Demand for rare-earth metals is skyrocketing, so we’re creating a safer, cleaner way to recover them from old phones and laptops

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Cristina Pozo-Gonzalo, Deakin UniversityRare-earth metals are critical to the high-tech society we live in as an essential component of mobile phones, computers and many other everyday devices. But increasing demand and limited global supply means we must urgently find a way to recover these metals efficiently from discarded products.

Rare-earth metals are currently mined or recovered via traditional e-waste recycling. But there are drawbacks, including high cost, environmental damage, pollution and risks to human safety. This is where our ongoing research comes in.

Our team in collaboration with the research centre Tecnalia in Spain has developed a way to use environmentally friendly chemicals to recover rare-earth metals. It involves a process called “electrodeposition”, in which a low electric current causes the metals to deposit on a desired surface.

This is important because if we roll out our process to scale, we can alleviate the pressure on global supply, and reduce our reliance on mining.

The increasing demand for rare-earth metals

Rare-earth metals is the collective name for a group of 17 elements: 15 from the “lanthanides series” in the periodic table, along with the elements scandium and yttrium. These elements have unique catalytic, metallurgical, nuclear, electrical, magnetic and luminescent properties.

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The term “rare” refers to their even, but scarce, distribution around the world, noted after they were first discovered in the late 18th century.

These minerals are critical components of electronic devices, and vital for many green technologies; they’re in magnets for wind power turbines and in batteries for hybrid-electric vehicles. In fact, up to 600 kilograms of rare-earth metals are required to operate just one wind turbine.

Rare-earth metals are essential components of electric vehicles.
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The annual demand for rare-earth metals doubled to 125,000 tonnes in 15 years, and the demand is projected to reach 315,000 tonnes in 2030, driven by increasing uptake in green technologies and advancing electronics. This is creating enormous pressure on global production.

Can’t we just mine for more rare metals?

Rare-earth metals are currently extracted through mining, which comes with a number of downsides.

First, it’s costly and inefficient because extracting even a very small amount of rare earth metals requires large areas to be mined.

Second, the process can have enormous environmental impacts. Mining for rare earth minerals generates large volumes of toxic and radioactive material, due to the co-extraction of thorium and uranium — radioactive metals which can cause problems for the environment and human health.

Third, most mining for rare-earth metals occurs in China, which produces more than 70% of global supply. This raises concerns about long-term availability, particularly after China threatened to restrict its supply in 2019 during its trade war with the US.

E-waste recycling is not the complete answer

Through e-waste recycling, rare-earth metals can be recovered from electronic products such as mobile phones, laptops and electric vehicles batteries, once they reach the end of their life.

For example, recovering them from electric vehicle batteries involves traditional hydrometallurgical (corrosive media treatment) and pyrometallurgical (heat treatment) processes. But these have several drawbacks.

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Pyrometallurgy is energy-intensive, involving multiple stages that require high working temperatures, around 1,000℃. It also emits pollutants such as carbon dioxide, dioxins and furans into the atmosphere.

Meanwhile, hydrometallurgy generates large volumes of corrosive waste, such as highly alkaline or acidic substances like sodium hydroxide or sulfuric acid.

Similar recovery processes are also applied to other energy storage technologies, such as lithium ion batteries.

It’s vital to develop safer, more efficient ways to recycle e-waste and avoid mining, as demand for rare-earth metals increases.
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Why our research is different

Given these challenges, we set out to find a sustainable method to recover rare-earth metals, using electrodeposition.

Electrodeposition is already used to recover other metals. In our case, we have designed an environmentally friendly composition based on ionic liquid (salt-based) systems.

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We focused on recovering neodymium, an important rare-earth metal due to its outstanding magnetic properties, and in extremely high demand compared to other rare-earth metals. It’s used in electric motors in cars, mobile phones, wind turbines, hard disk drives and audio devices.

Ionic liquids are highly stable, which means it’s possible to recover neodymium without generating side products, which can affect the neodymium purity.

The novelty of our research using ionic liquids for electrodeposition is the presence of water in the mix, which improves the quantity of the final recovered neodymium metal.

Unlike previously reported methods, we can recover neodymium metal without using controlled atmosphere, and at working temperature lower than 100℃. These are key considerations to industrialising such a technology.

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At this stage we have proof of concept at lab scale using a solution of ionic liquid with water, recovering neodymium in its most expensive metallic form in a few hours. We are currently looking at scaling up the process.

An important early step

In time, our method could avoid the need to mine for rare earth metals and minimises the generation of toxic and harmful waste. It also promises to help increase economic returns from e-waste.

Importantly, this method could be adapted to recover metals in other end-of-life applications, such as lithium ion batteries, as a 2019 report projected an 11% growth per annum in production in Europe.

Our research is an important early step towards establishing a clean and sustainable processing route for rare-earth metals, and alleviating the pressures on these critical elements.

