coupling control.

针对稀散金属镓提取过程存在的可溶性镓结构转化难和低浓溶液镓提取难的共性问题，以多元伴生明矾石资源为研究对象，通过研究镓结构活化重构促进镓预富集和杂质分离，在此基础上采用强化电解技术实现低镓多元溶液中镓的直接电解提取。通过本项目研究为多元伴生资源镓高效分离提供新思路。借助矿物结构表征技术和物化分离手段，在研究明矾石中镓赋存形式和迁移转化规律的基础上，优化焙烧机制；引入机械活化，借助对矿物晶格畸变和明矾石热分解行为分析，探明机械活化对明矾石中镓结构转化的作用规律，调控镓发生可溶性结构转化，促进镓的溶出和杂质分离。通过电极过程反应、扩散和成核动力学研究，解明三维多孔电极对镓电沉积作用规律，实现低镓溶液中镓强化电沉积；结合活化预处理对杂质离子转化过程分析，掌握杂质离子对镓电沉积过程的作用机理，建立杂质离子存在下镓强化电沉积动力学优化机制。通过过程耦合控制，达到镓高效分离的目的。

本项目以明矾石资源中镓的高效提取分离为目的，通过明矾石中镓结构的活化转化，力图实现生产溶液中镓预富集和杂质分离，为镓直接电解提取奠定基础，并通过调控阴极竞争反应强化生产溶液中镓的直接电解提取，实现低镓多元体系镓的强化富集分离。.在对铜尾矿中明矾石相富集过程的优化机制研究基础上，采用高温快速热分解和强化浸出工艺对明矾石精矿中铝、钾、镓进行综合回收利用。首先在紫金山铜尾矿浮选明矾石工艺的基础上研究了浮选药剂的组成对浮选明矾石精矿的作用规律，并且对不同粒级下明矾石精矿的矿相组成及主微量元素的分布规律进行研究。对明矾石中多元素协同提取工艺中各影响因素及最佳浸出条件进行系统研究，确定了钾、铝、镓提取的最佳工艺条件。引入机械活化强化浸出，初步探究了机械活化强化铝、钾、镓浸出的机制， .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。通过研究铜尾矿浮选明矾石精矿在KOH溶液中的直接浸出行为特性，并结合动力学分析解明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。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，从而增加精矿的反应活性增强，使铝和钾的浸出速率提高。.在研究三维多孔电极强化镓电沉积时，通过筛选高析氢过电位低镓析出电位的三维多孔材料电极，提高沉镓电流效率。在此基础上研究泡沫铜及铜板电极对镓电沉积反应动力学及扩散动力学的影响范围，通过间接的方法获得稳态条件下的极化曲线，计算得到泡沫铜及铜板电极镓电沉积动力学参数，解释泡沫铜孔结构对镓电化学反应和传质过程的促进作用。研究泡沫铜上镓电沉积过程，结合成核动力学分析孔结构对镓电结晶过程成核速率的影响，采用针对性手段缩短沉镓诱导期时间，强化镓电沉积过程。.本项目的研究实现了明矾石中铝、钾、镓的高效协同提取，具有广阔的应用前景和推广价值。