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Reliability Analysis of Hydraulic Systems of LHD Machines Deployed at Kiruna Iron Ore Mine
Published in T. Aven, Reliability Achievement, 2018
Uday Kumar, Bengt Kiefsjö, Sven Granholm
The dominating machine for loading rock in underground mines in Sweden is LHD machine (see Figure 1). LHD machines are used to pick up ore or waste rock from the mining points and for dumping it into trucks or ore passes.
Benefits of studies on Lhd reliability and availability for mines
Published in Vladimír Strakoš, Vladimír Kebo, Radim Farana, Lubomír Smutný, Mine Planning and Equipment Selection 1997, 2020
J. Paraszczak, J. Vachon, L. Grammond
Load-haul-dump machines (LHD) are in widespread use in underground hard rock mines. They are used in development and production, particularly in bulk mining (sublevel/blasthole stoping, sublevel caving, etc.), playing an important role in a production chain. Kumar and Huang (1993) simulated mine production system for the conditions of Kiruna iron ore mine (Sweden) and identified LHD as its critical link. They have stated that performance characteristics of this machine have great influence on production volume and mine productivity. Failures of LHDs result not only in direct production losses, but they themselves may be quite costly. Accordingly to Forsman (1995) corrective maintenance represents 25% of total operation cost of an LHD. There is also one more aspect associated with LHD failures. As seen in real life machines often fail far away from underground garage and sometimes it is too difficult to tow them there. In such cases mechanics must be dispatched to the disabled machine and do repairs right at the spot where a failure happened. In such circumstances every corrective maintenance action takes much more time it would take in a well lit shop, with a good access to the machine and with all necessary tools and spare parts readily available. No doubt that in the terms of a working time lost (both in production and in maintenance) such repairs are even more expensive. Since not only in the mines “time is money” conclusions are easy to draw. No wonder then, that reliability and availability of LHDs is an important issue. This is witnessed by a growing number of studies done on these machines in the last few years (for example: Kumar, 1989, Kumar & Vagenas, 1993, Piispa, 1993, Paraszczak and Perreault, 1994, Runciman et al., 1995, Grammond, 1996). Most of these studies were aimed at the determination of Mean Time Between Failures (MTBF) of LHDs and identification of their critical subsystems with regards to failure frequency. In few cases an issue of LHD maintainability was also addressed. The question of Mean Time To Repair (MTTR) and maintenance man-hours (MMH) have been investigated by Kumar (1989) and Grammond (1996) respectively. Piispa (1993) analyzed LHD up time and down time and their time components. All this research has provided a valuable background for a future work in this field. In our opinion however, too little effort has been made in order to show clearly to mine operators what are the benefits of such studies for them. This is probably why some mining people remain a bit skeptical in this respect. Concerning the above we have decided to present and discuss some practical results and conclusions that may be drawn from reliability and maintainability studies. Discussion will be based on our own work done on LHD machines, but one can easily notice that the issues and conclusions presented here are more general.
Real-time multi-agent fleet management strategy for autonomous underground mines vehicles
Published in International Journal of Mining, Reclamation and Environment, 2023
M. Gamache, G. Basilico, J.-M. Frayret, D. Riopel
All load-haul-dump (LHD) agents are responsible for reaching a site, loading ore/waste from it, transporting the material to trucks placed near the site, and dumping it into a truck. They also inherits the behaviour of the vehicle agent class. However, it has specific attributes such as a transportable bulk capacity, expressed in tonnes. LHD agents, like equipment agents, are equipped with a list of destinations to be visited during the day, and have the exact same interaction mechanism with the carrier. They are also governed by the same behaviour presented for equipment agents, the only exception being the need for coordination with trucks. Indeed, after arriving at the site and waiting, if necessary, for the end of the operations still in progress, the LHD can perform the loading activity only if a truck is also there, ready to be loaded.
Context-driven mean residual life estimation of mining machinery
Published in International Journal of Mining, Reclamation and Environment, 2018
Behzad Ghodrati, Seyed Hadi Hoseinie, Uday Kumar
As a result of technological advancements, mechanised and complex mining equipment like Load Haul Dump (LHD) machines are now being used in mining. For the introduction of such sophisticated capital-intensive machines to be profitable, the highest possible levels of availability and reliability must be achieved during operation. Performance of an industrial facility (e.g. mining) obviously depends on the reliability of the equipment used in it. The concept of reliability, availability and maintainability (RAM) have assumed great significance in recent years, given the increasingly competitive environment and rising operating/production costs [1].
Performance analysis of electric and diesel equipment for battery replacement of tethered LHD vehicles in underground mining
Published in Mining Technology, 2020
Antonio Nieto, Richard S. Schatz, Cihan Dogruoz
Choosing the type of LHD vehicles is important in underground mining. LHD vehicles vary according to their capacities and capabilities. Energy consumption is entirely dependent on the power supply, size, and the type of LHD vehicle in the underground mine. They are used to haul waste rock and ore from the production face in underground mines to haulage trucks, crushing stations, and ore dumping points. According to Kumar et al. (1989), preventive maintenance of the engines of LHD machines could reduce maintenance costs.