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  • 51.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Borrning av värmelager: teknik för produktionsborrning av långa grova hål för borrhålsvärmelagring i berg1985Report (Other academic)
  • 52.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Drill process monitoring in percussive drilling: a multivariate approach to data analysis1990Licentiate thesis, monograph (Other academic)
  • 53.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Drill process monitoring in percussive drilling for location of structural features, lithological boundaries and rock properties, and for drill productivity evaluation1997Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis deals with the application of percussive drill monitoring in the mining and underground construction industries. The technique has been used to provide information on different ground properties and conditions and for drill productivity evaluation. Five different test sites have been used: the OSCAR area in the Kiirunavaara magnetite mine in Kiruna, the Viscaria copper mine in Kiruna, the Zinkgruvan mine in south-central Sweden, the Glödberget tunneling site in Västerbotten county and the Hallandsåsen tunneling site in southern Sweden. A methodology has been suggested and tested for treatment of raw data in order to extract rock dependent parameter variations from variations generated by the drill system itself and other external influences. Prediction of rock hardness and fracturing can be done without initial calibration, providing a good foundation for interpretation by site personnel. The mining applications show that drill monitoring has a very high potential for ore boundary delineation and also for classification of existing rock types. In tunneling applications drill monitoring demonstrates a good capability of foreseeing rock conditions ahead of the tunnel face. Other benefits are the speed of the method, its practicality and the fact that it requires no additional equipment, time or access to the production front. The potential for detailed drill productivity evaluation by drill monitoring has been demonstrated. Detailed information of the time consumption for each activity in the drilling cycle can be presented as well as the distribution of the total production. With this information in hand an indication can be given as to how the overall drilling capacity can be increased. The impact on production of automation, new developments and organization can also be predicted with high accuracy.

  • 54.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Modern tools and equipment for tunnelling and drifting2009In: SRDM Safe & Rapid Development Mining 2009: Proceedings of the First International Seminar of Safe and Rapid Development Mining, Nedlands, WA: Australian Centre for Geomechanics, 2009Conference paper (Refereed)
    Abstract [en]

    Tunnelling is a key activity in infrastructure projects and in mine development and production. The speed of tunnelling has always been important, especially in underground constructions, where profit is often linked to how fast the job can be done. This is also valid for development in the mining industry. However, for the miner the situation is sometimes different, in that his ambition is to fulfil ore production targets with as small an input of resources as possible. This means that the main objective has been the utilisation of machinery and labour. In the mine development phase, on the other hand, a rapid access to the orebody is crucial, since it will yield a quicker pay back of the investment.Even if rapid development advance is a priority, it is important to recognise that modern tunnelling technique and equipment can provide additional benefits including: production control, improvement in tunnel and profile quality, characterisation of the surrounding rock mass, etc.During the past few years increased focus has been placed on communication technology improving the flow of information to and from the rig. Information on production, quality, maintenance, ground characterisation, etc., can be supplied by the rig if the technical framework is present. Logging functions have also been extended and can now provide detailed information on production, drill hole quality, the maintenance requirements and drill monitoring for geological and geotechnical characterisation of rock mass ahead of the face. Computerised drill plan design enables a drilling sequence to be designed by computer based on the tunnel design for each section. This technology is now in use and can assist with quality control such that the tunnel will be constructed according to the design with a minimum of over break. The risk of mistakes and faults is minimised and the rig navigation is the only weak point in the chain.This paper presents the state-of-the-art in equipment and tools for tunnel construction, and discusses the benefits available through better process quality control, better tunnel design control and improved knowledge of the surrounding rock mass and the rock mass ahead of the face.

  • 55.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    MWD-teknik som prospekteringsmetod vid bergborrning: state of the art1987Report (Other academic)
  • 56.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Probing ahead of the face with percussive drilling1996In: Tunnels and Tunnelling, ISSN 0041-414X, Vol. 28, no 1, p. 22-23Article in journal (Refereed)
    Abstract [en]

    Uncertainty regarding the nature of ground conditions can exist even after a well conducted site investigation. Fortunately, valuable information can be obtained by drilling horizontally from the face in the direction of the tunnel using microprocessor-based monitoring equipment. The equipment scans, measures, processes and store drill performance parameters. By establishing penetration rate, torque, trust, etc., an early evaluation of ground condition is possible. Probing ahead has been successful in several tunneling site investigations, among them was in Glodberget in Sweden

