Development of an efficient e-waste recycling and beneficiation method into separable precious metals

Abstract

The issue of e-waste recycling is the uncharted territory in in most developing countries with a full potential to be a source of secondary resources. Every year there are tonnes of electronic materials with precious metals in them that lie in the landfills as there are no economically viable methods to extract them. Many people have attempted to recover precious metals from e-waste and the challenge is to come up with a method that is fast, clean (environmentally friendly), cheap and safe. The aim of the research was to recover precious metals that are of high value such as gold using hydrometallurgical methods. To achieve the faster reaction rate, the process involved heating H2SO4 to about 70±10°C and then washing with water after using a 1:1 solution of water to HNO3 to get rid of other remaining metals. Afterwards, a 10:1 ratio of HCl to H2O2 was added in order to strip the components of gold. Precipitation of the gold solution was done using Na2S2O5 and left for 4 hrs to settle. The final result, after precipitating and drying , showed that with the devised method, it is possible to recover gold at a shortest possible period of 4 days.