Technical and environmental assessment of gold recovery from secondary streams obtained in the processing of waste printed circuit boards

The environmental impact assessment of the process was performed based on the mass balance data corresponding to the recovery of one kg of gold in the identified optimal operating conditions. The Biwer-Heinzle method was applied to determine the values of the General Effect Indices (GEI) for the input and output streams of the process. The GEI values were found to be quite small, close to the minimum possible, thus highlighting that the developed gold recovery process is not only efficient, but has an overall low environmental impact as well.