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The paper presents the calculation of the trajectory of an axisymmetric fracture propagation in an isotropic poroelastic medium considering fluid leakage and viscosity. The problem was solved using the extended finite element method (XFEM). It allows to obtain solutions containing a displacement jump with the help of discontinuous functions, and solutions near the crack tip with special asymptotic functions. This method can simulate the process of initiation and propagation of a crack in the direction that is dete...

A dynamic method has been developed for optimizing reload horizon of a cyclic and continuous technology complex (CCTC) with a combined road-conveyor-rail type of transport for round open pit fields, providing a rational depth of rail transport installation together with economically viable horizons for the location of the concentration horizon and reload from steeply inclined conveyors into the inner mine railway transport. Mining in border and deep zones of open pit mines is conducted in constrained conditions. C...

At all times, one of the most important criteria for evaluating the performance of a mining enterprise were its economic indicators. It is well-known that the enterprise will get that big profit, than earlier it will be able to learn the most effective way of development of production. In this regard development of qualitative methodology of assessment of economic efficiency of planning is very relevant as allows to receive indicators of economic effects from the implementation of a specific plan and on their basi...

Horizon control in underground coal mining is still largely based on the knowledge and experience of a human operator, while many other operations run fully automated in mines nowadays. Several control strategies have been developed for automatic horizon control in underground coal mines, but none of them worked satisfactorily for a long distance up to now, even if the used sensors execute their intended task already and were improved continuously. However, the behaviour of the mining system itself, especially the...

Autonomous passenger cars are becoming a trend today due to their role in saving human labour. However, in the field of earthmoving machinery, we can also witness a significant development in their autonomous operation. This paper deals with the possibility of using the autonomous operation of rollers and plate vibrators, intended for earth body compaction and the compaction of an upper asphalt road layer. In view of the growing share of automation and the associated computer applications for earthmoving machines,...

Corrosion represents a major problem in the flow assurance for the oil and gas industry. Carbon steel has been extensively used in oil and gas industry due to its cost-effectiveness, availability, strength, high durability and ductility. However, one of the biggest disadvantages of steel is highly susceptible to corrosion in the aggressive environments. Most of corrosion inhibitors are toxic, non-biodegradable and non-eco-friendly in nature, thus development of inhibitors based on natural resources are needed. In ...

Occupational noise exposure in the workplace is linked with a range of negative effects on human health. Many researchers agree that the noise-induced hearing loss is the second most common form of sensorineural hearing deficit, after the illness of age-related hearing loss. An extended exposure to occupational noise can generates devastating disability that is potentially 100% completely preventable. The hearing deficit begins at the higher frequencies and it develops gradually as a result of chronic exposure to ...

The use of the trenchless method of laying underground communications is a profitable alternative to the use of open methods. The method of vibro-impact immersion of steel pipes with an open front end into the ground is widely used. Regular cleaning of the pipe from the formed soil core is one of the most important operations in this technology. The parameters of the soil plug (density, linear dimensions) depend on the physical and mechanical properties of the soil in which the work is performed. The purpose of th...

Risk assessment is a concept introduced for analysing the safety level in workplaces in order to assess if enough and proper precautions have been taken or if their number and quality should be improved so that to prevent hazardous situations. The underground coal mining industry is very hazardous, facing serious fatalities related to work, workplaces and workers as a consequence of the high-risk processes carried out underground and of the hazardous toxic and explosive atmosphere. The use of electrical equipment ...

The paper presents the results obtained in the assessment of seismic action of blasting performed in four Romanian salt mines where small room ad square pillar method is applied. Function of the time taken to mine a level, of the size of the rooms in course of excavation, of the medium radius of the area with elastic deformations, and the results of the seismic measurements, the explosive charges possible to be blasted were established for each separate seam, providing in the same time seismic protection for the f...

Production of high-viscosity oil reserves is accompanied by digital modeling. Use of enhanced oil recovery methods involves the synthesis of optimal control of the injected agents? effects. The system for modeling of non-isothermal multiphase filtration processes currently under development is based on the use of the finite element method. This allows to detail the formation heterogeneities and processes taking place in the wells and in the near-well regions. The objective function includes minimization of water c...

