Unique geological find

The rock type is called nepheline syenite and Axel Sjöqvist was the first to carry out a proper analysis of the stone using modern methods.

Investigation of unique geological find

In Norra Kärr outside Gränna is the world's fourth largest deposit of heavy rare earth metals. The find is unique because it contains unusually high levels of the most sought-after metals and almost completely lacks radioactive substances. – Without rare earth metals, there will be no green transition, Axel Sjöqvist states. In December, he defended his thesis, which was about this geological find.

On a shelf in his study, he has a large rock with green and pink stripes. The rock type is called nepheline syenite and Axel Sjöqvist was the first to carry out a proper analysis of the stone using modern methods. – The rock is 1.5 billion years old and unlike most other rocks, it does not contain quartz. It is also rare; there are only about a hundred sites in the entire world, and in Sweden only the one in Norra Kärr. Because the site where the candy-striped rock was found, is close to Gränna, it is sometimes called grännait. But I don't think that's appropriate because it could be confused with granite.

Rare earth metals comprise a group of 17 elements, of which 16 occur naturally. However, despite the name, they are not very rare but are found almost everywhere in the earth's crust, Axel Sjöqvist explains. – On the other hand, it is rare to find them in sufficiently high concentrations to make it profitable to mine them. The metals are also often found together with radioactive substances, such as uranium and thorium, which makes mining both expensive and difficult. But the find in Norra Kärr contains almost no radioactive substances and will therefore be particularly interesting to extract.

It was in the late 18th and early 19th centuries that scientists began to discover the rare earth metals. A large number of the elements were actually discovered

by Swedes. But it was only recently, with modern technological development, that the rare earth metals have begun to be considered important, says Axel Sjöqvist.

– The elements have different properties that make them useful in a variety of different ways. They are used in monitors, laser beams, special glass, camera lenses, catalytic converters, batteries, and nuclear fuel rods, but also in cancer treatment as well as in X-ray and bone density equipment used for diagnostics. Most notable, however, is their use in the world's most powerful permanent magnets. Because the magnets are so strong, they can be made very small and put into headphones or mobile phone speakers, for example. But they can also be used in generators and electric motors to create more efficient wind turbines and electric cars that can be driven longer distances.

Technology development was previously fossil dependent. Now, it's dependent on metal instead, Axel Sjöqvist explains. – Manufacturing an electric car requires 6 times as much minerals as making an ordinary car and a wind farm on land requires 9 times as much metal as an equivalent gasworks. In order to manage the green transition, we must therefore find new deposits, not only of rare earth metals, but also of cobalt, copper, lithium and nickel, for example.

One way to reduce the shortage of metals is to increase the degree of recycling, Axel Sjöqvist points out.

– At present, practically nothing is recycled when it comes to rare earth metals, which of course is due to the fact that there are not yet that many electric cars or wind turbines to reuse. In the future, however, I believe that recycling will be important, not least because recycled metals are already separated, which of course they are not in nature.

The EU is a world leader in the production of wind turbines, but there is no production of rare earth metals here. Instead, the EU imports them from China, which is the world's largest producer of rare earth metals. It is problematic for several reasons, says Axel Sjöqvist. – On the one hand, production in China entails considerable risks both for the environment and for human health. But it is also worrying that the EU's Sustainable Development Goals, which include wind turbines and electric cars, are completely dependent on China. Consequently, the rare earth metals are now on the EU's list of raw materials that risk becoming scarce.

There are large deposits of rare earth metals in places other than China. One of the world's largest deposits is in Greenland. However, it contains high levels of uranium and thorium. – That is the reason why it will not be extracted. The Greenlandic parliament has in fact adopted a law that prohibits uranium mining and exploration for other metals in rocks with more than 100 ppm of uranium.

Opening a mine is a lengthy process. It involves obtaining an exploration permit and mining licence from the Mining Inspectorate of Sweden, as well as an environmental permit from the Land and Environment Court, which can take many years. Mining also often gives rise to environmental protests. This has happened in Norra Kärr, for example, where there is concern that Lake Vättern will be contaminated by mining operations, says Axel Sjöqvist.

– However, it is a bit of a contradiction to be in favour of a green transition at the same time as you are opposed to mining the minerals that will make such a transition possible. If the EU is to meet the Sustainable Development Goals it has set, it is also imperative to find new deposits of both rare earth metals and a number of other metals. To be able to do that in a good way will require increased knowledge, and I hope that my dissertation will contribute to that.

In order to manage the green transition, we must therefore find new deposits, not only of rare earth metals, but also of cobalt, copper, lithium, and nickel, for example.

AXEL SJÖQVIST

Text: Eva Lundgren Photo: Johan Wingborg

Facts

Axel Sjöqvist, Department of Earth Sciences, defended his thesis on December 10, 2021 entitled Ample Rare Elements: A Geochemical Anomaly in the Earth’s Crust at Norra Kärr. Rare earth metals are a group that includes 17 elements: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, and yttrium. Norra Kärr is ranked one of the most interesting sites in Europe, partly due to the high levels of heavy rare earth metals, which are the most sought after, and partly due to very low uranium and thorium levels. Swedish researchers are behind the discovery of most of the rare earth metals. In 1794, the chemist Johan Gadolin found a new substance in a mineral from Ytterby outside Stockholm, which he named yttrium. Another seven elements were later discovered in the same area and, in addition to yttrium, ytterbium, terbium and erbium, were also named after the site. Furthermore, holmium is named after Stockholm and scandium and thulium after Scandinavia. In 1803, Jöns Jacob Berzelius, together with the chemist Wilhelm Hisinger, also discovered the element cerium in the mineral cerite from the Bastnäs mine in Bergslagen. Further investigations led to even more discoveries, including lanthanum, neodymium, and praseodymium.