Solvent Extraction of Zinc from Burnt Tyre Ash using Tri Butyl Phosphate

Abstract

The article reports the solvent extraction of zinc (Zn) from burnt tyre ash using tributylphosphate (TBP) as an extractant. The increasing interest in environmental protection and resource recovery has prompted research into extracting valuable metals from waste materials, such as Zn from tyre ash, a significant secondary source. The optimal conditions for Zn leaching and extraction were determined through a series of hydrometallurgical processes. Zn was successfully extracted under specific HCl concentration, temperature, and pH conditions, with TBP showing effective performance as an extractant.  We found that increasing the initial concentration of TBP in kerosene improves the extraction efficiency of Zn from burnt tyre ash. The highest extraction rate achieved was 48.68% using 0.30 mol/L TBP at pH 4.5.  The relationship between log D and log [TBP] was done to determine how many moles of TBP were involved in the extraction system. A linear plot with a slope of ~ 1.00 was obtained and indicated the liberation of one mole of [H+] while extracting one mole of Zn2+ from the burnt tyre ash. The study highlights the potential for resource recovery from waste materials, contributing to both environmental sustainability and the supply of industrial metals.