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At the beginning of this century, a group of authors "self-developed" the Conversion Map for harmonizing data on the categories and amounts of geological and balance reserves of Serbia according to the terms and classes of mineral resources and reserves from the Western reporting system, and the codes of the UNFC system (United Nations Framework Classification for Resources - UNFC -2009). This three-dimensional system is based on the assessment of the maturity of the project through the assessment of the reliability of three axes: E (degree of economic and ecological validity), F (stage of technical feasibility assessment) and G (stage of geological assessment, and today according to the improved UNFC system from 2019-stage of reliability resources). The author, based on his own considerations and long-term studies of this problem, and with the fact that the UNFC system is not in use in Serbia, on the example of the Project of coal mining in the "Tamnava-Zapadno polje" deposit, considered a way for a qualified professional-formal recognition of coal reserves in the UNFC system. 2009, on the basis of data on coal mining and reserves that are still reported according to the "Regulations on classification and categorization of reserves of solid mineral raw materials and record keeping" of the former Yugoslavia from 1979. The coal mining project "Tamanava-Zapadno polje" according to the "maturity of the project" UNFC-2009, within the framework of E, F and G - the three-dimensional system is classified (in parts) into Sustainable projects (1, 1, 1), Potentially sustainable projects (2, 2, 1 or 2, 2, 2) and an Unsustainable project (2, 2, 3), without disputing other stronger considerations.

In April – May 2021, in the Khabarovsk Territory and Sakhalin Region in the Far East Federal District of the Russian Federation, the Federal Research Center "Geophysical Survey RAS" deployed temporary networks as a part of Large-Scale Research Facilities – continuous seismic monitoring of the Russian Federation, adjacent areas and the world. The deployment of new stations provided a reliable integration of real-time seismic data into a centralized monitoring system for the Sakhalin Region.The seismic study has been performed in the Uglegorsk District, Sakhalin Region, where the Solntsevsky brown coal deposit – the most potential on the island – is located. There were presented the data on seismic events of different origin recorded since the stations had been brought into service. Emphasis has been placed on considerable improvements in epicenter location accuracy and enhancing possibilities of determining earthquakes and industrial explosions. There are shown the results of monitoring for earthquake mechanism studies. The monitoring system that is currently available allows recording the representative earthquake events with ML≥0.5 in the immediate vicinity of coal mines, thus providing the possibility of improving control of blasting work and of weak and potential induced seismicity caused by multiple anthropogenic impacts on subsoil.

The paper is devoted to the problem of increasing energy efficiency of coalmine methane utilization to provide sustainable development of geotechnologies in the context of transition to a clean resource-saving energy production. Its relevance results from the fact that the anthropogenic effect of coalmine methane emissions on the global climate change processes is 21 times higher than the impact of carbon dioxide. Suites of gassy coal seams and surrounding rocks should be classified as technogenic coal-gas deposits, while gas extracted from them should be treated as an alternative energy source. Existing practices and methods of controlling coalmine methane need to be improved, as the current “mine – longwall” concept does not fully take into account spatial and temporal specifics of production face advancement. Therefore, related issues are relevant for many areas of expertise, and especially so for green coal mining. The goal of this paper is to identify patterns that describe non-linear nature of methane release dynamics in the underground boreholes to provide sustainable development of geotechnologies due to quality improvement of the withdrawn methane-air mixture. For the first time in spatial-temporal studies (in the plane of CH4-S) of methane concentration dynamics, according to the designed approach, the parameter of distance from the longwall (L) is introduced, which allows to create function space for the analyzed process (CH4 of S-L). Results of coalmine measurements are interpreted using the method of local polynomial regression (LOESS). The study is based on using non-linear variations of methane concentration in the underground boreholes and specific features of their implementation to perform vacuum pumping in the most productive areas of the undermined rock mass in order to maintain safe aerogas conditions of the extraction block during intensive mining of deep-lying gassy seams. Identification of patterns in the influence of situational geomechanical conditions of coal mining on the initiation of metastable gas-coal solution transformation and genesis of wave processes in the coal-rock mass allows to improve reliability of predicting methane release dynamics, as well as workflow manageability of mining operations. Presented results demonstrate that development of high-methane Donbass seams is associated with insufficient reliability of gas drainage system operation at distances over 40 m behind the longwall face. Obtained results confirm a working hypothesis about the presence of spatial migration of methane concentration waves in the underground gas drainage boreholes. It is necessary to continue research in the area of estimating deviation angles of “advance fracturing” zone boundaries from the face line direction. Practical significance of research results lies in the possibility to use them in the development of scientific foundation for 3D gas drainage of a man-made coal-methane reservoir, taking into account spatial and temporal advancement of the production face.

