On the basis of three selected examples, some problems attributed to the presence of voids resulted from mining operations in already commissioned underground coal mines are discussed. Continuous and discontinuous deformations of the ground surface (sinkholes and subsidence troughs) of anthropogenic origination implicate hazards for the ground surface, even many decades after completion of mining work. Nowadays, when decommissioning and flooding of numerous mines happens, ground movements as well as seismic events related to flooding of abandoned underground mines can be observed. The first case study draws attention to the problems of effective voids localisation methods as well as the reliability of grout injection operations for road construction purposes. The second case emphasizes a problem occurring often in areas with long and complex mining histories, meaning appropriate determination of origin, process and protective measures regarding occurred ground deformations, or damage to buildings. The third case describes specific effects on the surface (shocks and ground surface elevation) generated by the flooding of decommissioned mines.

The closure of coal mines does not terminate their impact on the environment. Gas emissions into the atmosphere are the one of the problems. The closed “Gliwice II” shaft has been selected for a series of measurements to assess greenhouse gas emissions from the closed mine; however, only CO₂ emission has been detected. The article compromises obtained knowledge about the rate of emissions and the influence of meteorological parameters on this phenomenon—baric tendency, difference in dry-bulb temperature between flowing gas and the atmosphere (buoyancy effect) and wind speed. In the course of the conducted research, it was detected that the highest amount of carbon dioxide emission was \(V_{{{\text{CO}}_{2} }}\) = 0.023 m³/s (which is 82.8 m³/h) when baric tendency of pressure drop was 0.57 hPa/h, and the difference between dry-bulb temperatures gas and atmosphere was +4.4 °C (the highest difference in the obtained results). The rate of CO₂ emissions varied from 12.7 to 162.3 \({\text{kg}}_{{{\text{CO}}_{2} }} / {\text{h}}\). Carbon dioxide was detected up to 43 m from the shaft. The results can be considered as a general conclusion about gas behavior when it flows from the underground sites to the surface in natural conditions and about gas concentrations near a point of emission, especially in the case of former mines. However, it may also be useful for other applications, e.g., the leakages from installations of underground coal gasification, or gas drainage.

The aim of the study was assessment of the influence of stainless steel 316 LVM surface modification on its functional properties. The analyzed steel undergone a surface treatment consisting of the following processes: mechanical polishing, chemical passivation and deposition of Al₂O₃ layers by Atomic Layer Deposition method. The proposed variant of surface treatment will undoubtedly contribute to improving the functional properties of stainless steel intended for implants. In order to assess functional properties of the steel, electrochemical studies, adhesion (scratch test), wetting angle tests and topography of surface (AFM method) were performed. The obtained results of the study showed clearly that the proposed by the authors way of surface treatment including: mechanical polishing, chemical passivation and deposition of Al₂O₃ layer by means of the ALD method effectively improves the corrosion resistance of stainless steel.

Wetlands represent a small proportion of all habitats. Still, they are very important features within the landscape, particularly in the ecosystem mosaic. They are composed of many specifically adapted organisms. Wetlands spontaneously establish and provide a significant source of heterogeneity...

Water that floods the mining complexes is drained on a constant basis when a mine is still active, but the situation changes the moment the mine is closed. This article presents the influence that flooding of mine workings has on a surface of a mining area using computer simulation. The evaluation of potential changes to the surface and scale of this phenomenon has been done using as examples the exploitation of mine deposit layers 702, 705, and 718 of the old Gliwice and Pstrowski mines. The performed numerical simulation showed that using numerical modeling of rock mass demonstrates the possibility of predicting uplifting of the surface caused by flooding of underground workings. Maximum designated value of surface uplifting amounts to around 34 mm/m. This value is relatively small and does not exceed 2% of subsidence caused by previous mining activity.

Polish hard coal mines commonly use hydromixtures in their fire prevention practices. The mixtures are usually prepared based on mass-produced power production wastes, namely the ashes resulting from power production [1]. Such hydromixtures are introduced to the caving area which is formed due to the advancement of a longwall. The first part of the article presents theoretical fundamentals of determining the parameters of gravitational hydraulic transport of water and ash hydromixtures used in the mining pipeline systems. Each hydromixture produced based on fine-grained wastes is characterized by specified rheological parameters that have a direct impact on the future flow parameters of a given pipeline system. Additionally, the gravitational character of the hydraulic transport generates certain limitations concerning the so-called correct hydraulic profile of the system in relation to the applied hydromixture characterized by required rheological parameters that should ensure safe flow at a correct efficiency [2]. The paper includes an example of a gravitational hydraulic transport system and an assessment of the correctness of its hydraulic profile as well as the assessment of the impact of rheological parameters of fine-grained hydromixtures (water and ash) produced based on laboratory tests, depending on the specified flow parameters (efficiency) of the hydromixture in the analyzed system.