Bio-hydrometallurgical recovery of high technologies metals from waste electrical and electronic metals
Responsible person : Fanny Lambert (PhD student)
Supervisors: Ir. David Bastin, Pr. Stoyan Gaydardzhiev
Industrial partener : Comet Traitements SA
Funding : Fonds de la Recherche Scientifique – Bourse FRIA
Project duration : 2 years, renewable
Key words : recycling, biometallurgy, printed circuit boards (PCBs), Waste electrical and electronic equipment (WEEEs), gallium, indium, rare earth.
Figure 1 : Printed Circuit Boards (PCBs)
The development of high technologies goods and environmentally friendly applications causes a strong demand of some raw materials. Photovoltaic panels, wind turbines, electric cars, flat-screens, cell phones, computers, etc. need a large panel of metals like antimony, tantalum, indium, lithium, gallium, etc. Predictions indicate that the demand of some of these metals (gallium, indium, germanium, neodymium, platinum and tantalum) will strongly increase in the future. The supply of these strategic materials will be an important challenge for Europe. The consumer goods recycling appears as a solution for the supply reassure and the strategic raw materials resources saving.
The project aims the development of an innovative process allowing the critical metals recovery (gallium, indium, rare earth) from printed circuit boards. The technology used is hydrometallurgy, in particular biometallurgy, which makes possible to limit the environmental impacts like residual waste producing, energetic expenditure and reagent consumption. Hydrometallurgy offers an alternative to pyrometallurgy. Pyrometallurgy is an efficient technique to recover some metals (copper, precious metals for example) from electronic waste but does not allow the recovery of critical metals like gallium and rare earths that are lost during the process.
Figure 4 : The periodic table of OSR (Old Scrap Ratio) for 60 metals. OSR is the fraction of post-consumer scrap in comparison to the total recycling flow (pre-consumer and post-consumer recycling). The table shows that gallium and indium recycling from post-consumer goods represents >1% of the total secondary production (United Nations Environment Programme, 2011).
The recovery of indium, gallium and rare earths from end-of-life consumer goods has not yet been established in an industrial way. The existing recycling only concerns the pre-consumer goods recycling, that is to say the recycling of production losses in which critical metals are well identified and concentrated. The project aims the critical metals recovery from post-consumer goods, in which they are disseminated in the matrix.