The article presents an assessment of the value of the post-industrial landscape in the town of Rydułtowy using a comprehensive approach. It includes: 1) Defining the scope of the study taking into account regional context; 2) Inventory of mining facilities; 3) Desk study; 4) Field research and interviews; 5) Value assessment and guidelines. For assessing the value of the post-mining landscape the Architectural-Landscape Units & Interiors method was selected. The usefulness of the proposed method for the post-industrial landscape assessment was demonstrated using the case of Rydułtowy, a mining town. This article also describes the history of the mining activities in the town of Rydułtowy. The significance of the more than 200 years of mining on the growth and expansion of the town as well as its identity is reviewed. Special attention is given to the history and the present state of the most prominent element of the landscape, namely the cone-shaped landfill – Szarlota. The guidelines resulting from applying the proposed landscape value assessment are useful for a number of stakeholders and future activities planned for both the cone heaps and the mining plant.

The structural system of a multiple strip-shaped pillar-roof is common in underground mine exploitation, and research on its mechanics and micro/macroeconomics is meaningful for utilizing strip-shaped pillar resources. A general model of the structural system of a multiple strip-shaped pillar-roof was established, the deformation mechanism of the model was analysed by material mechanics, and the deflection curve equations of the model were obtained. Based on the stress strain constitutive relation of the strip pillar and cusp catastrophe theory, the nonlinear dynamic instability mechanism of the structural system of a multiple strip-shaped pillar-roof was analysed, and the expressions of the pillar width for maintaining the stability of different types of structural systems were derived. The benefits of different structural systems were calculated using micro/macroeconomic theory, the type of the structural system was determined, and different recovery schemes were obtained. Theoretical application research was applied to a large manganese mine, and the results demonstrate that no pillar recovery was needed in 2016, a 9-m wide artificial pillar could be built to replace a pillar in 2017, and the construction of 14-m wide artificial pillars can be conducted in 2018.

The aim of the study was to develop an assessment methodology for the temperature of the surface of the friction pair during the braking for mine hoists. During the braking process, the work of friction is transformed into heat at the level of friction surfaces, and in case high temperatures are reached, the friction coefficient is influenced negatively, thus the risk of braking failure exists. In the first part of the study we measured the temperature of the friction surfaces for a particular case of hoist in real braking conditions. In the second part of the study is presented a theoretical model for the calculation of the temperatures resulted in the braking process for the hoist equipped with shoe brakes. The theoretical model for calculation was simulated numerically for a particular case in real braking conditions. Based on the conclusions resulted after the study, a series of hypotheses and recommendations for adjusting the control of the process parameters have been given out, in order to avoid the excessive heating of the brakes of the hoists and, respectively, their improved safety, maintenance and availability.

Subnetwork with two nodes shared with entire ventilation network can be separated as its part. For the network under common ventilation conditions, one of these nodes will become the subnetwork starting node, while the other will be the subnetwork end node. According to the graphs theory, such a piece of the network can be considered as a subgraph of the graph representing the entire ventilation network. A special feature of that subgraph is lack of predecessors of the subnetwork starting node and lack of successors of the subnetwork end node. Ventilation district of a mine may be often treated as a subnetwork. Vicinity is a part of the network which is not separated as subnetwork. In the case of a ventilation district its vicinity forces air flow through the district. The alternative characteristic curve of the vicinity can therefore be compared to the characteristics curve of a fictional fan that forces the airflow in the district.

The alternative characteristics (later in the text: the characteristics) of the vicinity of the ventilation district in an underground mine strongly influence air quantity and therefore play a crucial role in the reduction of methane, fire and thermal hazards. The role of these characteristics and proper selection of their approximating function were presented in the article.

The reduction of resistance of an intake stopping (having influence on entire resistance of a ventilation district) produces increased airflow in the district. This changes of airflow in the district caused by a variation in internal resistance (e.g. by opening an internal regulation stopping) depends on the characteristic of the vicinity of the district. Proper selection of its approximating function is also important for this matter.

