Last month, the internet flew into a frenzy over news that Apple recovered $US40 ($52) million worth of gold from old gadgets last year. That story turned out to be wildly oversold. But our eagerness to celebrate a tech company’s recycling victory speaks to a disturbing truth.
Artwork by Sam Wooley
We’re terrible at recycling rare and important metals from our devices.
Gold recycling is the recipe for a viral story, but there’s a group of metals that are even harder to come by, and far more vital to modern technology. Called rare earths, these obscure elements are sprinkled in virtually every consumer electronic, automobile, and green energy product on the market. They’re the spark that supercharges our technology, bringing us higher speeds, better performance, longer lifespans, and greater efficiency.
And yet after we use rare earths once, we discard them. Why?
“This is basically a problem of economics,” Alex King, director of the Critical Materials Institute, told Gizmodo. “When you’re trying to recover anything from post-consumer waste, the first thing you have to do is collect a large amount of it. Sometimes, the cost of that step exceeds the value of the metal you want to recycle.”
A group of seventeen chemically similar elements dispersed in low concentrations throughout our planet’s crust, rare earths are to technology like yeast is to bread. We only ever use a pinch, but that pinch is essential.
A dash of neodymium gives strength to the magnets inside hard disk drives, speakers, and electric motors. A dusting of dysprosium adds heat resistance. A speck of europium and terbium lights up our TVs in brilliant reds and greens. A thimbleful of cerium is used to polish our smartphone screens atomically smooth.
These metals and the wonders they have brought don’t come without cost. The mining process, which involves dissolving huge quantities of rock in powerful acids, poisons towns and generates lakes of radioactive waste. Naturally, production is centered China, where labour is cheap and regulations are lax. The environmental toll is one that all technology users implicitly — in many cases, unknowingly — accept.
But as demand for rare earths continues to grow, our dependence on China has left many worried about a future supply crisis. That’s why governments and technology companies alike are keen to see rare earth recycling take off.
“There is a great sense of urgency about this,” King said. “The electronics industry wants to have secure supplies of these materials. And some manufacturers feel a great deal of social responsibility.”
In reality, though, the barriers to recycling are huge. Take neodymium. Its main use is in the high-performance permanent magnets inside consumer electronics and automobiles. But common applications, such as the vibrating motor in your smartphone, only contain a microscopic amount.
“The concentration of neodymium in something like an earbud or an iPhone is not too different from the concentration in the ores we get these materials from in the first place,” King said. “But in practice, ores have a huge advantage, in that they are all in one place and they are all one type.”
Apple’s iPhone-disassembling robot Liam is one of the first machines capable of quickly taking apart a smartphone for recycling.
11 per cent
“A big challenge is that we don’t have enough supply at our recycling facilities,” said Sara Behdad, a product design analyst at the University of Buffalo. “There are many uncertainties, in terms of quantity, quality, and timing.”
Ted Miller, vice president of business development at the Philly-based e-waste collection center eForce compliance, told Gizmodo he’s expecting to see a lot more solar panels come in for recycling in the next ten years. Solar panels are full of rare earth metals — but as for finding downstream buyers keen to recycle them out? Forget it. “To get that rare earth material out is expensive — it would take a enormous number of solar panels,” Miller said. “We cannot find anybody to entertain the process.”
Some technologies do use large quantities of rare earths — wind turbines, for instance, can contain a ton-sized neodymium magnet. And where there’s one turbine, there are often dozens more.
In this case, would-be recyclers face a different challenge: the lifespan of the product is too long. A study published in 2013 found that by 2030, we could be recycling 1,000 metric tons of neodymium from wind turbines. But based on projections for wind energy growth, that will only cover 10 per cent of the industry’s rare earth need.
“If we want to transition to a sustainable energy economy using rare earth magnet-based technologies, the reality is that demand for rare earths would go up pretty fast,” Benjamin Sprecher, a rare earth metals expert at Yale’s School of Forestry and Environmental Studies, told Gizmodo. “Because of the time lags inherent to recycling, it will only be able to supply a fraction of that demand.”
Recycling rare earths is by no means impossible. Cerium oxide, a rare earth used as polishing powder, offers a prime example of how it can be done inexpensively.
For decades, tech manufacturers have relied on a cerium oxide-based slurry to buff optical glasses and silicon wafers. Until recently, used polishing powder was simply dumped down the drain. But in the early 2000s, chemists began devising methods for separating pure cerium oxide from silica and alumina impurities picked up during polishing. Following a global rare earth price spike in 2010, recycling cerium oxide became common practice.
“Nowadays, used cerium oxide is carefully collected, separated, sorted for size, and reused,” King said. “We’ve gone from zero recycling a very large amount, because it’s simple and because it’s used just by itself.”
Cerium oxide is special in this respect — inside our devices, rare earths are often mixed up together. But if we can devise efficient chemical separations, the thought of recycling a wide variety of rare earths starts to become less onerous.
Clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium. Image: Wikimedia
developing a simple, cost-effective method
Schelter’s lab has designed an organic molecule, called a ligand, which binds to neodymium and dysprosium, allowing the metals to be separated in minutes via a simple filtration process. In the lab, the procedure can achieve separations of up to 95 per cent; an important purity threshold for magnet manufacturers. His team is now applying the technique to other rare earth mixtures, including those found in compact fluorescent bulbs.
Scaling up from Schelter’s experiments — which use powdered rare earths in an environmentally-controlled lab — to the messy real world won’t be easy. “In principle, it’s so simple, but in practice, it’s really hard to make these elements pure from a mixture,” Schelter said.
Hopefully, by the time better chemistry sees its way into industrial application, we’ll have developed more viable e-waste streams. The Critical Materials Institute, for one, is spearheading an effort to mine the second largest application of rare earth magnets today: hard disk drives.
Hard disk drives have several promising attributes when it comes to recycling. They tend to be similar in size, shape and build, and they’re easy to take apart. Best of all? The world’s largest technology companies are already sitting on a goldmine.
“The big data centres run by Google, Facebook and the like have vast numbers of hard disk drives serving all of the data in the cloud,” King said. “Each of those data centres typically scrap several hundred thousand disk drives every year.”
The Critical Materials Institute is now working with e-waste recycling partners to begin tapping that waste stream. In a few years, King hopes data centres can become an important source of rare earth metals for the very devices they run on.
Data centres like this one in Hertfordshire are a potential treasure trove of rare earth metals. Image: Wikimedia
“We need better regulation around sourcing materials, recyclability of products, and design for disassembly,” said Marion Emmert, a metals chemist at the Worcester Polytechnic Institute. Emmert points out that in Japan, an island nation with few natural resources, recycling and re-use of e-waste is huge.
“Their regulations are geared toward sustainability because they have to be,” Emmert said. “I don’t think it’s by chance that one of the first recycling processes for nickel hydride batteries came from Japan.”
And as demand for rare earths grows, there’s no getting around the fact that we’re going to need more mines. The search for high-tech metals may usher in radical new industries seeking to tap everything from the ocean floor to nearby asteroids. But recycling can, and should, become part of the solution too.
“The technology exists to do this,” Schelter said. “It’s a question of do we have the capacity, and is it going to be economical to turn this into a viable component of the supply chain?”
Apple’s iPhone-disassembling, gold-harvesting robot may be a brilliant PR stunt. But it’s also a sign that the tech industry is starting to acknowledge the reality of living on a planet with scarce resources. If a fraction of the ingenuity that went into making that bot could be put toward solving our biggest recycling challenges, we’d be on our way to a sustainable future.