Rare earths are to industry like spices to cooking. Without them, recipes for the energy transition are less successful. Because the metals are, for example, in important components for wind turbines and electric cars. Until now, however, extracting rare earths has often been a dirty business at the expense of the environment. China still dominates the world market and has the upper hand when it comes to exports and prices. What has to happen for that to change?
They are silver-colored and relatively soft metals that do not occur in their pure form on earth. They have to be extracted from mined ores in a complex, multi-stage process. The end products are called rare earth oxide and rare earth metal. Rare earths consist of the chemical elements of the third group of the periodic table: scandium, yttrium and lanthanum. The group also includes the 14 elements that follow lanthanum, the lanthanides: cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.
Only a few of the estimated up to 200 rare earth minerals have been mined to date. The concentration of the metals in the ores is decisive for profitability. They are often mined together with other usable substances – for example phosphorus.
Recently, the energy transition has increasingly brought rare earths into the discussion. Because the metals are, for example, components in the construction of high-performance wind turbines, electric motors and energy-saving lamps. But they are also found in hard drives, flat screen televisions, lasers and fiber optic cables. In medicine, they play a role in X-ray technology and magnetic resonance imaging. Last but not least, the armaments industry also needs them.
The metals are not rare on earth, some are even more common than copper or lead. However, large ore deposits with a sufficiently high concentration are rare. According to the latest US Geological Survey, the largest producers for 2022 are China (210,000 tons), followed by the USA (43,000 tons) and Australia (18,000 tons). There are other mines in Russia, Thailand, Myanmar, India, Vietnam, Madagascar, Brazil and Canada, among others. Profitable deposits are suspected in Greenland – in areas where the ice is melting.
In January, Sweden reported a major suitable ore find in the Kiruna mining region in the north of the country. According to the state mine operator, approval procedures and tests could take another 10 to 15 years. The quantity of more than one million tons of rare earth oxides is estimated to be sufficient to cover a large part of the future EU demand for the production of permanent magnets for electric motors and wind turbines.
In Germany, occurrences in Saxony are known. The Delitzsch-Storkwitz deposit region has been scientifically researched for around ten years. However, the concentration of the metals in the ore has so far been considered too low to be profitable for extraction.
In the first quarter of 2023, the EU Commission wants to decide on an initiative with the aim of improving the EU’s supply of critical raw materials that are necessary for environmentally friendly technologies.
The European Commission counts rare earths among the raw materials with the highest supply risk. According to estimates, global demand for important rare earth oxides, for example for catalysts or magnets, will increase from 131,500 tons in 2020 to 188,300 tons in 2030 – if only to achieve climate goals with the help of wind power and electric cars. According to an analysis by the German Institute for Economic Research (DIW), 94 percent of EU imports of rare earths come from politically critical countries, above all China. The People’s Republic has the world market in its hands when it comes to mining and processing. The USA, which has since given up mining, has since gotten back into the business itself, also because of the China monopoly. Australia plans to greatly expand its production.
The Federal Institute for Geosciences lists possible dangers in the gradual extraction and processing of rare earths. These include, among other things, the development of toxic dust and radioactive residues during mining, because the chemical elements uranium and thorium can also occur in the mined ore. During further processing, exhaust gases containing sulfur as well as radioactive residues and residues containing heavy metals could arise. Refining results in high direct greenhouse gas emissions. In addition, a lot of water and electricity is needed during the entire process. There is a “certain risk potential,” writes Urs Peuker from the Technical University Bergakademie Freiberg. “And you don’t necessarily want that in the country.”
They were immense given the lack of environmental regulations. For a long time, the dirty part of extracting or processing rare earths was left to countries with lower environmental standards, such as China. According to a study by the Federal Environment Agency (UBA), there was an increased incidence of lung cancer in the population near the largest mine, Bayan Obo, in Inner Mongolia. Due to a lack of precautions, toxic substances also got into the rivers, the groundwater and the soil.
According to a UBA report, leaks in pipelines, seepage and inadequate sealing of the tailings ponds in the US Mountain Pass mine in California led to salinization and toxic and radioactive contamination of the groundwater in the sparsely populated region up until the 1990s. Since then, more than 20 million US dollars have flowed into the rehabilitation and modernization of the mining area. Overexploitation of nature can hardly be avoided in opencast mining: All mines resemble lunar landscapes.
From the point of view of geoscientists, environmental protection should play an important role when importing rare earths – in relation to the extraction and further processing of the ores. One possibility is certification, which could also curb illegal mining. New environmentally compatible plants cost a lot of money and are probably only possible with government support. In Australia, it is estimated that up to 550 million US dollars will be raised for an environmentally friendly two-stage treatment plant.
Among other things, the DIW recommends helping mining countries such as India and Brazil, which are less of a political concern, with environmentally friendly funding and removing trade barriers. It also makes sense to bundle inquiries from the EU. Furthermore, minimum reserves in the EU are worth considering. Improved recycling could also take effect in the long term. Despite the effort involved in producing rare earths, they are irreplaceable according to the Federal Institute for Geosciences. Since the metals are mainly used in offshore wind turbines and electric motors, their positive contribution to the energy transition outweighs the entire life cycle.
