A method of enriching rare earth by priority leaching and removing phosphorus and calcium from REE-bearing phosphorus ores

摘要

Abstract A rare earth enrichment method by priority leaching and removing phosphorus and calcium from REE-bearing phosphorus ores, is to mix REE-bearing phosphorus ores with recycled phosphorus acid solution with 15wt%-55wt% of P20 5 , 2-25 g/L Ca 2+, and 5wt%-45wt% available P20 5 at the solid-liquid ratio of 1:2-10, to stir the mixture to activate its reaction at the temperature of 20'C-70'C for 0.5-4 hours, and age 1- 5 hours to gain rare earth enrichment residue and lixivium by solid-liquid separation. Mix the gained lixivium with sulfuric acid and appropriate amounts of gypsum residue, where the molar quantity of added sulfuric acid is about 0.7-1 times of calcium molar quantity in the lixivium, and the added amount of gypsum residue is 10%-100% of the mass of REE-bearing phosphorus ores. Through reaction and filtering, get regenerated phosphorus acid and gypsum residue, part of which need to be washed and added water properly for mixture, back used as recycled phosphorus acid.