The methods of determination of the alternative characteristic curve of the district vicinity are presented. From these procedures it was possible to obtain the results of air quantities and differences in isentropic potentials between an inlet and an outlet to/from the ventilation district. Following this, the characteristics were determined by graphic and analytic methods. It was proved that, in contrast to flat vicinity characteristics, steep ones have a smaller influence on the airflow modification in the district (which are caused by a regulation of the district resistance). The characteristic curve of the vicinity determines the ability to regulate air quantity and velocity in the district.

Stemming plugs are one of the widely used accessory in surface mining operations. Stemming plugs assist conventional stemming material in gas retention and help in better fragmentation and explosive utilization. Effective use of the stemming plugs results in economic benefits and enhance the efficacy of the project. Economic and productive viability of stemming plugs have been conducted in depth by different researchers. Addition of stemming plugs to a new system requires ergonomic challenges for operators conducting drilling and blasting operation. Induction of a newer product in already established system is subject to overall positive feedback. This work investigates ergonomics of three different stemming plugs introduced to a limestone quarry in Pakistan. The stemming plugs were evaluated based on extra time needed, workers feedback, failures during operation, recovery time after failure and number of extra equipment required to carry out the operation. Points based matrix was established with likeliness of each plug and based on overall scores stemming plug 1 was most acceptable followed by stemming plug 3. Stemming plug 2 was disliked by operation and did not reach the level of acceptability of operators. This work will help stemming plug making industry in adapting to best practices by incorporating ergonomics of plugs in designing. Literature shows no previous work on ergonomics of stemming plugs.

The longwall mining system with fall of the roof is still the most common hard coal extraction system in Polish mining. Its utilization for selective coal seams’ mining results in the development of post-extraction gobs at different depths. Methane desorption phenomena from the coal seams in the stress release zones and migration of gas towards the area of operations, result in methane accumulating also after completion of coal exploitation. Methane which is not exploited from the gobs can migrate directly to the atmosphere e.g. through overlying layers, faults, workings or directly via an operated ventilation grid of an adjacent coal mine – contributing to the Greenhouse Gas effect. One of the methods to capture methane (Abandoned Maine Methane) from abandoned coal mines is to drill vertical wells through several post-extraction gobs from the surface.

This paper presents the results of drilling operations at the AGH-Wieczorek-1 well, where first time in Poland, down-the-hole-hammer (DTH) with casing-while-drilling (CwD) technology were used to drill through several post-extraction gobs. The AGH-Wieczorek-1 well with 440.0 m MD was successfully drilled without any complications. Finally, three post-extraction gobs and two coal seams were drilled. Additionally, results from drillability tests, which were performed during drilling operations, are presented.

Geographical Information Systems have become essential tools for land analysis and the subsequent decision making in many fields of human activity. In the field of mining, GIS applications have appeared in ore deposit modelling, environmental pollution, or planning of mining spaces. In this research, the powerful multicriteria tools of GIS platforms have been applied for the determination of an index that has been called “Exploitability Index”. This index allows analyzing a series of outcrops of industrial aggregates, to help in the selection of the most adequate one to be enhanced from a mining approach. The multicriteria analysis has been applied for its determination, and as a result of this research, a model is proposed. The main criteria that condition the decision have been established in this model, along with their subsequent hierarchization and their weighting. The proposed model is applied to a specific case: the analysis of a series of outcrops of industrial aggregates (ophites) in Cantabria, Spain. After defining the Exploitability Index for those ophitic outcrops, it has been observed that the only deposit that has been classified as very suitable for its exploitation is the only one that has been really exploited, supporting the proposed methodology.

The article attempts to transfer information from the Point Nuisance Method (PNM) used in Poland in the issue of protection of buildings in mining areas, to the system of inference based on Bayesian formalism. For this purpose, all possible combinations occurring in PNM were selected. The number of numerically generated patterns was 6,718,464 cases. Then, based on Python package Scikit-Learn, a classification model was created in the form of the Naïve Bayes Classifier (NBC). The effectiveness of three methods used to build this type of decision-support system was analysed, from which the Categorical Multinomial Naive Bayes (CMNB) approach was finally selected. With the created classifier, its properties were verified in terms of quality of classify and generalization. For this purpose a general approach was used, analysing the level of accuracy of the model in relation to training and teaching data, and detailed, based on the analysis of the confusion matrix. Additionally, the operation of the created classifier was simulated to determine the optimal Laplace smoothing parameter α. The article ends with conclusions from the carried out calculations, in which an attempt was made to answer the question concerning potential reasons for incorrect classification of the created CMNB model. The discussion ends with a reference to the planned research, in which, among other things, the use of more complex Bayesian belief networks (BBN) is planned.

