Materials Chemistry Sport Chemistry

What are the Tokyo 2020 Olympic medals made of?

Infographic on Tokyo 2020 olympic medal compositions. The gold medal weighs 556 grams and is 98.8% silver and 1.2% gold. The silver medal weighs 550 grams and is 100% silver. The bronze medal weighs 450 grams and is 95% copper and 5% zinc. This year’s medals are the first to be made entirely from recycled metals. The metals used to make all of the approximately 5,000 medals were extracted from used electronic devices donated across Japan. This amounted to approximately 32 kg of gold, 3,500 kg of silver, and 2,200 kg of bronze extracted from 78,985 tons of donated devices.
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The delayed 2020 Olympics are currently taking place in Tokyo, and setting a number of firsts. Obviously, it’s the first Olympics to take place without a public audience in the stadiums to watch the events. However, it’s also the first Olympics at which the medals are made entirely from recycled metals. This graphic takes a closer look at their composition and how the metals to make them were amassed.

This Olympics isn’t the first to use recycled metals to make the medals. The silver medals for the 2016 Olympics in Rio were made partly (30%) from recycled silver from sources including car parts, X-ray plates and mirrors. But the Tokyo Olympics is the first at which 100% of the metals for the medals come from recycled materials. This was no small feat – in fact, it was two years in the making.

In April 2017, the Tokyo Olympic Medal Project started. The goal: to salvage 100% of the metals required to make the approximately 5,000 Olympic medals from unwanted electronic devices. Electronic devices, including smartphones, harbour a large range of elements in varying quantities, though it would take a lot to amass the quantities required.

The amount of gold required for all of this year’s gold medals isn’t as much as you might expect from the individual mass of each medal – 556 grams – as the gold medals are actually made from silver with a thin layer of gold plate on top. Even so, you still need 6 grams for this gold plate for each medal. And it takes 35-40 mobile phones to salvage just one gram of gold.

In all, 32 kilograms of gold needed to be collected, and even more of the metals for the other medals: 3,500 kilograms of silver, and 2,200 kilograms of bronze (a combination of copper and zinc). In all, it took 78,985 tons of donated devices, including approximately 6.21 million mobile phones, to meet these targets.

While this is an impressive feat, it also emphasises the amount of electronic waste a country such as Japan generates. It’s estimated that the number of devices donated as part of this project represents just 3% of the country’s yearly electronic waste. With the reserves of some of the elements that are used to make our devices becoming increasingly depleted, it might not just be Olympic medal projects which are looking to salvage materials from existing devices.

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