  • 57.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Rock characterisation using percussive drilling1998In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 35, no 6, p. 711-725Article in journal (Refereed)
    Abstract [en]

    Despite considerable advantages such as reliable hardware, no disturbance in production, fast analysis and presentation of results and very low operational cost, the use of percussive drill monitoring to retrieve geological and geomechanical information concerns the drilled rock has not become a standard investigation tool in the underground industry. One major obstacle is the analysis of data. The monitored "raw" data can be affected by a significant influence from the operator, who often adjusts the drill settings in order to achieve the best drilling result. Furthermore, the advanced control system on a modern drill rig adjusts drill parameters independently to avoid drilling problems and damage to the drill string and machine. In order to use percussive drill monitoring in industrial applications, the performed analysis must be able to handle variations among monitored drill parameters, but still separate rock dependent variation from other influences on the monitored drilling data. Once the external influences on the drilling data have been normalised only leaving the rock dependant variation, rock properties can be predicted using theoretical or heuristic relations, or calibrated with observed rock conditions using statistical analysis. The method of analysis suggested in this paper is based on a step-wise normalisation of raw drilling data, where hole length dependent variation initially is removed, followed by a normalisation of the thrust dependent variation, and finally, by removing the influence of penetration rate on torque pressure. The analysis shows that major classification errors can be made if raw data are used instead of normalised data. The technique is applied on modern drill monitoring data from three different drilling sites, in crystalline rock masses in Sweden. The drill data selected were obtained during normal drilling conditions, where no special steps had been taken to promote the analysis or the interpretation. Examples from each site show good potential to predict ore boundaries and fracturing based on normalised drill parameters from percussive drilling.

  • 58.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    RQD predictions based on drill performance parameters1996In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 11, no 3, p. 345-351Article in journal (Refereed)
    Abstract [en]

    In tunnelling and in other underground constructions, a detailed knowledge of the rock mass to be excavated is essential for reasons of safety, reinforcement need and cost and time schedule for the excavation. This paper presents a new approach to how drill performance parameters can be used for rock quality designation (RQD) prediction. Predictions are based not only on traditional parameters as penetration rate and torque, but also on the variability of each parameter which shows a close correlation to fracturing. Since predictions are based on drill monitoring data with high resolution, the prediction can provide detailed information of the structural geometry of the rock mass ahead of the operation. Examples are given from a railway tunnel in northern Sweden built in granitic bed-rock

  • 59.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Elsrud, Rolf
    Atlas Copco Rock Drills AB.
    Rai, Piyush
    Banaras Hindu University, Varanasi.
    Drill monitoring for ground characterization in tunnelling operations2011Conference paper (Refereed)
    Abstract [en]

    Tunnelling is a key activity in infrastructure projects, mine development and production. The speed of tunnelling has always been important, especially in underground constructions where the profit is often linked to “how fast the job can be done”. Even if the speed always remains in focus, it is important to realise that modern technique and equipment for tunnelling can offer additional options such as characterisation of the surrounding rock masses and rock ahead of the face. This paper presents the State of the Art in drill monitoring of tunnelling rigs and discusses the technology and analysis used for drill parameters and presents some interesting results of rock mass characterization through international case studies.

  • 60.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Gustafson, Anna
    Kumar, Uday
    Performance of automated LHD machines: a review2009Conference paper (Refereed)
    Abstract [en]

    The importance of LHD (Load Haul Dump) machines in most mine operating systems is evident today. The cost of operation and maintenance is one of the challenges, while high availability and reliability are others. The latter will be increasingly important when automatic LHD machines are used more frequently. A key factor for automated LHD system is the planned maintenance process, as all corrective maintenance or accidental break-downs rapidly deteriorate the production system where operators are not present and maintenance personnel not available on short notice. A challenge for manufacturers is to improve the engineering design of their machine and related components (hydraulic systems etc) so as to make them more reliable and also making the machine easy to maintain. The demands on the overall communication systems and new and higher competence and skills needs on operation and maintenance personnel are a few factors that make many mines reluctant to the higher investments in Automated LHD systems. This paper reports some experiences with automated LHD machines in Scandinavia and the rest of the world and examines some of the issues that make the application of automatic LHD machines restricted by large operators and prohibitive by small mines. It also deals with the maintenance aspects of automated LHD systems and provides some initial considerations from a major Scandinavian research project in the field.

