Let me be honest, I don’t know much about Earth metals but I do know that electronic production needs them. Mobile phones, computers, and other devices need them.
The growing population of humans means that we’ll need more of them, because we need those gadgets now. It’s not a good idea to keep digging for these precious metals, though. Effective recycling is what we should do instead.
It’s just that, our current e-waste recycling has a lot of drawbacks. They include high cost, pollution and risks to human safety, and also environmental damage.
An ongoing research by a collaborative team done from the research center Tecnalia in Spain has developed a way to use eco-friendly chemicals to get those metals back.
Now, I’m gonna try my best to simplify things for you, but I don’t have any background in science so it may not come out good, so bear with me.
Electrodeposition is the newly-developed process involved to recover the rare metals. In this process, a low electric current causes the metals to deposit on a desired surface.
If this research becomes established and more recycling facilities use it, then we’ll reduce our dependence on mining and be able to supply globally in an eco-friendlier way.
Humanity needs more rare-earth metals as it progresses
I mentioned that I don’t know much about metals, so I obviously didn’t know which ones are included in the list of rare metals. Yeah, my geography sucks.
Well apparently, rare-earth metals is simply a collective name for a group of 17 elements. 15 from the “lanthanides series” in the periodic table, along with the elements scandium and yttrium.
They’ve got unique catalytic, metallurgical, nuclear, electrical, magnetic and luminescent properties.
It’s called rare because even though their distribution around the world is even, it’s scarce.
And as I mentioned before, they’re important components for electronic devices and technologies, both the usual and the green one.
We can find them in magnets for wind power turbines and in batteries for hybrid-electric vehicles. Did you know that we need 600 kilograms (about 1300 pounds) of rare-earth metals to operate a single wind turbine?
In 15 years, the annual demand for rare-earth metals has doubled to 125,000 tons. In 2030, it’ll may reach up to 315,000 tons because there will be more demand in green technologies and up to date electronics.
What about mining for more rare metals?
It’s not good idea because it has a number of cons. First of all, it’s inefficient and expensive—extracting just a small amount of rare-earth metals needs large areas.
Then, we need to consider the environmental impacts. Mining for these precious metals generates large volumes of toxic and radioactive material, due to the co-extraction of thorium and uranium.
Considering that mining can involve child labor, this can become not only an environmental but also social issues.
Third, most mining for these metals happens in China, a country that produces more than 70% of global supply. It can be a concern, where can we get more of them in the future?
The problem with our current e-waste recycling
According to the researchers, yes, we can recycle e-waste and get the metals back. But it’s not always a good choice.
For example, recovering them from electric vehicle batteries involves traditional hydrometallurgical (corrosive media treatment) and pyrometallurgical (heat treatment) processes.
Pyrometallurgy involves multiple stages that require high working temperatures (around 1000 C or 1832 F). As if that doesn’t sound good, it also emits pollutants lie CO2, dioxins, and furans into the atmosphere.
On the other hand, hydrometallurgy generates large volumes of corrosive waste like highly alkaline or acidic substances like sodium hydroxide or sulfuric acid.
You may think that this happens only to EV batteries, but no. This also applies to other energy storage technologies like the good old lithium-ion batteries.
New process developed in this research
As I mentioned, in this newly-developed process, the researchers tried to find a sustainable method to recover those metals using electrodeposition, striving to tackle the problems we’re currently facing and also in the future.
While the process itself is not something new and already used to recover other metals, they’ve designed an environmentally friendly composition based on ionic liquid (salt-based) systems.
The researchers focused on recovering neodymium. It’s an important rare-earth metal because of its great magnetic properties, making them extremely high in demand compared to other rare-earth metals.
I honestly didn’t know this, but we use neodymium in electric motors in cars, mobile phones, wind turbines, hard disk drives and audio devices. But I digress.
Ionic liquids are used because they’re highly stable. Meaning, it’s possible to recover neodymium without generating side products, affecting the neodymium purity.
The new thing about this research using ionic liquids for electrodeposition is the presence of water in the mix. That improves the quantity of the final, recovered neodymium metal.
Previous methods recover neodymium metal using controlled atmosphere, but the researchers stated that they could do it without.
Additionally, the process needs a working temperature lower than 100 C (212 F). Basically, they both are key considerations to industrializing that technology.
“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,” said Cristina Pozo-Gonzalo, one of the researchers.
An early step that could lead to something bigger
The researchers believe that their method could avoid humanity’s dependence on mining for rare-earth metals and ultimately minimize the generation of toxic and harmful waste.
They also believe that they could help increase economic returns from e-waste.
A 2019 report projected an 11% growth of lithium-ion batteries in production in Europe. That means that there will be more e-waste at the end of their lifespan. And that’s just from one type of device.
Pozo-Gonzalo concluded, “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.”
Speaking about Li-ion batteries…
A team of researchers from Texas A&M University could lead battery production away from cobalt, another troublesome metal.
Rather than using metals, this new battery technology utilizes polypeptides.
Dr. Karen Wooley, distinguished professor in the Department of Chemistry, said,
“By moving away from lithium and working with these polypeptides, it really takes us into this realm of not only avoiding the need for mining precious metals, but opening opportunities to power wearable or implantable electronic devices and also to easily recycle the new batteries.”
Since it’s made from proteins, these batteries are degradable, non-toxic, and recyclable.
According to Dr. Jodie Luthenkaus, “The rate of recycling lithium-ion batteries right now is in the single digits. There is valuable material in the lithium-ion battery, but it’s very difficult and energy intensive to recover.”
Well, maybe the newly-developed technology above could also tackle this challenge. But it’s always nice to have alternative solutions to our current problems.
Sources
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