At national and world wide level, raw materials consumption is steadily increasing due to industrial development and population growth. In this context, production of basic raw materials, and in particular of fossil fuels, natural gas and coal, is constantly increasing. For underground coal mining are used a complex network of horizontal, vertical and inclined mine workings with the purpose of extraction, transportation and evacuation of coal. Associated with the system of mine workings, there is a ventilation net...

At the present stage of greening of the old productive units, the demolition process using blasting works have an increasing application due to the reduced time consumption, labor and expenses. A large number of demolition works by using explosives and characterized by a high degree of difficulty, have shown that the use of the blasting technique is a proper alternative from the point of view of efficiency, quality and security. Each construction creates a special case, the calculation of the blasting parameters a...

Peat belongs to renewable energy sources; therefore, research into the state of reserves, use and development of peat extraction and processing technology is of great relevance, especially in areas with harsh climatic conditions. On the other hand, other sources of energy, such as coal and hydrocarbons, are exhausted and depletable. Against this background, the development of innovative technologies for peat extraction in harsh natural and climatic conditions is of great interest and prospects. One of such regions...

Phosphates are one of strategic mineral resources that provide the food safety of any country. The specific feature of the raw-material base in the Kola region is the endogenic type of apatite deposits. All industrial reserves and resources of apatite-nepheline ores (ANO) are confined to PZ alkaline-ultrabasic carbonatite complexes and, mainly, to the Khibiny massif (KM). 15 unique apatite-nepheline deposits and occurrences are located here. Some of them are the world-class scale. ANO of the KM are highly eco-frie...

In the development of mineral deposits by the underground method, geomechanical processes are manifested, which significantly affect the quality of ore, the cost of production and the safety of mining operations. Insufficiently valid choice of geomechanical steady spans of outcrops can lead to a sudden collapse and formation in clearing workings, thereby reducing the safety of mining. The work provides a definition of sustainable roof exposures of the clearing workings according to the method of S.V. Vetrov for fr...

Self-heating and autoignition are the precursors of spontaneous combustion. All coals can be self-heat in mines or in storage; but only if the conditions are favourable they may autoignite, when the coal interact with the oxygen in the air. This is first step in the spontaneous combustion. In storage, the temperature of a stockpile is determined by the type of coal, particle size, oxygen concentration of the air, balance of the heat of coal oxidation, moisture content of the coal etc. Coal naturally oxidizes over ...

Emergency management is a complex task, involving precise coordination of numerous activities and people, as well as fast decision-making in environments where critical, vital information, might often be missing. Despite all technical and technological progress, most industries record accidents with human casualties and property damage. For this reason, the presence of special intervention ? rescue teams at economic units is critical, because they can ensure a quick and efficient response to confine / eliminate da...

The tensile properties of conveyor belts significantly affect their use in practice. Research is focused on the determination of the influence of sampling direction on the tensile strength and the elongation of 3 types of fabric conveyor belts. The carcass material determines the tensile properties of the conveyor belt. The carcass of a fabric conveyor belt is formed by several layers of textile plies. The textile plies are created by crossing the system of warp and weft fibres. The warp represents a set of fibres...

Intervention and rescue activity in special conditions can be conducted under special requirements only by trained and authorized personnel using personal protective breathing equipment. The decisive factor for the success of an intervention and rescue operation in toxic or chemically aggressive environments lies, among others, in optimum and efficient design of rescue personnel?s training process, in connection with their testing in environments with high temperature and humidity. Heat is normally generated as a ...

Vulnerability to stress occurs during the person's biography, depending on psycho-emotional trauma, experiences of severe psychological stressful situations, including how the individual succeeded in managing them. Some people have a constitutional or psychological vulnerability to the action of traditional stressors, being more prone to psychic stress. The multifactorial complex of non-specific factors that modulate the individual response necessarily includes personality traits, acquired during the individual's ...

The paper approaches a series of researches that concern the finding of a solution for modernizing the cutting wheels of the extraction tower of Slanic Prahova salt mine. With this in view and starting from the observation that the former solution is worn out, a new variant has been conceived and designed in order that it might be applied to the structure of the extraction tower without important changes. Specialized software has been used for the assisted analysis and designing, which is able to provide the corre...