In this study, the compressive deformation of crushed sandstone was tested using a crushed rock deformation-seepage test system, and the effects of various factors, including crushed rock grade, grade combination, water saturation status, and stress loading method (i.e., continuous loading or cyclic loading and unloading), on the compressive deformation of crushed sandstone was analyzed from four perspectives including stress-strain, bulking coefficient, deformation mechanism and energy dissipation. The results indicate that the stress-strain relations of crushed sandstone are closely associated with all factors considered, and are well represented by exponential functions. The strain observed for a given applied stress increased with increasing crushed rock grade throughout the loading period. Crushed sandstone grades were combined according to a grading index (n), where the proportion of large-grade rocks in the sample increased with increasing n. The bearing capacity of a water-saturated crushed sandstone sample with n = 0.2 was less than that of an equivalent dry sample for a given applied stress. The stress-strain curve of a water-saturated crushed sandstone sample with n = 0.2 under cyclic loading and unloading was similar to that obtained under continuous loading. Observation and discovery, the deformation mechanism of crushed sandstone was mainly divided into four stages, including crushing, rupture, corner detachment and corner wear. And 20% of the work done by testing machine is used for friction between the crushed sandstone with the inner wall of the test chamber, and 80% is used for the closing of the void between the crushed sandstone, friction sliding, crushing damage.

Monitoring the stress change of bolt and knowing the anchoring condition in a reasonable and effective way, accurately, can effectively prevent tunnel accident from breaking out. The stress of rock mass around the roadway is usually transferred to the anchor rod in the form of axial load, so it is of great significance to study the axial load of the bolt. In this paper, a full size anchoring and drawing experiment system was designed and established, innovatively, which realized the pull-out test of 2.5 m prestressed end Anchorage and the full-length Anchorage by using the new resin anchorage agent under vertical and horizontal loads. Through the application of fiber Bragg grating (FBG) sensing technology to the test of full-scale anchor rod, the axial force distribution characteristics of the end Anchorage and the full-length Anchorage anchor rod were obtained under the action of pre-tightening torque and confining rock pressure. The comparison indicates that the proportion of high stress range accounts for only 17.5% and the main bearing range is near the thread end of anchor rod, the proportion of main bearing range of end Anchorage is 83.3%, and the feasibility of FBG force-measuring anchor rod is verified in the field. The research results have certain reference value.

Knowledge of the way in which minor and trace elements occur in coal is one of the most important geochemical indicators of coal quality. The differences between the methods of binding elements in coal in each coal seam and the variability of this feature of coal in the basin profile have not been discussed so far. These coal features were identified in a group of selected coal seams (209, 401, 405, 407, 501, 504, 510, 615, 620) in the Upper Silesian Coal Basin (USCB). At the same time, the differences in the role of identified mineral and maceral groups in concentrating specific elements in coal is highlighted. Identical or similar tendencies of changes in the way in which As and V, Ba and Rb, Co and Pb, Co and Zn, Mn and Pb, Pb and Zn, Co and Rb, and for Cr and Cu occur in the coal seams in the USCB profile was found. Changes in the mode of occurrence of As and Pb in coal in the USCB profile were probably influenced by carbonate mineralization. The changes in the mode of occurrence of Mni and Pb in the coal were probably determined by dia and epigenetic sulfide mineralization, while the content of Ba, Cr, Rb, Sr, and V in coal from these deposits was affected by clay minerals. It was observed that the greater the degree of the carbonization of the organic matter of coal, the lower the content of As, Mn and Pb in coal and the higher the content of Ba and Sr in coal.

