Smartphones: Behind the Screen

by Beth Crowston, PhD student. Originally published in issue eight of Resonance.

SmartphoneThe number of smartphone users has increased dramatically in the decade following the release of the first iPhone. From an initial market of 122 million buyers, there are now an estimated 2.3 billion consumers worldwide; set to rise to over a third of the global population by the end of 2018.1 The actual number of handsets in circulation exceeds this even further, as people update their mobile phone to keep up with improving technology and tuck old handsets away in a cupboard to be long forgotten about. But how much do people know about the chemical complexity of the gadget in their pocket, and are there enough resources to keep up with the ever-increasing demand?

What makes a phone smart?

There are 83 stable (non-radioactive) elements on the periodic table and at least 70 of them can be found in varying amounts in an average smartphone. This equates to 84% of all the stable elements! Of these, 62 are metals; with copper, gold, platinum, silver and tungsten featuring predominantly, as these metals make up the main micro-electrical components as well as the wiring and solder. However, it is thanks to the rare-earth metals that smartphones have many of their ‘smart’ features.

Of the 17 rare-earth metals, only element number 61 (promethium) cannot be found within a smartphone due to its radioactive nature. Praseodymium, neodymium and gadolinium all aid the communication features through the speakers and microphone, and dysprosium, terbium and neodymium all assist the phone’s vibration function. The remaining rare-earths are used to produce the vivid colours in the screen and reduce UV light penetration into the phone. But how abundant are these elements? And how easy are they to extract?

The Chemical Elements of a Smartphone

How rare are the elements?

The rare-earth metals are actually adequately prevalent in the earth’s crust; the main issues occur because trying to extract them is extremely difficult, time-consuming and costly to mine. However, the supply of the metals is finite, and once they have been used there is currently no suitable replacement.

Unfortunately, recent statistics reveal that around only 10% of unwanted handsets are recycled, as many go forgotten at the back of a drawer or are simply just thrown away. This is a cause for concern, as it is predicted that in 20-30 years’ time we may not have access to the supply of these useful metals.

One million recycled mobile phones could liberate nearly 16 tonnes of copper, 350 kg of silver, 34 kg of gold and 15 kg of palladium, and so the task of recovering these metals is one worth undertaking. But how easy is it to extract and separate the metals for reuse in a new handset?

Recycling smartphones

Most of the mobile phones that do make it to the recycling bin are exported to countries such as China, where they are chemically broken apart to get at the valuable contents. However, the recovery processes used are not responsibly operated. A town in south-eastern China called Guiya has the largest volume of mobile phone waste in the world, which has led to the residents having health problems, as well as the soil, rivers and air becoming polluted with highly toxic chemicals such as lead, arsenic, mercury and chromium.

Even countries that try to responsibly recycle smartphones on their own land such as Australia, face problems such as the high costs of industrial smelting and the environmental implications of using harsh chemicals. So is there a better solution to the problem?

What can we do?

In an ideal world, smartphone consumers wouldn’t update their handset every 11 months and there would be less of a demand on the resources in the first place.

This is an unlikely solution to the issue, however, due to how quickly technology is advancing. Even looking for potential alternatives has bleak prospects as substitution is very difficult and the replacement metals may still have supply issues eventually anyway. Another hopeful avenue for recycling electronic waste is using hydrometallurgical techniques that can be housed in a shipping container and transported wherever necessary. However, this technology has yet to be applied to smartphones.

Although we don’t have an ideal solution right now, a project called the Critical Raw Material Recovery in the EU is working towards collecting particular resources that are economically important including the rare-earths, and so a responsible answer to our recycling

Read more from Resonance

References:

  1. 2.4bn smartphones users in 2017, says e-marketer, MobileMarketing
  2. The Chemical Elements of a Smartphone, Compound Interest