Cristina Pozo-Gonzalo, Senior Research Fellow, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Victoria’s new feral horse plan could actually protect the high country. NSW’s method remains cruel and ineffective

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Don Driscoll, Deakin UniversityFeral horses are a catastrophic problem for the environment, particularly in the high country that crosses the New South Wales and Victoria border. To deal with this growing issue, the Victorian government has released a draft feral horse action plan, which is open for comment until April 23.

It comes after Victoria’s old action plan from 2018 proved ineffective, with feral horse numbers increasing in the most recent counts in 2019. This is similar to New South Wales’ current performance, where feral horses are legally protected and numbers are essentially unmanaged.

This new Victorian plan has flaws, but it’s still likely to perform better than the old plan (and the very low benchmark set by NSW), as it generally aims to deploy evidence-based management of national parks.

As Victoria gets on top of its feral horse problem, NSW will be left further behind with a degrading environment and rising costs of horse management.

The feral horse threat

Feral horses degrade ecosystems and threaten native Australian species with their heavy trampling and excessive grazing. They damage waterways and streamside vegetation which, in turn, threatens species that live in and alongside the streams, such as the alpine spiny crayfish, the alpine water skink and the Tooarrana broad-toothed rat. All of these are threatened species.

Damage from feral horses could worsen as ecosystems recover from the extensive 2019-20 eastern Australian bushfires. Horse grazing could delay animals’ habitat recovery and horse trampling could exacerbate stream degradation after fires.

In fact, there are 24 species that need protection from feral horses after the fires, as identified by the Australian government’s wildlife and threatened species bushfire recovery expert panel in September.

All of this ecosystem destruction translates into substantial economic costs. Frontier Economics released a report in January this year showing the potential benefits of horse control in Kosciuszko National Park was A$19-50 million per year. The benefits accrue through improved recreational opportunities, improved water quality and reduced car crashes involving feral horses.

In contrast, horse control could cost as little as A$1 million per year and up to $71 million, depending on the methods used. Frontier Economics concluded the costs that are incurred by keeping feral horses far outweigh the cost of eradication.

Alpine water skinks are among the vulnerable native species threatened by feral horses.
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Victoria’s new feral horse plan

The draft Victorian feral horse action plan aims to:

1. remove isolated populations on the Bogong High Plains within three years and prevent new populations from establishing
2. contain and reduce feral horses in the eastern Alps by removing 500 horses in the first year
3. use the most humane, safe and effective horse control methods.

The first aim makes complete sense. Removing small populations will always be more humane, cheaper and better for the environment than leaving them uncontrolled.

The second aim is perplexing. Based on 2019 surveys, the draft action plan says there are approximately 5,000 horses in the eastern Alps and the population is growing at 15% per year. If the government continues to remove 500 horses per year after the first year, it could see the population rise to more than 9,000 over ten years, despite culling 5,000 horses in that time.

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In contrast, removing 2,000 horses per year could see the population controlled within three years. Reducing horse numbers rapidly results in the fewest horses having to be culled in the long term.

The third aim of the Victorian draft action plan gives appropriate and strong emphasis to animal welfare. Controlling horse numbers can be morally challenging, and requires a clear understanding of the trade-offs.

Without horse control, native animals are killed when their habitat is destroyed, unique Australian ecosystems are degraded, horses themselves starve or die of thirst in droughts, and the economic costs of inaction escalate. To avoid these costs, horse numbers must be reduced by culling.

This is the grim reality, but with careful attention to animal welfare, the draft strategy will ensure horse control is managed humanely, with control methods based on evidence rather than hyperbole.

Money wasting in NSW

Victoria’s plan is in stark contrast to the NSW government’s approach. In 2018, the NSW government passed the so-called “brumby bill”, which protects feral horses in Kosciuszko National Park.

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The current method of control in NSW is to capture the horses and transport them to an abattoir if they cannot be re-homed. But evidence shows culling has fewer animal welfare concerns than this method.

And in the latest round of money-wasting horse management, the NSW government trapped 574 horses over the past year, but released 192 females and foals back into the park. If the program is aimed at reducing horse numbers, releasing the most fertile animals back into the population is counter-productive.

Feral horses are exacerbating the damage from recent bushfires in the High Country.
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What’s more, removing 300-400 horses per year has little impact on overall numbers. There are around 14,000 horses in Kosciuszko National Park, with a growth rate of 23% per year. This means more than 3,000 horses must be removed just to prevent the population from getting bigger.

The high country without feral horses

If the Victorian draft plan can be improved to invest in rapid horse reduction and ecosystem restoration, we can expect to see quagmires created by trampling horses return to functioning ecosystems and the recovery of threatened species.

Stream banks can be stabilised and then dense grass tussocks and sedges will return, creating homes for threatened skinks, crayfish and the Tooarrana broad-toothed rat.

While Kosciuszko’s alpine ecosystems continue to decline under the NSW government’s political impasse, the Victorian Alps will become the favoured destination for tourists who want to see Australia’s nature thriving when they visit national parks.

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Don Driscoll, Professor in Terrestrial Ecology, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.