The aim of the article is to present the results of laboratory analyses determining the content of rare earth elements (REE) in hard coal type 31.1. Coal was extracted directly from the mining excavation located in the Upper Silesian Coal Basin. Mass spectrometry tests with ionization in inductively coupled plasma (ICP-MS), were aimed at the quantitative analysis of the share of REE in coal, taking into account the economic aspects of recovery of these elements. Fine ground hard coal samples and ashes obtained after coal burning were assessed for the rare earth elements concentration. Results of the rare earth elements concentration (lanthanum and cerium) in hard coal are similar in the values obtained in previous tests. The current analyses present higher concentration of europium or neodymium. The article also contains the concept of possible future research work, consisting in the recovery of rare earth elements using, among others, a classifying hydrocyclone.
Rare earth elements (REEs), particularly neodymium (Nd), dysprosium (Dy), and praseodymium (Pr), are critical in the production of neodymium–iron–boron (NdFeB) magnets used in electronic devices, wind turbines, and electric vehicles. Due to the limited availability of these metals, their recovery from waste electronic equipment such as hard disk drives (HDDs) offers a promising solution. The aim of this study was to develop a method to grind NdFeB magnets obtained from the physical recycling of HDD. The recycled magnets were ground using a planetary mill. A review of the literature highlights the limitations of the currently used grinding methods, which require energy-intensive pretreatment processes, specialised conditions, or expensive equipment. This study employed a Fritsch planetary mill, tungsten carbide grinding balls, and ethanol as a grinding medium. NdFeB magnet samples (120 g) were ground for different durations (0.5 h–15 h) at a speed of 300 rpm, using a cyclic operating mode to minimise material heating. The resulting powders were analysed using a laser particle analyser, an optical microscope, and an X-ray diffractometer. The results enable the determination of optimal grinding parameters, achieving an average particle size (d50) below 5 μm, which is essential for further processing and new magnet production. Finally, the economic and environmental aspects of producing the neodymium alloy were analysed.
Existing shortages on the market of critical and strategic raw materials and problems with the supply chain of selected raw materials, mainly those from China, indicate the need to develop recycling technologies for devices containing the above-mentioned materials. The aim of this work should be to ensure a sustainable supply of raw materials for industry in the EU. One potential source of raw materials may be small-power wind turbine generators equipped with permanent magnets (NdFeB). This research allowed for the development of a methodology for disassembling a generator containing NdFeB magnets in order to determine the shares of individual elements. Due to the significant shares of critical and strategic elements in permanent magnets, a detailed economic analysis was carried out. Based on the research results, economic benefits resulting from the recovery of valuable elements were indicated. The significant market value of critical and strategic raw materials contained in neodymium magnets was demonstrated. The risk of the loss of supplies, the recycling rate and the possibility of replacing the elements in permanent magnets were assessed.
Achieving high shares of variable renewable energy in coal transition regions requires large-scale energy storage solutions that can be deployed rapidly and cost-effectively. This study addresses the pressing need to identify underground infrastructure by developing a national-scale screening framework for adiabatic compressed air energy storage (A-CAES) integrated with thermal energy storage (TES) in post-mining shafts. A multi-criteria decision analysis (MCDA) tool is constructed to rank active and non-decommissioned shafts using eight engineering-relevant parameters grouped into geometry, casing condition, and hydrogeology, enabling transparent down-selection under limited and heterogeneous data. Applied to the Polish shaft inventory (228 shafts), the approach identifies 52 priority candidates and estimates a total storage potential of approximately 4100 MWh for systems with a maximum air storage pressure of 5 MPa and a round-trip efficiency of about 67%, demonstrating the value of a rapid decision filter before resource-intensive geomechanical modeling and site-specific design. The results support a shift in decommissioning practice from irreversible backfilling toward targeted conservation of high-value shafts for energy-storage reuse, strengthening the circular-economy rationale and contributing to just-transition pathways in coal basins. The proposed screening tool provides a practical, reproducible basis for investors and public authorities to prioritize assets and accelerate early project development for shaft-based A-CAES systems.
The article presents a sensitivity analysis of the carbon footprint for different modes of transporting neodymium magnets over a selected route, in the context of their environmental impact and sustainable development. Neodymium magnets, widely used in modern technologies such as wind turbines, are essential for renewable energy sources, making the selection of environmentally optimal transportation crucial. The calculations included road, rail, inland waterway, and air transport, using available emission calculators, which allowed for an analysis using averaged emission indicators for each mode of transport. Additionally, a comparative analysis was conducted with the SimaPro program to verify the consistency and accuracy of the results. The findings indicated that rail transport, with access to low-emission infrastructure and a reduced carbon footprint per unit of mass, is the most efficient option for CO2 emissions reduction, whereas air transport, despite its speed, generates the highest emissions per ton of cargo, making it the least environmentally friendly alternative. A t-test analysis was also conducted to statistically validate the results for each transportation option.