Highly Selective Recovery of Scandium over Aluminum from Sulfuric Acid Leaching Solution of Red Mud Using Ionic Liquids
Year: 2026
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Extracting scandium (Sc) from red mud facilitates the comprehensive management of this solid waste, mitigating its environmental impact, while securing a sustainable supply of this critical metal. Two ionic liquids (ILs), [lauryl betaine][bis(trifluoromethanesulfonyl)imide] ([HLaur][Tf 2 N]) and [cocamidopropyl betaine][bis(trifluoromethanesulfonyl)imide] ([HCoca][Tf 2 N]) were used to separate Sc 3+ from Al 3+ in H 2 SO 4 aqueous solution. At pH 3.0, [HLaur][Tf 2 N] showed higher Sc 3+ extraction efficiency (44.4 vs 36.4%) and better selectivity over Al 3+ compared to [HCoca][Tf 2 N]. The optimal conditions for [HLaur][Tf 2 N] extraction were determined as follows: a [HLaur][Tf 2 N]-to-Sc 3+ molar ratio of 5.8:1, an extraction time of 40 min, 0.5 mol·L –1 Na 2 SO 4, and pH ≥ 3.0. The extraction process was found to follow a cation exchange mechanism involving sulfate ions. Quantitative stripping of the loaded Sc 3+ was achieved using a 0.035 mol·L –1 H 2 SO 4 solution. FT-IR analysis and recycling tests indicated that [HLaur][Tf 2 N] maintained its structural integrity over six cycles. Even in a simulated red mud leachate with high Al 3+ and low Sc 3+ concentrations, [HLaur][Tf 2 N] exhibited strong Sc 3+ selectivity, and a total extraction efficiency of 94.4% was achieved after five extraction stages, with the residual Sc 3+ concentration as low as 0.26 mg·L –1 .
Source: ACS Omega
Authors: Xiang Su, Huipeng Liu, Honghao Li, Yanxi Zhou, Ruibing Bai, Qiuhan Yu
Institution: Pingdingshan University
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
OpenAlex ID: W7143703781