Properties of Particulate Matter in the Air of the Wieliczka Salt Mine and Related Health Benefits for Tourists

This study aimed to evaluate the mass concentration of size-resolved (PM1, PM2.5, PM4, PM10, PM100) particulate matter (PM) in the Wieliczka Salt Mine located in southern Poland, compare them with the concentrations of the same PM fractions in the atmospheric air, and estimate the dose of dry salt aerosol inhaled by the mine visitors. Measurements were conducted for 2 hours a day, simultaneously inside (tourist route, passage to the health resort, health resort) and outside the mine (duty-room), for three days in the summer of 2017 using DustTrak DRX devices (optical method). The highest average PM concentrations were recorded on the tourist route (54–81 µg/m3), while the lowest was in the passage to the health resort (49–62 µg/m3). At the same time, the mean outdoor PM concentrations were 14–20 µg/m3. Fine particles constituting the majority of PM mass (68–80%) in the mine originated from internal sources, while the presence of coarse particles was associated with tourist traffic. High PM deposition factors in the respiratory tract of children and adults estimated for particular mine chambers (0.58–0.70), the predominance of respirable particles in PM mass, and the high content of NaCl in PM composition indicate high health benefits for mine visitors.

Theoretic and experimental research on the possibilities for moderning and reabilitating the extraction installation of the Slănic Prahova salt mine

The paper deals with the subject of rehabilitation and mechanical modernization of the extraction plant within the mining operation of the salt mine from Slanic Prahova region. The extraction plant serves the 23 August mine shaft of the Unirea mine, and also this mine has been converted into a tourist mine. The rehabilitation of the extraction installation consists in the change of the cutting wheels from the extraction tower due to excessive degradation, requiring the redesign under strict conditions, and also the rehabilitation and extension of the saline water extraction system from the tourist mine. The modernization of the extraction plant consists in the change of the DC hoist engine with an asynchronous engine of the same energy power and research on the possibilities of increasing the cable transport capacity with technical changes made to the extraction tower, mine shaft and the sump. Modernization and rehabilitation carried out on the extraction installation at the Slanic Prahova salt mine, will provide a safety in operation and efficiency to using the necessary electricity for hoist engine operations.

Classification of underground mining works within the Tg. Ocna salt mine from the point of view of gas emissions

According to the new classification method, salt mines and underground work or areas where methane has not been observed but for which methane has been observed in boreholes found in rock massifs are considered to be fire mines / mine areas or mining work. This new classification allows only the effective areas of exploitation to be maintained in the wire regime, the rest of the salt mine being considered non-wire. The purpose of this paper is to determine the rate of methane (explosive gas) and carbon dioxide (oxidizing gas) in the mining operations of the Tg-Ocna salt mine, given its classification.

GEODYNAMICS

The most dangerous exogenous geological processes (EGP) in terms of the amount of damage caused to economic objects include: landslides, karst, flooding, abrasion, mudslides, etc. The distribution and intensity of EGP are determined by the peculiarities of geological and geomorphological structure of the territory, its tectonic, neotectonic and seismic regime, as well as hydrological, climatic, hydrogeological paleo- and modern conditions. Solotvynsky salt mine is one of the oldest enterprises in Transcarpathia. The field has been exploited since the Roman Empire. In 1360, a settlement of salt miners, Solotvyno, was founded on the site of the mine, which later became a center of salt production and a royal monopoly. There are a total of nine mines in the field. In 1995-1996 and 2001, floods began flooding mines. In 2005, landslides and karst abysses intensified in Solotvyno, leading to damage to residential buildings, roads and infrastructure. There was a complete flooding of the mines of two mines. Currently, dangerous natural and man-made processes are observed on the territory of the salt mine and adjacent territories. This is mainly salt karst, both underground and surface, the collapse of areas in the location of mines, as well as landslides. Therefore, the purpose of the research is to conduct a geodynamic audit of SOLOTVYNSKY SALT MINE SE and the surrounding area with the possibility of identifying areas with subsidence or rise of the earth's surface, which are gradually slowing down, accelerating or developing at a constant rate. Output data. Radar interferometry data in the period from April 30, 2016 to June 25, 2018 were used for research and performance of geodynamic audit of SOLOTVYNSKY SALT MINE SE and the adjacent territory. Modern methods of interferometric processing of satellite radar data are used in the work: the method of "PS" – the method of constant scatterers, and the method SBAS – the method of small baselines. The method of geometric leveling was used to measure vertical displacements in some places on the earth's surface in order to verify interferometric data. Monitoring of the area of interest was carried out using modern technologies of satellite radar interferometry. According to the results of observations of landslides and individual objects by space (radar interferometry) and ground (geometric leveling) methods, a high correlation of data was recorded and the presence of zones of active subsidence in the mining area was confirmed.

Mining-induced Land Subsidence Detected by Sentinel-1 SAR Images: An Example from the Historical Tadeusz Kościuszko Salt Mine at Wapno, Greater Poland Voivodeship, Poland

There are many mines in Poland that have been in operation for over 100 years, with theTadeusz Kościuszko mine being a large salt mine in Wapno, northern Poland. The mine was closed in1977 due to the greatest catastrophe in the history of Polish mining, but in the first days of 2021, a verylarge hole has been created in this area due to land subsidence. This article uses InSAR technology withSentinel-1 images to determine settlement and ongoing deformation in this mine. The study results areuseful for policymakers, managers, and authorities because land subsidence has caused serious anddangerous effects on people living in the area. The results processed by the Persistent Scatterer InSAR(PSInSAR) method with the Sentinel Application Platform and the Stanford Method for PersistentScatterers software packages show that deformation in the Wapno village area has been detected in bothresidential and non-residential areas, with maximum subsidence of up to −19 mm/yr. The subsidence inthe mine reaches −12 mm/yr, and that at surrounding area range from 0 to −18.8 mm/yr.

