As our supply of some essential elements dries up, it’s time to start urban mining. Emma Davies reports
In Short
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Supply of several elements, including helium, phosphorus, indium and galliumis predicted to exceed demand in the near future
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Rare earths used in magnets and electronics are not scarce, but are difficult to separate and purify
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The west relies on China to supply rare earths, but as China’s domestic demand grows, alternatives are desperately required.
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Recycling and alternative sources are being explored, but they may not arrive quickly enough to plug the short term demand gap
Last October, China started building the world’s biggest off-shore wind farm in Bohai Bay, a few hours from Beijing. The country is constructing wind farms on an unprecedented scale – surely good news given its insatiable appetite for coal. But each megawatt of power a wind turbine generates requires up to one tonne of rare earth permanent magnets. The elements used in the magnets – neodymium, dysprosium and terbium – are in short supply and the west is in danger of losing access to them as China’s domestic needs soar.
Unfortunately, the green future of the UK and much of Europe also relies heavily on wind turbines rich in rare earths. And it’s not just green technology that is under threat – many of our everyday electronic items, from iPhones to LCD televisions, depend on the same critical elements.
Rare earths are not the only elements causing supply concerns – elements such as helium, phosphorus and copper are beginning to slip from our grasp.
‘The periodic table is a thing of real beauty to chemists but we are staring at the possibility of not being able to access parts of it,’ says Mike Pitts, of the UK’s Chemistry Innovation Knowledge Transfer Network.
Pitts and his colleagues have compiled an ‘endangered element’ periodic table where red elements are under ‘serious threat’ of becoming unavailable in less than a century (see facing page). Helium is marked red, as are the semiconductor staples gallium and indium. Meanwhile, the rare earth metals rank near the top of most ‘critical’ lists.
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Source: Royal Society of Chemistry
By Emma Davies