The application of fluidized fly ash in underground mining excavations is limited due to its significant content of free calcium and calcium sulfate. In order to increase the amount of utilized fly ash from fluidized beds, it should be converted to a product with properties that meet the requirements for mining applications. This research presents the results of an attempt to adapt fluidized fly ashes for use in underground mining techniques, by means of carbonation and granulation. Carbonation was performed with the use of technical carbon dioxide and resulted in the reduction of free calcium content to a value below 1%. Granulation on the other hand, resulted in obtaining a product with good physical and mechanical parameters. The performed mineralogical and chemical studies indicate that trace amounts of “binding” phases, such as basanite and/or gypsum are present in the carbonized ash. The addition of water, during the granulation of carbonized fluidized fly ash, resulted in changes in the mineral phases leading to the formation of ettringite and gypsum as well as the recrystallization of the amorphous substance. It was confirmed that the carbonization and granulation of flying fluidized ashes positively affects the possibility of using these ashes in underground mining excavations.

A simple empirical study on the orientation, diameter, and extent of radial fractures (long and short) at the vicinity of the face-perpendicular preconditioned boreholes is described. Homogenous and heterogeneous mining faces were considered when studying the orientation of radial fractures, four and five face-perpendicular preconditioning practices were used to investigate the outspread and diameter of radial fractures from one blasted drill hole to another. Long radial fractures were observed to be developed along the direction of the maximum principal stress and short radial fractures were observed to be developed along the direction of the intermediate principal stress in a homogenous mining face. On the other hand, long radial fractures were observed to be developed along the direction of the intermediate principal stress, while short radial fractures were observed to be developed along the direction of the maximum principal stress when the mining faces subjected to heterogeneous rock mass. The diameters of the radial fractures observed were inconsistent and were not nine times the diameter of the original borehole. Furthermore, the extent of radial fractures from one borehole to another was noted to be gradually improved when the additional of preconditioned borehole was in place. This study maintained that the orientation of radial fractures is mostly controlled by the rock properties, however, extend and the diameters of the radial fractures are controlled by rock properties, the effectiveness of the stress wave and gas pressure and brittleness of the rock mass.

The prediction of rock cuttability to produce the lignite deposits in underground mining is important in excavation. Moreover, the certain geographic locations of rock masses for cuttability tests are also significant to apply and compare the rock cuttability parameters. In this study, sediment samples of two boreholes (Hole-1 and Hole-2) from the Sagdere Formation (Denizli Molasse Basin) were applied to find out the cerchar abrasivity index (CAI), rock quality designations (RQD), uniaxial compressive strengths, Brazilian tensile strengths and Shore hardnesses. The Sagdere Formation deposited in the terrestrial to shallow marine conditions consists mainly of conglomerates, sandstones, shales, lignites as well as reefal limestones coarse to fine grained. A dataset from the fine grained sediments (a part of the Sagdere Formation) have been created using rock parameters mentioned in the study. Dataset obtained were utilized to construct the best fitted statistical model for predicting CAI on the basis of multiple regression technique. Additionally, the relationships among the rock parameters were evaluated by fuzzy logic inference system whether the rock parameters used in the study can be correlated or not. When comparing the two statistical techniques, multiple regression method is more accurate and reliable than fuzzy logic inference method for the dataset in this study. Furthermore, CAI can be predicted by using UCS, BTS, SH and RQD values based on this study.

Coal waste stockpiles – as artificial formations being a result of the exploitation of underground coal deposits – are constantly influenced by external factors, such as rock mass movements affecting the stability of the stockpile body and changing weather conditions, leading to a cycle of aerological phenomena which intensify the self-heating of the deposited material. Together with the occurrence of external factors, the stored material is also characterised by a set of internal features (also called genetic) that have a direct impact on the kinetics of the self-heating reaction.

The paper focuses mainly on the issue of external factors such as the inclination angle of the stockpile, erosion of the slopes and thermal insulation of the layers of the stored material, which affect the phenomenon of self-heating of the material. Studies of impact of these factors on the thermal stability of coal waste stockpiles are important in the aspect of secondary exploitation of the stockpiles as well as during their reclamation or revitalisation. The numerical solutions presented in the paper should be treated as guidelines that define the directions of analysis for specific cases.