The present work shows the dimensions of the pollution caused by the mining activities within the Rosiuţa quarry. The negative impact of mining activities on the environment is a direct one, which is strictly related to the actual extraction of the deposits of useful mineral substances and the other indirectly, related to the mineral processing activity. Surface mining is a source of dust pollution throughout its life, from the moment the land surface began to be disturbed until the entire surface was again covered by vegetation. The surface exploitation activity of the lignite developed in the Roşiuţa quarry is the main source of air pollution, especially with suspended powders and sedimentable powders. The excavated coal has a low mechanical resistance, to which low humidity is added, especially in hot weather. leads to the formation of powders. The air quality in the area of influence of the mining perimeter is mainly affected by the technological processes in the quarry, the dump and the coal deposit, by the increase in certain points of the mining perimeter of the concentration of powders.

For the application of a wide forehead method, decisive is an assessment, respectively, selection of the type and construction of self-propelled hydraulic support, both for horizontal and vertical excavation concentrations. This is especially important in the excavation of coal seams whose immediate floor and roof are composed of clay sediment. In the last decades, this theme has not been more fully explored in the coal mines in Serbia, and its processing has the character of original research, whose aim is, with the obtained research results, to contribute to the development of mining science. The coal deposit 'Poljana', with a comprehensive expert analysis, was assessed as promising for activation in the production sense, especially taking into account the certified reserves of quality coal and natural-geological conditions favorable for the use of mechanized wide forehead excavation systems. It is particularly important that the research is related to concrete the working conditions, with a particular emphasis on the geo-mechanical aspect and its connection with selection the type and construction of the self-propelled hydraulic support.

The present work shows the dimensions of the pollution caused by the mining activities within the Rosiuța quarry. The negative impact of mining activities on the environment is a direct one, which is strictly related to the actual extraction of the deposits of useful mineral substances and the other indirectly, related to the mineral processing activity. Surface mining is a source of dust pollution throughout its life, from the moment the land surface began to be disturbed until the entire surface was again covered by vegetation. The surface exploitation activity of the lignite developed in the Roşiuța quarry is the main source of air pollution, especially with suspended powders and sedimentable powders. The excavated coal has a low mechanical resistance, to which low humidity is added, especially in hot weather. leads to the formation of powders. The air quality in the area of influence of the mining perimeter is mainly affected by the technological processes in the quarry, the dump and the coal deposit, by the increase in certain points of the mining perimeter of the concentration of powders. [ABSTRACT FROM AUTHOR]

The main aim of a coal deposit model is to provide an effective basis for mine production planning. The most applied approach is related to block modeling as a reasonable global representation of the coal deposit. By selection of adequate block size, deposits can be well represented. A block has a location in XYZ space and is characterized by adequate attributes obtained from drill holes data. From a technological point of view, i.e., a thermal power plant's requirements, heating value, sulfur and ash content are the most important attributes of coal. Distribution of attributes' values within a coal deposit can vary significantly over space and within each block as well. To decrease the uncertainty of attributes' values within blocks the concept of fuzzy triangular numbers is applied. Production planning in such an environment is a very hard task, especially in the presence of requirements. Such requirements are considered as target values while the values of block attributes are the actual values. To make production planning easier we have developed a coal deposit model based on clustering the relative closeness of actual values to the target values. The relative closeness is obtained by the TOPSIS method while technological clusters are formed by fuzzy C-mean clustering. Coal deposits are thus represented by multi-attribute technological mining cuts. [ABSTRACT FROM AUTHOR]

