RECYCLING METHOD FOR HEAVY RARE EARTH ELEMENT AND RECYCLING METHOD FOR RARE EARTH MAGNET

• Main Authors: HIROTA, Koichi, SAKAKI, Kazuaki, IWANO, Eiichiro
• Format: Patent
• Language: English
• Published: 14.12.2023
• Subjects: CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

A method for collecting a heavy rare earth element from a heavy rare earth element-containing molten salt electrolysis residue and recycling the heavy rare earth element, the method includes: a step of mixing coarse particles of the molten salt electrolysis residue with a fluorinating material followed by firing, to fluorinate the coarse particles of the molten salt electrolysis residue; a step of pulverizing the coarse particles of the fluorinated molten salt electrolysis residue to obtain a powder of the molten salt electrolysis residue; and a step of mixing the powder of the molten salt electrolysis residue with R, an R-M alloy, or an R-M-B alloy (wherein R is one or more types of rare earth elements selected from the group consisting of Y, La, Ce, Nd, Pr, Sm, Gd, Dy, Tb, and Ho, M is a transition metal such as Fe or Co, and B is boron), heating and melting the mixture, separating a molten alloy from slag, and selectively extracting the heavy rare earth element into the molten alloy. Provided are a method for recycling a heavy rare earth element that is capable of efficiently recycling a heavy rare earth element that is rare in an alloy form similar to a product, and a method for recycling a rare earth magnet by using an alloy obtained by the recycling method.