Optimization of Magnesium Salt Rare Earth Enrichment Disposal Process

The magnesium sulfate leaching-magnesium oxide enrichment process is currently the primary method employed for ionic rare earth ore mining in the Gannan Area of Jiangxi, China. The current disposal process results in the generation of water-washed residue with a high residual rare earth content during the subsequent extraction of rare earth elements from magnesium salt rare earth enrichment (MREE). This represents a significant loss to the rare earth recovery rate and yields. In this study, we optimized the existing disposal process using a combination of sulfuric acid preferential dissolution and stepwise filtration. Under the optimized conditions, the rare earth content in the water-washed residue decreased significantly from 4.58 to 0.37%, representing a remarkable reduction of 91.92%. Simultaneously, the rare earth yield increased substantially from 48.46 to 96.09%, resulting in a notable improvement of 47.63%. This optimized process not only resolves the MREE disposal challenge at its source but also holds promising prospects for industrial application.