title: Sulphuric acid influence on liquid-liquid extraction of Co(II) and Zn(II) by MIBK from NH(4)SCN medium.
abstract: Liquid-liquid extraction of Co(II) and Zn(II) by methylisobutylcetone (MIBK) has been studied systematically from NH(4)SCN/H(2)SO(4) media. The influence of sulphuric acid concentration on the percentage of extraction of Co(II) and Zn(II) has been discussed. It is shown that sulphuric acid concentration has not the same effect on distribution curves of Co(II) and Zn(II). Thus, it is possible to have a separation of Zn(II) of Co(II) when [NH(4)SCN] is 0.5 mol l(-1) and [H(2)SO(4)] is about 2 mol l(-1). Under these conditions the separation factor (S(Zn/Co)) is around 580. The results are treated in terms of thermodynamic activities in aqueous phase, to determine the composition of the extracted complexes (M:SCN(-)) and to discuss the extraction mechanism.
authors.affiliation: Instituto de Investigaciones Cientificas, Universidad de Guanajuato, Cerro de la Venada s/n, 36040 Guanajuato, Mexico.
authors.forename: M
authors.initials: M
authors.lastname: Avila Rodríguez
authors.forename: J A
authors.initials: JA
authors.lastname: Barrón Zambrano
authors.forename: A
authors.initials: A
authors.lastname: Alatorre Ordaz
authors.forename: R
authors.initials: R
authors.lastname: Navarro Mendoza
authors.forename: T I
authors.initials: TI
authors.lastname: Saucedo Medina