title: Mathematical modeling of cadmium(II) solvent extraction from neutral and acidic chloride media using Cyanex 923 extractant as a metal carrier.
abstract: This paper describes experimental work and the mathematical modeling of solvent extraction of cadmium(II) from neutral and acidic aqueous chloride media with a Cyanex 923 extractant in Exxol D-100. Solvent extraction experiments were carried out to analyze the influence of variations in the composition of the aqueous and organic phases on the efficiency of cadmium(II) extraction. In neutral and acidic chloride conditions, the extraction of cadmium(II) by the organophosphorous extractant Cyanex 923 (L) is based on the solvation mechanism of neutral H(n)CdCl((2+n)) species and the formation of H(n)CdCl((2+n))L(q) complexes in the organic phase, where n=0, 1, 2 and q=1, 2. The mathematical model of cadmium(II) extraction was derived from the mass balances and chemical equilibria involved in the separation system. The model was computed with the Matlab software. The equilibrium parameters for metal extraction, i.e. the stability constants of the aqueous Cd-Cl complexes, the formation constants of the acidic Cd-Cl species and the metal equilibrium extraction constants, were proposed. The optimized constants were appropriate, as there was good agreement when the model was fitted to the experimental data for each of the experiments.
authors.affiliation: Department of Chemical Engineering, Universitat Politècnica de Catalunya, EPSEVG, Av. Victor Balaguer s/n, 08800 Vilanova i la Geltru, Spain. agnieszka.leopold@upc.edu
authors.forename: A A
authors.initials: AA
authors.lastname: Leopold
authors.forename: M T
authors.initials: MT
authors.lastname: Coll
authors.forename: A
authors.initials: A
authors.lastname: Fortuny
authors.forename: N S
authors.initials: NS
authors.lastname: Rathore
authors.forename: A M
authors.initials: AM
authors.lastname: Sastre
mesh_terms: D002104:Cadmium / Q000302:isolation & purification*; D002712:Chlorides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents / Q000737:chemistry*; D015233:Models, Statistical; D012997:Solvents
chemical_list: D002712:Chlorides; D007202:Indicators and Reagents; D012997:Solvents; D002104:Cadmium