Coal deposits in the south of the Far East are characterized by complex geological factors, which is due to the inclined occurrence the enclosing layers and coal seams, high pressure of underground water, the presence of water-bearing sandy-pebble and gravel-pebble sediments, the presence of numerous faults and various inclusions, the presence of island permafrost. In the exploration of deposits, the low efficiency of previously used electrical exploration methods, including electrical sounding and profiling, was noted. In this paper, it is shown that increasing efficiency in the solution of some mining and geological tasks is associated with the use of the electrical tomography method. This method has advantages in the conditions of weak differentiation of rock resistivity due to the high density of obtained parameters. With the use of electrical tomography, the tasks in the allocation of tectonic disturbances and coal seams uplift under quaternary sediments, estimation of the landslide slopes structures on the coal pit edges have been solved. Successful results were obtained in isolating the weathered layer of the bedrock, sandstone outcrops under the soil-vegetative layer in the upper part of the section, the bedrock surface on the deposit’s flanks and the covers of effusive rocks on the surface.

Entirely new method of graphic representation of data stored in database is elaborated within frame of processing of system for rapid evaluation of coal deposits. Petrographic and geological symbols have been generated mostly by creation of singular pattern for each rock type including its impurities and other features. However, such a conventional symbols do not allow represent number of combinations of features typical for rocks in real occurrences. Any further information (for instance calcareous impurity, coal fragments etc.) multiplies the existing number of patterns. The consequence is that there are many patterns for only most frequently occurring coal, rock and transitory rock types. The main principle of new symbol creation is based on mutual combining of symbols. Thereby all essential characteristics of coals and rocks can be represented graphically in whatever combination while preserving lucidity and non-ambiguity conditions. Representation of particular proportions of three-grain sized components in rock indicating by adverbial expressions of highly, slightly and medium (for instance slightly sandy highly silt clay) is enabled. Particular types of coal occurring in transition rocks are represented by appropriate graphical symbols according to genetic type. Problems with old terms of coals and rocks according to other types of classification were taken into consideration. At elaboration of the system, hitherto valid regulations, usage and standards were consulted. The resultant system is simple and easy to control in face of options it enables.

Assessment of cutoff calorific grade is an important parameter for production, planning, and making decisions in coal deposits. Cutoff calorific grade is defined as the value that discriminates between ore and waste within a given deposit. The normal statistical distribution model will serve as an important tool for examination of cutoff calorific grade. In this article, the Seyitomer coal deposit in Kutahya (Turkey) cutoff calorific grade was measured by a normal statistical distribution model. Through the results from the model, it was determined that there are tonnage rate and mean of calorific grades involving the identification of cutoff calorific grades. Finally, the model shows that a normal statistical distribution model can be applied successfully to the mining design and make it possible to manage a future coal deposit. [ABSTRACT FROM PUBLISHER]

The aim of this article is to inform about the spatial distribution of the lignite qualitative parameters and total lignite reserves in the Czech Part of the Vienna Basin-The South Moravian Lignite Coalfield (SMLC). The total reserves were estimated on the basis of several composed variant digital models of individual seams in four partial area of SMLC. Calculations of the reserves resulted from the identified spatial distribution of chemical-technological parameters obtained from the thousands analysis of samples taken from more than 4,000 exploration works. The basic model of the deposit was so-called geological model characterising genetic evolution of the deposit and defines the spatial positions of the coal seams. Subsequently developed variant economical models spatially define the selected areas by the quality of lignite expressed by the limits of ash yield. Based on the created models, it was found that in the past just 3-7 % (depending on the variant model) of the total lignite reserves SMLC had been extracted. The presented geological reserves are currently using the existing mining technologies only partially mineable. [ABSTRACT FROM AUTHOR]