In recent decades, two different approaches to mine ventilation control have been developed: ventilation on demand (VOD) and automatic ventilation control (AVC) systems. The latter was primarily developed in Russia and the CIS countries. This paper presents a comparative analysis of these two approaches; it was concluded that the approaches have much in common. The only significant difference between them is the optimal control algorithm used in automatic ventilation control systems. The paper describes in greater detail the algorithm for optimal control of ventilation devices that was developed at the scientific school of the Perm Mining Institute with the direct participation of the authors. One feature of the algorithm is that the search for optimal airflow distribution in the mine is performed by the system in a fully automated mode. The algorithm does not require information about the actual topology of the mine and target airflows for the fans. It can be easily programmed into microcontrollers of main fans and ventilation doors. Based on this algorithm, an automated ventilation control system was developed, which minimizes energy consumption through three strategies: automated search for optimal air distribution, dynamic air distribution control depending on the type of shift, and controlled air recirculation systems. Two examples of the implementation of an automated ventilation control system in potash mines in Belarus are presented. A significant reduction in the energy consumption for main fans’ operation obtained for both potash mines.

The correct management of underground works, petroleum and gas reservoirs and geothermal applications relies on the hydromechanical behaviour of rock masses. We describe a laboratory approach to measuring permeability for different types of rock specimens. A laboratory system was designed and set up using rock mechanics equipment (a servo-controlled hydraulic press, a Hoek cell, a pump for injecting water and a scale for measuring the volume of water flow). To verify the validity of the permeability measurements, tests were carried out on a reference porous rock (Corvio sandstone), with results showing good agreement with those published in the literature. Tests were subsequently carried out on artificially fissured granite specimens with different joint patterns, submitted to various confinement stresses up to 20 MPa. Results showed good agreement with traditional Klinkenberg test results. Other tests done with artificially fissured specimens are described for demonstrative purposes.

Blasting cost prediction and optimization is of great importance and significance to achieve optimal fragmentation through controlling the adverse consequences of the blasting process. By gathering explosive data from six limestone mines in Iran, the present study aimed to develop a model to predict blasting cost, by gene expression programming method. The model presented a higher correlation coefficient (0.933) and a lower root mean square error (1088) comparing to the linear and nonlinear multivariate regression models. Based on the sensitivity analysis, spacing and ANFO value had the most and least impact on blasting cost, respectively. In addition to achieving blasting cost equation, the constraints such as fragmentation, fly rock, and back break were considered and analyzed by the gene expression programming method for blasting cost optimization. The results showed that the ANFO value was 9634 kg, hole diameter 76 mm, hole number 398, hole length 8.8 m, burden 2.8 m, spacing 3.4 m, hardness 3 Mhos, and uniaxial compressive strength 530 kg/cm2 as the blast design parameters, and blasting cost was obtained as 6072 Rials/ton, by taking into account all the constraints. Compared to the lowest blasting cost among the 146-research data (7157 Rials/ton), this cost led to a 15.2% reduction in the blasting cost and optimal control of the adverse consequences of the blasting process.

In this work, the support of two general galleries located in poor quality rock mass and subjected to the influence of high thickness coal layer exploitations is designed and optimized. The process is carried out in four phases:

A first preliminary support is defined employing different geomechanical classifications and applying the New Austrian Tunnelling Method (NATM) using bolts and shotcrete.

An instrumentation campaign is carried out with the goal of analysing the behaviour of the support. The study noticed the failure of the support due to the time of placement of the different elements.

A back-analysis using the Flac and Phases software has allowed the evaluation of the properties of the rock mass and the support, the study of the influence of the time of placement on the component elements (bolts and shotcrete), and the redefinition of that support.

Subsequently, a new support is designed and optimized through numerical modeling after the start of mining without experience in these sizes of sublevel caving that caused the failure of the previously designed support. The new support is formed by yieldable steel arches that are more suitable to withstand the stresses generated by nearby mining work.

In the Canary Islands, groundwater is the main source of drinking water. Groundwater mines have been the system used by the engineers of the archipelago to collect water from the ground. The Canary Islands are volcanic with soils characterized by being rich in uranium, the disintegration of which gives rise to radon gas. In this study, radon gas levels in the mines on two islands of the archipelago have been measured to study exposure to this gas in the galleries. Results show values much higher than the European regulatory limit concentrations.

