Browse

The work given has been aimed at consideration of methodical approaches for the feasibility study of perspective in mineral deposits development, and based on it, preliminary ranking of criteria which should be applied relative to the Arctic solid mineral deposits. Authors used a formal logic method (analysis synthesis). It was revealed that both the domestic and foreign approaches cannot be applied directly for the feasibility studies of the Arctic solid mineral deposits because they consider the arctic condition...

Increasing the efficiency of the mechanization of the brown coal layers extraction requires updating the equipment from the technical endowment of the brown coal pits. The EsRc 1400?30/7?630 excavating machine with impeller represents the main tool from the endowment of the brown coal pits in our country. The cup runs displacement operation of the rock, its performance being found with the highest rate in labor productivity growth and reduce specific costs. It is realised, in this paper, with the help of the CAD/C...

In the paper underground monitoring measurement system for continuous measurement of load changes in instrumented rockbolts was presented. The use of anchor casings creates an effective method of protecting underground mine excavations in KGHM Polska Mied? S.A. mines. Foundation for technical assumptions of original monitoring method was trial measurement period carried out in two underground copper mines of KGHM Polska Mied? S.A. between 2005 and 2008. The main aim was to receive interaction between load variatio...

Great problem of mechanical hard rock mining is low durability of mining tools. In Department of Mining, Dressing and Transport Machines, AGH UST in Cracow new solutions of mining tools and their holders were developed. In paper, a special tool to replace traditional rotary pick (so called crown-shaped pick), new lubricated holder for rotary-tangential picks, asymmetrical disc cutters, results of laboratory, field and industrial tests were described. Crown-shaped pick has the same type of handle as standard soluti...

The acceleration and deceleration periods during each race of a vertical transport installation may be considered as periods of transitional processes where kinematics and dynamic measures variations take place (acceleration, speed and forces) as well as some electric measures (actuating motorпїЅs current). Considering T as the duration of the process, for the minimisation of the installed power, the minimisation of the energy dissipated in the system is imposed during the transitional period: ? ? ? ? ? ? T 2 1 0 ...

The present step brings forward a series of calculation methods for the parameters of the anchored support, their number being therefore the expression of the difficulty when describing the phenomena which occur during the interactive cooperation between the anchors and the surrounding rock. The methods used the most by European mining are the analytical methods (the Bieniawski method, the self-supporting beam method and the method of the interaction between the massive rock пїЅ anchor пїЅ time) and the numerical ...

The paper presents numerical modelling results for ventilating a blind excavation, if there is a leakage into a failure zone. The leakage value of air seeping through the failure zone (binomial law of resistance) was estimated by a formula describing in-situ tests results at the Kola Peninsula mines. The blind excavation ventilation process was simulated based on a previously developed two-stage methodical approach: 1st stage пїЅ calculation of aerodynamics with applying a standard ?k ?? ? -turbulence model; 2nd s...

The scientific paper deals with the multi-criterion optimization of the teeth that are used on the buckets of bucket wheel excavators. From past theory and practice, it is known that geometry of the tooth greatly influences the cutting parameters and the endurance and the strength of the tooth itself. The dependencies between the cutting forces, the penetrating forces, the specific energy on the rake angle and the relation between this last one and the robustness of the tooth are somewhat contradictory, so in the ...

The aim of this article is to describe the possibility of increasing the service life of the rod eye on a tilting platform that is used to tilt heavy barrels between the two differences in heights in transport lines. This mode of transport was selected for the lack of space in a given area of a production line, which does not allow the implementation of an inclined plane, which would be structurally easier. Rotating those barrels by 90пїЅ that is achieved during this way of transport, is desired for subsequent tec...

The annual extraction of aggregates in the Czech Republic is between 45 - 50 mega tones. [5]. Many studies for better results of quarries are undertaken. In this paper is solved the question of optimizing. It is solved the optimizing of cost on coal quarries also. The situation on stone and coal quarries is different. There are requirements for stone production, but the production of coal is in decrement. Comparison and solving both situations seems to be useful. The relationships between different production proc...

