Gold recovery from waste printed circuit boards of mobile phones by using microwave pyrolysis and hydrometallurgical methods

Table 3 Studies regarding gold recovery from waste PCBs

Process	Reagent	Recovery rate (%)		Ref.
Process	Reagent	Original	Adjusted*	Ref.
Leaching	Cyanide	95.0	57.0	[35]
Leaching	Thiourea	90.0	54.0	[23]
Leaching	Iodine-iodide	98.5	59.1	[21]
Leaching	Aqua regia	95.2	57.1	[24]
Leaching	DMF-CuCl₂-CaCl₂ system	99.2	59.5	[25]
Precipitation	None	99.3	59.6	[25]
Leaching	Thiosulfate	94.7	94.7	Present study
Leaching	Aqua regia	95.1	95.1
Precipitation	H₂O₂	95.3	95.3
Precipitation	HClO₄	98.5	98.5

*Adjusted recovery rate equals original recovery rate times (100–40%), assuming that the loss of gold due to shredding and grinding processes is 40%

ISSN: 2468-2039