Safely Refining Critical Materials
The U.S. isn’t on track to produce and import enough raw inputs for the energy transition. Read about a new process for refining metals that could transform the supply chain.
By Alan West and Jeff Fitts
A global energy system powered by renewable electricity won’t require the constant supply of new material the way it requires fossil fuels today. The raw materials that go into equipment like batteries, solar panels, and wind turbines aren’t destroyed — those minerals will be reused again and again.
In fact, there will eventually be enough material circulating through the economy that recycled minerals will satisfy most of the demand for nickel, lithium, and other important metals.
But we’re not there yet. Over the next several decades, the U.S. and global economies will need an enormous pulse of newly mined materials to electrify the existing energy system and stock the circular supply chains of the future.
Existing mining and processing technologies aren’t up to this challenge. That’s why we and our colleagues are urgently pursuing advances in metallurgy that will increase the efficiency, safety, and sustainability of refining these materials at industrial scale.
The cost of green technology
Electrifying the energy system will require huge quantities of copper and nickel. While estimates vary widely, the International Energy Association (IEA) predicts the global energy system will require roughly 4 million tons of nickel per year and 20 million tons of copper per year by 2040.
The process of mining and processing nickel and copper already comes at steep human, environmental, and economic costs. The prevailing methods for transforming mined material into usable metals — techniques called pyrometallurgy — require heating ore to 1000 or 2000 degrees Celsius. These smelting processes consume enormous amounts of fossil fuels, pollute the air and water, and leave behind toxic waste that’s difficult and expensive to manage safely.
The environmental cost of just one facility is so great that the U.S. government hasn’t permitted a new one since environmental regulations were instituted in the 1970s. Instead, nearly all of the copper and nickel supply is processed in low-income countries with lax or nonexistent regulations. A large portion of the copper that is mined in the U.S. is shipped abroad for processing.
Manufacturing nickel and copper in the quantities needed for the energy transition presents another challenge: The highest quality ore has already been mined and smelted. The ore being mined today is a challenge for existing smelters, which were designed to handle higher quality feedstocks.
A new approach
Over the past several years, researchers at Columbia Engineering have developed new methods for processing nickel and copper ores more safely. Today, roughly 20% of ore is processed using an approach called hydrometallurgy. In contrast to pyrometallurgy, hydrometallurgy produces manageable waste streams and requires much lower temperatures.
In 2022 and 2023, we published papers detailing how hydrometallurgy can be used to process copper sulfide ore likely to be mined over the next several decades. West’s research group has demonstrated in the lab how copper sulfide ores could be processed using these methods. We’re pursuing work on similar processes for nickel and other critical materials.
Importantly, these methods can be employed in smaller facilities that are cheap enough to build beside mines.
For mining communities that haven’t benefited from the higher incomes associated with refined products, hydrometallurgy offers the chance to safely earn a larger share of the value their minerals provide end users.
Commercializing the technology
Still Bright, a startup founded by a PhD student from West’s group, is currently working to validate this technology for industrial-scale copper production. The company has established a business model and obtained investments to support scaling the process to a size that will overcome many deployment barriers.
We are also leveraging our work on copper to develop a process for the production of feedstock for battery-grade nickel refineries. The process is being developed with minerals from a significant minable resource in northern Minnesota.
In the lab, we have developed a process capable of producing roughly one kilogram of nickel per day. While our ultimate goal is to scale the process to match the output of existing nickel smelters, which produce roughly 100 tonnes of nickel per day, our intermediate goal is a process that produces 20 kilograms per day. At this scale, we will be able to overcome the major deployment barrier by reassuring potential customers that we have identified and addressed any “unknown unknowns.”
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Alan West | Image
Jeff Fitts |