Turning Coal Waste Into Rare Earth Metals For Renewable Energy

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When talking about climate change and other environmental issues, we tend to spend a lot of time talking about the ills that come from burning coal. Even when pollution mitigation measures are taken, the result isn’t perfect and there’s no reduction of CO2 emissions. On top of that, coal’s carbon emissions are around twice that of burning natural gas, so there’s really no redeeming it. Fortunately, the market has largely selected coal for extinction, as coal has become a lot more expensive than natural gas and renewables for the generation of electricity.

What gets talked about less often is what gets left behind when a coal operation closes. Mines have a lot of rejected material, and the mine itself needs to be cleaned up. Enormous piles of coal refuse sit near old and abandoned mines, while the mines themselves leak acid through drainage and pollute groundwater. At power plants, coal ash gets piled up nearby after burning, and the ashes get left behind when the plant closes. Between these two types of waste to clean up, there are thousands of sites all over the United States.

Grist recently shared the story of a great solution that’s developing to not only solve this problem, but let the country walk away with a vast amount of rare earth minerals.

The DOE’s Efforts To Extract Rare Earth Minerals From Coal Waste

In recent years, the US Department of Energy has been funding a number of pilot plants, where scientists experiment with the best ways to remove valuable rare earth minerals from coal waste. So far, DOE has allocated about $19 million for further research into how much of the valuable materials can be extracted from it. When a technique shows promise, then the site will get additional funding to work toward making the technology work at scale.

So far, plants in Wyoming, West Virginia, North Dakota, Utah, and Kentucky are either under construction or in planning.

“I think we need about three years to develop the technologies and prove them in the field, and then a couple of years to scale up to demonstration scale,” Scott Quillinan, the director of the Center for Economic Geology Research at the University of Wyoming, told Grist. “So I think you’re looking at about the five- to seven-year time scale for commercial deployment.”

The Challenges

There’s a big challenge, though: extracting the rare earths without creating bigger problems than are solved with them.

Laboratories are already pretty good at extracting small amounts of the minerals from coal waste, and at very high purity. Unfortunately, these usually involve creating more pollution, or creating acid waste that’s a net negative. On top of that, it’s very expensive, so nobody ends up winning with current methods.

“We need to find environmentally friendly ways to do this,” Stephan Oborny, a scientist with the Kansas Geological Survey, told Grist. “That’s the tough part.”

The Benefits

There’s already a requirement to clean up mining sites, no matter what. Because it’s already being done, it makes a lot more sense to come up with some rare earth minerals in the process. “We’re already actively reclaiming a lot of these abandoned mine sites,” Virginia McLemore, the senior economic geologist for New Mexico’s Bureau of Geology and Mineral Resources told Grist. “If it should be that rare earths are in those wastes, then it becomes attractive.”

As it stands, companies operating the mines already have to pay fees into a mine cleanup fund to cover the cost of cleanup once the mine closes up shop. If the profitable extraction of these metals can be added to the process, a portion of the money from selling them can go toward mine cleanup while the rest benefits whoever is recovering the minerals. This gives everyone incentive to continue the process and helps even more mines get cleaned up.

Towns in coal country that now struggle without the mining and power generation jobs stand to benefit a lot from this arrangement. Instead of shriveling up and dying, or becoming a town of aging (and often sick) retirees without healthcare, these mining towns can do a lot better than the many mining ghost towns that dot the American west. These towns can instead live on in a second wave of benefit from the mines.

The larger benefit comes to the United States as a whole. By recycling these minerals from coal waste (as well as from other types of waste and used products) it can open up an important source of these strategically important metals. They’re not only used in batteries, but also in solar panels, electric motors, and wind turbines. If the US is going to transition away from fossil fuels and toward renewables, it’s going to require a lot more of these minerals than are available on the market today.

Grist says that at present, most of the rare earth mining and production happens in China, and that leaves the US in a strategically bad spot. Relying on a rival country, and one that there are tensions with, for these important minerals is not only bad policy, but could set the transition to renewables back in the future were international relations to worsen.

Making Good From Bad

Clearly, getting this figured out and put into widespread use is going to be a challenge, but it’s a challenge worthy of pursuit. As Grist’s interviewees pointed out, these pilot plants not only stand to make a lot of money selling these valuable minerals, but they also can help fund and promote the cleanup of mining sites. This is definitely a win-win for everyone.

Perhaps more importantly, this gives an opportunity to get rural Americans and Americans from predominantly red states to feel invested in renewables instead of seeing them as the enemy. People who feel like renewables and environmentalism took everything away from them will fight against them. People who feel like they’re being included in the benefits of the process, and people who depend on the process for their family’s future have a lot of incentive to stand with us and promote a transition away from fossil fuels.

This not only helps people (and we at CleanTechnica like people), but it also helps make the situation more politically feasible. If this all works out, it’ll be a huge win.

Featured image by Jakec, CC-BY-SA 4.0. Modified by Jennifer Sensiba.


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