Synergistic extraction of heavy rare earths by mixture of α-aminophosphonic acid HEHAMP and HEHEHP

• Published in: Journal of rare earths Vol. 37; no. 4; pp. 422 - 428
• Main Authors: Zhao, Qi, Li, Yanling, Kuang, Shengting, Zhang, Zhifeng, Bian, Xue, Liao, Wuping
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2019
• Subjects: Heavy rare earths; HEHEHP; Synergistic extraction; α-aminophosphonic acid extractant; HEHEHP; Heavy rare earths; α-aminophosphonic acid extractant; Synergistic extraction
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/j.jre.2018.07.013

Synergistic extraction of heavy rare earths (REs) were investigated in chloride media by the mixture of (2-ethylhexylamino)methyl phosphonic acid mono-2-ethylhexyl ester (HEHAMP) and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (HEHEHP). The maximum synergistic enhancement coefficients (R) of Lu, Yb, Tm, Er, Y and Ho are 2.89, 2.76, 2.54, 2.14, 2.14 and 2.06, respectively, when the mole fraction XHEHAMP is 0.5. The synergistic separation factors of the heavy REs are obtained (βY/Ho = 1.31, βEr/Y = 1.61, βTm/Er = 1.78, βYb/Tm = 1.76, βLu/Yb = 1.20). The extracted complex is determined to be RE[H(EHAMP)2][H(EHEHP)2]2 by the slope analysis method. The loading capacities of the mixtures consisting of 15% HEHAMP and 15% HEHEHP for Y and Lu are about 26.59 g/L (Yb2O3) and 27.25 g/L (Lu2O3), respectively. The mixtures of HEHAMP and HEHEHP show a remarkable synergistic effect on the extraction of REs. [Display omitted]