Mining Critical Raw Materials from Waste Printed Circuit Boards by Thermo-Mechanical Disassembly

EU dependence on critical raw materials poses a serious risk of fragility and vulnerability, mainly in strategic sectors such as energy and defense. Electronic boards contain high concentrations of metals, particularly copper and lead, comprising critical raw materials. Urban mining offers the possibility to recover these metals, but continuous innovation is necessary to make extraction processes more efficient, productive and cheap. Contamination is an issue which reduces the extraction performance and increases pollution and costs. Thermo-mechanical disassembly can be used to separate electronic components from boards, by removing the soldering alloy. A thermo-mechanical disassembly process, currently under patenting (namely “impact desoldering”), allows the separation of electronic components and soldering alloys from the boards by impact. It has been applied to 4 kg of waste boards to separate the printed circuit board from the electronic components, and the soldering alloy has been melted to make an ingot. A further thermo-mechanical process has been also applied to extract copper sheets from the disassembled printed circuit boards, by rolling.