Method for producing rare-earth magnets, and rare-earth-compound application device

A method for producing rare-earth magnets by applying a powder containing one or at least two selected from an oxide, a fluoride, an oxyfluoride, a hydroxide, or a hydride of R2 (wherein R2 represents one or at least two selected from rare-earth elements including Y and Sc) onto sintered magnet bodies made of an R1—Fe—B-based composition (wherein R1 is one or at least two selected from rare-earth elements including Y and Sc) and heat treated to permit R2 to be absorbed in the sintered magnet bodies, the method comprising:

• providing a coating tank having net belt passage openings at two mutually facing side walls individually and a net belt conveyor for conveying the sintered magnet bodies, the net belt conveyor arranged to pass through the net belt passage openings, so that a plurality of the sintered magnet bodies on the net belt conveyor can be continuously conveyed horizontally through the net belt passage openings;
• continuously feeding to the coating tank a slurry dispersing the powder in a solvent, so that i) a level of the slurry in the coating tank is held at a position higher than an upper surface of the sintered magnet bodies on the net belt conveyor to immerse the sintered magnet into the slurry, and ii) the slurry continuously overflows from an upper end portion of the coating tank including the net belt passage openings and the level of slurry is continuously maintained to be at a level above a lower part of the net belt passage openings;
• placing the plurality of the sintered magnet bodies on the net belt conveyor and continuously conveying the sintered magnet bodies on the net belt conveyor horizontally through the net belt passage openings so that the sintered magnet bodies are immersed into the slurry in the coating tank to apply the slurry to the sintered magnet bodies;
• and
• drying the sintered magnet bodies to remove the solvent of the slurry thereby continuously applying the powder onto the plurality of sintered magnet bodies.