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PROBLEM TO BE SOLVED : To provide a method for producing rare earth-iron-nitrogen-based magnet powder, with which magnetic properties of the magnet powder is improved by improving a wet processing step in fabricating raw material powder for a bond magnet using a rare earth metal, and suppressing elution of the main alloy phase of the magnet after acid cleaning.
SOLUTION : A method for producing rare earth-iron-nitrogen-based magnet powder has steps : to mix rare earth oxide powder, iron powder, and at least one reducing agent powder selected from an alkali metal, an alkaline earth metal, or a hydride of them at a specific ratio; to heat the mixture in an inert gas atmosphere so that the mixture is reduced and diffused; successively to cool the obtained reaction product in an inert gas atmosphere; succeedingly to raise temperature of the reaction product and to subject the reaction product to nitriding treatment; and subsequently to disintegrate the obtained nitriding treated product by charging the product into water, and subsequently to wet-treat the obtained slurry with acid cleaning and water cleaning. In the wet treatment step, the water cleaning is conducted within 1.5 hours since completion of the acid cleaning, in a condition where pH of the slurry is 9 or more.
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