Recycling efforts in the UAE for e-waste

Printed circuit boards (PCBs) are currently being dumped in landfills or incinerated which is causing a serious environmental harm in the form of toxic gases or leached hazardous compounds. PCBs contain high amounts of precious metals; about 20 wt% copper, 0.04 wt% gold, 0.15 wt% silver, and 0.01 wt% palladium. The extraction of these metals from PCBs is both profitable and environmentally worthwhile. Hence, this study aims to design a commercial process to extract these four metals from PCBs of computers and mobile phones. This paper discusses the relevant market analysis and research that led to the selection of these metals and PCB sources. Furthermore, the proposed extraction process has been sub-divided into three stages: (1) Physical separation, (2) metal recovery, and (3) waste treatment. Stage 1 involves size reduction to ~1 mm diameter, followed by the corona electrostatic separator and the hydro-cyclone which separate metals from nonmetals. Stage 2 separates individual target metals from each other by hydrometallurgical processing. This stage involves the dissolution of metals in sulphuric acid and aqua regia, followed by the application of EMEW electrowinning technology which results in metal purities of up to 99.99%. Stage 3 includes the treatment of byproducts according to environmental, health, and safety standards. Keywords—Electronic waste management, precious metals printed circuit board (PCB), recovery