Extraction of Zinc from Spent Alkaline Batteries Using Cyanex 272 Impregnated on Polyurethane Foam

Abstract

In this study, zinc, which is an important industrial metal and a major component of alkaline batteries, was extracted from spent alkaline batteries using polyurethane foam (PUF) impregnated with the solvent Cyanex 272. The impregnation of PUF with Cyanex 272 was confirmed using Fourier transform infrared spectroscopy. Relevant experimental factors (such as pH, solvent concentration, absorbent dosage, temperature, and flow rate) affecting the extraction of zinc were investigated. Fourier transform infrared spectroscopy showed that PUF can be easily impregnated with Cyanex 272. The optimal conditions for this Zn recovery are: pH 4; extractant concentration = 0.4 M; adsorbent dosage = 5 g; temperature ≈ 338 K; and extraction time = 60 min. The Avrami fractional-order kinetic model was the best model for describing the kinetic data, while the Bohart–Adams model was the best model for the data of the columnar study. The results show that the solvent impregnation method is an effective technique of zinc extraction from spent alkaline batteries; ≈95.7% of Zn was recovered from the sample after elution with 6 M HCl. Hence, Zn can be effectively recovered from solution (spent batteries) using PUF impregnated with Cyanex 272.