A green technology for recovery of gold from non-metallic secondary sources

Abstract

A process for the recovery of gold from processed gold-plated printed circuit boards, gold-coated bangles and gold-coated mirrors is described. It is based on heating the scrap material along with an "eco-friendly" or "green" reagent, 20% (v / v) formic acid solution to boiling temperature to separate the inorganic component from epoxy resin in gold-coated mirrors. Dissolution of base metals is affected using a strong oxidizing agent, 20%(w / v) potassium persulphate, which is also "eco-friendly" or "green"; and heating to boiling temperature. Recovery of gold is achieved by melting. The recovery efficiency is on par with the cyanidation process. The process can be scaled up and adopted by all categories of industries. © 2006 Elsevier B.V. All rights reserved.