Synergistic separation of Co(II)/Li(I) for the recycling of LIB industry wastes by supported liquid membrane using Cyanex 272 and DR-8R

The separation of Co(II) and Li(I) from simulated solution of lithium ion battery (LIB) industry wastes has been studied by a supported liquid membrane (SLM) process. The synergistic effect of mixture of the extractants Cyanex 272 and DP-8R on the permeation rate and separation factor of Co(II) and Li(I) from dilute aqueous sulfate media using a supported liquid membrane (SLM) technique has been examined. A microporous hydrophobic PVDF film was used as the solid support for the liquid membrane. The extractants Cyanex 272 and DP-8R and mixture of those were used as mobile carriers. The effects of different parameter such as stirring speed, pH of the feed solution, extractant concentration in the membrane phase, Co(II)/Li(I) concentration in the feed solution, and H2SO4 strip acid concentration, on Co(II) flux (JCo(II)) and Li(I) flux (JLi(I)) have been studied and compared. For all of the systems studied, Co/Li are optimally separated in the acidic pH region of 5.0−6.0. The best separation factor of 497 was achieved at pH 5.00 using a mixture of Cyanex 272 and DP-8R at a concentration of 750 mol/m3 in the membrane phase, a strip acid concentration of 100 mol/m3, and a stirring speed of 350 rpm. The separation factors for all three systems under the respective optimum experimental conditions have been calculated and compared. Qualitatively, they follow the order: mixed-extractant system > Cyanex 272 > DP-8R. This sequence may be quantitatively expressed as: mixed-extractant system ≈ 3 × Cyanex 272 ≈ 15 × DP-8R.