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In the process of hydraulic fracturing (HF), pressurized fluid is supplied to an isolated interval of the well. This causes the formation of an artificial crack, the growth direction of which greatly affects the method efficiency. It is especially important to take this into account when designing in-mine hydraulic fracturing for the solid minerals development. In this case HF is carried out close to underground workings and other inseam boreholes and these factors can influence the stress-strain state of stimulat...

In the paperwork are presented aspects regarding uncertainty involved in the process of spark ignition assessment for intrinsically safe equipment. In the first part of the paper was presented the explosion risk. In the field of power generation and also, in a lot of other fields of industrial activities, the occurrence of flammable substances is a common fact. As a consequence, an explosion risk can occur. On the other hand, the installations placed in areas endangered by presence of flammable substances should b...

Anthropic activities involve the extraction of the transformation and use of natural resources. During the process of extraction at the surface or underground of useful minerals, particles or gases resulting from the natural rocking or release from the rock mass appear in the working environment. The process of transforming useful mineral substances is carried out on the surface in enclosed enclosures, involving the use of complex technological processes. During the course of these technological processes, explosi...

Stress agents are only potentially stressful, generating psychological stress only under certain conditions, even if some of them are able of generating stress reactions in most individuals. Therefore, effects of stressors depend not only on their own characteristics but also on attributes of the subject receiving their action such as quality and breadth of emotional responses, adaptive strategies available and mobilized in the created interaction etc. Specific responses to a situation that potentially endangers l...

The activity of evaluation and verification of industrial ventilation installations has a strong preventive role in terms of explosion risk mainly due to the fact that of the three determining elements that can lead to an explosion phenomenon, ventilation installations can determine the presence of two elements namely the presence of fuel (gases, vapors, dusts, mists) and the source of initiation (hot surface, flame, sparks of mechanical origin, electrical sparks, static electricity, etc.). The development of expe...

This research describes such a problem as increasing the productivity of wells and the oil recovery coefficient by conducting various geological and technical measures, which based on correlation, regression, and statistical analyzes. These methods allow to analyse a possible interconnection of two or more numbers of indicators, also identifying the problematic well stock, and selecting a set of measures aimed at improving the efficiency of field development, including various geological and technical measures. Ex...

Background: the exposure to high levels of vibrations could induce health problems resulting in the damage of joints, muscles, other than pathologies connected to the circulation and the sensory nerves. These phenomena are often related to the use of machines that require high efforts, repetitive movements, or not ergonomic postures. Methods: 13 Radial Arm Polisher Machines (RAPM) of different manufacturers and different ages were investigated in order to analyze the vibrations produced during a whole process of m...

Occupational diseases linked to noise risk are still one of the most important employment problems, particularly in the quarry activities. Many negative effects on human health can arise after long exposure to noise in an occupational context. To protect workers' health and prevent hearing problems, employers must provide to workers with hearing protection equipment. In recent years, however, there have been many problems with the use of hearing protection devices. These have a highly mitigating effect but can iso...

The purpose of this paper is to determine the rate of methane (explosive gas ) and of carbon dioxide (axphysants gas ) in the mine workings of Praid salt mine. Currently in Romania there are six salt mines which exploit the salt through underground mine workings: Praid salt mine, Tg. Ocna salt mine, Slanic Prahova salt mine, Ocnele Mari salt mine, Cacica salt mine, and Dej salt mine. Of these six, in three salt mines occurred gas and salt eruptions: Praid salt mine, Slanic Prahova salt mine and Tg. Ocna salt mine....

A ventilation system is defined by performing air exchanges between the indoor and outdoor environment with the purpose of creating environmental conditions as close to the required thermal comfort conditions. Before installing a fan, it is necessary to analyze the space in which it is to be used and the method of compensating the exhaust air (mechanically with another fan or naturally with dimensioned grids). The most important factors to consider when choosing a fan are: the volume of the space, the number of sh...

Conveyor belts are used for a long period of time in the industry branches where potentially explosive atmospheres could occur. The use of conveyor belts in industrial spaces with danger of explosive atmospheres, implies fulfilling by these of certain safety requirements, in order to prevent the ignition sources of explosive atmospheres. The need to provide the highest level of protection in the industrial spaces with danger of explosive atmospheres led, on the one hand, to the use of conveyor belts with adequate ...

