Zinc Chloride and Hydrochloric Acid Coextraction from Galvanizing Pickling Waste in the Presence of Iron(II). Results with Hollow Fiber Membrane Contactors

Abstract

Spent pickling acid from the industrial galvanizing process currently requires specialist disposal, yet there is the potential to recover the zinc as a valuable metal. In this work, we compare the extraction of zinc using tributyl phosphate from real galvanizing effluent and laboratory prepared solutions. Both commercial and handmade hollow fiber membrane contactors are used for this purpose. While the zinc is effectively extracted, care must be taken to prefilter the solution upstream of the membrane contactor to minimize crud formation and interfacial effects. The extraction of both zinc and HCl from the effluent is satisfactorily described using mathematical models for both the multicomponent equilibria and mass transfer balances. In development of the multicomponent equilibrium model, the thermodynamic equilibrium constants obtained from the ZnCl2–NaCl–HCl aqueous system were found to be applicable to the ZnCl2–FeCl2–HCl system.

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 .…”

Continuous Transport of Zn(II) by Ammonium Chloride Media via Supported Liquid Membrane System

“…There are several methods for the recovery of zinc‐bearing, such as solvent extraction [18, 19], adsorption [20], ion exchange [1, 21–23], carbonization [24], precipitation and liquid membrane separation processes [25–28]. Although the solvent extraction is very successful in industry, it will inevitably consume a large amount of expensive extractants when enriching the low‐concentration metal ions.…”

“…There are several methods for the recovery of zincbearing, such as solvent extraction [18,19], adsorption [20], ion exchange [1,[21][22][23], carbonization [24], precipitation and liquid membrane separation processes [25][26][27][28].…”

Non-dispersive solvent extraction of p-toluic acid from purified terephthalic acid plant wastewater with p-xylene as extractant

“…Thus, the simplest liquid-liquid extraction configuration is sufficient for purifying the PTA wastewater, and the PT acid does not need to be recovered from the extractant after NDSE. With the advantages of no emulsification and high extraction efficiency (Pabby and Sastre, 2013), NDSE has been used in many applications, including the chemical separation of pesticides (Đorđević et al, 2014), bisphenol A (Gupta et al, 2014), toluene (Barati et al, 2014), fermentation products , zinc chloride and hydrochloric acid (Lum et al, 2014), 1-butanol and acetone (Moreno et al, 2014), cephalexin (Hao et al, 2014), Co (Vernekar et al, 2013), Lu (Kumrić et al, 2012), U (Dixit et al, 2013), Zn (Samaniego et al, 2007), and Cu (Ren et al, 2008). However, there have been no published studies of NDSE applied to PTA wastewater.…”