Page 30 - Bullion World Volume 4 Issue 2 February 2024

Bullion World | Volume 4 | Issue 2 | February 2024

purification techniques like cementation, ion exchange, issues like acid mist and noxious gases. With auto-
solvent extraction, activated carbon adsorption, and stripping of cathode tubes, the emew system doesn't
electrowinning. require additional stripping equipment, distinguishing it
from conventional electrowinning cells.
In the digestion stage, PCBs are preprocessed into
non-ferrous particles containing metals like gold, Inadequate management of e-waste not only results
silver, copper, and PGMs. During digestion, copper is in missed financial opportunities but also contributes
dissolved, while gold, silver, and PGMs emerge as a to global warming. Failing to recycle metals from
residue in less than 24 hours, ready for further recycling e-waste necessitates investments in mining and refining
into pure metal or sale to precious metal refineries. operations for primary metals, which may become more
expensive due to declining metal grades in ores.
Digestion + Electrowinning in E-Waste recycling:
Post-digestion, a direct current is applied, electro- Consider that the global value of raw materials in
depositing copper onto the cathode. Although e-waste generated in 2019 amounted to about $57
conventional electrowinning has limitations like low billion USD. Unfortunately, only a small fraction of this
selectivity, high operating costs, and safety concerns, sum was recovered.
the emew electrowinning system overcomes these
issues. Its cylindrical cells enhance mass transfer, Positive changes are underway. Europe and the US
producing high-purity copper cathodes even at lower already recycle nearly 40% of electronic waste, with
concentrations. other countries following suit. Since 2014, the number
of countries with some form of e-waste regulation has
The emew system utilizes a closed system, rapidly increased from 61 to 78. However, enforcement remains
circulating electrolyte across the cathode, reducing lacking in many cases, leading to improper recycling
overall acid consumption and waste generation. It practices.
ensures a safer working environment by eliminating

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