High copper recovery from scrap printed circuit boards using poly(ethylene glycol)/sodium hydroxide treatment

Recycling scrap printed circuit boards for recovery of valuable metal resources is a major environmental issue. Most available disposal technologies are not environmentally safe. Here, printed circuit board particles were subjected to solvothermal treatment using poly(ethylene glycol)/sodium hydroxide. Results show that residual ratio of bromine varied with temperature, treating time and sodium hydroxide addition. The optimal temperature, treating time and sodium hydroxide addition were 180 °C, 10 h and 0.4 g, with the lowest residual bromine ratio of 1.7%. After treatment, the separation of residue was done by gravity separation and the purity of copper in the recovered metallic components was 97.8%. The recyclability of scrap printed circuit boards before crushing was also compared, the residue of which yielded a complete separation of copper foils and glass fibers. The purity of copper in the foil was achieved at 96.6%. We conclude that this novel process represents an applicable way to recycle high value resources from scrap printed circuit boards.