A process for the extraction of zinc from zinc waste effluent

Abstract

The present invention relates to a process for the extraction of zinc from zinc waste effluent. This invention particularly relates to the extraction and recycling of zinc from rayon waste effluent by solvent extraction with bis(2,4,4-trimethylpentyl) monothiophosphinic extractant (Cyanex 302), stripping of zinc-loaded organic with sulphuric acid and producing pure zinc sulphate, which can be used in the spinning bath of the rayon plant. The novelty of the present invention is the production of pure zinc sulphate solution from rayon waste effluent using Cyanex 302 leaving all the calcium in the raffinate as compared to available other processes. The purified zinc sulphate could be recycled to the spinning bath of the rayon plant or zinc metal/salt could be produced. The raffinate solution could be discharged in the sewerage without affecting the environment. The process not conserves the natural resources but also meet the strict environmental regulations.