RE(E)-mining what’s left behind: unravelling the mineralogy, distribution, and mining potential of REEs in Grängesberg IOA mine wastes (Bergslagen, Sweden)

Other conference contribution, 2025

Rare earth elements (REEs), as a group, make up the raw materials scored with the highest supply risk and economic importance out of the numerous critical raw materials listed by the European Union. This is due to the very limited source of REEs and its key-role in a wide range of high-tech applications (e.g., electro-magnets and high storage capacity batteries), many of them related to the green energy infrastructure and the defense industry. As is with most of the metals needed for an energy transition, demand predictions show high increases for REEs – up to seven times current production by just 2040   (European Commission, 2023). To achieve these goals and predictions, we need to re-envision what mining is, and what is being mined.

Kiruna-type iron-oxide-apatite (IOA) deposits in the Bergslagen region (central Sweden) were mined for centuries, with the largest deposit being the Grängesberg ore field – mined from the 1500s until 1989. The Grängesberg mining operation is since 1989 inactive and all that is left after the ~150 million tons of ore production (Allen et al., 2013), besides the open pits, are large piles of gangue waste material (e.g., 3.46 dry Mt Indicated Mineral Resources at the Jan-Matts tailings dam; Lindholm, 2021). At the time of production, the Grängesberg ore was solely processed for iron bearing minerals. However, as is apparent in the deposit type name (IOA), apatite is present in significant concentrations in the ore. It at the time it was viewed as waste rock and deposited as stamp sands in large waste piles.

Apatite, along with monazite that also occurs in the Grängesberg ore (e.g., Jonsson et al., 2016), are both well-known hosts of REEs. The presence of these minerals in the mine waste poses a possible ‘new’ source for REE in Europe. This study aims to constrain the mineralogical occurrence, distribution, and type of REEs, and other critical metals, in the mine waste from the Grängesberg deposit to evaluate the potential of extracting these metals.