The article focuses on studying new Baltic amber processing technologies. This topic is relevant primarily for regions where amber is being mined commercially, including for the Kaliningrad region of Russia, where the largest industrial amber deposit in the world is located, developed by one enterprise ? the Kaliningrad Amber Factory. Having a specific production structure with a large share of amber for pressing and amber for chemical processing against the background of increasing amber production, the Kaliningr...

Both surface but especially underground rescue activities in industrial environments presenting risk of explosive / flammable or toxic gases, are difficult because of major risk of fires or explosions in a very short time. Dense smoke can make rescue work even more difficult and time becomes an extremely important factor, especially when workers are caught in the affected area and it is assumed that they could be alive. The technological development of last years has allowed the miniaturization of equipment and oc...

The greatest destruction of the soil cover and natural landscapes occurs during the development of the field by open pit mining. As a result of the development of the field, a complete change in the relief occurs, disruption of water and air balances, which leads to disruption of the ecosystem as a whole. To stabilize the state of the environment, it is necessary to implement a set of environmental, economic and social measures to restore environmental components. In this case, it is necessary to take into account...

The purpose of the research is to assess the current condition of and determine ways of solving the problem related to the improvement of management of subsoil use processes and objects from the standpoint of interests of the state, business and society. The applied methodology is based on the study of the main provisions of official laws and regulations and policy documents, the application of methods for collecting, processing and analyzing information related to this topic, the demonstration of actual performan...

Explosive mixtures generated in technological installations by processing, handling and storage are generally complex and in many cases cannot be assimilated with existing specific data. When ignited, they can burn rapidly and result in a considerable explosion force, when in mixture with air in proper proportions. Therefore, for establishing with certainty the requirements of the technical equipment which can be used in potentially explosive atmospheres generated by air / combustible dust mixtures, it is necessar...

Industrial ventilation requires a deep knowledge of fluid dynamics, heat dissipation, flow of complex fluids, steady state and transient conditions, operating problems, contamination inside and outside of installations, etc. In the field of industrial ventilation, the conditions of the indoor environment, called the indoor air quality and the exposure of employees to them, are very important. In industrial installations, the emission regime for contaminants may be 10-100 times higher than in non-industrial install...

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...

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...

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 ...

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 ...

Facilities and technical systems used in coal mines have limited durability. This is the result of very difficult conditions in which they are used. In particular it applies to environmental conditions and not entirely predictable load states of these facilities. Mining machines and devices are also exposed to various types of hazards, which in many cases significantly reduce their durability. For this reason, it is very important to properly use them and supervise and monitor their work. In this respect, huge res...

The hazard of tecnogenous earthquakes caused by mining of mineral deposits is increased if they occur at economically developed regions with ecologically dangerous objects. A deep coal mine of the Sinvay deposite in China is an example when seismicity due to mining was an important factor influencing both the mining conditions and ecological environment. At a more than 1000m mining depth the power of rock bursts rose to 107 J and they manifested themselves as minor earthquakes on the earth surface. The increasing ...

Calculation of the mining support in tunnels and/or underground facilities can be based on application of contemporary numerical methods, but sometimes it can be performed with the classical methods too. These methods can be found to be used in order to choose variants and ways of supporting, but also in the moments that unpredictably appears during the construction of facility. Before installing a permanent mining support, these methods can help the projector at the selection of type of support and ways of tempor...

The former village Rosiuta, now neighborhood of Motru city, located in Motru mining basin, is surrounded by sterile waste dumps and lignite storage platforms. These are a constant source of particulate matter which is carried by the wind over the inhabited area and affects the quality of breathing air. In order to evaluate the powders dispersion from these sources, it was made chemical and granulometric analysis of the particulate matter on several material samples collected from the area. Based on various meteoro...

The paper presents the results of theoretical and practical research on developing the infrastructure for assessment of overall risk (explosion / occupational terrorist attack) associated with unwanted events such as major accidents that can occur at explosive storehouses for civilian use. The scientific research outlined in this article was carried out within the NUCLEU Project PN 16 43 02 15 - ?Research on increasing safety levels at technical facilities for storage of explosives for civil use?. The key element ...

The planned maintenance activities of the mining technological equipment are carried out on the principles of risk management and is done in order to prolong their duration of operation and to reduce the production cost. The quick possibilities of reducing production losses due to accidental stoppages of quarries and underground exploitation equipment, depend on the establishment and application of reconditioning methods of the subassemblies and spare parts that are frequently defects and replacement. The rotary a...

