Selective and efficient extraction of Cu(II) from a complex sulfate solution containing Co(II), Fe(II), Cu(II), and Zn(II) using DZ988N

A green and efficient process for the stepwise extraction of Cu, Ni, Co, Mn, and Li from hazardous waste with a novel solvent extraction system of D2EHPA-NNPA

“…10(e), to ensure that the extraction process reaches equilibrium, the actual number of extraction stages is one more than the theoretical number. 57 Additional, during the counter-current extraction process, the pH was adjusted with sodium hydroxide at appropriate intervals to maintain a constant pHe, as the pH decreases slightly after extraction. After the counter-current extraction process, the target metal ions concentration in the raffinate was about 0.001 g L −1 .…”