METHOD FOR RECOVERING RARE EARTH ELEMENTS

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PURPOSE : A method of recovering rare earth materials is provided to selectively dissolve the rare earth oxide component by using mine, an oxidation agent and a reducing agent and to separate selectively impurities including a coexisted iron ion by separating in advance solid from liquid at a specific pH.CONSTITUTION : Slurry containing the rare earth oxide is mixed with an oxidation agent and a reducing agent and an acid under the mixing condition and melted. After a pH of the obtained rare earth materials solution is controlled at the proper condition, a non-soluble component is separated by a solid-liquid separating unit, a carbonic acid rare earth(85) is segregated by adding an ammonium bicarbonate in the solution, the carbonic acid rare earth is separated from the obtained carbonic acid rare earth containing slurry and the rare earth oxide is manufactured by plasticizing it. The generated rare earth materials are collected. The strong alkaline agent is added in the ammonium salt aqueous solution separating the carbonic acid rare earth, the ammonia is generated and condensed, the ammonia aqueous solution is collected. A solution of the ammonium bicarbonate(70) or the slurry is formed by contacting carbon dioxide generated from the process. The solution or the slurry of the obtained ammonium bicarbonate is reused as the precipitation agent forming the carbonic acid rare earth.© KIPO 2009