Abstract End-of-life NdFeB magnets are an important secondary source of rare-earth elements (REEs) and cobalt. Recycling of these magnets can also mitigate the supply problems of its constituent critical REEs (mainly neodymium and dysprosium). The recycling of bonded NdFeB magnets has received much less attention than that of sintered NdFeB magnets. In this study, a novel flow sheet is presented for recycling of bonded NdFeB magnets that is applicable to sintered magnets as well. Demagnetized magnet powder was mixed with 25 or 40 wt./vol% NaOH solution and baked at 150 to 200 °C for 30 to 540 min. In this way, REE metals were transformed into their corresponding hydroxides, whereas iron metal formed NaFeO2. By washing the reaction mixture with water, 96.5% of Na was recovered as NaOH and Na2CO3, whereas 90.3% of B was recovered as borax. The calcine containing REE hydroxides and iron oxide was then leached at 60 or 90 °C with 20 vol% Versatic Acid 10 diluted in an aliphatic diluent. >95% of the REEs were dissolved, with

中文翻译：

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钕铁硼磁体的碱焙和溶剂冶金浸出

摘要 报废 NdFeB 磁铁是稀土元素 (REE) 和钴的重要二次来源。回收这些磁铁还可以缓解其组成关键稀土元素（主要是钕和镝）的供应问题。与烧结钕铁硼磁体相比，粘结钕铁硼磁体的回收受到的关注要少得多。在这项研究中，提出了一种新的流程表，用于回收粘结 NdFeB 磁体，该流程也适用于烧结磁体。退磁的磁粉与 25 或 40 wt./vol% NaOH 溶液混合，并在 150 至 200 °C 下烘烤 30 至 540 分钟。通过这种方式，REE 金属转化为其相应的氢氧化物，而铁金属形成 NaFeO2。通过用水洗涤反应混合物，96.5%的Na以NaOH和Na2CO3的形式回收，而90.3%的B以硼砂的形式回收。然后在 60 或 90 °C 下用脂肪族稀释剂中稀释的 20 vol% Versatic Acid 10 浸出含有 REE 氢氧化物和氧化铁的煅烧物。> 95% 的 REE 被溶解，其中