Restructuring of the exploitation of the coal deposit in the carboniferous area of the Jiu Valley in Romania is part of a quarter-century closure program and the use of minerals has been reduced by 10 times compare with the production achieved at the level 1989. In the last 10 years, the use of the coal in the steel production was abandoned, the production being processed only for electric and thermal energy needs. At present, 4 production units (Lonea, Livezeni, Vulcan and Lupeni) are operating in this area, out ...

Mining-and-industrial heritage ? underground workings, open areas of former mining works, natural caves and underground cavities are, in many cases in critical condition and pose a safety threat to the tourists visiting those. On the other hand, such places, have significant historical, technological and landscape value. Moreover, these objects are also crucial for the development of tourism, attracting a lot of visitors by their uncommonness. Underground space for tourism purposes is often used by the specialists...

The efficiency of drilling and blasting works can be assessed in many ways, depending on the desired effect. The evaluation can be performed on the basis of the quality of the explosives used for rock extraction. On the other hand, the correct assessment should include the results of drilling and blasting works. One of the parameters that are commonly used in the quality evaluation of explosives is the in situ velocity of detonation measurement, which is a direct indicator of the efficiency of the utilised explosi...

The solving of the project of the Czech Republic Technology Agency TACR dedicated to microbial methane genesis in geological conditions of the Czech coal basins is under way from 2018. The target of the project is clean methodology of coal. The main attention of the 2018 research was devoted to the geological research of the brown and hard coal basins and to the selection of the optimum localities for sampling. This paper briefly summarises the geological situation of coal basins, stratigraphy of different coal se...

The test-measuring complex was created to study deformation and strength properties of rock samples with joints under direct shear conditions, under two types of boundary conditions: constant normal load (CNL) and constant normal stiffness (CNS). The updated version of the International Society for Rock Mechanics (ISRM) ASTM D 5607-08 standard was taken as the basis of the laboratory method for determining the shear strength of rock joints. Tests were performed on samples with joints from artificial geomaterial ? ...

The article reveals the role and importance of the coal mining industry in the structure of the fuel and energy complex of Russia. It reveals the main problems of the coal mining organizations in Russia, both at the macroeconomic level and at the level of economic entities. The possible ways of increasing the efficiency of the coal industry are investigated on the example of Kuzbass. Russia has one of the world's largest mineral resources potential, which is the basis of guaranteed economic and energy security of ...

The process of training on the training complexes depends on the realism of the user's interaction with the developed virtual world. Despite the implementation in recent years of many ways to manage virtual objects, the problem of realistic human movement remains relevant. The use of conventional treadmills is justified in the entertainment field. In the field of training of the personnel of ergatic systems it is necessary to model more precisely a relief of a surface on which the user moves. Therefore, in this ar...

In the study, heavy metal concentrations were determined from the Certej creek, basin in surface waters by using inductively coupled plasma emission spectrometry as an analytical method (ICP-OES). In order to assess the toxicity effects, the toxicity of various elements such as ( As, Cd, Cr, Cu, Pb, Ni, Zn etc.) were studied, these elements having an increased toxicity even at low concentrations. The purpose of this work is to determine their concentrations by the inductively coupled plasma emission spectrometry m...

It is known that the main reserves of diamonds in Russia are concentrated in the territory of the Republic of Sakha (Yakutia) and for many decades determine the volume of their production. Many years of experience in the development of open-pit diamond deposits have led to an excessive increase in the depth of the quarries, which creates the danger of working in the lower horizons, as well as an increase in the cost of production due to an excessive increase in overburden. The paper proposes the introduction of a ...

The lecture deals with the issue of newly approved territorial ecological limits. Mining - technical conditions of mining or mining - geological conditions together with the optimal choice of the concept of mining procedures predict the efficient and safe use and extraction of a reserved mineral deposit in a given mining area. The mining space must be determined and define on the basis of mining ? geological conditions of every mining location due to the application of all the principles contained in the Mining la...

