Eco-Friendly Electrowinning for Metals Recovery from Waste Electrical and Electronic Equipment (WEEE)

The amount of waste electrical and electronic equipment (WEEE) has been intensely increasing over the recent decades. In this view, the efficient recovery of metals from WEEE will allow a secure supply of raw materials and will contribute to a circular economy. Among many factors currently affecting the contribution of recycling, is the lack of suitable technologies for WEEE treatment in an environmentally friendly way. Current trends in eco-friendly technologies applied for gold, silver, copper, and tin recovery by electrowinning are reviewed in this paper. In addition, a case study on the perspectives of tin electrowinning has been evaluated. Tin can be present in rather high quantities in WEEE; moreover, its price is about three times higher than that for copper. The electrorecovery of tin has been carried out in cooperation with JSC Elektronikos perdirbimo technologijos. The eco-friendly process based on electrowinning from citric acid-containing leachates is elaborated. The citrate-based solutions have been chosen because citric acid is considered to be an environmentally friendly component. A high deposition rate and current efficiency have been achieved at a deposition potential -0.85 V at 60 degrees C. However, additional steps would be beneficial to diminish the interference of metals present in the scraps, such as Pb(II) and Cu(II), on tin electrorecovery.

Automated summary

The increase in waste electrical and electronic equipment (WEEE) has led to the need for efficient metal recovery to ensure a secure supply of raw materials and contribute to a circular economy. However, the lack of environmentally friendly technologies for WEEE treatment is hindering recycling efforts. This paper reviews current eco-friendly technologies for the recovery of gold, silver, copper, and tin by electrowinning, with a focus on tin recovery as a case study. The use of citric acid-containing leachates as an environmentally friendly process for tin electrowinning is discussed, although further steps are needed to address the interference of other metals in the scraps.