Study on Extraction of Rare Earth Chloride from Low-grade Rare Earth Ore Leachate

With an organic phosphoric acid as extractant, from a certain type of rare earth ore extraction process leachate direct production of rare earth chloride, in the φ20 centrifugal extractor interlocking tests showed technology is feasible. First with ammonia leaching solution - sodium sulfide regulated pH = 5, to remove heavy metal ions of aluminum ion and 90%, compared to obtain a liquid impurity O / A of 1/5 ~ 1/10, 2-stage countercurrent extraction, the extraction of rare earth The rate is greater than 95%. The rare earth organic phase was treated with 6 mol/L hydrochloric acid, compared with O/A of 10/1 to 15/1, and the third-stage countercurrent stripping was carried out, and the rare earth stripping rate was 97%. The rare earth concentration of the stripping solution is above 150g/L RE2O3, and after evaporation, solid rare earth chloride is obtained, and the purity is RE2O345%~46%.

The raffinate can be returned to the leaching without treatment, which eliminates the pollution of the wastewater and has the value of popularization and application. Rare earth, leaching, solvent extraction The rare earth concentration of the weathered rare earth ore leaching solution is mostly in the range of RE2O2l~5g/L. The main process used for recovering rare earth from the past is oxalic acid precipitation to form oxalic acid rare earth, and then the fired rare earth oxide is sold as a product. Can directly convert the leachate dilute sulfuric acid rare earth mother liquor into a rare earth chloride product, which is a new process beneficial to rare earth mines and rare earth separation plants. It can not only use expensive oxalic acid, but also change the structure of mine products and produce rare earth chloride. ...