METHOD FOR RECOVERING A NANOPARTICULATE LANTHANIDE-METAL-METALLOID POWDER ALLOY BY MAGNETIC RECOVERY, AND PRODUCT

A method for recovering a nanoparticulate lanthanide-metal-metalloid powder alloy by magnetic recovery, and product, pertain to the field of hard magnets or magnetic bodies made of inorganic materials that contain elements of the lanthanide series in the form of microparticles with nanometric scale grains, and aims at the preparation of high coercive isotropic powders from sintered parts produced from an alloy composed of at least one element of the series of the lanthanides (LA), at least one transition metal (MT) and at least one metalloid (ML), and represented by LA-MT-ML, using the HDDR process without any alloying element, additive or surface modifier with Dy. The novelty and inventive step thereof lie in a modification of the recombination step, which shortens the time required, such that the entire HDDR process takes less than 120 minutes, which is shorter than the time mentioned in the available literature. The novelty and inventive step of the product lie in an intrinsic coercive value of the reprocessed material of at least 90% of that of the part to be recycled. The resulting product consists in a nanoparticulate isotropic material, with an average particle size from 10 to 300 micrometres, preferably 50 micrometres, in which each particle of the material obtained after the HDDR process can have grains of 50 to 500 nanometres, preferably 300 nanometres. The product can be used in applications that require high resistance to demagnetisation, such as motors, either as powders or as solidified parts, without or without binders, and can be regarded as a low cost option for replacing magnetic oxides, since the raw material is a waste material and no additional process is required, besides the HDDR process and the binder. L'invention concerne un procédé de récupération d'alliage lanthanide-métal-métalloïde en poudre nanoparticulaire avec récupération magnétique et produit, trouvant une application dans le secteur des aimants ou corps magnétiques durs de matières inorganiques contenant des éléments du groupe des lanthanides sous forme de microparticules formées par des grains à l'échelle nanométrique, ayant pour but la préparation de poudres isotropes à haute coercivité à partir de pièces frittées fabriquées avec un alliage constitué par au moins un élément du groupe des lanthanides (LA), au moins un métal de transition (MT) et au moins un métalloïde (ML), cet alliage étant représenté par LA-MT-ML, avec recours à un traitement HDDR sans quelconque éléme