The modelling of water and hydrochloric acid extraction by tri-n-butyl phosphate

Abstract

Tri-n-butyl phosphate (TBP) is a common solvent used for extracting metal ions from acidic solutions. In this work, the extraction of water and acid by TBP was modelled up to 16. molal HCl, which is considerably above the range of existing work. The solubility parameter and thermodynamic equilibrium constant for the formation of each extracted species were determined using both experimental and literature data. The resulting model was able to successfully predict both the water and hydrochloric acid extraction by undiluted TBP or TBP diluted in aliphatic solvent within this concentration range. Water was shown to be extracted as the mono-hydrate H 2O.TBP at lower water activities and the di-..