The annual extraction of aggregates in the Czech Republic is between 45 - 50 mega tones. [5]. Many studies for better results of quarries are undertaken. In this paper is solved the question of optimizing. The relationships between different production processes in quarries are very important matter. On the relationships between the manufacturing processes depends the economic effect of operation. The paper presents patterns in the organization of mining, which mutually related. Using computational methods and the...

One of the frequent problems that needs to be addressed when mining coal deposits is the presence in the working face of cohesive materials having high mechanical strength in relation to the average rock to be excavated. These are generally called пїЅhard formationsпїЅ or пїЅhard inclusionsпїЅ and are in the form of either continuous layers or boulders. This problem is of particular importance in Europe where lignite deposits are exploited in large opencast mines utilizing Bucket Wheel Excavators (BWEs) as the mai...

Conveyor belt loop operates in a system comprising a series of belt segments and the splices between them. Splices are the weakest parts of a loop. Depending on the splicing technology, the spliceпїЅs strength, durability and reliability may vary significantly. Vulcanized splices offer the highest strength and durability. In the case of steel cord belts, such splices are practically the only technology available. In the case of textile belts, adhesive and mechanical splices may also be used. Although mechanical sp...

The authors have revealed particularities in destruction of the rock mass by the system of borehole charges and substantiated the least seismic hazardous blasting schemes which allow decreasing out-contour disturbances and providing more qualitative crushing of rock mass. It has been shown that for the boreholes with 250 mm diameter the least seismic hazardous blasting scheme is one with borehole line placed at the angle of 105пїЅ to the bench wall. At that, the stress level in the out-contour rock mass decreases ...

This paper presents results for a research of the possibility of applying the combined methods of mining in construction of the underground premises in coal mines in the Republic of Serbia. The purpose of this study is to process the application and effects of combined (standard) methods of a pit remises construction through coal with a goal to find new technology of construction which will result in more productive and rational ways of their building. This study includes the analysis of the construction of pit pr...

During mining activities the constructions on the surface are usually influenced. Extent and time course of negative influences is dependent on array of geological, hydro geological and mining conditions and last not least also on the way of implementation of line construction (i.e. how it is ready to react to these awaited influences). In the past for that reason the array of calculation methods working with more or less precision with using for prognosis of influence of mining activities (i.e. influence of minin...

Mining activity represents an important source of harmful emissions into the environment and general impact on the environment. In the Ostrava industrial region this activity represents one of the most serious sources of potential risk for the environment and public health. The article deals with the problem of emissions of a mining enterprise from the point of view of air pollution and potential influence of air pollution on public health for the population. In particular it deals with air pollution impacts from ...

Healthy and safe working conditions underground, especially in areas with potentially explosive atmospheres depend mainly on the method of operation and management of the ventilation system. For underground extraction of coal are running a complex network mining vertical, horizontal and inclined role extraction, transportation and evacuation the surface. Associated system of mining works has the air network to ensure the oxygen necessary for workers, diluting explosive gases and toxic substances and preparations t...

A switch to combined automobile-conveyor transport is offered, i.e. cyclical and continuous method, at an early stage of the development of steeply falling deposits, based on usage of advantages of the safe intensive development of working zones along the steep open pit edges at a number of open pit mines on the territory of Kazakhstan. It is possible to shift from traditional approaches of cutting a new pit banks by advance of the cut trench with the minimum dimensions on the round-shaped open-pit fields. Decreas...

When it comes to workplaces characterized by a high degree of hazard and liability, such as mine intervention and rescue in major risk environments the most important element is the convergence of the skills required by job and skills of the individual, this being the guarantee of successful vocational selection. Along with psychological selection, training / retraining and physical training in conditions as close as possible to the reality of future interventions, under the action of stress factors that cause neg...

