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外文资料原文Directions of changes of hard coal output technologies in PolandTurek Marian*Central Mining Institute, 40-166 Katowice, Polanda b s t r a c t The author presents the results being the effect of the analysis of innovative rate of individual technologies applied in opening up, development and extraction works which was carried out within the project: “scenarios of technological development of hard coal extractive industry”. After presentation of opening up, development and extraction technologies that are applied in Polish hard coal industry and their classication with regard to innovation degree the author describes those technologies in a detailed manner. He brings attention to the most effective systems for hard coal deposits opening up, development and their extraction, including the extraction of the residual coal. The attention is also paid to the safety level of the applied technologies.Keywords: Technologies Manridng Materials transport Mechanisation Development 1. IntroductionThe presented analysis of innovativeness of individual technologies of the hard coal production process was carried out in the framework of the project entitled “Scenarios of technological development of hard coal extractive industry” 1. In the framework of conducted investigations the division into the following tech-nological areas was performed （Fig. 1） 2.For individual technological areas the corresponding with them technologies were presented according to their innovativeness degree with the division into disseminated and development technologies. The following innovativeness criteria were adopted 3.1） 2BdDisseminated technologies, medium innovativeness level,2） 2CdDisseminated technologies, high innovativeness level,3） 1AdDevelopment technologies, low innovativeness level,4） 1BdDevelopment technologies, medium innovativeness level,5） 1CdDevelopment technologies, high innovativeness level.For each technology group the following time periods of implementation of distinguished innovative technologies were singled out 4:1） until 2010,2） until 2015,3） until 2020 and,4） after 2020.The technologies counted among the time period until 2015 constitute the optimistic variant of development of the hard coal mining sector. The technologies implemented with lower intensity, i.e., until 2020 constitute the variant of sustainable development of hard coal mining. Technologies counted among the time period after 2020 constitute the pessimistic vision of the mining sector development 5.Among the variants of optimistic scenarios of development of underground deposit extraction technology were counted （Table 1）6,7.Among variants of sustainable and pessimistic scenarios of development of underground deposit extraction technology were counted （Table 2） 8.2. Extraction technologiesThe optimistic variants of extraction technologies constitute the most effective systems for hard coal deposits and extraction of remainders.The basic systems of hard coal deposit extraction in Poland will remain longwall systems of different forms, with the distinct superiority of the longitudinal or diagonal system with roof caving. The main directions of longwall system development will aim at the improvement of system effectiveness and safety level through9:1） improvement of reliability of individual equipment elements,2） development of an effective construction of self-slideable dam in hydraulic stowing systems,3） development of the plough technique for the needs of extraction of seams with thickness below 1.5 m,4） modication of driving and improvement of maintaining of gate roads including crossings with the longwall,5） improvement of thick coal size yield,6） better adaptation to natural hazard conditions, especially rock burst, re and methane hazards,7） use of remote steering systems and automatics.Fig. 1. Technological areas.Remainder deposits, located within pillars and seam parts with irregular forms will gradually force the use of short-front systems, especially open end systems （pillar-open end） and roadway systems; their chief advantages are 10:1） possibility to use the known and commonly applied mechanisation of mining operations,2） considerable elasticity from the aspect of adaptation to changeable mining and geological conditions of coal seams,3） possibility to extract seam parts with complicated forms,4） possibility of mining and power plant wastes disposal in post extraction voids,5） considerably reduced impacts of extraction on the surface（roadway system）.Table 1 Underground deposit extraction technologies of optimistic scenarios.In the sustainable variant of development of extraction technologies possible to implement until 2020 the following technologies were distinguished:1） Fundamental directions of development of short-front open end systems will to a high extent be in line with the directions assumed for longwall systems, however, there will appear additional elds of activities such as 11:a） development of a getting system using one-organ cutterloaders with increased capacity,b） determination of possibilities, determinants and technologies to conduct operations in conditions of a short （20e30 m） “blind working”.2） The thick seam deposits of the saddle group in areas that do not require surface protection should become in the nearest future the terrain for operational tests of the longwall sublevel caving system and possibly the open end-sublevel caving system. Signicant is the fact that these systems were and are effectively applied for coal seam extraction in the European or Chinese mining industry, often also in difcult mining and geological conditions.Basing on European experience there exist the possibility to start in the Polish mining industry operational tests to use the longwall sublevel caving system and open end-sublevel caving system. Detailed analyses will require some elements of this technology mainly connected with occupational safety and mined coal contamination. To them belong among others 12:1） assessment of impact of this system on the re and rockburst hazard increase and indispensable prevention scope relating to these hazards,2） modication of construction of powered （sublevel cavingrelated） support with respect to geological and mining conditions occurring in the Polish hard coal mining,3） development of an effective system of mined coal transportation from the longwall using one or two chain conveyors, basing on the analysis of deposit use coefcient and mined coal contamination degree.In spite of high innovativeness, among the