Work

Tailored synergistic hydrophobic eutectic mixtures for ultra‐selective recovery of cobalt from calcium‐rich solutions

Year: 2026

Type: article

Abstract: The selective recovery of cobalt (Co) from industrial wastewater is increasingly important for sustainable resource utilization but remains challenging in calcium‐rich media. In this work, a hydrophobic eutectic mixture was tailored by pairing tri‐ n ‐octylamine as the hydrogen bond acceptor with bis ‐ (2,4,4 ‐ trimethylpentyl) ‐ phosphinic acid as the hydrogen bond donor. This system integrates highly selective Co extraction with saponification‐free and diluent‐free operation, achieving a separation factor (SF Co/Ca ) exceeding 3389.4. Mechanistic analysis suggested that Co was extracted in the form of chloride‐rich anionic complexes. Using a counter‐current extraction flowsheet, effective separation of trace Co (0.50 g/L) from calcium‐rich saponification wastewater (Ca >40 g/L) was achieved. The Co concentration in the stripping solution reached 19.3 g/L, enabling subsequent precipitation of high‐purity CoCO 3 and resulting in an overall Co recovery of 96.2%. This work provides a feasible strategy for the selective recovery and enrichment of Co from industrial wastewater.

Source: AIChE Journal

DOI: 10.1002/aic.70626

Authors: Zhizhuo Yang, Qianwen Chen, Xigui Gao, Shuainan Ni, Chengliang Xiao

Institutions: Zhejiang University, Tianma Microelectronics (China)

Language: English

Topic: Extraction and Separation Processes

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production

Open Access status: bronze

Funders: National Natural Science Foundation of China, Zhejiang University