  • 61.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Holme, Kirsten
    Drill monitoring for geological mine planning in the Viscaria copper mine, Sweden1997In: CIM bulletin, ISSN 0317-0926, E-ISSN 1718-4169, Vol. 90, no 1013, p. 83-89Article in journal (Other academic)
    Abstract [en]

    When mining high grade, narrow ore bodies, the mining method often implies a very detailed knowledge of the ore contacts to avoid unacceptable ore loss and waste rock dilution. During the past decade, the use of microprocessor based drill monitoring equipment has become an accepted technique, even for percussive drilling. On the basis of the recorded drill performance, such as penetration rate, torque pressure, thrust etc., a fast evaluation of the lithological sequence of the ore zone can be made. In order to evaluate the potential of percussive drill monitoring to provide detailed information of the geometry of the ore body, the technique was tested in the Viscaria copper mine in Sweden during 1996. To provide understandable information to the mine geologist, great emphasis was placed on the separation between the drilling response generated by variations in rock conditions from variations caused by the operator and the drill system. Due to the complicated geology in Viscaria, the drilling response presented to the geologists was separated in two independent signals, one representing the hardness of the rock and one representing the inhomogeneity (fracturing) of the rock. With those signals a good separation between different rock types in the ore horizon was achieved. The experience from the Viscaria copper mine is that drill monitoring not only can be used to locate contacts between rock types, but also to characterize rock conditions and, often, also to specify the exact rock type present. Because it is possible to get the drill monitoring information very quickly it is a valuable complement to diamond drilling for increasing the specific knowledge of the geology and the ore body.

  • 62.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Kristoffersson, Thomas
    Rock mass characterisation using drill and crushability monitoring: A case study2011In: International Journal of COMADEM, ISSN 1363-7681, Vol. 14, no 2, p. 44-52Article in journal (Refereed)
  • 63. Schunnesson, Håkan
    et al.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Automation and mechanisation in Scandinavian mining industry: trends in technologies and management2006In: Journal of Mines, Metals and Fuels, ISSN 0022-2755, Vol. 54, no 12, p. 280-286Article in journal (Refereed)
    Abstract [en]

    With several mining companies looking for ways to reduce costs and increase productivity, and be competitive in international market, the automation of mining operation has been the focal point of many mining companies all over the world. Because of the increasing interest in automation, many equipment manufacturers are either offering or gearing up to offer a wider range of equipment line to meet the customer requirements. The paper reviews some of the recent developments in automation and mechanization of metal mining operations with a special reference to Scandinavian mining companies.

  • 64.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Automation of mine production system: trends in technology and ICT application2010In: Journal of Mines, Metals and Fuels, ISSN 0022-2755, Vol. 58, no 3-4, p. 54-58Article in journal (Refereed)
    Abstract [en]

    With increasing scales of automation, and integration of various mining equipment and unit operations to replace humans with machines at all levels in mining operation, the issue of effective operation and maintenance have become very critical for the economic viability and competitiveness of mining business. Today systems are expected to perform autonomously round the clock and the importance of availability, reliability, flexibility and controllability are of prime importance. A closer look at such systems today shows that data collection, analysis and information flow are essential prerequisites for the competitiveness of the industry. If these prerequisites are not optimal, it is almost impossible to make correct decisions under dynamic conditions. The paper presents some example from the industry and discusses possible implementation in the mining sector to meet the challenges involved in semiautonomous or autonomous operations.

  • 65.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Lundholm, Ingvar
    Luleå tekniska universitet.
    EMX System AB, MWD-teknik för hammarborrning: fältförsök i Oscarområdet, Kiirunavaara1989Report (Other academic)
  • 66.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Mozaffari, Shahram
    Luleå tekniska universitet.
    Production control and optimization in open pit mining using a drill monitoring system and an image analysis system: a case study from Aitik copper mine in Sweden2009In: Journal of Mines, Metals and Fuels, ISSN 0022-2755, Vol. 57, no 9, p. 244-251Article in journal (Refereed)
    Abstract [en]

