Kinetics of Zinc Recovery from Spent Pickling Effluents

Abstract

This work has focused on the study of the kinetics of zinc removal from spent pickling effluents by means of membrane-assisted solvent extraction (NDSX), as the main step in the valorization process of the metal. Tributyl phosphate (TBP) and service water were used as extraction (EX) and back-extraction (BEX) agents, respectively. Working with hollow fiber membrane contactors, kinetic experiments were performed in order to analyze the influence of operation variables on the rate of zinc separation. A mathematical model that considers diffusion through the organic membrane as the main kinetic resistance was developed, and the membrane mass transport coefficient was estimated by means of the parameter estimation tool gEST (from gPROMS) to obtain a value of K m = 3.89 × 10-4 m/h. Simulated results agreed satisfactorily with experimental data, thus confirming the validity of the kinetic model and parameters.

A review on methods of regeneration of spent pickling solutions from steel processing

“…The membrane based extraction can be realized in the system of two modules with the organic phase circulating in the shell side of the modules [64,[67][68][69][74][75][76][77][78] or in one module in which polymeric support is impregnated with the organic phase -SLM [79]. Zn(II) transport through supported liquid membrane (SLM) impregnated with 30% Cyanex 923 in Solvesso 100 is controlled by diffusion in the aqueous solution, and needs a long time.…”

“…The effective receiving phases are water and 1 M NaCl for NDSX and SLM, respectively. Membrane based NDSX seems to be competitive with classical SX because of low maintenance cost, non-dispersion of the fluid phase and the high interfacial area [74]. Additionally, the most recent studies have proposed emulsion pertraction technology (EPT) as an alternative to NDSX.…”

Selective Recovery of Zinc over Iron from Spent Pickling Wastes by Different Membrane-based Solvent Extraction Process Configurations

“…In the zinc-based surface treatment sector, conventional solvent extraction and MBSX are being used for the management of passivation baths − and SPS. − Regarding the latter, previous works have focused on the viability of the MBSX process configurations, i.e., nondispersive solvent extraction (NDSX) and emulsion pertraction technology (EPT) also referred as pseudoemulsion based hollow fiber strip dispersion (PEHFSD). These configurations differ in the way of contacting the fluid phases and the number of the membrane contactors involved .…”

An overview of the mathematical modelling of liquid membrane separation processes in hollow fibre contactors

“…Liquid membranes have traditionally been employed for both gas/liquid and liquid/liquid mass transfer; in the latter, selective membranes have found applications in industrial,5–7 biomedical8–10 and analytical fields11, 12 as well as in hydrometallurgical processes13, 14, wastewater treatment15, 16 and remediation of polluted groundwater 17…”