pessimistic variant of development of extraction technologies should be counted the chamber-pillar system with capacity 1000 t/day and underground coal gasication.Mainly because of relatively difcult geological and mining conditions we can assume that the adaptation of the chamber-pillar system to coal seam extraction in Polish mines will not be possible.Underground coal seam gasication is undoubtedly a development technology. However, the current state of resources and technological reasons indicate that in the nearest future theTable 2 Underground deposit extraction technology of sustainable and pessimisticscenarios.implementation of this system on an industrial scale should not be expected. The determination of determinants of application of hard coal underground gasication in Poland and development of an appropriate for it technology should be, however, the subject of research and development work. Therefore we assume that the implementation of this extraction system will follow after 2020. Simultaneously with deposit opening and development systems and its extraction in the optimistic variant should be developed and implemented the specied in the scenario mechanisation systems, and allow achieving a sufcient level of Polish mining. Among optimistic technologies that could be implemented or quickly developing can be counted （Table 3） 13.Among sustainable mechanisation technologies was counted only the installation of the energy-cooling system with the use of motors supplied with methane with innovativeness on the level 1C.All technologies mentioned above will be applied in extraction systems in connection with system technologies of supply, informatics and automatics.3. Deposit opening, development operations and their mechanisationThe most optimistic variant of opening technologies is deposit opening using inclines from the surface and opening deposit structure; they are characterised by low execution costs and short realisation time.In roadway workings are commonly used and will be in the future two basic technologies of roadway working driving, i.e., heading machine technology basing on the use of heading machines, and the blasting technology, where rock getting will be realised with the application of explosives. The main factor deciding about the selection of driving technologies will be the properties of rocks occurring in the cross-section of the driven working （workability, occurrence type and their structure）. Among technologies basing on the use of heading machines we can distinguish.3.1. Mining using heading machines by means of the milling methodIt should be expected that the number of applied arm heading machines, mining point-wise, of medium and heavy type, will increase. This will concern mainly the development of systems of remote steering of heading machine work, remote machine operation from the surface and communication with it from an optional place for monitoring and control of its technical condition, steering of the direction of workings driving with the use of a technology similar to GPS or an alternative one, system of monitoring and communication for the automatic control of absorbed power of the getting organ, vibrations of machine elements, temperature, system for prole control of the driven working or systems for invasionless determination of rock type and properties as well as occurrence of gas outburst and water hazard at the workings life （in terms of distance） of georadar type.Using the experience of domestic producers and users of arm heading machines as well as the results of investigations carried out in Polish research centres, should be performed elaboration and execution of construction of drivers cabin equipped with an air-conditioning installation, adopted to work in conditions of rock-burst occurrence.Moreover, conceptions should be developed relating to new solutions of getting tools such as; bit tools, disc asymmetrical minitools, solutions of lubricated cutter holders in order to work out new getting techniques and organs to be applied in the case of compact and very compact rocks. When working out machine work steering systems and control of technical condition and Table 3Optimistic technologies available to implement or developing.system for the control of prole of the driven working, one should use also the experience relating to the application of neuron networks.In the case of arm heading machines getting point-wise in order to increase their effectiveness, will be developed and applied rst of all self-propelled working platforms for the transport and assembly of roadway support, and next the temporary hydraulically powered roadway supports.The above mentioned scenario of development of driving technology mechanisation of roadway workings through mining using arm heading machines by means of the milling method constitutes an optimistic development variant.3.2. Mining by means of special heading machines using nonconventional getting techniquesTaking into consideration the experience regarding the application in the world of heading machines using the technique of the so-called back undercutting and their possible competitiveness in relation to currently used heading machines, especially during the driving of roadway workings in compact and very compact rocks, their further development and wider application can be predicted.These machines, in conditions of lower energy consumption of the mining process than in the case of currently used heading machines allow to drive roadway workings in rocks with high compactness and uniaxial compressive strength, exceeding 160MPa. They allow obtaining very high daily advances, which may amount to more than 25 m. They allow, when using the microprocessor steering system, to drive workings with facultative cross-section.Heading machines of these types are designed rst of all to drive workings in difcult and very difcult mining ability conditionsTaking into consideration:1） the necessity to drive in the nearest future several roadway workings in compact and very compact rocks,2） the competitiveness of special heading machine solutions in relation to heading machines used currently,3） the necessity to apply in new conceptions advanced solutions regarding the materials and technology,It should be expected that in the nearest time numerous changes relating to the construction and work technology of both special heading machines using active tools and heading machinesgetting by use of the back undercutting method will be introduced. After the application of these changes using active