Recycling of valuable metals from poly cracker ash of printed circuit boards (PCBS) by physical beneficiation and hydrometallurgical treatment

In the present paper, recovery of valuable metals from the poly-cracked ash obtained by
pyrolysis of discarded PCBs has been studied following physical beneficiation and a
hydrometallurgical process alternate to smelting. The ash is subjected to comminution for the
separation of metallic components from non-metallic fractions by scrubbing, tabling and froth
flotation which enriched the metal in the concentrate ~97% which was further screened to
separate high and low metal concentrate. The finer fraction containing ~12% metallic value was
leached in acidic solution. Almost all (Cu, Pb, Fe, etc) were leached in 4M HNO3 at 90◦C in 75
min at a pulp density 100 g/L. The characterization of both ash and residues were made by XRD,
EPMA, EDS, etc. to validate the experimental results. The metals from the leach liquor could be
recovered/separated using solvent extraction techniques which can further be processed to get
pure metal salts/ sheets.