Mass transfer of zinc(II) extraction from hydrochloric acid solution in the Lewis cell

Extraction of zinc(H) from model hydrochloric acid solutions was studied by Lewis cell mixing the bulks of both phases and keeping a stable interfacial surface. It was found that Lewis cell experiments, although dynamic in nature, support the extracting of ZnCl2*2 TBP and H2ZnCl,*2TBP chlorocomplex from model solutions containing 5 M Cl- and 0.55 M H+. The initial fluxes of zinc(II), HCl, Cl-, chloride present in the zinc(II) complex and water depend upon the concentration of tributyl phosphate and the mixing rates. The diffusion step in the organic phase gave a higher resistance to the mass transfer than the diffusion step in the aqueous phase. The physical transfer of small water molecules was less sensitive on the mixing rates than the transfer of bulky zinc(II) chlorocomplex.