Mining is a dirty business. Can new technology do anything about this? † national geography

In March, U.S. President Joe Biden ordered increased federal funding and resources to extract metals and minerals needed for batteries for electric vehicles, including nickel, cobalt, graphite and lithium. The presidential decree highlighted one of the most controversial facts about energy conversion: Switching from polluting fossil fuels to green, renewable energy and electric vehicles requires more mining – traditionally one of the most polluting industries.

Mining involves excavating large quantities of ores and then transporting them to processing plants, where they are ground and the metal from the ore is filtered and concentrated. Finally, useless ore residues and rinsing water are removed. Entire lands are cleared to gain access to the ore-rich underlying soil and to build the associated infrastructure. This often uses significant amounts of energy and water, pollutes the air and sometimes produces very toxic waste.

But now a whole range of new technologies are available, ranging from artificial intelligence to CO extraction2 to the atmosphere, with which so-called critical minerals and metals – which are necessary for energy conversion – can be extracted in a more sustainable way than before.

As the world moves from fossil fuels to solar panels, wind turbines and electric vehicles, the demand for these materials is likely to explode. As a result, the private sector and countries such as the United States are increasingly recognizing the importance of rapid development and introduction of new technologies. In a recent report on strengthening the energy supply chain in the United States, the US Department of Energy emphasized the importance of federal support for “environmentally friendly and sustainable” methods of mining the critical minerals of the future.

According to Douglas Hollett, the department’s special adviser on critical minerals and materials, the department believes that critical mineral extraction is no longer just about exploration and exploitation.

‘Now it’s about: Let’s track these minerals, but work more efficiently and achieve the lowest possible impact on the environment along the entire value chain. We look at all aspects from the exploration phase and processing to the end of the life of the products made with these minerals, ”says Hollett.

Mining for data

Long before a mine opens, geologists are sent to drill holes in the ground to locate valuable ore deposits. This exploration phase is usually the least harmful phase for the environment, but here too there is room for improvement. A small but growing number of new exploration firms believe this can be achieved by extracting … data.

Startups like KoBold Metals use artificial intelligence and advanced scientific data analysis techniques to uncover evidence for the presence of battery metals in vast amounts of public and historical data. This data is collected during field research – again using artificial intelligence. Co-funded by Bill Gates’ Breakthrough Energy Ventures initiative, KoBold aims to make discovery rates 20 times more accurate than before, significantly reducing the amount of land that needs to be disturbed to demonstrate ore exploration.

Holly Bridgwater, an exploration geologist at the innovative Australian geology firm Unearthed, believes KoBold’s goals are “achievable”, as mining exploration rates have traditionally been very low: geologists estimate that less than one in 100 mining sites ends up promising enough to be a real mine.

KoBold is conducting fieldwork this summer in several locations in Canada and Zambia, where the company has identified signs of nickel and cobalt deposits. But according to technology director Josh Goldman, it will take the company “two years more or more” to determine if these sites can be extracted. If the company can use artificial intelligence to find hidden but very rich ore deposits, that approach could also reduce the further impact of mining on the environment, Goldman says.

‘If you find low-quality ores, dig up large amounts of material’ to extract some metal, he explains. “This means that an enormous amount of waste material is created. The detection of very high quality ores is therefore crucial. ‘

Renewable energy

So locating higher quality ores can reduce the environmental impact of the mining process, but traditional mining methods still have major environmental and climate impacts. Transport, grinding and processing of ores is an energy-intensive process; the mining sector is responsible for six percent of global energy consumption and 22 percent of total CO2emissions. While many mining companies have now switched to providing renewable energy, and some are experimenting with alternative modes of transport, such as hydrogen-powered trucks, the industry is still largely dependent on fossil fuels to power its heavy machinery and factories.

But for at least one of the critical minerals, lithium, a cleaner approach may be available. Lithium is used as an energy carrier in batteries for everything from smartphones to electric cars, and global demand for the metal could be 40 times higher in 2040 as a result of the shift to electric cars.

For decades, researchers have been researching the possibility of extracting lithium from geothermal brine. This hot and very mineral-rich soup is pumped up from deeper layers by some geothermal power plants to generate electricity. According to Michael Whittaker, a researcher at the Lithium Resource Research and Innovation Center at the Lawrence Berkeley National Laboratory, the entire lithium extraction process is designed to run on clean geothermal energy in this way. The extraction of lithium from geothermal brine also has the advantage that much less water is used than by evaporation of mineral-rich brine from shallow layers, from which lithium is extracted in huge open-air basins on Argentina’s salt flats and Chile.

Before large amounts of lithium can be recovered through the geothermal process, a number of obstacles still need to be overcome. According to Whittaker, the lithium concentration in geothermal brine is ‘relatively low’ compared to South American brine. Other elements such as sodium and potassium are also often present in geothermal sources in much higher concentrations than lithium, which does not make it easier to extract the metal. According to Whittaker, hot geothermal brine is pumped up into existing power plants and sprayed back into the ground after cooling. That process is currently going far too fast in extracting lithium from it, which means that these companies are extracting less value from their production process than they could.

Despite technical challenges and commercial setbacks, the US Department of Energy and the private sector see a future for the geothermal method. Rough estimates of the composition and supplies of geothermal brine indicate that a colossal amount of lithium is hidden beneath the Salton Sea, an extremely salty lake in southern California.

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