The rocks exploited in quarries have certain physical, mechanical and technological characteristics that favors the intense wear, especially by abrasion of the active surfaces of the subassemblies of the technological equipment. Some spare parts and subassemblies are subject to similar wear phenomena, as is the case with the excavators bucket teeth in the lignite pits and the loaders cup teeth in the basalt pits. In the case of the basalt aggregates which are the main raw material needed for the development of the...

Under intense stress, energy consumption undergoes essential changes that largely depend on functional characteristics of the respiratory system, which in turn are in close correlation with the body?s training degree and physical demand. During a pronounced dynamic effort, there is a progressive decrease in blood oxygen saturation and an increase of pulse. Cardiac rhythm is a physiological parameter commonly used in telemonitoring as it allows the assessment of rescuer?s general condition, heart rhythm disorders b...

In the combustion processes the nature and concentration of the developed gaseous effluents depends on the type of materials that are subject to combustion as well as on the conditions in which the oxidation processes take place. The purpose of this paper is the experimental determination of the combustion parameters and the study of the developed gaseous effluents from several combustible materials. The production of gaseous products resulting from combustion results in different yields depending on several param...

The decisive factor in the process of under pressure networks inspection is determined by the correct choice of the control method in order to observe with great attention the possible faults caused by the physical wear and tear resulting from the long use. Emphasis is placed on safety conditions of under pressure equipment, which include mandatory minimum technical requirements for periodic checking of under pressure networks for pressurized, liquefied or dissolved gas. Defectoscopy is a set of procedures used to...

Protecting human labors process seeks to eliminate and/or reduce the potential causes of injury and disease in order to achieve full control of risks from hazards associated. With all the technical progress and technology in most industries, and especially in the oil and natural gas, there are failures with casualty and property damage. For this reason, it is indispensable the presence of the special intervention and rescue teams to limit/ liquidation, failure that generates explosive atmosphere and/or toxic and r...

The purpose of this expertise is to evaluate by mathematical modeling the stability of the slag and ash deposit Compartment II Emergency Cicani, which will be carried out on the past site of the Cicani Mid-East compartment by elevation with a height of 3,0-3,5 m, up to + 178mdMN. The deposit will be made using the "thick slurry" technology, having as foundation the deposition of slag and ash existing in the Cicani Middle + East (existing) compartment, made by the hydraulic transport technology. The basses of the e...

The technology of cutting with a laser beam today is a widespread solution for thermally cuttable materials. In mechanical engineering laser technologies currently, belong among the most progressive ways how a person can act on materials within the production process. Machining and processing materials using a laser is based on the conversion of light energy into heat energy. According to the active environment, a distinction can be made between three basic types of lasers - gas, solid state and semiconducting. Th...

The technology of oxy-cutting is a widespread solution for thermally cuttable materials nowadays. This article discusses the use of oxy-cutting technology on CNC machines. This technology is particularly suitable for unalloyed and low-alloy steels and cast steels. With the help of this technology, it is possible to cut sheets ranging from 3 to 1000 mm. For sheets with a thickness of 20 mm it is preferable to use a laser or plasma technology. When cutting with an oxy-fuel the workpiece it is initially heated on the...

One of the reasons for spontaneous combustion of coal waste dumps is the air intake into the body of a dump. Despite the measures taken to isolate the bases and dump slopes, spontaneous combustion of dumps occur in many countries around the world. That breeds a hypothesis that spontaneous combustion process is facilitated by placement of a dump in the geodynamically active zone of the earth's crust. In geodynamically active zone, due to its high permeability, the interaction of the dumps with environment occurs. P...

Coal mining causes undesirable terrain subsidence due to caving in of the overlying rocks into the already excavated space. Subsidence deforms the terrain, damages structures on the surface and water flows, which results in the formation of inaccessible wetlands and swamps, and these areas need to be reclaimed. The problem of large flooded areas as a result of mining activities also concerns an area known as пїЅKozinecпїЅ, which is located between KarvinпїЅ and Doubrava in the Czech Republic. That territory has lo...

Since the beginning of deep mining for the acquisition of minerals or driving galleries, later tunnels, man has faced the problem connected with draining used and polluted air (the so-called mine air), and transport of fresh air to the workplace. Since time immemorial, mine air has influenced and prevented the work of miners and drifters, as well as of the mechanized technology. The most significant factors of air pollution include exhaust fumes of mechanisms used in the performance of work, blasting fumes and, ob...

