Abstract:
In this paper, the research status and progress on metallurgy, separation and purification process for different rare earth resources in China are reviewed. At present, the metallurgy methods for mixed rare earth minerals mainly include concentrated sulfuric acid roasting-water leaching, alkaline decomposition process and acid leaching-alkali dissolving process; the metallurgy methods for bastnaesite mainly include oxidation roasting-sulfuric acid leaching, alkali metallurgy and pyrometallurgy process. The hydrometallurgical technology for weathering crust leached rare earth ores is mainly composed of ammonium sulfate in-situ leaching and ammonium bicarbonate precipitation process, however, which is currently being replaced by cleaner magnesium salt leaching process. Rare earth separation and purification methods mainly include chemical precipitation, solvent extraction, ion exchange, extraction chromatography and liquid membrane separation methods. On the basis of comprehensive comparison between the advantages and disadvantages of different separation and purification methods, a new method is proposed for rare earth separation and purification-extraction precipitation process; besides, related suggestions are put forward for the comprehensive utilization of rare earth resources.