Why you should recycle your old smartphone

Monday 18 March 2019

Two geologists, Dr Arjan Dijkstra and Dr Colin Wilkins from the University of Plymouth’s Sustainable Earth Institute have analysed the mineral content of a typical smartphone. They ground the phone to a very fine powder by putting it in a blender then oxidised the dust at 500 oC with sodium peroxide, Na2O2. The residue was dissolved in acid solution and then analysed in detail using a mass spectrometer.

Smashing up a smartphone in a blender (Image: University of Plymouth)

The phone used in the tests contained 33 g of iron, 13 g of silicon and 7 g of chromium, as well as smaller quantities of other abundant substances. Perhaps of more importance though in terms of the Earth’s resources the phone also contained many critical elements including 900 mg of tungsten 70 mg of cobalt and molybdenum, 90 mg of silver and 36 mg of gold. In addition the phone also contained several rare Earth elements including 160 mg of neodymium, 30 mg of praseodymium, 5 mg of gadolinium and 2 mg dysprosium.

They make the point that this means that concentration-wise, a phone has 100 times more gold – or 10 times more tungsten – than a mineral resource geologists would call ‘high-grade’. All of these must be mined by extracting high value ores of scarce elements which is putting a significant strain on the planet. Each year something like 1.4 billion smartphones are manufactured around the world – it is vital that all smart phones should be recycled rather than just being discarded.

This researched is well documented in the following video produced by Plymouth University.


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