Equilibrium analysis of the reactive liquid–liquid test system ZnSO4/D2EHPA/n-heptane

Analysis of a hydrometallurgical route to recover base metals from spent rechargeable batteries by liquid–liquid extraction with Cyanex 272

“…The leaching step has been investigated using a factorial analysis design. In the liquid-liquid extraction study, the separation level of several metals according to their equilibrium pH has been assessed and stoichiometric reactions have been proposed based on the model valid to the test system ZnSO 4 /D2EHPA by the European Federation of Chemical Engineering (EFChE) [22] in order to simulate the metal separation process with Cyanex 272.…”

Extração Por Solventes Sinérgica Aplicada À Separação Níquel/Cálcio Com Cyanex 272 E D2ehpa

“…As fases aquosa e orgânica foram agitadas a 400 rpm utilizando-se um agitador magnético por 5 minutos. Esse tempo é suficiente para que as reações de extração atinjam a condição de equilíbrio químico, com base em estudos anteriores (Mansur et al, 2002;Morais e Mansur, 2004;Mansur e Dorella, 2007;Mantuano et al, 2008;Mansur et al, 2008;Guimarães, 2014). Durante a agitação, fez-se o controle de pH mediante adição de gotas de solução aquosa de NaOH ou H 2 SO 4 .…”

Selective extraction of zinc(II) over iron(II) from spent hydrochloric acid pickling effluents by liquid–liquid extraction

“…For the extraction of zinc sulfate with D2EHPA, n = 1.5 and m depends on the diluent (m = 1 for aromatic diluents and m = 2 for aliphatic ones [18]). In addition, the molecular structure of the zinc-complex species formed in the organic phase depends on the metal loading level in this phase: ZnR 2 RH at low loading conditions [15,19,20], and ZnR 2 [15] or (ZnR 2 ) 4 [20] at high loading conditions. In the case of Cyanex 272, n = m = 2 for bivalent cations such as Zn, Co, Cu and Mn in sulfate media giving MR 2 (RH) 2 species [17,21,22] although the complex ZnR 2 (RH) has also been proposed [23].…”

“…Much research work has been concentrated on the study of zinc extraction with D2EHPA [di-(2-ethylhexyl)phosphoric acid], which selectively extracts zinc from other bivalent transition metals such as Cu, Co, Ni and others [13,14]. Recently, the reactive system ZnSO 4 /D2EHPA was adopted by the European Federation of Chemical Engineering as the standard system for research studies in equipment when mass transfer and reaction rates must be accounted [15]. In recent years, phosphinic acid extractants like Cyanex 272 [bis (2,4,4-trimethylpentyl)phosphinic acid] were commercialized (mainly to separate Co from Ni) and, even more recently, monothio and dithio analogues to Cyanex 272 have been made available for industrial applications, e.g., Cyanex 302 [bis (2,4,4-trimethylpentyl) monothiophosphinic acid] and Cyanex 301 [bis(2,4,4-trimethylpentyl) dithiophosphinic acid], respectively.…”