The reaction of zinc chloride with Cyanex 923 (phosphine oxide) in Solvesso 100 has been studied from acidic calcium chloride solutions. The distribution coeffient of zinc is independent of equilibrium pH, thus, suggesting a solvation extraction mechanism. Experimental data indicate that the reaction is exothermic (ΔH° = −55.2 kJmol−1). Slope analysis for the system at various Cyanex 923 concentrations reveals the formation in the loaded organic phases of species which probable 1:2 (Zn: Cyanex 923) stoichiometries. The stoichiometric factor of water in the extraction reaction was found to be 0, 1 or 2, whereas experimental data indicated that two chloride ions are involved for each metal extracted.
References
1.
ThorsenG., in Handbook of Solvent Extraction, p. 709. LoT.C., BairdM. H. I., and HansonC. (eds.), J. Wiley & Sons, New York, 1983.
2.
LiZ.C., Hydrometallurgy, 1986, 16, 231.
3.
AmerS., LuisA., and CaravacaC., Rev. Metal., 1994, 30, 27.
4.
HarrisonG., LakshmananV. I., and LawsonG. J., Hydrometallurgy, 1976, 1, 339.
5.
VerhaegeM., Hydrometallurgy, 1975, 1, 97.
6.
AlguacilF.J., CoboA., and CaravacaC., Hydrometallurgy, 1992, 31, 163.
7.
BenitoR., MenoyoB., and ElizaldeM. P., Hydrometallurgy, 1996, 40, 51.
8.
NakashioF., SatoH., KondoK., and KawahoY., Solvent Extr. Ion Exch., 1986, 4, 757.
9.
SatoT., ShimomuraT., MurakamiS., MaedaT., and NakamuraT., Hydrometallurgy, 1984, 12, 245.
10.
RitceyG.M., LucasB. H., and PriceK. T., Hydrometallurgy, 1982, 8, 197.
11.
NogueiraE.D., and CosmenP., Hydrometallurgy, 1983, 9, 333.