The paper presents a brief outline of the European Union Climate and Energy Package in early 2020, as well as the EU’s plans in this respect until 2030 (Winter Package and Green Deal) and even further until 2050 (EU’s climate neutral target). Also the current condition of power generation in Poland and challenges for Polish energy sector in the nearest future are discussed. The Energy Policy of Poland until 2040 (EPP 2040) is analysed in relation to possible risks and dangers. Some improvements are proposed in regard to the implementation of the document. In addition, the current volume and perspectives of hard coal and lignite mining in Poland until 2040 are discussed and compared with an expected demand for coal in Polish power plants and combined heat and power stations. On the basis of the prognosis of energy consumption in the period 2031-2040, there seems to appear a serious risk of energy shortage due to a possible delay in a nuclear power project and lack of lignite mining at the level defined in EPP 2040 policy. Therefore, some variants of providing the security of energy supplies are taken into account and thoroughly analysed in the paper.

The article presents a comprehensive economic analysis of a CO2 injection project in one of the Polish oil fields for both increased production (CO2-EOR) and underground storage (CCS). An interesting differentiator of this work is the use of a multilayered reservoir, which is actually not one reservoir but several located in the same place, as an example. It allows the optimization of the processes of injection, production and storage. Such projects are becoming more and more important because recently, after a period of long-term stagnation, costs of carbon allowances have started to rise which affects e.g. the electricity market in Poland. This can be an important incentive for the development of CCS technology, especially in combination with CO2-EOR. In the case of very high costs of carbon emissions rights CCS may turn out to be a cheaper solution. Economic efficiency is the main determinant of the EOR project’s success, as well as a very significant factor influencing the potential development of CO2 underground storage. Results are based on the numerical simulation of a combined CO2-EOR and CCS project. This analysis has been divided into two parts. The first uses a standard, deterministic approach, based on the DCF method and NPV indicator. It also provides a detailed sensitivity analysis, with particular reference to the impact of oil prices and the cost of carbon emissions rights on a project’s profitability. The second part of the economic analysis is probabilistic and involves estimating the maximum amount of CAPEX using the Monte Carlo method. Two cases were taken into account. The first assumes that the CO2 emitter pays for CO2 storage and the price is equal to 80% of the emissions rights price (with storage revenue). In the second one the emitter does not pay for storage (without storage revenue).

There is an airflow velocity boundary layer near tunnel wall when the air is flowing in the underground coal mine. The thickness and distribution of the airflow velocity boundary layer could influence the discharge of harmful and toxic gases that enter the ventilating airflow through this flow interface. It may also have a major impact in coal mine gas explosion. The results of field measurements and simulation experimental data are used to research airflow velocity boundary layer in a flat walled mine roadway, which is considered in turn: as unsupported, I-steel sectioned arch or bolted and shot create supported cross section. By referenced to other literature studies that consider boundary layer characteristics and the analysis of on-site and experimental data sets we obtain the corresponding airflow velocity boundary layer characteristics for each of the supported roadway sections. The airflow velocity within the boundary layer increase is assumed to follow a logarithmic law given by the expression: u = a Ln(x) + b. It is concluded that the thickness of the airflow velocity boundary layer is observed to significantly decrease with the airflow center velocity and to increase with roadway wall roughness. The airflow velocity distribution is found to be described by the equation: u = (m1v + n1)Ln(d) + m2v + n2, for the three types coal mine tunnel taking into account the influence of center airflow velocity.

The purpose of this research is to substantiate a technical solution for improving the working conditions for the thermal factor in the extraction of oil by the thermoshaft method using the mine refrigeration technology. The review of manufacturers and technical characteristics of refrigeration technology in Russia, CIS countries and Western Europe was conducted. It was shown that the use of a water cooling machine in the mine air conditioning system will reduce the air temperature in the oil production gallery to the required values and will allow to abandon the long-term construction of a surface stationary refrigeration station. Normalization of the thermal regime reduces the costs of benefits and compensation for work in harmful labor conditions and improves the quality of service of production wells by operators. The practical significance is that the proposed project for the introduction of air conditioning has a high level of profitability, and its payoff will occur in the second year of operation.