10.6084/m9.figshare.7243730.v1
Walner Costa Silva
Walner Costa
Silva
Roger de Souza Corrêa
Roger de Souza
Corrêa
Pedro Rosário Gismonti
Pedro Rosário
Gismonti
Júlio Carlos Afonso
Júlio Carlos
Afonso
Rubens Souza da Silva
Rubens Souza da
Silva
Cláudio Augusto Vianna
Cláudio Augusto
Vianna
José Luiz Mantovano
José Luiz
Mantovano
RECOVERY OF LEAD AND NOBLE METALS AFTER PROCESSING PRINTED CIRCUIT BOARDS FROM CELL PHONES BY LEACHING WITH MIXTURES CONTAINING HYDROGEN FLUORIDE
SciELO journals
2018
PCB
metals recovery
acidic leaching
gold
silver
hydrofluoric acid
2018-10-24 02:43:49
Dataset
https://scielo.figshare.com/articles/dataset/RECOVERY_OF_LEAD_AND_NOBLE_METALS_AFTER_PROCESSING_PRINTED_CIRCUIT_BOARDS_FROM_CELL_PHONES_BY_LEACHING_WITH_MIXTURES_CONTAINING_HYDROGEN_FLUORIDE/7243730
<div><p>This work examines the leaching of printed circuit boards (PCBs) from cell phones in aqueous solutions containing HF + H2O2 or HF + NaClO under mild experimental conditions. The PCBs were not ground but were previously treated with 6 mol L-1 NaOH at 50 ºC for 1 h to remove their soldering mask. The HF + H2O2 mixtures leached copper and base metals (except lead) at 35-40 ºC, leaving a solid residue containing lead and noble metals. Leaching was fastest (1 h) when HF and H2O2 concentrations were at least 5 mol L-1 and 3 mol L-1, respectively. The processing of the solid residue is also described in detail. It was leached with water at ~90 ºC followed by HNO3aq. at 25 ºC. Lead, palladium and silver were recovered in this order, leaving gold as final solid. After 1 h at 35-40 ºC, 5 mol L-1 HF + 0.3 mol L-1 NaClO mixtures leached the base metals, copper, gold and palladium. Gold was recovered by liquid-liquid extraction with methyl isobutyl ketone. Silver precipitated as chloride. This salt was isolated by leaching with NH3aq. Loss of fluoride ions (as HF) was below 0.5 wt.% after leaching and handling the solid residue.</p></div>