Leaching of copper and tin from used printed circuit boards after thermal treatment.

The hydrometallurgical route of copper and tin extraction from printed circuit boards (PCBs) of used personal computers after thermal pretreatment is discussed. The samples were thermally pretreated within temperature range of 300-900°C during 15, 30 and 60 min. Two methods of the thermal pretreatment were studied: burning and pyrolysis. The leaching solution of 1 M HCl at 80°C was used. The original as well as thermally pretreated samples were leached. The weight losses within the range from 5 to 35% were achieved. The increase of burning temperature causes the copper extraction into solution up to 98%, while copper extraction into solution from non-burned samples was up to 6%. In the case of the tin leaching the highest extraction was achieved when the original sample was leached. The increase of the burning temperature caused the lowering of the copper extraction. The increase of the pyrolysis temperature enhances copper and tin extraction.