I AM writing this column from Lyme Regis on the south coast of England, a place very dear to my broken heart, and not just because I am a fossil hunter. My late wife and I spent many a happy holiday here pottering about looking for ammonites.
Now would be an unwise time to do the same. Just before I arrived, the town was battered by Storm Ciarán, causing several cliff collapses and leaving the beaches vulnerable to more. But yesterday was like summer; I swam in the perfectly flat sea. Today, it is lashing with rain. Something very weird is going on with the weather. Why could that be?
Whether Storm Ciarán was caused or intensified by climate change isn’t yet known. But it is clear we need solutions, fast. I heard about an innovative and promising one a few weeks ago, and I want to focus on that. On the surface, it sounds deathly dull – I immerse myself in this stuff so you don’t have to – but bear with me.
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The technology is called coal waste separation and I heard about it in a hosted by the US National Academies of Sciences, Engineering, and Medicine. In a nutshell, this means cleaning up old coal mine waste for ecosystem restoration. That is great in and of itself. But there are three other potentially massive upsides.
The US has thousands of abandoned coal mines, often heavily contaminated with coal refuse called tailing waste (or slag heaps as we charmingly call them in the UK), as well as ash ponds where the waste from burning coal is stored. They are largely left as they stand, perpetuating the toxic legacy of fossil fuel production.
But according to at the Office of Fossil Energy and Carbon Management within the US Department of Energy, these “wastes” are anything but. Coal contains a lot of useful stuff besides chemical energy, and when it is burned, these compounds are left behind and concentrated. Tailing waste and ash ponds are, if not a gold mine, then at least a lithium one.
Lithium is one of the “dynamic dozen”: 12 elements and minerals that are central to clean energy technologies ranging from wind turbines to electric vehicle batteries. The other 11 are cobalt, dysprosium, gallium, germanium, graphite, iridium, manganese, neodymium, nickel, platinum and praseodymium.
The US has pledged that 100 per cent of its electricity will be generated from clean energy technology by 2035. Achieving that will require many of the dynamic dozen. But there are long-standing worries about their global supply and the environmental damage of their extraction. Much of the resource is in China, Indonesia and the Democratic Republic of the Congo, which the International Energy Agency has described as “a concern from a geopolitical point of view”.
Enter Old King Coal. Coal waste (in the US at least) contains absolutely tonnes of the stuff. Coal ash alone contains an estimated 288,000 tonnes of lithium, enough to supply the US market for 130 years. It is also rich in cobalt, neodymium, dysprosium, platinum, iridium, gallium and germanium. The last two of these are needed for the semiconductors that will be used in sensors and controllers for the clean tech.
“It’s significant enough to meet some of these clean energy targets that we have,” said Wilcox in the webinar. “I’m really excited.”
There are other reasons to be excited. Not only does coal waste contain those crucial elements, some of it is rich in magnesium and calcium. These aren’t being lined up for extraction, but as a material for negative emissions tech. Coal waste containing magnesium and calcium reacts with carbon dioxide and locks it away as solid carbonates.
Coal waste is also often situated in communities blighted by the loss of jobs in mining. They need new jobs and often have the skills that will be required to develop a minerals extraction industry. Win, win, win, win.
But there is a way to go. The purity of the elements is typically modest, said Wilcox, and the separation technologies to recover and refine them are in their infancy. The cost of doing so is also unknown. But the US Department of Energy is burning the midnight coal to work out how to do it.
And if coal doesn’t work out, there are that could be tapped. These include asbestos mine tailings, “red mud” from aluminium production, brines from geothermal power plants, phosphogypsum wastes from phosphoric acid and fertiliser production, e-waste, conventional landfills and even sewage sludge.
Of course, if the US does develop a coal waste separation industry, it is unlikely to share the bounty. But many other countries, including the UK and Germany, have plenty of slag of their own. Coal may be on its way out, but its legacy could help to save us from the storms of our own making.
Graham’s week
What I’m reading
Discover Dorset: Fossils by Richard Edmonds.
What I’m watching
The Fall of the House of Usher on Netflix.
What I’m working on
Planning a blustery walk on the beach.
Graham Lawton is a staff writer at New Scientist and author of Mustn’t Grumble: The surprising science of everyday ailments. You can follow him @grahamlawton
