Editor of Circular Magazine Ian Farrell asks why we don’t take better care of the planet’s rare materials given their significant value.
The rarity of metals such as platinum, neodymium and indium is surpassed only by their importance to present-day technology. So why don’t we take better care of them? And what can we do to ensure their continued supply?
The technology that underpins our way of life relies on some extraordinary metals with truly unique chemical properties. From smartphones and computers to aircraft engines and deep-water pipelines, metals such as platinum, indium, gold and neodymium are absolutely crucial.
Unfortunately, these elements are in short supply – there is just not much of them to be found on our planet.
A good example is iridium, which exists at just two parts per billion in the Earth’s crust and is thought to have been carried here from outer space by meteor impacts. Iridium ore is mined in Haiti, Myanmar, South Africa and Russia – usually, as a by-product of copper or nickel mining – and just 7.5 tonnes of the metal is produced worldwide every year. Compare that with the 190 tonnes of platinum and 2.47 billion tonnes of iron mined annually and you start to see the scale of the problem.
We are now at a point where if we are going to mitigate climate change, we are going to have to deploy technologies quickly and at scale.
Our dependence on these rarest of metals isn’t just an issue for consumer gadgets and computers, however. The green technology that we’re depending on for our future energy needs also makes heavy use of these elements.
“We are now at a point where if we are going to mitigate climate change, we are going to have to deploy technologies quickly and at scale, and that’s going to heavily impact our use of critical raw materials such as these,” says Professor Matthew Davies, head of the applied photochemistry group in the department of engineering at Swansea University.
Davies’ research looks at alternative designs for devices, such as solar cells, that do not rely on critical raw materials (CRMs). He acknowledges that moving away from a fossil fuel-based economy could save a massive amount of carbon, but make us dependent on minerals instead of oil. “Driving an electric vehicle is, of course, better for the environment than a fossil fuel-based vehicle, but it needs 10 times the amount of minerals – particularly in batteries,” he says.
There is currently no commercial photovoltaic (PV) solar-cell technology that doesn’t have a materials supply concern attached to it. Conventional silicon-based PV panels make use of silver, supplies of which could be used up by the end of the decade, Davies claims.
We lack the infrastructure to recycle panels efficiently, but that’s not beyond our scope.
“It’s a big challenge, of which the silver industry is already aware,” he says. “They have succeeded in reducing the amount of silver in the panels significantly over the past 10 years, but we don’t treat silicon-based waste very well at the moment, which compounds the problem. We lack the infrastructure to recycle panels efficiently, but that’s not beyond our scope. It can – and must – be done.”
The first solar panels onto the market are now coming to the end of their life and are starting to enter waste streams. Davies estimates that 100 million tonnes of solar-panel waste is going to hit the market mid-century, all of which contain valuable silver that can be recycled.
“With devices such as this, the amount of critical raw material used reduces as the technology matures,” Davies says. “So, we have to collect those early solar panels – the ones with the most silver – and get that back into circulation. But those are also the ones we are in most danger of missing, because of the lack of current infrastructure.”
An element of competition
Problems such as this are compounded when there is competition for a CRM from other sectors. Rare-earth metals are needed for wind turbines, hydrogen electrolysers, solar panels and batteries, but they are also in demand for smartphones, computers and other gadgets.
Davies is of the opinion that the need for green tech is so important that its deployment cannot be delayed by consumer electronics – but even he admits that society’s love of smartphones is irresistible. “We recognise that, if you give people the choice between a new phone and a solar cell, they will choose the phone,” he says.
We have the opportunity to design in circular thinking and make sure end of life is designed in from the start.
The average smartphone contains around 20 critical raw materials, with 6-10 of these expected to run out within our lifetimes. This is why scientists such as Davies are busily investigating alternatives. His group has successfully used fluorine-doped tin oxide in solar panels, replacing indium, which is also used in smartphone touchscreens. “We have the opportunity to design in circular thinking and make sure end of life is designed in from the start,” he says.
Sitting on a gold mine?
Perhaps the best-known precious metal is gold, which is also crucial to electronics. One organisation looking to reclaim gold from waste electrical and electronic equipment (WEEE) is the Royal Mint, which is currently building a dedicated WEEE recycling facility in South Wales.
“We’re about 60% of the way there,” says the organisation’s commercial director, Mark Loveridge. “We have the equipment on the ground and are now going through our factory acceptance testing, and buying feedstock to test run through the different sections.”
The The Royal Mint process uses chemistry developed by Canadian tech company Excir to extract gold from the WEEE at room temperature. For commercial reasons, Loveridge can’t talk about the fine detail, but he says the initial dismantling of waste items is key. “The biggest thing here is about depopulating the circuit board at the start. We’re trying to make sure that we apply the right amount of energy in the right places,” he says.
The biggest thing here is about depopulating the circuit board at the start.
“We take off the capacitors, the IC [integrated circuit] chips, etc. The board that’s left is shredded, as it contains some surface gold.”
The initial drive of the project is to recycle gold, but other metals are on the Royal Mint’s radar. “In value order, there are things such as palladium, then gold and silver, then other stuff like steel, aluminium and tin. We’re looking to extract all of these things from the WEEE we get in and find a treatment route for them. For the plant as a whole, less than 1% of waste comes out at the end,” Loveridge says.
As we move away from fossil fuels, there is clearly a danger that we could swap a dependence on oil for a dependence on minerals – kicking the consumption can further down the road. Protecting these valuable materials is going to need a joined-up effort by designers, consumers and waste managers. Circularity in a decarbonised world is not just a “nice to have”, it’s essential for a sustainable way of life.
