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.

Gravity beneficiation is a key operation in mineral processing and waste recycling, enabling the production of concentrates with required quality. Among gravity separators, pulsating jigs remain widely applied due to their robustness and adaptability. This study evaluates the KOMAG laboratory jig for upgrading diverse feedstocks: hard coal with variable ash content, gravel aggregates with organic impurities, post-mining waste, and battery scrap. Tests were performed on a two-chamber jig with an air-pulsation system and advanced control. The results confirmed the feasibility of obtaining coal concentrates with 8%–10% ash at 59%–71% yield, complete removal of organic contaminants from aggregates with minimal losses, and recovery of combustible fractions from post-mining waste with favourable separation parameters (d₅₀ = 1.569 g/cm³, imperfection = 0.191). Beneficiation of shredded battery scrap achieved 74%–88% plastic removal and over 99% metallic recovery. Industrial implementations of KOMAG pulsating jigs validated these findings, showing high efficiency in coal, aggregate, and waste processing. This study demonstrates the versatility of pulsating jigging and its relevance in sustainable resource management, confirming that laboratory results can be effectively scaled to industrial practice.

This study explores the concept of an innovative underground storage facility for liquefied natural gas (LNG), utilizing repurposed post-mining shafts. The design incorporates segmental cryogenic tanks, enabling safe and efficient storage of LNG in a structurally optimized environment. This facility also serves as a potential regional transshipment hub, supporting gas distribution to southern Poland and neighbouring countries, while leveraging existing mining infrastructure.Key technical aspects of the design include the adaptation of abandoned shafts, the installation of reinforced concrete foundations to support substantial loads, and the placement of cryogenic tanks within self-supporting steel frames. The study addresses technical challenges such as shaft geometry constraints, geomechanical stability, and thermal management for cryogenic conditions.The storage system offers significant capacity over 2000m3, with a single shaft section accommodating LNG volumes equivalent to dozens of transport tankers. This concept demonstrates the technical and economic benefits of reusing mining infrastructure, including reduced construction costs and maximized spatial efficiency. Moreover, it aligns with the principles of sustainable development and supports the just transition of post-mining regions.

The development of renewable energy sources requires the development of technologies and further expansion of energy storage infrastructure on global markets. One type of energy storage is thermal energy storage(TES). Ongoing researches aim at improving the efficiency of storage and heat transfer in such installations. An important element of these installations is the reservoir that accumulates thermal energy. The following work presents research on new geomaterials based on waste materials, mining raw materials and mixed materials based on them, which could potentially be used as materials for the construction of a packed bed or resevoir that stores thermal energy in TES. These materials, due to the possibility of forming almost any shapes, should exceed the efficiency of aggregate minerals. Additionally, their utilization can partially or fully eliminate mining waste, thereby promoting circular economy principles.

Repurposing decommissioned mine shafts into energy storage systems (e.g., Compressed Air Energy Storage or pumped-storage hydroelectric plants) requires verifying their integrity under reversed stress state conditions. Given the lack of analytical solutions in the literature dedicated to assessing rigid linings subjected to high internal pressure, this study addresses this research gap .The objective was to construct a mathematical model based on the Kirsch solution for elastic media and the modified Coulomb-Mohr criterion, incorporating thermal loads. The model was implemented in the proprietary computational tool PRESS-SHAFT.Verification of the model on a real-case scenario led to conclusions that are counter-intuitive in light of classical mining geomechanics. It was demonstrated that the critical weak link of the structure subjected to pressures up to 8 MPa (the maximum expected value for such facilities) is not the deepest section, but the near-surface zone (0–80 m) . In this area, due to low lithostatic stresses, there is a risk of stability loss via hydraulic fracturing .Regarding the deep sections of the shaft, the model confirmed general stability at maximum pressure but identified a potential risk of shear failure under unfavorable conditions during the storage discharge cycle (internal pressure drop). Ultimately, it was shown that with the application of reinforcements in the shallow zone, the shaft adaptation is technically safe.

Increase in the share of renewables in the energy mix of European Union gained interest in the large scale energy storage technologies. One of the promising technologies is the Compressed Air Energy Storage (CAES) where in conventional approach compressed air is stored in the cavern. An alternative solution that was developed at the Silesian University of Technology is to use a post-mining shaft for adiabatic compressed air energy storage (A-CAES). Availability of post-mining infrastructure and large number of shafts in European coal basins (over 178 shafts only in the Upper Silesia Coal Basin) shows a significant potential of this solution. In order to select a proper shaft with a considerable volume a screening tool was developed that uses multicriteria analysis for an initial selection of shafts that could be used for this technology. This tool takes into account shaft depth, diameter, type of shaft collar lining, water inflow rates and other criteria that are important for safety and energy capacity of the system. The presentation shows results of analysis of the shafts screening tool and case study for one of the shaft located in Poland.