Uranium mining is the first step in the nuclear fuel cycle to produce energy. In the nuclear fuel cycle, main steps are; Mining / Milling, Conversion, Enrichment, Nuclear Fuel Fabrication, Reactors, Reprocessing of the spent fuel and Waste Management. In the first step, there are three main methods for uranium ore extraction. These are; Open Pit Mining, Underground Mining and In-Situ leaching (ISL/Lixiviation). All forms of mining methods create health risks for people and hazard for the environment. In this study...

The article deals with the treatment of terrain and the following forestry reclamation in the Erv?nice area situated near the city Most at the foot hills of Ore Mountains. It considers the impal of using secondary energy products for the reclamation of this previously mined area on ground water, surfac ewater, air and noise. The area had previously been used as sands and gravel waste disposal and in the last years efore there clamation there had been some natural restoration of the biotopes on the brought sands ub...

According to the European Commission, critical raw materials are defined as пїЅthose which display a particularly high risk of supply shortage in the next 10 years and which are particularly important for the value chainпїЅ. Therefore, when considering a raw material criticality, two main parameters are taken into account: its economic importance and supply risk. Technologies which a decade ago were considered high tech became current today, and raw materials once considered as minor, have gained importance. Parti...

The article summarised course of activities in trachyandezit (Latit) quarry (tephrite) in Bra?any location starting from mining working permit phase until termination of activities and subsequent redevelopment and reclamation of quarry residual pit. Redevelopment and reclamation of territory after mining is one of the main activities of Severo?eskпїЅ doly a.s.The paper provides data on the Bra?any opencast mine, namely the geography, environmental situation, climatic, hydrologic, geological and hydro-geological co...

The scientific paper proposed deals with the reliability analysis of the average usage time of the brake pads as components of the braking system of the industrial front-end loader and transporter machinery used in mining operations in Romania. The research was conducted at the request of several mining companies in Romania, that are using the front-end loader and transporter machinery in their daily operations. The study is based on the empirical information and the preliminary reliability results that were recor...

Non-electrical equipment has been used for over 150 years in industries in which likely to occur a potentially explosive atmospheres and a great deal of experience has been gained in the application of protective measures for reducing the risk of ignition of such atmospheres to an acceptably safety level. For using non-electrical equipment in potentially explosive atmospheres, it became necessary to produce ignition protection concept standards which clearly defined these protective measures and incorporated the e...

The Cukar 2 east ore body represents the latest explored ore body within the Mucim Mine with possibilities to enter exploitation stage in near fututre. Calculated ore-bearing coefficient in the Cukar 2 east ore body was 0.40%, meaning that within the ore body boundaries 60% of mass is not mineralized somehow, which is compatible with remaining three ore bodies within the Buchim porphyry copper mine. The calculated value of variation coefficient (V) has shown value of 71.39% that is in the range of 43-100%, which d...

The solving of European Commission (Research Fund for Coal and Steel) research project пїЅBucket wheel excavators operating under difficult mining conditions including unmineable inclusions and geological structures with excessive mining resistanceпїЅ is under way from 2015 to 2018. The Brown Coal Research Institute j.s.c. is a member of the research team comprising Czech, Polish, Romanian and Greek technical universities and companies. The main task of the year 2016 was the realisation of the three long term meas...

The paper presents the investigation results of rock mass state change regularities taking into account geological and mining factors by complex methods. The authors consider complexing of results from the cluster analysis of seismic events with numerical modelling of stress state in the rock mass on a case study of the Yukspor deposit (the Khibiny rock massif, Murmansk region, Russia). The time and dimensional analysis of the Yukspor depositпїЅs seismic regime was performed. The cluster groups of seismic events w...

One of the most significant elements of every machine operation is its control system. Proper design, construction and operation of the control system is the key factor for correct and efficient operation of a machine. This particularly applies to mining machinery operating in hazardous environments and exposed to loads which cannot be fully predicted. Such machines must be therefore characterized by high reliability, durability, readiness and safety. In order to fulfil all these requirements, a machine must be eq...

