Method for extracting aluminum and enriching lithium from lithium-rich bauxite waste rock by coupling magnetic separation for iron removal with sulfuric acid roasting

Abstract

The present invention proposes a method for extracting aluminum and enriching lithium from lithium-rich bauxite waste rock by coupling magnetic separation for iron removal with sulfuric acid roasting, belonging to the technical field of solid waste comprehensive utilization. In the present invention, lithium-rich bauxite waste rock is crushed and ground, and iron is magnetically separated to obtain low-iron lithium-rich concentrate and iron-containing tailings; concentrated sulfuric acid is added for roasting and maturation, followed by water leaching, filtering and washing, and solid-liquid separation to obtain filtrate; a crystallization agent is added to the filtrate for evaporation, concentration, and crystallization, and after cooling at room temperature, ammonium aluminum sulfate crystals are obtained; the crystals are then placed in an organic purification agent solution for stirring and washing at room temperature, and after solid-liquid separation, a lithium-containing solution and ammonium aluminum sulfate are obtained; the ammonium aluminum sulfate is calcined to prepare alumina, and the lithium-containing solution is evaporated and concentrated to enrich and obtain a lithium-rich solution. The present invention achieves the comprehensive utilization of valuable aluminum and lithium components in lithium-rich bauxite waste rock, and has the advantages of low energy consumption, practical recyclability, high recovery rates of valuable aluminum and lithium components, high purity of the alumina product, and low extraction cost, making it easy for industrial application.