Nonideality in two-phase systems of copper(II) extraction from sulfate solutions with LIX64N in kerosene

Abstract

Distribution equilibrium of Cu ²⁺ between sulfate solutions and kerosene containing LIX64N was studied. Distribution ratio of Cu ²⁺ increased with increase in the concentration of extractant (10–50 mol/dm ³) and the initial aqueous pH (1∽5). A simplified model with three parameters was proposed to describe the equilibrium behavior, in which the non-idealities in both aqueous and organic phases were considered. Under the conditions studied (initial pH 2–5; Cu ²⁺ concentration <10 mol/m ³; LIX64N concentration 10–50 mol/m ³), it was shown that the results calculated by the present model were in reasonable agreement with the measured ones (standard deviation <12.3%). This model gave a prediction comparable to the one estimated based on Davis equation for correlation of aqueous-phase activity alone, but superior to the one calculated based on the regular solution theory of Hildebrand/Scott for correlation of organic-phase activity alone.

Keywords:

• Extraction equilibrium
• Distribution ratio
• Nonideality
• Copper(II)
• LIX64N

Acknowledgments