ABSTRACT

Red mud as the main byproduct generated during alumina extraction from bauxite. Owing to the high iron content in the red mud and the high correlation between iron and scandium during the leaching process, it is necessary to extract the iron from the red mud and to further enrich the scandium in advance for the acid leaching extraction of scandium. In this research, the theory of red mud segregation roasting ore phase reconstruction is proposed, so that the iron and scandium in the red mud undergo a corresponding transformation, thereby achieving iron recovery in magnetic separation concentrate by magnetic separation, and enrichment of scandium in magnetic separation tailings. On this basis, the effects of temperature, leaching time, solid to liquid ratio and hydrochloric acid concentration on the leaching of scandium in magnetic separation tailings were studied optimal leaching process conditions and determine the leaching kinetics. A maximum Sc leaching efficiency of 83.94% was obtained at optimum leaching conditions of 200 rpm agitation speed, hydrochloric acid solution 20%, 80°C for 3 h, and solid/liquid ratios 1:10 (g/mL), −74 µm sample particle size. The process of leaching scandium with magnetic separation tailings conforms to the kinetic characteristics of multiphase liquid-solid region reaction, the apparent activation energy of scandium is 26.77 kJ/mol, and the leaching efficiency of scandium is controlled by the chemical reaction step.

摘要

赤泥是从铝土矿中提取氧化铝过程中产生的主要副产物。由于赤泥中铁含量较高，且在浸出过程中铁与钪的相关性较高，需要提前从赤泥中提取铁，进一步富集钪，以进行酸浸提钪。本研究提出赤泥偏析焙烧矿相重构理论，使赤泥中的铁和钪发生相应的转化，从而实现磁选磁选精矿中铁的回收，磁选中的钪富集。分离尾矿。在此基础上，温度、浸出时间、研究了固液比和盐酸浓度对磁选尾矿中钪浸出的最佳浸出工艺条件，并确定了浸出动力学。最佳浸出条件为 200 rpm 搅拌速度、20% 盐酸溶液、80°C 3 h、固液比 1:10 (g/mL)、-74 µm样品粒径。磁选尾矿浸出钪的工艺符合多相液固区反应的动力学特征，钪的表观活化能为26.77 kJ/mol，钪的浸出效率受化学反应步骤的控制。在200 rpm搅拌速度、20%盐酸溶液、80°C 3 h、固液比1:10 (g/mL)、-74 µm样品粒径的最佳浸出条件下获得94%。磁选尾矿浸出钪的工艺符合多相液固区反应的动力学特征，钪的表观活化能为26.77 kJ/mol，钪的浸出效率受化学反应步骤的控制。在200 rpm搅拌速度、20%盐酸溶液、80°C 3 h、固液比1:10 (g/mL)、-74 µm样品粒径的最佳浸出条件下获得94%。磁选尾矿浸出钪的工艺符合多相液固区反应的动力学特征，钪的表观活化能为26.77 kJ/mol，钪的浸出效率受化学反应步骤的控制。