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The underground mining of a deposit leads inevitably to the deformation of the surface as well as to the destruction of the buildings located in the area of influence of the extraction. Therefore, the rocks surrounding the excavation, created by the extraction process, go from the initial equilibrium state of tensions (triaxial) to a biaxial or even uniaxial stress state. This secondary state of tension leads to the occurrence of rock breaking phenomena in the areas where their resistance are exceeded, respectivel...

The current state of the mining industry is characterized by a tendency to rapid deepening of mining, which leads to an increase in the mineral excavation self-cost and negatively affects the safety of production. The effectiveness of an underground geotechnology largely depends on the correct choice of methods and schemes for ore and rock transportation, which is becoming increasingly important, with deepening mining. Currently, the most common transports in underground mining are rail and road vehicles; mine hau...

Underground hard coal exploitation is accompanied by a series of natural hazards. Their number and intensity increase along with the growing depth of exploitation. Amongst the most dangerous hazards in the mining industry, one can distinguish the following: methane hazards, seismic hazards (including the rock-burst hazard) and coal dust explosion hazards. They are a common issue in Polish coal mines, thereby making it necessary for coal mines to identify the level of these hazards. It can also be assumed that ther...

Underground hard coal exploitation leads to the formation of granular porous media. These media occur both in the underground parts of mines and on the surface. In the underground areas, these are the caving goaves of longwalls and the caved-in roof rocks in active mine headings. On the surface, these are most commonly the post-mining waste dumps. In both of these cases, a crucial role is played by the knowledge on the resistance of air and gases flowing through these media. In the case of underground exploitation...

The purpose of this paper is to determine the rate of methane (explosive gas) and of carbon dioxide (asphyxiating gas) in the mine workings of Dej salt mine. In Romania there are six salt mines which exploit the salt through underground mine workings: Dej salt mine, Tg. Ocna salt mine, Slanic Prahova salt mine, Ocnele Mari salt mine, Cacica salt mine, and Praid salt mine. The purpose of the present paper work is to establish the methane release (explosive gas) and the carbon dioxide release regime in mine workings...

The paper presents model-in-the loop simulation results of the roadheader cutting speed control system. The roadheader is equipped with an 132kW induction motor supplied from the frequency inverter. The output frequency is calculated by a PI speed controller on the basis of speed error (signal difference between a reference signal from the load controller and the measured signal from the incremental speed encoder). The whole control system model (involving an inverter model, sensor model, induction motor linearize...

Belt conveying belongs to high-performance, economically and energy efficient continuous system. Optimization of this conveying systems makes possible reducing the total operating costs up to 30%. For this reason is necessary to choice of the suitable structural elements. Conveyor belt is the most important element of this system and quality of its strength properties is a needful prerequisite for a smooth operation of belt conveyors. Insufficient quality of strength properties has a negative effect on the reliabi...

It is a certainty that a rock massif is a very complex environment, known only partially; in the laboratory we cannot produce all the details encountered in situ; therefore, most of the properties determined experimentally not fully express their real value that they have in rock massif. As theoretical basis we might consider theory of similitude initiated by Newton, in the sense of similarity that we can establish to the boundary between theory and experiment. Based on this and considering the applicable theorems...

In a practical context and with a tendency to generalize the dependence between monoaxial and triaxial compressive strength of rocks and qualitative characteristics and also properties of connection between the elements that form the skeleton of studied rocks were analyzed. This qualitative connection was highlighted by means of void index and apparent specific weight. The obtained correlation can be generalized to any type of rock, if it takes into account the amount of adsorbed and absorbed water, the direction ...

The main aim of this study is separation of different populations for sulfur and phosphorus as harmful materials using fractal modeling in the Jalal-Abad iron ore, SE Iran. The elements are dangerous for steel production and environment and classification of those elements is important for excavation of iron ores. For this purpose, the grade distribution models for sulfur and phosphorus were generated using ordinary kriging geostatistical model. Then, the various sulfur and phosphorus populations were delineated b...

The belt conveyance plays an important role in mining, bulk material transportation, raw materials processing, and in many other areas (e.g., metallurgy, wood-cutting, and energetics) where large quantities are transported over the distances ranging from a few meters to several kilometres. A conveyor belt, as the basic element of the mining transport, is of particular economic significance. Increasing the belt service life, which can be achieved by reducing the wear of conveyor belts, has a high priority. The top ...

This article aims at developing a method to establish a model employment arrangement based on mining companies using a taxonomic approach and a similarity measure as well as potential practical applications of the presented studies. In order to establish the model employment arrangement, the author uses the production parameters of mining companies significantly affecting the number of employees. As a result, the following algorithm has been proposed: arranging mines into typologically homogeneous groups using the...

The progress (evolution) of a civilization based on natural resources development has resulted in permanent natural environment destruction. By the beginning of the third millennium it has become evident that exploitation of the planet's mineral resources, being the basis for the existence and progress of civilization, is the cause of the global environmental crisis. The Mining Institute has substantiated a methodology of restoration of natural ecosystems (ecological restoration), which consists in using an idea o...