Improving the Stability of the Directional Room G 31-33, Horizon 210 - East, Ocnele Mari-Coceneṣti Salt Mine, By Reinforcement with Anchors and Shotcrete

The rock salt deposit from Ocnele Mari - Coceneşti was mined by the method with rooms and small square pillars, at the levels + 226m and + 210m. Although the saline is not deep, certain instability phenomena (cracks, exfoliations) have occurred in the resistance structures (pillars, ceilings), especially in the G31-33 directional room, horizon 210E. These instability phenomena were also highlighted following the 3D finite element numerical modelling. In order to prevent the degradation of the mining excavations and the resistance structures, the affected surfaces were supported with anchors and reinforced shotcrete. The ceiling of the consolidated section of the G31-33 directional room, horizon 210E is monitored by the systematic measurement, on topographic landmarks mounted on the ceiling, of the vertical and horizontal displacements.

Rheological stratification in impure rock salt during long-term creep: morphology, microstructure, and numerical models of multilayer folds in the Ocnele Mari salt mine, Romania

At laboratory timescales, rock salt samples with different composition and microstructure show variance in steady-state creep rates, but it is not known if and how this variance is manifested at low strain rates and corresponding deviatoric stresses. Here, we aim to quantify this from the analysis of multilayer folds that developed in rock salt over geological timescale in the Ocnele Mari salt mine in Romania. The formation is composed of over 90 % of halite, while distinct multiscale layering is caused by variation in the fraction of impurities. Regional tectonics and mine-scale fold structure are consistent with deformation in a shear zone after strong shearing in a regional detachment, forming over 10 m scale chevron folds of a tectonically sheared sedimentary layering, with smaller folds developing on different scales in the hinges. Fold patterns at various scales clearly indicate that during folding, the sequence was mechanically stratified. The dark layers contain more impurities and are characterised by a more regular layer thickness compared to the bright layers and are thus inferred to have higher viscosities. Optical microscopy of gamma-decorated samples shows a strong shape-preferred orientation of halite grains parallel to the foliation, which is reoriented parallel to the axial plane of the folds studied. Microstructures indicate dislocation creep, together with extensive fluid-assisted recrystallisation and strong evidence for solution–precipitation creep. This provides support for linear (Newtonian) viscous rheology as a dominating deformation mechanism during the folding. Deviatoric stress during folding was lower than during shearing in the detachment at around 1 MPa. We investigate fold development on various scales in a representative multilayer package using finite-element numerical models, constrain the relative layer thicknesses in a selected outcrop, and design a numerical model. We explore the effect of different Newtonian viscosity ratios between the layers on the evolving folds on different scales. By comparing the field data and numerical results, we estimate that the effective viscosity ratio between the layers was larger than 10 and up to 20. Additionally, we demonstrate that the considerable variation of the layer thicknesses is not a crucial factor to develop folds on different scales. Instead, unequal distribution of the thin layers, which organise themselves into effectively single layers with variable thickness, can control deformation on various scales. Our results show that impurities can significantly change the viscosity of rock salt deforming at low deviatoric stress and introduce anisotropic viscosity, even in relatively pure layered rock.

Non-Destructive Acoustical Rock Bolt Testing System with Intelligent Filtering in Salt Mine ‘Wieliczka’

This article presents the application of a self-excited acoustic SAS system for non-destructive testing (NDT) for roof-bolt housings in laboratory and real mine conditions. The proposed system with a filtering mechanism was applied to the J64-27 composite anchors. The conducted tests allowed successful confirmation of the usefulness of the system in the detection of rod defects, damage of the mechanism coupling the anchor to the rock mass and testing of the stress state of the anchor itself. The proposed filtering system allowed eliminating the effect of jump change of frequency in the limit cycle of self-excited system. The proposed method is a novel solution for safety diagnostics of bolt housings in mining applications.

Preliminary Investigation of Microplastic as a Vector for Heavy Metals in Bye-ma Salt Mine, Wukari, Nigeria

This study is aimed at the preliminary investigation of microplastics as carrier of heavy metals pollution in surface sediment. Heavy metals concentration was determined by FAAS while microplastics characterization was analysed by ATR-FTIR spectrophotometer. The results obtained showed high level of lead (Pb) concentrations which ranged from 21.37 - 32.80 mg/kg across the sampling sites while Cd has the least concentration between 0.04 - 0.80 mg/kg. The concentration of Pb and Cd were above the USEPA permissible limit in sediment. The following absorption bands; 2978.19, 1728.28 and 1458.23 cm-1 with the functional groups; C-H stretch, C=O stretch and CH2 bend indicates the presence of Ethylene vinyl acetate (EVA) in site S2 and S4 respectively. Other microplastics found in the sampling sites are Nylon, Nitrile, Polycarbonate and Poly propylene. This indicates that there is identical distribution of the microplastics in the sampling sites. The quantities of microplastics isolated ranged from 8.11 - 8.16 g across the sites. Aquatic organisms fed on these polymeric materials because of their unique appearance. Hence, heavy metals adsorption will lead to higher concentrations on microplastics which could be ingested and lead serious complication in their intestine.