A process for extracting precious metals from spent printed circuit boards and automobile catalysts

Abstract

In this work, a novel process to simultaneously extract precious metals such as gold, palladium, and platinum from spent printed circuit boards (PCBs) and honeycomb-type auto catalysts by smelting without the addition of any collector metals has been developed. The process uses metal components such as copper, tin, and iron contained in spent PCBs as the collector metal and spent auto catalysts as a slag formative. In each experiment, spent PCBs and auto catalysts were crushed, incinerated, and melted after adding fl uxes and carbon. Up to 90% of the gold, palladium, and platinum in the raw materials were extracted in a Cu-Sn alloy phase.

A Novel Process for Extracting Precious Metals from Spent Mobile Phone PCBs and Automobile Catalysts

“…As shown in Fig. 2, the melting temperature of the spent PCBs is expected to be over 1673 K. It was reported by previous researchers that the melting temperature of the spent auto catalysts is over 1873 K. 5) Such high melting temperature means that a lot of energy is necessary to dissolve and accumulate the precious metals contained in the spent PCBs and auto catalysts into a molten metal pool. Thus, suitable fluxes are needed to lower their melting temperatures.…”

“…5) Waste-copper slag and spent auto catalysts were first crushed into small particles with a diameter of from 0.5 to 1.0 cm, respectively. Spent predict the melting temperature of the spent mobile phone PCBs.…”

Selective recovery of palladium from waste printed circuit boards by a novel non-acid process

“…Very few researches have been carried out on the recovery of palladium [6,[17][18][19]. Besides, the forgoing methods developed for palladium recovery could not overcome the shortcomings of hydrometallurgy, such as time-consuming or economically infeasible, and series of acid or caustic leaching is necessary.…”

Estudo cinético da lixiviação de metais de placas de circuito impresso obsoletas.

“…Por meio de processos químicos de deposição, o cobre preenche as áreas do laminado não cobertas pela tinta, que será removida em seguida. A tabela 7 apresenta dados para a composição de placas de circuito impresso obtidos na literatura (GOOSEY; KELLNER, 2002;HAGELÜKEN, 2006;KASPER et al, 2011;KIM et al, 2004;OISHI et al, 2007;. Pode-se notar que não há homogeneidade nos dados, uma vez que os materiais utilizados na confecção das PCI dependem do processo produtivo, da patente, da localização geográfica e da disponibilidade dos materiais (VEIT et al, 2006).…”

“…Tabela 7 -Composição em massa para diferentes PCI obsoletas (GOOSEY; KELLNER, 2002;HAGELÜKEN, 2006;KASPER et al, 2011;KIM et al, 2004;OISHI et al, 2007; Os produtos obtidos após os processos acima descritos sofrem um processo de enriquecimento em certos metais, como pode ser visto na tabela 9 (VEIT et al, 2006), que apresenta a concentração dos metais nas frações obtidas após as separações magnética e eletrostática para placas de circuito impresso de equipamentos eletroeletrônicos (computadores, TVs, etc) obsoletos.…”