A recovery strategy of Sm, Co for waste SmCo magnets by fatty acid based ionic liquids. (1st November 2020)

• Record Type: Journal Article
• Authors: Chen, Qianwen; Ni, Shuainan; Ai, Guanghua; Zhang, Tao; Sun, Xiaoqi
• Is Part Of: Minerals engineering. Volume 158(2020)
• Publication Date: 2020-11-01
• Subjects: Fatty acid -- Ionic liquid -- Extraction -- Recycling -- Sm, Co separation; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2020.106581
• Languages: English
• ISSNs: 0892-6875

Abstract

Graphical abstract: Highlights: FAILs were first studied to recover and separate Sm, Co for waste SmCo magnets. Na2 C2 O4 was used as a stripping agent to avoid the extra chemical consumption. Higher purities of CoCl2 and Sm2 O3 were obtained. The FAILs revealed good stabilities in the separation process. 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 Na2 C2 O4 and NH3 ·H2 O. The produced salty wastewater with lower concentration from the process could be recycled. Sm2 O3 with a purity of 99% were obtained by roasting the Sm2 (C2 O4 )3 at 800 °C for two hours. The whole process was simple and sustainable, illustrating its potential for industrial applications.