A simple and nearly-closed cycle process for recycling copper with high purity from end life printed circuit boards

•Nearly-closed two-step process for recovering Cu and Al from PCBs residue.•A first step, based on mild concentrated acid, allowed Cu and Ag extraction with high yield.•A second step, based on chelating ion exchanger, for Cu purification.•Recovery of 75% of Cu from the PCBs residue into a Cu solution with 99.0% purity.•Recovery of 85% of Al, as Al(OH)3, from the raffinate.

The large amount of Cu present in printed circuit boards (PCBs) residues, usually about ten times more than the Cu amount present in rich-content minerals, makes these residues an attractive secondary source of Cu. Thus, the main aim of this work was to develop a simple and nearly-closed two-step process to recover Cu from PCBs residues with high purity.Firstly, a multi-element leaching solution, containing 78% of the total amount of Cu present in the residue together with other metals, was obtained using acidic (HNO3 2 mol/L for 210′ at 50 °C) conditions. In a second step, a bispicolylamine resin was used to recover Cu with high selectivity from the multi-element (59.0% Cu) leaching solution and a final Cu solution with high purity (99.0%) was obtained after eluting, with H2SO4 4 mol/L, the Cu retained in the column.Additionally, the amount of Al (85%) leached from the residue, present in the raffinate, was totally recovered as a solid of Al(OH)3.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide