Search

Currently, one of the main problems in the extraction of useful minerals in term of environment is their transport in quarries. With the requirements to reduce the noise of the belt conveyor track, we were looking for a suitable solution to reduce it. So, we started thinking about attaching rollers made of a material other than steel. The final solution was to insert classic rollers in polyurethane beds called suspension cartridge - which are roller holders made of polyurethane and reinforced with a steel liner to withstand loads, wear and other environmental influences. This paper describes the development of cartridges. The solution must also take care about their complexity and production economics. The noise reduction also depends on hardness of the cartridges, so we made in 3 polyurethane hardness - 70 Shore, 80 Shore and 90 Shore. The next part describes the testing machine that we have developed for test the noise of every type of cartridges. The purpose of the tests was to determine the sound pressure levels of the noise according to the used roller holders - classic and in the suspension cartridges with different shore. We can state that our design of the roller holders can reduce the sound pressure level by at least 2.3 dB for the softest cartridges. Although it may seem not much, but this value in mining conditions is, however, very good and in the case of further modifications of the cartridges, the achieved values could be even better. [ABSTRACT FROM AUTHOR]

The basic requirement placed on any machine system, technology and machine as a whole must be clearly based on the assurance of safe operation and operational reliability, and this is where maintenance is the systematic tool to achieve them. Technical diagnostics is a part of every maintenance and thus becomes one of the decisive maintenance tools in its comprehensive concept. Much attention is now being paid to lignite mining in the Czech Republic, especially when we are talking about the extraction of coal for its subsequent use in the production of electricity and thermal energy. As part of the recent trend, specific methods of opencast lignite and overburden mining, their transport, storing and warehousing are being compared and economically evaluated. In this context, considerable emphasis is placed by mining companies not only on reducing the environmental impact of mining, but also on the overall efficiency of mining operations, the balance of which can be improved by increasing the operational reliability of individual components of technological units and reducing operational costs. The aim of this article is to briefly introduce the reader to the implementation of state-of-the-art systems in the process of technical diagnostics and maintenance integrated in the operating conditions of the opencast brown coal mine of the Czechoslovak Army (hereinafter referred to as CSA). Specifically, in this case it is an unmanned vehicle (called BRUS - Unmanned Rotorless Universal System, sometimes also DRON), which was acquired by the SEVEN Group. The main purpose of this project is to acquire such a means, which will reliably increase the safety of employees, but also the safety and performance of the technology operated. [ABSTRACT FROM AUTHOR]

Belt conveyors constitute an important part of the machinery for the underground and surface mining of materials. In the course of time, conveyor belts proved to be the most efficient way of transporting material, which is still valid not only in the mining industry. For the transport of rocks to a mine disposal site, a combination of multiple belt conveyors is necessary. Places of transfer belong to the most stressed parts and there are frequent breakdowns. They operate in difficult conditions and are subject to high impacts of strain. The impact bench is often subjected to the opposing requirements. Designers make attempts to meet the maximum of these requirements when designing new types of such benches. For the proper operation of any conveyor belt, it is necessary to solve issues with the impact of materials on the belt. The material transported from one conveyor to another is problematic mainly when there are large pieces with relatively sharp edges in combination with a drop height of fall and an inappropriate angle of impact. Furthermore, engineers lay emphasis on the best moderation of the impact energy produced by this material, so that the impact effects are not transmitted to the supporting frame of the conveyor. In this way dynamic stress is limited. During their transport, especially in the places of pouring these materials, where the material is crushed due to a large impact height, a large amount of dust is generated. Many technical solutions can be used to eliminate dust on conveyor belts, for which the common solution is the use of variously shaped covers for the transfer points. Different types of impact beds can also be used, with the impact part designed to lower the amount of crushed coal and allowing for the use of vertical side seals. The aim of this article is to point out the possibility of reducing damage to the conveyor belts in these places through the use of impact benches. Depending on the type of the impact bench there is also a change of dustiness during pouring and a different distribution of the material on the conveyor belt. [ABSTRACT FROM AUTHOR]

Today, there are high demands for ecological solutions to the problems associated with all human activities, and therefore there is great pressure on surface mines to contribute to the reduction of dust and noise in the extraction of raw materials. Under this pressure, the mining company is trying to find a solution that would benefit all parties - ecologically and economically. The noise level of belt traffic in surface quarries, especially at night, exceeds 60 dB, which significantly disrupts the surrounding populated areas. After analysing the main sources of noise, we found that the main sources of noise in long-distance belt transport include carrier rollers and their storage in idlers. Therefore, we have set the goal of our solution, which we will deal with, the problem of construction of individual roller holders in idlers, including materials for production. A novelty today is the use of special soundproof rollers for belt conveyors. High-quality HM 150 quality rollers with lower vibrations and a significant reduction in noise emissions from Sandvik are characterized by a reduced noise level of conventional cylinders by up to 15 dB. So far, these rollers have also been tested in the Czech Republic. At present, there is also an effort to use all-plastic rollers, the use of which is unrealistic for economic reasons. [ABSTRACT FROM AUTHOR]

Cases of breakthrough on conveyors belt occur very often during the transport of heavy material in surface mines. The annual cost of their repairs in the Czech Republic is around two million euros. Therefore, we expected a constructional solution for impact points, which would reduce the dynamics of impacts and thus prevent to destroy the conveyors. In addition to reducing the number of punctures on conveyor belts, there has also been a significant reduction in dust in the area of transfer points. This article therefore deals with the issue of significant reduction of the dynamics of impact and thus elimination the puncture of conveyor belts, which will significantly reduce the cost of the conveyor belts and the cost of the entire extraction. The main benefit of this article is a detailed description of the impact bed with impact bars, which we designed and tested directly in operation. Its priority in addition to impact bars, which absorb the energy of the impact, are suitably located disc springs on the impact bed. The use of new types of impact beds significantly increases the lifetime of conveyor belts and also reduces dust in the area of rock impact, which will have an impact on the environment, not only in places of impact, but also in the entire surface mine and its surroundings. Currently, the whole world is focusing on environmental issues, where noise and dust are at the forefront of the problem. This only confirms that this is a very serious problem that needs to be addressed. [ABSTRACT FROM AUTHOR]

Rubber offers adjustable mechanical properties so that widely used as an engineering material, such as belt conveyor. During application, rubber belt conveyor is subjected to various forces and exposed to different environments that lead to degradation. Therefore, the estimation of the service life of rubber product is important. In this study, belt conveyor cover was made of natural rubber blended with ethylene propylene diene monomer (NR/EPDM). The blend was prepared by controlling the curatives migration in order to get balanced properties. Service life estimation was carried out by accelerated aging in an air-circulated oven at 70, 85, 100, 115 and 130 °C for times ranging from 3 to 14 days depending on aging temperature (ISO 11346:2014). The hardness of the blend was monitored and its changes were employed in the estimation. Arrhenius relation was applied to express the degradation kinetics of the belt conveyor. Crosslinking has dominated the degradation mechanism because hardness tended to increase by aging time and temperature. It was assumed that the changes in hardness following the second-order reaction. The service life of the belt conveyor can be estimated using the equation:t =(X/1+X)/CA0(exp(−6.1022−2740.2/RT)) where, X is the conversion (allowable remaining hardness), H0 is the initial hardness and T is the absolute temperature in which the belt. Service life was greatly affected by temperature and the end of life (EOL) criterion. The activation energy of degradation was 22.78 kJ/mol. [ABSTRACT FROM AUTHOR]

During the extraction of minerals in underground mines or surface mines all material extracted must be transported long distances. This transport is usually done using belt conveyors. For the transport of rocks to a mine disposal site, a combination of multiple belt conveyors is necessary. This material must be poured from one belt conveyor to another. At the places of transfer, the upper protecting layers of the conveyor belts are often damaged due to the impact of the material. This deterioration of contact layer can lead to damage to the frame or to a significant tearing of the conveyor belt, which can cause a malfunction of the entire transport system. Since the repair of the damaged conveyor belt is time-consuming, it has very negative economic consequences for its operation. The material transported from one conveyor to another is problematic mainly when there are large pieces with relatively sharp edges in combination with a drop height of fall and an inappropriate angle of impact. The aim of this article is to point out the possibility of reducing damage to the conveyor belts in these places through the use of impact benches. Depending on the type of the impact bench there is also a change of dustiness during pouring and a different distribution of the material on the conveyor belt. [ABSTRACT FROM AUTHOR]

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 risk, too. [ABSTRACT FROM AUTHOR]

The effectiveness of enrichment process of run-of-mine copper ore (at KGHM's ore enrichment plants) depends on the selection of appropriate working parameters of processing machines which are customized mainly to fit the fed rock type. Therefore, the knowledge of lithological composition of run-of-mine copper ore fed to the ore processing plant can significantly improve the effectiveness of the enrichment process. The issue of optimization of enrichment processes with the help of the use of in-situ sensor technology (pellets carrying saved information) for determination of parameters of run-of-mine copper ore transported from mining faces to ore enrichment plants is the subject of international research project DISIRE. The starting point for considerations on the issues covered in DISIRE project is determination of composition of run-of-mine copper ore transported from mining faces to ore enrichment plants. Therefore, the simulation of run-of-mine copper ore flow within the selected part of one KGHM mine's continuous transport (belt conveyors) network was scheduled in DISIRE project. Simulation required the identification of quality and quantity parameters of run-of-mine copper ore hauled from drift faces to belt conveyor's loading points. Identified quality and quantity parameters of run-of-mine copper ore were analyzed in relation to their variability and mining department from which run-of-mine copper ore was hauled from. Conducted analyses were based on the data acquired from channel samples taken from drift faces which is stored in the mine's ore production monitoring system (MOPRONA). The average Cu grade in run-of-mine copper ore hauled from mining departments to specific belt conveyor's loading points was determined on the basis of Cu grade in each lithological layer (rock type) at drift faces. It was shown that on the basis of currently used methodology of lithology identification for run-of-mine copper ore hauled to loading points and storing the data in MOPRONA system it is not possible to accurately identify the parameters of final stream of run-of-mine copper ore as delivered to ore enrichment plants. It is due to the large number of variables (both geological and technological) defining the final quality of run-of-mine copper ore entering the ore enrichment plants, which need to be further investigated in details. [ABSTRACT FROM AUTHOR]

In Polish underground copper ore mines belt conveyors are the most common transport facilities. In KGHM Polish Copper SA there are over 100 km of belt conveyors. To increase reliability of the transportation system there are built numerous ore bunkers ensuring continuity of the excavation during 5 working days of the week and on weekends, during which ore bunkers feed processing plants. In addition, some conveyors were built as reverse ones what in cases of emergency can provide alternative routes to supply ore to hoisting shafts. The modelling of ore flow in transportation system is complicated by the fact that conveyors operate continuously when loaders and trucks loading ore from mining faces on conveyors and vertical transport by skips operate cyclically. The real solutions resulting from meeting needs to achieve certain output with real capabilities provided by current machinery is difficult to model and optimize it theoretically in a such complicated transportation system. Therefore, a good simulation models can be used for that. Simulation analysis can be conducted in order to analyze reliability of transportation system due to emergency downtimes creates huge losses in production as well as in order to lower unit transportation costs due to yearly transportation needs are great (over 34 million tonnes of ore) and costs are high. Analysis of mass flow through transportation system allows to try finding hidden reserves to increase production without additional investments. Another aspect of the simulation research, which lately has got growing interest in mining worldwide is monitoring of ore quality changes along the transportation routes from mining faces to processing and metallurgy plants. Without the knowledge of ore lithological composition and useful mineral content on conveyor belts with enough time advance there will be no possibility to adjust beneficiation processes according to it. Possibility to trace and then to control mixing of ore from hundreds of mining faces in transportation system is necessary to adjust mining advances in order to attain optimal feed in processing plant and stabilize it for the time necessary to improve yield through adjusting controlled parameters and optimization of the whole technological line from ore identification and extraction through transportation to processing and metallurgical plants. Without good tools for modeling and simulation of transportation processes in such complex systems as exists in KGHM's mines and capability to trace quantity and quality of the ore loaded and transported it will not be possible. [ABSTRACT FROM AUTHOR]

Belt conveyors are crucial machines involved in ore transportation from the dumping point to the shaft. Because of that, their trouble-free operation has indisputable impact on the overall economic performance of the mine. Even short unpredicted breakdown can influence the production and suppress the income, what is highly undesirable. In order to monitor condition of the belt conveyor system components several quantities are measured (i.e. electric current consumption, temperature of different belt conveyor components, belt speed, mass of the transported ore, etc.). In this paper we try to detect the damage in drive unit basing on the gearbox temperature and the engine electric current consumption. One can expect that there is strong relationship between these features. Moreover, it could be beneficial to analyse smoothed current due to its high variability. Indeed, it is showed that the averaged electricity consumption is able to explain the gearbox temperature dynamics accurately. The model is fitted on the historical data and the forecast of the temperature-current relation is performed. Finally the forecast is compared with the observed data. It is assumed that once the damage occurs, the real observed relationship between current and temperature readings significantly differs from the model output. The obtained results illustrate the possibility of multivariate context based fault detection. [ABSTRACT FROM AUTHOR]

The transport of material in underground mines represents one of the key parts in deep mining, for it is impossible to execute mining processes without it. In the course of time, conveyor belts proved to be the most efficient way of transporting material, which is still valid not only in the mining industry. Conveyor belts in mines often suffer damage, as they are perforated by falling rocks. On the other hand, their surfaces are less frequently worn by the moving pieces of transported material. Furthermore, engineers lay emphasis on the best moderation of the impact energy produced by this material, so that the impact effects are not transmitted to the supporting frame of the conveyor. In this way dynamic stress is limited. In this work you can find impact bench bars design, which can eliminate all the above mentioned shortcomings. Transported material here does not fall directly onto the belt conveyor with idlers, but onto the belt sliding above the impact bars. This design ensures a better reduction of the impact energy caused by falling material, and also reduces the bouncing of these rocks on the conveyor belt. Last but not least, this impact bench significantly reduces dustiness caused by falling material. [ABSTRACT FROM AUTHOR]

A sort of intelligent protection system for conveyor belt was designed, which mainly aimed at the phenomenon of belt slipped, belt broken, overloaded and coupling broken etc. It was designed by using intelligent instrument, monitoring software and fault detection technology, furthermore, the software and hardware were described. The protection system can automatically detect, diagnose corresponding fault, and give alarm signal with sound and light to stop the fault belt machine in due course. The application effect has proved that the protection system can improve intelligent degree of the whole burning coal transport and reduce the manual greatly and save a lot of funds for enterprise. [ABSTRACT FROM PUBLISHER]

What is characteristic of any technological process as well as any equipment is its acoustic manifestation in the course of operation. This signal is a manifestation of the function of equipment, its condition and impacts on material treated. The acoustic signal arises due to mechanical vibrations; the acoustic signal being, as a matter of fact, mechanical vibration of the air. On the basis of analysis of acoustic signals and mechanical vibration developing in the technological process at the opencast mine, especially in the course of long-distance belt transport, information on material mined was searched for. I have concentrated upon signals within the audible range; it means sounds and corresponding mechanical vibrations. Our paper is aimed at a carried-out analysis of both acoustic signals and mechanical vibration, which are formed within a technologic process on an open pit mine; and special attention is paid to the material quality. [ABSTRACT FROM AUTHOR]

A part of the overburden from the Veliki Krivelj open pit copper mine, operating within the RTB Bor -- Group Serbia, is disposed into the cavity of the closed open pit Bor. Disposal system is a combined truck/crusher/belt/boom spreader system with the designed productivity of 4700 t/h. The system started operation in 1998 but with only half of the productivity of 2350 t/h since only one of two designed crushers was installed. The end point of the system is a boom spreader OU-1 which initially had a 15 m long boom. The boom was reconstructed on two occasions to reach 30 m at first and then, during 2010 to reach 45 m in length. During both reconstructions the drive unit of the belt conveyor on the boom remained the same During 2011 second crusher was installed and the system became capable of achieving its full productivity. During the test operation under full load it was noticed that the drive unit does not have sufficient power and that belt conveyor gradually loses its speed. The noticed behavior of the system was a serious problem and constraint to achievement of the designed productivity. The operation of the system was analyzed in order to determine the causes of the problem and the results of the analysis are presented here. [ABSTRACT FROM AUTHOR]

Complex measurement of motors of the drive station of the belt conveyor of a long distance belt transport line was carried out at a brown coal transport line in an open pit mine in the Czech Republic in frame the MPO TIP FR-TI1-537 project solution. A supplementation of usual electrical measurement of the drive with other physical quantities measurement was the aim of the measurement as well as gaining knowledge of their and their derivates relations. The paper contains a brief description of the drive station measurements and their results. [ABSTRACT FROM AUTHOR]

The paper establishes dynamic model of the belt conveyor system with finite elemental method, and designs H∞ the robust controller with the disturbance attenuation, ensure the stability of the system. The lower-order controller is designed by utilizing the frequency-weighted right coprirne factor(FWRCF) controller reduction with special weights enforcing the stability of closed-loop system of reduced orders. Finally, comprehensive simulations are carried out. The simulation results demonstrate that the controller order can be considerably reduced, and that the closed-loop performance is only slightly degraded when the reduced-order controller replaces the full-order controller. The effectiveness of the FWRCF controller reduction is also proved. [ABSTRACT FROM PUBLISHER]

This paper discusses possible energy savings that can be achieved by changing the control of belt conveyors used to transport baggage in a baggage handling system used at airports. Significant savings are possible by carefully controlling the delay time of belt conveyors during which they runs idle. The theoretical tools to assess the possible energy savings and experiments required to find the input for these tools are discussed. A study of possible energy savings in the baggage handling system of a Dutch airport is presented. [ABSTRACT FROM PUBLISHER]

In order to ensure the belt conveyor operation reliable and safe, centralized monitoring and control is very necessary. This paper takes the belt conveyor for coal mine as the background, designs the monitoring system based on PLC technology. The system is composed of PLC and touch screen. It is used to control the machine and display running information real-time. The hardware and software of the system station is designed by S7-300 PLC, including the module setting of PLC and its interface wires. After introducing the system design, simulation is made in the software PLCSIM. The simulation results illustrate the effectiveness and correctness of the proposed method. [ABSTRACT FROM PUBLISHER]