Ganesh Manekar, Dipankar Shome and Mukund Chaudhari
MOIL Limited is operating 7 underground and 3 opencast mines in central India and producing annually more than 1.3 million tonnes of various grades of manganese ore. The underground mines are operating at shallow – 90 m at Munsar mine to moderate – 353 m at Balaghat mine below the surface with horizontal cut and fill (HCF) or its variant method of stoping with post filling by hydraulic sand stowing. The Munsar mine is being worked underground since 1903. The opencast mining is presently stopped. The ore body below the opencast quarry is geological continuity of the area excavated in past by opencast method of mining. The underground mining is done through the adit in three levels i.e. 270’L, 220’L, 170’L and by incline in western part of the property at 70’L. The horizontal drift development has been developed in the manganese ore body with sill drive of 5 m above the sill pillar in lower level at 70’L and barrier pillar of 5 m thickness is left for protection of upper level at 170’L. Valuable mineral has been locked in sill pillar and therefore rock mechanics investigations have been carried out. On the basis of study now the drift development has been carried out in footwall rock at 70’L, (-) 30’L and below levels and it has improved the minable manganese ore by about 20%. In this modified HCF stope design, an alternative fill material in place of sand, which has been developed in house by use of overburden (OB) material after treatment, has been used for hydraulic stowing. The experimental trials find out that the alternative fill material of OB is more compact and forms a non-expansion floor for the men and machines in the stope. This will certainly help in the introduction of mobile underground mining equipment for drilling in the stopes and mechanical mucking, transportation and loading of the ROM. The paper presents rock mechanics investigations and future use of alternative fill material of overburden material after heat treatment for better safety and productivity at Munsar Mine of MOIL.
Przemysław Bodziony, Michał Patyk and Zbigniew Kasztelewicz
Rational solution for mining equipment based on the use of haul trucks, excavators, wheel loaders and crunchers should result from thorough analysis of technical and economic issues – both cost-related and exploitational - which can have a crucial impact on the cost of minerals extraction. Moreover mining equipment should be selected with consideration for all vital parameters in specific exploitational conditions and even the exploiter’s preferences. This selection should consider hitherto disregarded criteria, such as mean availability and structure utilization of machinery systems with the aim to improve the same. Methodology presented in the paper illustrates practical application of MCDM and one particular method of this type – the Analytical Hierarchy Process (AHP) – for resolving the problem in specific exploitational conditions of mineral resource in surface mining AHP method covers a multi-criteria approach based on a compensation strategy to model preferences and assuming variant comparability. Taking into account the preferences of the evaluator, which determine the subjectivity of comparative evaluation, is the core of the multi-criteria approach, which treats such preferences Considering the above issues, the following paper is an attempt to develop new and universal criteria as well as a method of evaluation and selection of means of mining equipment for mineral resource surface mines.
During the exploitation of mineral raw materials, a cutting tool is an element that is directly in contact with the unmined stone being cut. The most commonly used cutting tools include conical picks. The increasing pressure to reduce mining costs causes an increasing demand for affordable and reliable ways to increase the reliability of mining machines. Abrasive wear is the most common process affecting the wear of shearer picks, hence a good and simple laboratory method for assessing rocks abrasivity is needed. The new method was developed in the aspect of selection of conical picks with appropriate protection of the pick working part, increasing its durability. The method involves the assessment of mass abrasive wear of a standard steel pin and rock sample, and the determination of the abrasivity index Wz of the tested rock, as the ratio of the mass loss of the steel pin to the mass loss of the rock sample. The article presents the procedure of conducting tests, construction of a laboratory test stand and the use of the developed method to assess the abrasivity of gangue rocks occurring in the currently cut tunnel excavations of Polish hard coal mines.
Accumulation of low-grade iron ore tailings (IOTs) generated during the processing of high-grade iron ore has become a great threat to environment. Although wide range of research works has carried out to recover the iron values from the IOTs, but the solid recovery value has limited to ca. 50% in Indian context. In order to attain a maximum iron recovery and to utilize these solid wastes for future needs, an attention has shed on the topics of hydrometallurgy and applied nanomaterial synthesis from IOTs. Iron containing nanoparticles (ICNs) have huge potential in environmental and energy related applications. A wide range of synthesis methods has developed to produce ICNs from the mine waste. It is evident from the recent research works that converting waste materials into value added products are gaining more attentions. Objective of this review is to analyse the green synthesis routes to prepare ICNs from mine waste, starting from the physio chemical identification of waste material followed by discussion on various methods of ICNs synthesis routes from mine waste. It includes selective leaching method. Finally, the use of ICNs for environmental application had discussed in brief
This paper presents simulation studies on the aerodynamics of vehicles moving in an organized column. The object of research is a column that consist of three vehicles of the same type (homogeneous column). In this research geometry of Ford Transit was used. As a part of the studies, the air drag forces acting on individual vehicles were calculated. The results are presented in dimensionless drag coefficient. The influence of the distance between cars on the generated force was also determined. In the first stage of the work, a numerical model was developed based on the Ahmed body reference structure. The calculations were carried out for 9 different velocities. The obtained results of the drag coefficient were compared with the work of other authors. The applied turbulence model and parameters of the boundary layer were used to create a numerical model of a moving column of vehicles. Mesh independence for numerical model of van was verified. The Finite Volume Method was implemented in the ANSYS Fluent program and used for the calculations. The use of supercomputers was necessary due to the large size of the grid.
