MATHEMATICAL-MODELING OF MEMBRANE EXTRACTION OF GOLD(III) FROM HYDROCHLORIC-ACID SOLUTIONS

A mathematical model describing the selective extraction of gold(III) from hydrochloric acid solutions into a membrane consisting of Aliquat 336 chloride immobilized in poly(vinyl chloride) (PVC) is developed. The extraction rate is assumed to be governed by both the rate of chem ical reactions occurring at the interface and the diffusion of the Ali quat 336 chloride species within the membrane. The fairly good agreeme nt between the model and experimental results confirms its validity an d shows that the model can be used successfully for the mathematical d escription and optimisation of membrane extraction utilised in analyti cal and process systems as well as in environmental chemistry. (C) 199 7 Elsevier Science B.V.