Contributing towards a circular economy utilising critical raw materials from waste electricals

Summary

The UK economy is highly reliant upon imports of technology metals (TMs), considered ‘critical’ due to their high relative economic importance and high relative supply risk and demand for which is forecast to increase by a factor of 20 for certain materials (EC JRC, 2016). TMs are defined as any “rare” metal or a metal that is in demand, available, and used for the purpose of furthering technology and engineered systems. TMs consist of Critical Raw Material (CRM) metals, platinum group metals (PGMs), precious metals (PMs), nickel and tin. TMs will be used to reference these materials throughout the report, unless the discussion is about specific materials or groups of materials.

This report reviews a wide range of different technologies that have been developed for the recovery of TMs. These include pre-processing methods that can be used to prevent the losses of TMs in the dust fractions and which allow for better segregation of the TMs to aid their recovery.

The technologies reviewed include:

• Solder removal as a pre-treatment process;
• Electrohydraulic fragmentation, steam gasification and super critical water for breakdown
down of printed circuit boards;
• Pyrometallurgical methods using heat for metal recovery; and
• Hydrometallurgical methods using acids, ionic liquids, bio absorption and ion exchange for
metal recovery.