Efficient diglycolamic acid extractant for separating and recycling Au(III). (1st May 2020)

• Record Type: Journal Article
• Authors: Zhao, Zhigang; Chen, Peng; Yang, Fan; Liao, Qiuxia; Zhang, Yang; Zhao, Panpan; Guo, Wanghuan; Bai, Ruixi; Cai, Chunqing
• Is Part Of: Minerals engineering. Volume 150(2020)
• Publication Date: 2020-05-01
• Subjects: Diglycolamic acid extractant -- Precious metals -- Recyclability -- Separation -- Solvent extraction; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2020.106254
• Languages: English
• ISSNs: 0892-6875

Abstract

Highlights: D2 EHDGAA was synthesized which had high extractability for metals. D2 EHDGAA exhibited high selectivity to Au from Pd, Pt, Rh, and Cu in a short time. The extraction mechanism of Au and Pt were two and one extractants, respectively. The Stripping of Au was completely with low concentration of thiourea. The extraction could be recycled for 5 times with efficiency decreased less than 4%. Abstract: The type of diglycolamic acid extractant N, N -di-2-ethylhexyldiglycolamic acid (D2EHDGAA) was examined for selective extraction and separation of Au(III) in acidic chloride solutions containing Pd(II), Pt(IV), Rh(III), and Cu(II). The separation factor βAu/Pt = 959.3 was observed in 7 M hydrochloric acid. The extraction of Au(III) was quick, and extraction equilibrium was reached in less than 5 min. The n -dodecane and kerosene diluents had a notable effect on the extraction of Au(III) with the D2EHDGAA, and the D2EHDGAA had excellent capacity in n -dodecane and kerosene. However, the selectivity coefficient of Au(III) and Pd(II) was better in n -dodecane (βAu/Pd = 1070) than in kerosene (βAu /Pd < 0.1) of 4 M hydrochloric acid. The extraction mechanisms of the Au(III) and Pt(IV) were investigated, and the results suggest that one metals ion is extracted with two and one extractants in 1 M HCl concentration. The D2EHDGAA-based n -dodecane extracting phase was easily activated using a low-concentration thiourea aqueous solution (0.01 M). The recyclability of D2EHDGAA for five cycles was investigated, and its efficiency decreased less than 4%.