It seems like just about everybody on the planet has a cell phone. Last year more than 1.4 billion were produced. Aside from communications, they have become one of the major ways that we get our news, pay our bills, and entertain ourselves. According to the Consumer Electronics Association, cell phones have a life-expectancy of 4.7 years.
Because cell phones are replaced every five years, recycling needs to be an important part of mobile communication manufacturing. But, what materials make up a cell phone and are they valuable? To answer that question, researchers at the University of Plymouth, in the U.K., came up with an interesting way to determine what’s inside a cell phone.
A variety of different materials are used to make up a cell phone—some of them are very valuable. (Image source: University of Plymouth)
Put it in a Blender
To analyze the materials, Dr. Arjan Dijkstra and Dr. Colin Wilkins, geologists from the University’s School of Geography, Earth and Environmental Sciences, put a cell phone in a blender and reduced it to dust. They then took the blended phone and mixed it at almost 500°C with a powerful oxidizer, sodium peroxide. They were able to do a detailed analysis of the resulting solution in acid to determine what chemicals were present in the cell phone.
As expected, abundant materials such as iron, aluminum, chromium, and silicon made up the majority of the cell phone construction. For example, the results showed the phone used in the tests contained 33g of iron, 13g of silicon and 7g of chromium, as well as smaller quantities of other abundant substances.
The Valuable Stuff
These abundant materials are of little value for recycling. However, the cell phone also contained a number of critical elements. These included 900mg of tungsten and 70mg of cobalt and molybdenum, as well as 160mg of the rare earth element neodymium and 30mg of praseodymium.
"There are also rare elements such as neodymium, praseodymium, gadolinium and dysprosium, not to mention quantities of gold, silver and other high value elements. All of these need to be mined by extracting high value ores, which is putting a significant strain on the planet,” said Dijkstra in a university news release.
The phone contained 90mg of silver and 36mg of gold. This means that concentration-wise, a phone has 100 times more gold than a mineral resource geologists would call ‘high-grade’. To create just one phone you would need to mine 7kg of high-grade gold ore. In other words, “mining” cell phones for gold should be more profitable than operating a gold mine.
Beyond the economic advantages of recycling the materials in a cell phone, there are also socially responsible reasons to do so. “Mining can be part of the solution to the world’s problems. But we are now in a climate where people are becoming more socially responsible and interested in the contents of what they are purchasing. Partly on the back of this, several of the major mobile phone companies have committed to upping their recycling rates. It is a positive sign that the throwaway society we have lived in for decades is changing, and we hope this project will encourage more people to ask questions about their own behaviors,” said Wilkins.
The sourcing of certain materials used in cell phones and other electronics, such as cobalt that comes from a conflict region, should also be recycled instead of winding up in a landfill.
The University of Plymouth researchers worked in tandem with Devon-based animation company Real World Visuals to produce a short and fun video which demonstrates the amount and variety of the Earth’s resources used each year in global mobile phone production. Antony Turner, CEO at Real World Visuals, said, “We have enjoyed collaborating with Arjan and Colin to find a way to bring this research alive and make it accessible to the wider public. I now view the phone in my pocket not just as a window on the world but also as a store of precious metals. I wonder where these metals have come from and whether they will be re-used after the phone is discarded.”
Senior Editor Kevin Clemens has been writing about energy, automotive, and transportation topics for more than 30 years. He has masters degrees in Materials Engineering and Environmental Education and a doctorate degree in Mechanical Engineering, specializing in aerodynamics. He has set several world land speed records on electric motorcycles that he built in his workshop.
September 10-12, 2019
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