The effect of mechanical–physical pretreatment on hydrometallurgical extraction of copper and tin in residue from printed circuit boards from used consumer equipment

• Mechanical–physical pretreatment was realized in three different procedures.
• Key processes: electro-dynamic, cross-flow air sifter and air table separation.
• Leaching experiments were carried out in 1 M and 2 M HCl at 80 °C.
• Cross-flow air sifting: highest accumulation of metals in a residue fraction.
• The highest Sn extraction was achieved from fraction after cross-flow air sifting.

This work is focused on studying mechanical–physical pretreatment of printed circuit boards from used consumer equipment followed by extraction of copper and tin from residue fractions by leaching in hydrochloric acid solutions. Mechanical–physical pretreatment was realized in three different procedures. Key processes were electro-dynamic separation, cross-flow air sifter separation and air table separation, respectively. Leaching experiments were carried out in 1 M and 2 M HCl at 80 °C. The results show that cross-flow air sifting leads to the highest accumulation of non-ferrous metals in a residue fraction. From this fraction, the highest extraction of tin with minimal copper extraction was achieved.