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.

The paper presents the financial potential of recycling waste electronic equipment (WEE) in the form of printed circuit boards, hard drives, and lithium-ion batteries. Metal contents in selected types of WEE were presented, as well as their price and importance from an environmental, economic, and geopolitical perspective using indicators of relative supply risk and abiotic depletion potential (ADP). The potential benefits that recycling can bring to the company and the environment were presented. Furthermore, the mass balance and value of recovered metals were estimated for southern Poland, and potential possibilities for the management of the remaining separation products were presented. Finally, verified physical recycling methods for the presented WEE were described.

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.