The paper deals with the purchase and sale of electricity in companies like huge opencast brown coal mine. Regulation of electric energy usage is still an underrated component of automatization equipment in some companies. If good energy regulation methods are being used, not only financial saving will be achieved, but also energy supply and distribution system quality will get better. This article describes one of the most important systems for saving money and effectively managing the use of electricity in the m...

This article aims at determining the optimal number of organizational levels in a company's hierarchical structure. Based on this, the author establishes a certain number of managerial levels that simultaneously create the levels in the structure of the priority communication system ? information exchange ? in an organization. Also, the role of managers in an efficient and effective information flow is presented. Businesses that operate by market principles must strive for the highest possible efficiency and effec...

The publication concerns the issue of losses and gains related to the rock mining activity in the whole business life cycle of a mining undertaking in relation to: mining entrepreneur, communes, local communities and the environment. The analysis of the issues was conducted for three specific stages of a mining undertaking: identification of geological resources and technical and economic analyses of an undertaking, preparatory works, deposit opening and mining as well as winding up of the mine. The conducted anal...

The paper is aimed at estimating the abundance of polymetallic nodules in the Pacific area is administered by the Interoceanmetal Joint Organization (IOM) using statistical and geostatistical methods. Polymetallic nodules occurring in the Clarion-Clipperton zone in the Eastern Pacific Ocean contain numerous metals, of which the most important are Co, Cu, Ni, and Mn. In the area administered by the IOM, the four genotypes of nodules are marked with the following symbols: D and D1 (diagenetic), H (hydrogenic), and H...

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 methane hazard is one of the main natural hazards occurring in underground hard coal mining. This hazard is related to the potential ignition and/or explosion of methane when mixed with air. The underlying cause of this problem is methane release from the body of coal, the goaves with caving and the excavated coal area. The region most vulnerable to this hazard in coal exploitation during longwall ventilation using the U-type system from the exploitation field borders is the intersection of the longwall and th...

The accelerated ageing affects the quality of an important element of the belt conveyance ? a conveyor belt. This paper analyses the resistance of the belt cover layers to the deterioration caused particularly by the accelerated ageing. The investigation was carried out using the fabric conveyor belts of the P 2000/4 type (4-layer textile belts with a polyamide carcass, the strength of 2,000 N/mm) at different ageing periods. The effect of ageing on the rubber cover layers was identified on the basis of the observ...

The investigated lead - zinc ore panel is located in the Blaznei Valley ore deposit, Romania. Applying traditional methods for determining the average thickness proves useful in its exploration, although there are only four points of thickness measurement, located in each corner of the exploration panel. Later, in the second stage of the exploitation process (preparation), when the exploration panel becomes an operating (exploitation) panel by contour mining of four workings, two groves on direction and two runs, ...

The target of this article is the providing of the brief information about preventing the dust spreading problems solving during operations of machinery equipment in brown coal open pit mines and in coal dumps. The main part of this paper briefly describes operation tests of the new rotary mist unit realized during last years. The increased concentration of the dust in the air causes important health hazard. The dust is very bother factor. The occurrence of the dust in operation area is the source of danger fire r...

Various methods are used in the mining of minerals, where the transport of material is an integral part. This paper deals with the transport problem of backfill material from surface stock to underground tank. To solve the problem is applied the capacitive calculation of transport using 2 trucks and a loader. The calculation is complemented by graphic models. The backfill material is available on 5 surface stocks. It is possible to transport the material directly to the workplace from each heap, which is not effec...

The article presents the second part of the results of asymmetrical disc tools laboratory tests. The first part of this study was presented at SGEM International Conference in 2017. Asymmetrical disc mining tools can be used for mechanical mining of hard rocks, as an alternative to blasting methods. The study was conducted on a dedicated laboratory stand, with an installed drive power of 80 kW. Stand consists of rotating rock sample, mined by special plate equipped with asymmetrical disc tools by a so-called under...

Natural sources can contribute with significant radiation quantities toward the total radiation exposure that humans receive. The majority of this natural radiation is harmless to humans in the ambient environment. However, radon, a large component of the natural radiation which humans are exposed to, can pose a threat to the workers health when radon gas accumulates in poorly ventilated occupational settings. Radon is the most hazardous natural source of radiation. Even if it is an inert gas, having no color, tas...

The paper deals with the negative effects of mining on the transport network in the Moravian-Silesian area, especially is focused on problems reflected in construction layers of transport-related structures (railways, roads, area storage and handling areas). With the extraction downturn, the sources and objectives of transport have changed including the characteristics of transport flows of all traffic roads and connections. Various measures for all transport modes situated in Moravian-Silesian region are identifi...

The target of this article is the presentation of the first steps of solving the project No. TH03020368 from the programme EPSILON titled ?The optimisation of the shape and material of ground and mining machines research?. The main topic of this article is the optimization of the tooth shape and primarily the optimization of the materials used for manufacturing of cutting bodies of the ground and mining machines. This research is necessary for increasing of efficiency of mining process in conditions of the Most Ba...