Krzysztof Kołodziejczyk, Radosław Ptak and Jakub Korman
Currently, obtaining energy from renewable sources, as never before, it has become one of the most important areas, but at the same time challenges in human activities. This is the effect of many factors simultaneously, including because of the media trumpeted the greenhouse effect, the necessity of reducing CO2 emissions, shrinking natural resources, and thus the desire to protect their welfare including conservation (including natural resources) for future generations. The paper presents the results of preliminary numerical analyzes of work for vertical axis wind turbines equipped with air guides. The carried out analyzes indicate the potential possibility of using this type of construction in practice. The obtained power factor value is higher than in classic wind turbines with a vertical axis. The conducted analyzes also indicate the possibility of optimizing the proposed constructional solution in order to increase efficiency of obtaining energy from the wind.
Numerous underground coal mines were in operation in the Borsod coal basin in northeastern part of Hungary until the beginning of this century. The main area of utilization of the mined out coal beside power and heat generation was supplying households with fuel mostly for heating. In the beginning of the 1990ies the power plants in question were shut down for economic, environmental and technical reasons. Consequently all the mines were closed no later than 2004 and thousands of miners lost their jobs. A new perspective of coal mining can be enabled by other ways of utilization of coal, e.g. coal chemistry, etc. Safe and modern equipment and technology enabling high output, clean coal, furthermore high rate of yield are targeted. Opportunity of sustainable underground coal mining in the north-eastern part of Hungary is discussed in the paper. Analysis of the properties of coal deposits using three-dimensional (3D) modelling are used for considering opportunities of new mining operations. Models are being developed.
CM is a globally renowned machine, designed to work as a mass production technology for underground coal. Different major coal producers across the globe are using this technology for decades to produce underground coal efficiently. India is also one of the major players globally in the arena of coal production and adopted this cutting edge technology since last decade by implementing at. few of the selective underground coal mining projects. Performance of CM technology is influenced by the geo-mining condition, fleets of other ancillary units and reliability of subsystems while implementation of this system depends largely on the extent of reserve. These aspects generate a scope of large scale research and development in this field. Overall Equipment Effectiveness (OEE) is the parameter to benchmark the equipment performance globally. OEE is the product of equipment availability, performance and product quality. This mining machine based paper focuses on the Overall Equipment Effectiveness (OEE) of the complete CM based operation to identify the vulnerable systems, which helps to design proper preventive maintenance programme. The CM based system is divided into few subsystems, such as; electrical, cutter, gathering arrangement, traction, hydraulic, chassis, feeder breaker, shuttle car, CM conveyor and out-bye conveyor. The downtime data used for this analysis is collected from an underground coal mine situated in the central part of India, belongs to one leading coal producing company of the country. From analysis it was found that, electrical systems and conveyors are among most vulnerable systems and deserves more care during maintenance. On the basis of these results recommendations are made to redesign the Preventive Maintenance Programme, in order to avoid the lower availability as well as lower OEE.
Michał Stawowiak, Marcel Żołnierz and Zenon Rożenek
The article presents the method and results of experimental tests of the coefficient of friction between a steel rope and friction lining. The BECORIT K22 and BECORIT K25SB floor coverings were tested. The tests were carried out in accordance with the recommendations of the new German standard: DIN 21258 – Lubricants and impregnating agents for drive discs and transport ropes in mining – safety and testing requirements. The authors in this article emphasize that the Becorit K22 and K25SB linings are used for the wheels of propeller drums of mining machines. Characterized by high coefficients of friction (μ ≥ 0.25), also in cases of extreme weather conditions on the surface. The chemical properties of BECORIT linings ensure their resistance to swelling in the event of different oils and lubricants as well as mine waters. The material of which the claddings are made ensures very good machinability during rolling of rope grooves with the use of turning or milling tools. BECORIT K22 plastic cladding is particularly suitable for use in hoisting machines, where the rope base forms a large overlap angle on the wheel grooves (max 1°31'), which causes its lateral wear faster. BECORIT K22 material in this case provides a higher service life compared to other materials. Due to the way they are mounted on the wheel, they are made as 1-piece (monolith) or bipartite. In this article, moreover, the structure and principle of operation of the measuring station on which the tests were carried out are presented in great detail.
Aleksandra Wagner, Ahmad Gholami, Katharina Maletz and Ina K. Talmo
The studies included 2 water bodies in Cracow (Kraków), 6 water bodies in the commune of Zabierzów (Cracow County) and 4 in the commune of Niepołomice (Wieliczka County). The studies were carried out in June 2018 and May 2019. The ways on management of the water bodies were compared. Problems related to revitalization were identified. One of these problems is the preservation of biodiversity. In some cases revitalization reduces biodiversity. This can happen due to the liquidation or limitation of the reed bed zone. Such a situation was observed in the water bodied of Zelków and Karniowice (com. Zabierzów). Both have ornamental functions now. Removal of most of reed does not disturb mallards (Anas platyrhynchos), but makes it impossible to nest for other birds such as moorhen (Galinula chloropus). Moorhens were observed in two former fish ponds in Staniątki (com. Niepołomice) and in the pond of the Kaczeńcowa street. In one of them revitalization caused the diminishing of the water area, but did not change the character of the water body. Bird species were recorded at water bodies.