According Act No. 157/2009 Coll., on mining waste management, the Czech Geological Survey carried out a project of the Operational Programme Environment in 2010пїЅ2012. The project was entitled пїЅInvestigation of closed and abandoned mining waste facilities posing a serious threat to the environment or human healthпїЅ. The aim was to create an inventory of hazardous mining waste facilities and to develop a methodology for their assessment. In the Czech Republic, 300 potentially hazardous mining waste sites were i...

This paperwork is based on the data emerged from a conducted research related to a moisture influence on ignition sensitivity of air-methane gas mixture. For the purpose of this demarche it were used method of signal processing approach as it is data filtering and mathematical transform of the experimental data. In the first part of the paper, it was presented the spark test apparatus used for the experimentation and the results of the experimental data obtained during the tests with mixture air-methane and moistu...

The balancing devices in cable tension, DEC's, linking the extraction vessel (SKIP) and cables binding devices, DLCпїЅs, and are designed to equalize the tension in cables of extraction plant (multicable). The paper presents a new solution design of the screw-nut mechanism of initial tension cable for the uniformity tension and horizontal positioning of the rocking mechanism. The extraction vessels cables are attached to those by means of binding devices and equipment. Binding devices and equipment should be safe ...

Hydraulic fracturing is a widely used in the hydrocarbon production industry to stimulate oil and gas flow from traditional and shale formations. This technique is one of the essential elements of borehole mining technologies and is designed for controlled impact on the rock mass during the development of solid, liquid and gaseous mineral resources. The creation of a system of traversing cracks in the rock mass that are parallel to each other is of great practical interest for many geotechnical issues such as impr...

The process of Underground Coal Gasification involves risks of uncontrolled/unpredictable course of the gasification process. To minimize the risks of contaminants leaking outside the georeactor zone in the event of emergency is of a significant importance when aiming to maintain safe course of the process. The article presents methods and measures aimed at reducing the risk. These methods are based on reduction of the impact of released gaseous contaminants generated during the process. In order to achieve it, a ...

Dust is one of the major hazards that affect workers in the mining industry. Currently, there are many technologies that help reduce the dust load on the miners. But looking at the statistics of professional and profession-related diseases, it can be seen that the incidence of diseases caused by various industrial aerosols is not reduced. This indicates that the existing methods are not sufficiently effective. It is not excluded that the very method of estimating the dust load on workers is not correct and needs t...

The problem of stress state evaluation is really actual for the underground structures been exploited for a long time. Stress and deformation monitoring give opportunity for hazard prevention and planning operation mode of the underground facility. One of the most common methods of deformation control is convergence measurement, but transformation of measured data into stress state of underground structures is quite difficult. A technique for stress state evaluation of underground structures on the base of the ana...

The quality of bucket wheel excavators (BWEs) operations is largely influenced by the physical-mechanical (structure, mineralogical composition, plasticity, anisotropy, degree of fracturing etc.) and technological properties (compressive strength, tensile strength, shear strength, compaction, consolidation, cutting resistance etc.) of the rocks. If the excavated materials are relatively homogenous, without intercalations with excessive cutting resistance, it is not difficult to conduct the technological process. I...

Schemes of mining and construction operations have been developed for inclined trenches on the open pit edge, where transport platforms and safety benches using the drilling and blasting method of rock mass preparation are located. The volume of mining operations is calculated taking into account the dislocation of a part of the open pit edge of the deep open pit mine for placement of loading points at the bottom of inclined workings. A new scheme of conducting mining operations implementing steeply inclined conve...

The worldwide development of studies concerning volcanic-related deposits caused renewed interest in epithermal mineralizations in Sardinia and a prospecting program was developed in the eighties. A series of field surveys showed that hydrothermal alteration halos are widespread in the Tertiary volcanic terrains, and AuпїЅAg bearing mineralized outcrops were detected in a few localities. An exploration program was performed which reached the ore evaluation stage in two areas. The first economically viable gold dep...

The paper deals with the study of Powered roof support analysis, taking into account the interaction with surrounding rocks. In this respect, an analytical model of kinematics and load of the shield, a differential model of the shield-rock system equivalent stiffness and a Fuzzy logic based analysis of the parameters variation are presented. In the first two models, the classical approach of shield mechanics, the loading scheme was modified by taking into account the horizontal force acting between the roof and th...

The authors propose a method for automated processing of seismic data obtained in high-stress rock masses structured as hierarchy of blocks with a view to detecting seismically active zones and seismic event clusters within a mine field. The processing algorithm is developed based on the statistical theory of classification and cluster analysis. Suitable for zoning of seismic data, FOREL family algorithms include algorithms based on the idea of incorporating objects in the zones of their highest concentration into...