Research Progress on the Alkaline Medium Decomposition Process of Rare Earth Concentrates

Rare earth elements possess unique physicochemical properties and are extensively used in high-tech fields including electronics and aerospace. The decomposition process of rare earth concentrates is critically important. This paper reviews recent progress in research on alkaline decomposition processes for rare earth concentrates and elucidates the advantages of various alkaline systems. The single-alkaline-medium decomposition for rare earth concentrates addresses the shortcomings of traditional acid-based methods, particularly their tendency to emit harmful gases. The dual-alkaline-medium process facilitates the recovery and the high-value use of associated elements such as fluorine (F) and phosphorus (P). The acid-alkaline combined process integrates the benefits of both approaches, enabling rare earth extraction at lower temperatures, significantly reducing acid and alkali consumption, and diminishing environmental pollution. The integration of microwave heating and mechanochemical-assisted processes with alkaline media decomposition enhances the efficiency of rare earth elements and reduces the consumption of decomposition agents and energy. Results show that alkaline media decomposition technology will be a primary research direction for sustainable, low-energy, and high-efficiency rare earth metallurgy. Given current challenges in recovering valuable elements from alkaline wastewater, the further development of smelting and separation processes for rare earth ores in alkaline media is crucial.