tools, these technologies and machines can be successfully applied in the Polish mining industry when opening new deposit parts.The above described scenario of development of driving technology mechanisation of roadway workings through mining using special heading machines applying non-conventional getting techniques constitutes an optimistic development variant 14.3.3. Mining using drilling and blasting by means of explosivesThe technology of blast hole drilling, loading and ring using explosives is currently the only alternative technology for mechanical roadway driving, possible to be applied in mining and geological as well as organisational and technical conditions existing in Polish coal mines.Taking into consideration the remarks presented below, i.e.,1） highmanoeuvring ability andmobility of autonomous roadway complexes,2） possibility of work of autonomous roadway complexes in different mining and geological conditions,3） achieved in determined organisational and technical conditions sufciently good exploitation results,4） necessity to drive in the nearest future, in short time, a big number of roadway workings in difcult mining and geological conditions （in very compact rocks） and with large cross-section, 5） effectiveness decrease of mechanical getting along with increase in the compactness of mined rock solid connected mainly with wearing out of getting tools.It should be expected that in the nearest time changes in the construction and work technology of autonomous roadway complexes, driving the working through blast hole drilling, loading and ring using explosives will be introduced. The number of applied autonomous roadway complexes will increase, including rst of all two-arm gadding cars. This will allow drilling quickly, from one machine arrangement, blastholes enabling the driving of roadway workings with large cross-sections. The application of a microprocessor system of control and steering of the extension arms work will allow serving both extension arms from one place, by one operator. Moreover, the control system will allow obtaining a better arrangement of drilled holes, and thus more accurate workings prole and better cooperation of support with the rock mass. For the current use of such systems it will be necessary to develop a system of steering of workings driving direction using a technology similar to GPS or alternative technology, as well as systems of appropriate drilling parameter steering in the function of physico-mechanical properties of the rock, in which the holes are drilled. This will allow full optimisation of drilling process parameters and reduction of the time of duration of this process to the minimum. Any larger changes in the construction and technology of narrow-face side-pouring loaders are expected. Already currently they are equipped with systems allowing their high effectiveness, for nstance the Load Sensing system reducing power consumption.On account of possible work in conditions of rockburst and temperature hazard occurrence, for both machines will be required he development and application of reinforced operators cabins, equipped with an air-conditioning system.For the minimisation of the impact of water and gas outburst hazard occurrence it will be also necessary to carry out and implement systems of invasionless determination of the type and properties of rocks and appearance of these hazards at the workings life （in terms of distance） of georadar type.In order to increase daily advances, when using autonomous roadway complexes, will be developed, executed and applied in the rst sequence self-propelled working platforms for the transport and assembly of roadway support. Furthermore, this will allow facilitating and increasing the safety of workers employed at the face.In the next sequence will be developed, executed and applied temporary powered hydraulic roadway supports, protecting the machines working at the face and allowing additional driving advance increase.The above mentioned scenario of mechanisation development of technology roadway working driving technology through mining by means of drilling and ring using explosives constitutes a sustainable development variant3.4. Modernisation of roof bolting technologiesRoof bolting technologies with the use of drilling-bolting extension arms installed on heading machines and bolting cars are modern technologies of the future, which after adaptation to the conditions of the Polish coal industry can considerably decrease the workings driving costs and increase the advance of development work.With respect to mechanisation of the bolting technology changes should be expected, which will comprise: 1） introduction of technologies of simultaneous driving and bolting with the use of heading machines of special construction, enabling the driving of workings both of arch and rectangular form,2） automation of the bolting process,3） monitoring of technical parameters of rock mass and roof bolting （measuring bolts, endoscopic tests, control of workings convergence,4） optimisation of binders, glue and cement charges used for bolt fastening in the rock mass in order to receive appropriate connection and short binding times, what will increase the workings driving advance,5） dissemination of injection bolting technologies and use of exible bolts,6） larger mechanisation of fastening technology in the rock mass of long rope and string bolts with high load-bearing capacity （more than 500 kN）.The presented above scenario of development of bolting technology mechanisation of workings constitutes the sustainable development variant.4. ConclusionsFrom investigations carried out in the framework of the presented project it results that in Polish hard coal mines the development of innovative technologies does not depend directly on the anticipated annual production quantity. It has been ascertained that more and more difcult natural as well as mining and technical conditions generate the growth of hazards for people employed there and conducting of mine operation. The assigned tendencies in the eld of extraction system development nd currently application in the mining practise. The analysis of the innovativeness level performed in the framework of assessment of technology condition allowed to indicate solutions, which will be used in the next years. The implementation of fundamental solutions will allow increasing the effectiveness of the mining production process. However, the necessity of growth of nancial outlays for investigati
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