Reducing CO2 emissions results in decarbonisation and in consequence ? mine closure. There is a need to find innovative solutions for economical managing of abandoned sites, while ensuring risks to public and the environmental safety. This new approach to repurposing mine sites, which was presented in the article may take advantage of existing mine infrastructure and contribute to the local community, environmental and economy after the mine has been closed down. The aim of this study is to present potential benef...

The analysis of extensive seismological databank of one of deep mines of Norilsk?Talnakh polymetals deposits was performed to assess the shock hazard statement of rock massifs. The kinematic parameter is proposed for estimation of shock hazard of rock massifs which is based on kinematic characteristics of seismic processes. This parameter is the ratio of the migration speed of the equivalent seismic energy release center and the apparent speed of the aftershocks of individual large seismic events within the contro...

The underground mining development in Low Tatras focused primarily on gold, silver and partly iron ore exploitation began in the Middle Ages. At the end of the 16th century, manually created mining underground spaces (vertical shafts and horizontal galleries) were already 100 m deep and several hundred meters long. The mines were situated also at the top of the mountain range at an altitude of approximately 1400 meters above sea level. During the 16th century silver mine called St. Michal was created on the ridge ...

Mining industry is still the only supplier of mineral resources, both metals, coal and other useful mineral substances. Transportation represents an integral part of the logistics system in each mining company. The most frequently used mineral transportation system is the truck transport. Loading and transportation is important part in the extraction and processing of minerals. The selection of loading and transport means affects the efficiency and performance of the whole operation. A choice of an appropriate loa...

The safety conditions of the underground works carried out for the coal mining process are ensured by longwall supports. The particularities of the system of hydraulic powered roof supports are given by structure of the supporting component, by the pumping station and respectively by the operating liquid and the length of the wall the activity of which needs to be ensured. The pumping stations used for the supply of the roof supports, also called hydraulic assemblies, are composed of: the oil in water tank, the pu...

One of the major problems associated with excavation of the copper deposits in underground mines in Poland is the relatively high level of seismic activity. Numerous high-energy tremors can negatively affect the stability of underground workings and can have a destructive impact on the infrastructure located at the surface as well. As predicted, the seismic activity increases along with the depth of mining operations. Therefore, in order to face these threats, a number of organizational and technical prevention me...

Experience in the use of enhanced oil recovery methods shows that the main factor responsible for efficiency of the treatment is the correct choice of a particular technology for certain geological and physical reservoir conditions and the stage of development. Considering complex geological structure and low productivity of high-viscosity oil reservoirs in the Volga-Ural petroleum province, development of an integrated stimulation technology is a priority. The paper presents a promising concept of formation stimu...

This paper reports on a study of the sorption of toluene vapours on three medium-volatile bituminous coals from the Vaclavovice, Paskov and Trojanovice mines in the Upper Silesian Basin in the Czech Republic. The coal samples were characterized using various petrographic, chemical and porous texture analysis methods. Toluene sorption and desorption isotherms were measured on powdered coal samples at temperatures of 30°C and 50°C and at pressures ranging up to saturation, using a gravimetric sorption analyzer. The ...

The problems of geodynamic safety assurance in mining are common for many countries with developed mining industries. Considerable results have been achieved in Russia in solving rockburst problem, yet in the last decades this problem is transforming into man-triggered seismicity problem. Induced earthquakes in areas where mines had been flooded, seismic activity in previously safe regions, re-activation of tectonic faults, violent man-triggered earthquakes in open pit operations have been registered. As a matter ...

Substances that have chemical energy are known under the generic name of explosives. The chemical energy resulting from the decomposition of explosive substances has constituted and will continue to be one of the main forms of energy used in many sectors of the economy as well as in the military field. The technical experience accumulated so far has demonstrated that it is very difficult for a simply characterization of the explosion. Thus, in order to achieve this it is necessary to know the thermo-chemical chara...

One of the complicating factors in oil production is the deposition paraffin, as a result of which the production well rate is decreasing and the Electric submersible pump failure occurs. The main factors influencing the intensity of paraffin formation are: downhole temperature, gas evolution, hydrocarbon composition in each phase of the mixture, high viscosity of oil, change in the velocity of the gas-liquid mixture. To solve problems, the thermal method is used, which consists in artificial increase of the well ...