Two types of brown coal can be distinguished in Poland - 'soft brown coal' and 'hard brown coal', the latter being of higher rank. Hard brown coal is divided into dull and bright types. This division is based on an increasing degree of coalification (rank). According to globally recognized nomenclature for coal technology, brown coal is categorized as a low rank energetistic raw mineral with the release of low-rank C ortho-lignite (soft brown coal), low-rank B meta-lignite (dull brown coal), and low-rank A sub-bituminous coal (bright brown coal - ECE UN/50, ISO-11760). In Poland and Europe, ortho-lignite is an essential energetistic raw mineral. Its share of the energy balance of many EU member states is considerable. Deposits of ortho-lignite in Poland and Germany are among the largest in Europe, and together they comprise the Atlantic Hemisphere of brown coal deposits. In contrast, deposits of meta-lignite and sub-bituminous coal in Europe, despite its numerous occurrences, are rather small. In the balance sheet of European countries, it is not an attractive raw mineral. In Europe, deposits of meta-lignite in Mesozoic sediments appear frosted. Marine conditions of the sedimentation of these rocks were not conducive to the deposition of coaly sediments. There were only periods of marine regression in certain epochs (brakish sediments), such as the Late Triassic (Rhaetian, Keuperian), Early Jurassic, Doggerian, and a few Cretaceous periods. From these periods numerous but small deposits of coal, or just its natural occurrence, have been preserved. Coal deposits of Mesozoic meta-lignite are mostly in the formof cratonic construction. They are characterized by thin coal formations containing a small number of coal seams, which, however, can be thick and can have a good technological quality. The most famous European meta-lignite deposits are Fuveau-Di Larzac (France), Hagenes (Sweden),Moravska Trebova and Sokolovo (Czech Republic), and Belgorod-Obojansk (Russia). Also entered into the European register of deposits are the Mesozoic Polish deposits Zawiercie in the Krakow Monocline and the northern part of the Holy Cross Mts of the Kamienna river region. Coal deposits of the Cenozoic Period of dull (meta-lignite) and bright (sub-bituminous coal) types in Europe aremore numerous. Their genesis ismostly orogenic, related to the final stages of formation of themountains of the Alpine system. There are small deposits of coal formed in the intermountain and foredeep tectonic zone. Igneous phenomena of orogenic systems in general are the cause of a higher rank and higher quality coal. Well known deposits of meta-lignite and sub-bituminous coal are located in the Alps and Apenines - Monasgue (France), the Piemont-Ligurian Riviera (Italy), Hirschberg and Meissner (Germany), the Carpathian Mts localites of Ajka and Tatabanya (Hungary), Silwaniei and Petroºani in Romania, the Carpathians region in Ukraine, and also in the Balkans foredeep (Pirin and Perni in Bulgaria). There are a few Polish deposits in this period. They occur in the local intermountain basins in the Carpathians (Orawa and Nowy S¹cz Basins), in the Sudetes Mts (e.g. Lusina- Udanin, Strzegom), and in the Carpathians foredeep. These are mostly small deposits of ortho-lignite. The exceptions are the non-industrial coal deposits Grudna Dolna and the lower parts of the deck in the Orawa-Nowy Targ Basin (Lipnica Wielka), representing mainly meta-lignite. As mentioned, there are few instances of Polish meta-lignite and sub-bituminous coal and they have no economic importance. Their classification has been carried out according to rank on the basis of existing Polish documentation as well as works of its studies. The main criterion for ranking the coal was random reflectivity (Rr o) and petrologic characteristics. Coal from 0.33 to 0.40% (random reflectivity) is considered to bemeta-liginite, with coal from 0.41 to 0.50% considered to be sub-bituminous coal. In Poland, 20 regions were found. The register covers the Mesozoic deposits platform (rarely to the Cenozoic period) and orogenic deposits mostly to Cenozoic, not having the characteristics of coaly formations (e.g. the Carpathian Flysch and the Podhale Flysch sediments, southern Poland). Coal in this rank has no economic significance in Poland. However, it is an important element in the cognitive theory of coalification. [ABSTRACT FROM AUTHOR]

The planning stages of mining require comprehensive and detailed analyses. The proper determination of the orebody boundary is one of the most important points to provide optimum model structure and projections. The limits can be determined by different methods based on the site geology. Although some three dimensional ( 3D) models were proposed for providing detailed information concerning a mine deposit, developing a solid model via a 3D approach is novelty. In other words, surface modeling should be performed for creating a solid model and determining limits of the deposit. In this way, sensible generation of the surface model can be achieved. This study investigated the estimation capability of the polynomial approach, which is a novel spatial interpolation method, for modeling a coal deposit surface. The performance of the proposed model was compared with some conventional methods in the literature. The results showed that the polynomial interpolation method is an effective method to employ for surface modeling of a mine deposit. [ABSTRACT FROM AUTHOR]