Abstract Cleaner and lower-cost recovery and separation of samarium(III) and cobalt(II) from waste SmCo magnets can effectively alleviate supply risks of the strategic metals. Based on this goal, a family of renewable, low-cost, biocompatible, non-toxic fatty acid-based ionic liquids (FAILs), including [N1888][DA], [N1888][LA] and [N1888][PA] were synthesized and developed for the separation of Sm(III)/Co(II) from samarium-cobalt simulated solution. The effect factors, i.e. equilibrium time, FAIL molar concentration, salting-out agent concentration and initial pH of aqueous solution were investigated. The extraction mechanism was proposed to be ion association by slope analysis and FT-IR. Under the optimized extraction conditions, a higher purity CoCl2 (99.5%) product was obtained by a simple extraction-stripping-washing process with the consumption of Na2C2O4 and NH3·H2O. The produced salty wastewater with lower concentration from the process could be recycled. Sm2O3 with a purity of 99% were obtained by roasting the Sm2(C2O4)3 at 800 °C for two hours. The whole process was simple and sustainable, illustrating its potential for industrial applications.

中文翻译：

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脂肪酸基离子液体回收废钐钴磁铁中钐、钴的策略

摘要 从废钐钴磁铁中更清洁、更低成本地回收和分离钐（III）和钴（II），可以有效降低战略金属的供应风险。基于这一目标，一系列可再生、低成本、生物相容性、无毒脂肪酸基离子液体 (FAIL)，包括 [N1888][DA]、[N1888][LA] 和 [N1888][PA]合成和开发用于从钐钴模拟溶液中分离 Sm(III)/Co(II)。考察了影响因素，即平衡时间、FAIL摩尔浓度、盐析剂浓度和水溶液的初始pH值。通过斜率分析和FT-IR提出提取机制是离子缔合。在优化的萃取条件下，得到更高纯度的 CoCl2 (99. 5%) 产物通过简单的萃取-汽提-洗涤过程获得，消耗 Na2C2O4 和 NH3·H2O。该过程产生的低浓度含盐废水可以回收利用。通过将 Sm2(C2O4)3 在 800 °C 下焙烧 2 小时，获得纯度为 99% 的 Sm2O3。整个过程简单且可持续，说明其在工业应用方面的潜力。