Politecnico di Torino - Corso Duca degli Abruzzi, 24 - 10129 Torino, ITALY

+39 011 090 6100 info@tech-share.it

Precious materials from electronic circuit boards

Circular economyElectronic circuit boardsHydrometallurgical processPrecious materials recoveryRare earthsRecyclingRiciclaggioWEEE


The recovery of metals and other materials from waste electric and electronic equipment represents a major opportunity that relates both to their high value and their re-use in hi-tech components and products. The demand for such materials has remarkably increased in recent years, thus giving rise to critical issues related to their supply, particularly because their availability is both limited and conditioned by the monopoly held by primary producers.

Technical features

The method uses hydrometallurgical techniques (in liquid form), carried out at almost room temperature, low-priced and with limited gas emissions in the air, allowing the almost integral recovery of gold and stannic oxide from electronic circuit boards in the first extraction phase using nitric acid. Further phases of the process allow for the recovery of silver, copper and lead sulphate with scalable degree of purity based on market needs.

Possible Applications

  • Precious metals and rare earths recovery from electric and electronic equipment waste;


  • Low operating temperature;
  • Low energetic costs;
  • Limited gas emissions in the air;
  • Scalability and flexibility;
  • High selectivity (95% recovery rate – both performance and purity);
  • Low plant implementation costs.