Prospech Limited (ASX: PRS) has announced the successful collection of a 500-kilogram bulk sample from the historic Lanthanide Concentrate Stockpile (LnCS) at its Korsnäs REE Project in western Finland. Prospech, founded in 2014, engages in mineral exploration in Slovakia and Finland, aiming to discover and develop critical elements such as rare earths, lithium, cobalt, copper, silver, and gold resources. The company is taking steps to be a part of the mobility revolution and energy transition in Europe.
The bulk sample is now undergoing metallurgical test work programs in both Finland and Australia. In Finland, a 200-kilogram portion has been dispatched to Oulu University, a member of the European Union-funded REMHub consortium, for characterisation, flotation, and REE leaching tests. The remaining 300 kilograms are being sent to commercial laboratories in Australia specialising in REE processing for parallel studies. These studies are designed to optimise extraction and purification pathways for REEs from the Korsnäs project.
The Australian program involves a two-stage bench-scale metallurgical test work campaign on the 300-kilogram bulk sample, which grades approximately 2.55% TREO (Total Rare Earth Oxides). The first stage focuses on upgrading the concentrate through characterisation, regrinding, cyclone desliming, and flotation. The second stage involves preliminary hydrometallurgical testing, including acid bake, caustic cracking, and staged neutralisation to remove impurities. These tests aim to establish a viable processing flowsheet and support the economic case for extracting strategic light rare earths.
According to Prospech, these tests are exploratory and do not constitute a development decision. The company’s goal is to unlock value from the historically overlooked resource. The Korsnäs Pb-REE deposit was mined from 1958 to 1972, with REE concentrate produced as a by-product. Prospech’s sampling in June 2024 confirmed the high-grade nature of the stockpile material, with results showing 2.55% TREO and a neodymium + praseodymium oxide (NdPrO) enrichment ratio of 31%.
