Assessment of gold and silver in assorted mobile phone printed circuit boards (PCBs): Original article

Recovery of Lead and Noble Metals After Processing Printed Circuit Boards From Cell Phones by Leaching With Mixtures Containing Hydrogen Fluoride

“…[1][2][3][4] The current global production of WEEE is expected to increase rapidly at an alarming rate of 20-25 million tons per year, 4,5 with an estimated growth rate going from 3% up to 5% per year. [6][7][8] This fast obsolescence makes the linear 'extraction-productionusage-disposal' chain even more resource-intensive, increasing, therefore, their impacts on environment, human health and economy. This scenario is aggravated by the peculiarities of WEEE: they contain more than a thousand different substances, many of which are high-valued or highly toxic.…”

“…Hence, a copious mobile phone waste of more than 8.2 billion objects is expected to be accumulated worldwide in the coming years. 7 The composition of a PCB from a cell phone varies from model to model of each brand. Its basic structure is the copper-clad laminate consisting of glass-reinforced epoxy resin and a number of metallic materials.…”

“…Its basic structure is the copper-clad laminate consisting of glass-reinforced epoxy resin and a number of metallic materials. 7,11,12 The elements in mobile phones may be categorized as precious metals (Au, Ag), platinum group metals (Pd, Pt, Rh, Ir and Ru), base metals (Cu, Al, Ni, Sn, Zn and Fe), hazardous metals (Hg, Be, Pb, Cd, As and Sb), scarce or trace elements (In, Te, Ga, Se, Ta and Ge). 7 PCBs from cell phones contain copper, silver, gold and palladium in higher concentrations than their respective ores.…”

“…7,11,12 The elements in mobile phones may be categorized as precious metals (Au, Ag), platinum group metals (Pd, Pt, Rh, Ir and Ru), base metals (Cu, Al, Ni, Sn, Zn and Fe), hazardous metals (Hg, Be, Pb, Cd, As and Sb), scarce or trace elements (In, Te, Ga, Se, Ta and Ge). 7 PCBs from cell phones contain copper, silver, gold and palladium in higher concentrations than their respective ores. 2,4,5,12 From an economic perspective, recycling mobile phones is very attractive.…”

“…2,4,5,12 From an economic perspective, recycling mobile phones is very attractive. 7,8,14,15 About 30% of gold, 20% of palladium and 12% of silver come from secondary sources. 7,16,17 Yet, the fact that such a highly complex concoction of various valuable and sometimes hazardous materials are intermingled in such a small volume poses serious engineering challenges for the recovery and recycling of the constituent materials.…”