Transport systems are an important component of intra-plant logistics. Their role is the provision of transport services in order to ensure the efficient functioning of the individual processes. The quality and reliability of the transport system greatly affects the efficiency of intra-plant logistics. The extractive and mining industries are particularly sensitive to these indicators and parameters of transport technologies. The use of transport technology in this industry is dependent on a number of factors. The...

Drilling by the submersible drilling hammer is one of the progressive technologies in drilling of boreholes and it is currently being widely applied method for the drilling works. Use of the submersible hammers disposed in the borehole - drilling directly above the drilling tool - entails number of advantages. The most important is the energy loss prevention. Submersible drilling hammers are gradually and successfully replacing the surface hammers, which have been widely used for many years in Slovakia and in the ...

A starting point for roadheader robotisation (understood as a fully autonomous machine) is to automate the cutting process, which is the basic working process carried out by such machines. In case of boomпїЅtype roadheaders, it consists in automatic control of the movement of cutting heads to ensure that the face surface can be worked with optimum process parameters. This will guarantee high drilling efficiency (drilling advancement) and lower energy consumption, reduced dynamic loads and elimination of overloads....

The use of coal resources has contributed to the economy of Jiu Valley over a long period of time. Considering the long-term role of coal, many experts believe that the coal-based energy is sustainable, ensures energy security, and may become a growth factor in the area. The knowledge and technologies improvement for coal extracting from the Jiu Valley mining basin, where many mines were closed due to lack non-performing loans and lack of profitability, represents a first step in the sustainable rehabilitation of ...

The paper deals with the theoretical and practical analysis of the influence that the cutting direction of the bucket wheel excavator has on the digging forces acting on the wheel. Usually, when the terrace cut technology is applied, the bucket wheel of the excavator cuts vertical chips where mainly the perpendicular to stratification digging method is predominant. All the laboratory trials - done on the test rig - were conducted mainly for this type of vertical chip cutting. In cases when the drop cut method is a...

Jiu Valley represents one of the most important areas for coal mining in Romania, thus industrial development has generated a high level of health and safety at work issues. At work places in mining industry, the staff of the woodworking workshops is exposed to various concentrations of dust, possibly leading, in time, to occupational illnesses. Thus, wood processed in mining unitsпїЅ workshops is utilized for temporary support of coal faces, wrapping underground mining, insulation dams, ventilation doors, etc. Th...

Talc-bearing rocks in Kallievo-Murennanvaara deposit are associated with ultramafic rocks of peridotite-picritic series. Serpentinized rocks in the picritic portion of the sequence remained unaffected by talc alteration. Peidotitic komatiites, occurring below picrites which were altered to talc-carbonate rocks by carbon dioxide and then to talc-chloritic rocks under the influence of silica and alumina (the result of granite formation), were productive for soapstone. Kallievo-Murennanvaara soapstone deposit, is loc...

This paper presents a technical solution proposed for the mining drilling equipment command system, used for digging the horizontal mining works. The manufacturing industry of mining machinery in Romania and from different countries achieved a wide range of equipment for digging the horizontal mining works. As a result of the activity undertaken by a research team from the University of Petrosani, the drilling equipmentпїЅs with one manipulator arm (IMP-1) and two manipulator arms (IMP-2) were designed and constru...

Evaluation of explosion-proof protected electrical equipment in scope of certification is extremely important considering the risk of explosion that has to be minimized in order to ensure life safety and health of workers and to prevent damaging of property and the environment, as well as free movement of goods when they meet the essential safety requirements at European level. The purpose of this paper is to present the tests carried out on the cable entries with type of protection increased safety and flameproof...

In the Czech Republic, the production of energy using fossil fuels - particularly coal - is still a major proportion of total production. The energy sector is and will remain one of the most important areas of the Czech economy, ensuring supply of electricity and heat to the population and industrial enterprises. In the power and heating plants is burned primarily domestic brown coal mined in opencast mines in the north-western part of the Czech Republic, namely, Usti Region. For combustion of biomass in the Czech...

