Solvent extraction equilibrium modeling for the separation of ammonia, nickel(II), and copper(II) from the loaded LIX84-I

• Published in: Minerals engineering Vol. 172; p. 107132
• Main Authors: Wang, Shubin, Li, Jie, Narita, Hirokazu, Tanaka, Mikiya
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2021
• Subjects: Ammonia scrubbing; LIX84-I; Nickel(II) and copper(II) stripping; Separation equilibrium model; Solvent extraction; Ammonia scrubbing; Nickel(II) and copper(II) stripping; Solvent extraction; Separation equilibrium model; LIX84-I
• ISSN: 0892-6875; 1872-9444
• DOI: 10.1016/j.mineng.2021.107132

•Established equilibrium model for solvent extraction system of NH3-Ni-Cu-LIX84-I.•Capable of predicting reaction efficiencies from the initial conditions.•Studied the process of NH3 scrubbing – selective Ni stripping – Cu stripping.•Validated the model by quantitative agreement with the experiment. A novel solvent extraction equilibrium model has been developed to separate nickel and copper from the loaded LIX84-I (active component: 2-hydroxy-5-nonylacetophenone oxime dissolved in a nonpolar diluent, ShellSol D70) formed by the extraction from ammoniacal alkaline solutions. The targeted process consists of the scrubbing of ammonia and subsequent selective stripping of nickel(II) followed by stripping of copper(II), in which sulfuric acid is used in each step. The present model considers the equilibria of extraction of copper, nickel, and ammonia; distribution of metal-extractant complexes; and solution equilibria in aqueous and organic phases and was compared with the experimental results under varying sulfuric acid concentrations and phase ratios. As a result, this model was shown to accurately predict the equilibria after scrubbing and stripping from the initial operational conditions. This model is also applicable to the extraction of copper and nickel from an ammoniacal solution and thus facilitates the design, optimization, and control of the ammoniacal process for the separation of copper and nickel.