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...

Production and consumption of electricity is, in contemporary society, the significant technical indices and social level you have reached. The use of electricity involves electric power systems (ESS), representing the large technical systems, which shall incorporate the Assembly plants for the production, transportation, distribution and consumption of electricity. Within the framework of the ESS are retrieved hydroelectric power plants (CHE), which represents about 25 percent of the installed power in power stat...

For underground extraction of coal are running a complex network mining vertical, horizontal and inclined role extraction, transportation and evacuation on the surface. Associated system of mining works has the ventilation network to ensure the oxygen necessary for workers, diluting explosive gases and toxic substances and evacuated heat and humidity from the underground. For air evacuation from the underground workings, from the point of entry of fresh air to the polluted air exit point, is used powerful fans loc...

Computer assisted design and simulation are essential stages in the process of creating a new technical product. The paper presents the utilization of cutting parts, equipping 2K-52 machines, as fundamental element in the development of modified cutting parts for KSW-460NE machine. This modification has been possible due to the study of the machine?s cutting parts with the help of CAD/CAE software. Adapting the cutting parts to KSW-460NE machine has been imposed by the geological-mining conditions of the coal laye...

The paper presents the results of the analysis of the accuracy of estimates of copper resources in parts of a Cu-Ag deposit in the Lubin-Glogow Copper District (LGCD) (Poland) where samples were not collected (test areas). The estimation was based on the samples collected from excavations surrounding the areas scheduled for mining activities, while the evaluation of the accuracy of the estimates was based on data obtained during the exploitation. The estimates of resources in the examined area were based on a 3D s...

In order to ensure energy security, at national level, coal constitutes an important source, though its share in the energy mix is reduced in the past few years in favor of clean technologies and on the background of the fall in the energy consumption. Where can be located in the project of energy security, the production of coal, exploited in the mining units in the Jiu Valley and valorized at the two power plants, Mintia and Paroseni-components of the Hunedoara Energy Complex, amid the request for intervention f...

Biomass belongs among renewable energy sources and its representation in national energy strategies is increasing due to the limited supplies of fossil fuels. One of the options for substitution of fossil fuels is short rotation cropping systems for woody biomass as a method of reclamation and revitalization of anthropogenic soil profiles during restoration activities in the areas after brown coal mining. The scope of the project "Methodology of sustainable agricultural management in anthropogenic damaged landscap...

The Cu-Ag deposit exploited in the Lubin-G?og?w Copper district (LGCD) in Poland is located in the Permian Rotliegend (sandstones) and Zechstein (shale and carbonate rocks) formations. The three main lithological series are not internally homogenous; within them, a total of 16 individual lithological units can be determined. The differentiation between lithological, mineralogical and geometallurgical ore properties is a criterion used to distinguish between main and individual lithologies in the deposit area. A sy...

The subject of the study was to characterize three deposit parameters of Pacific polymetallic nodules (the content and the abundance of nickel and the nodule abundance) using classical statistical methods. The input data points come from 448 sampling points of a bed area of about 48,000 km2 in the Clarion-Clipperton fracture zone (approx. 1,000 km west of the coast of Mexico). The sample points formed a pseudoregular grid with an average distance between them of about 10 km. On the basis of these, the basic statis...

A tough requirement for the development of the Partomchorr apatite-nepheline ore deposit containing rare-earth elements is a performance of environmental safety of production, because a sanitary zone of the projected mining and processing plant sides with the boundaries of the existing Simbozersky nature reserve and the created Khibiny national park. The studies have substantiated reasonability of the Partomchorr deposit development by a combined mining method; in the first stage step-by-step mining of four open p...

The basis for safety management is the assumption that safe conditions as well as safe behaviour at work do not arise spontaneously, but must be worked out according to a pre-approved program. It is known that preventive actions have a much greater importance and sense than the removing of a damage resulting from accidents. Therefore, it is necessary to take measures aimed at improving the working conditions, equipment and conduct of employees hired in the mine. The presented article is an attempt at a practical a...

Typomorphic features of placer gold from alluvial deposits of the Bolshaya Kuonamka river basin, draining Eastern framing of the Anabar massif are studied in order to identify association types of primary sources and places, promising for their discovery. Based on identified indicators of gold, it is defined that, ore manifestations of low-sulfide gold-quartz association are the main primary sources of gold-bearing placers. Identification of palladium gold in association with platinoids, as well as its intergrowth...

During the process of conceptual designing of earthmoving or construction boom type machine we have must ensure that it is applicable in practice, meaning stable. Unfortunately, not every time is design of upper structure of such a machine ideal in consideration of position of centre of gravity and that is the reason why are stabilizing outriggers usually attached. This article talks about possibilities of use various schematic drafts of stabilizing outriggers for earthmoving and construction machines on the wheel...