The minerals exploitation by explosives in quarries presume a high energy development for the applied blasting techniques with a proper design parameters establishment according in the field conditions where the blasting will carried out. For an optional rock blasting in field to obtain a certain granulation together with the maintaining the risk levels of blasting (seismic waves, fly-rocks, shock waves pressure) in a non - hazardous field, must to be applied sequential detachment of rocks from the massive with th...

The performances of the excavation machines depend largely on the tool and overall machine characteristics and on the other hand on physical mechanical characteristics of the excavated rock. There were more theories based on analytical deductions to explain the main cutting parameters on the basis of basic physical mechanical properties of the excavated rock. In this paper we use a new methodology, based on reliable laboratory data, which make possible to obtain correlation and regression formulas in order to pred...

Discussed are analyses and studies of an innovative method for managing active mining impact on future urban areas. Taking into consideration legal, methodological, engineering, economic, environmental, and social aspects, the solution represents an interdisciplinary attempt to address active mining damage problems. The examination follows a number of theoretical and practical analyses in addition to standard, numerical, and statistical calculations, as well as econometric models based on case studies and EU guide...

The use of pneumatic energy in industry as well as in the tertiary system is quite frequent representing 10% of the industrial electricity consumption in the European Union, the life span of compressors being relatively long, namely between 14 and 16 years depending on the installed power. Although the compressed air demand of a coal mine is covered by performant compressors manufactured by well-known producers there still are multiple possibilities to increase their energetic efficiency. The working method is con...

When building the foundations of a machine tool, demands must be placed on high quality and, above all, on their stability during their entire lifetime. In practice, however, it shows that these requirements are not always fully met on the customerпїЅs side when laying foundations. In the course of working, these foundations are subsequently damaged and their uneven decline occurs, which results in a change of the machine alignment, and thus it also influences the accuracy of production. For the supplier of the ma...

The specific energy consumption is mainly influenced by kinematics and dynamic measures of vertical transport installations as well as by the compatibility of different composing parts and their subcomponents. The optimisation of kinematics and dynamic parameters characterising a transport cycle is decisive considering the energy consumption. Also considering the operation of the vertical transport installations, as well as the character of the variation of kinematics and dynamic parameters during a race, it has b...

Mineral fuels are among the non-renewable natural resources. For this reason, would be addressed in a responsible and rational use. Mineral fuels are among the so called strategic raw materials, the use of which is essential to the national economy and energy security. Raw materials base in Slovakia as regards energy raw materials consists mainly of brown coal, lignite and uranium, part of the oil and natural gas. To determine the prospects for the use it is necessary to know the quantity of reserves and the econo...

Currently mobile mining machines, including primary ones, such as drilling and bolting rigs, or used in underground mining of metal ores, are most commonly driven by internal combustion engines. Due to the large depth of mining, this type of drive provides a number of disadvantages, including a large generation of fumes, heat and noise. The solution to this problem seems to be the use of the electrical battery drives, similarly as is the case in motor vehicles. The article presents the assumptions and boundary con...

The article deals with the structural design of the test equipment for analysis of coatings for hose conveyor belt conveyors. Processed list of existing test facilities in the world. Currently, there are various devices for testing materials using a bi-axial tension. The measuring device of its own production to measure axial forces in the conveyor belt, pipe conveyor is also the Technical University of Kosice. On it is possible to perform various tests conveyor belts by means of which the various measurements and...

Jiu Valley mining area is one of Romania where currently exploiting a coal deposit, which has important reserves of balance that can ensure beneficiaries' needs (CET Paroseni and CET Mintia) over a period of several decades. Structural changes that have occurred in the Romanian economy since 1989 have generated, but layoffs / redundancies collective personnel reorganization / activity restrictions in the mining units and the closure of some mines with no prospects of viability. All this led to a sharp economic dec...