    Optimization of the mining process can have a significant impact on the production of the mine. Monitoring systems are important tools to generate information for different decision makers in the mine. In opencast mining, blasting plays the main role in rock fragmentation and the productivity of the mine. Therefore, data and information for optimizing blasting and fragmentation are essential. Drill monitoring and image analysis are two systems that are available today for the mining industry. This case study demonstrates the power of integration of these two systems for production control, providing information required for the optimization of blasting. The data in this study is extracted from the Aquila drill management system and the Split-online image analysis system, which are installed in Aitik mine, the largest open pit copper mine of Europe, located in the north of Sweden

  • 67.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Mwagalanyi, Hannington
    Luleå University of Technology.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Shovel teeth monitoring and maintenance in open-pit mines2011In: International Journal of COMADEM, ISSN 1363-7681, Vol. 14, no 1, p. 3-10Article in journal (Refereed)
  • 68.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nordlund, ErlingLuleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    MassMin 2008: Proceedings of the 5th International Conference and Exhibition on Mass Mining, Luleå, Sweden 9-11 June 20082008Collection (editor) (Other academic)
  • 69.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Palo, Mikael
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Arasteh Khouy, Iman
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Från mätdata till underhållsbeslut: hjulslitage och spårkrafter2011Report (Other academic)
    Abstract [sv]

    Denna rapport beskriver resultaten från projektet ”Från mätdata till underhållsbeslut” där avdelningen för drift och underhållsteknik/JVTC vid Luleå tekniska universitet på uppdrag av MTAB följt hjulslitaget på två malmvagnar under ett års tid. Under perioden har vagnarnas rälkrafter registrerats vid JVTC:s forskningsstation i Sävast.

  • 70.
    Schunnesson, Håkan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Sturk, Robert
    Luleå tekniska universitet.
    Drill monitoring at the Hallandsås project in Sweden1997Report (Other academic)
  • 71.
    Shekhar, Gurmeet
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Gustafson, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Boeg-Jensen, Patricia
    Luossave-Kiirunavaara AB, Kiruna, Sweden.
    Malmgren, Lars
    Luossave-Kiirunavaara AB, Kiruna, Sweden.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Draw control strategies in sublevel caving mines: A baseline mapping of LKAB's Malmberget and Kiirunavaara mines2018In: The Southern African Journal of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 1543-9518, Vol. 118, no 7, p. 723-733Article in journal (Refereed)
    Abstract [en]

    The Malmberget and Kiirunavaara mines are the two largest underground iron ore operations in the world. Luossavaara-Kiirunavaara AB (LKAB) uses sublevel caving (SLC) to operate the mines while maintaining a high level of productivity and safety. The paper enumerates the loading criteria and loading constraints at the mines and outlines details of mine design, layout, and geology affecting the draw control. A study of the various draw control strategies used in sublevel caving operations globally has also been done to establish the present state-of-the-art. An analysis of the draw control and loading operations at the Malmberget and Kiirunavaara mines is summarized using information collected through interviews, internal documents, meetings, and manuals. An optimized draw control strategy is vital for improving ore recovery and reducing dilution in SLC. Based on the literature review and baseline mapping study, a set of guidelines for designing a new draw control strategy is presented. The draw control strategy at Malmberget and Kiirunavaara is guided by a bucket-weightbased drawpoint monitoring system that is part of the overall framework. Both mines employ a draw control strategy that considers the production requirements and mining constraints while regulating the loading process through an empirical method based on bucket weights and grades. However, in the present scenario of fluctuating metal prices and increasing operational costs a new draw control strategy is needed which is probabilistic in nature and can handle the uncertainties associated with caving operations.

  • 72.
    Shekhar, Gurmeet
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Gustafson, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Boeg-Jensen, Patricia
    LKAB.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Draw control optimization along the production drift in sublevel caving mines2016In: Seventh International Conference & Exhibition on Mass Mining : (MassMin 2016), Sydney: The Australian Institute of Mining and Metallurgy , 2016, p. 241-249Conference paper (Refereed)
    Abstract [en]

    The amount of material extracted from each blasted ring in sublevel caving mines is vital when deciding the overall mine production target. The orientation of the production drifts is normally perpendicular to the strike of the orebody, and rings are blasted from the hanging wall side to the footwall side in a retreating manner. For an inclined orebody, a given ring will contain different amounts of material based on its relative position along the production drift. This layout creates a distinctive problem with respect to the extraction ratio optimisation along the axis of the production drift. This paper describes the current drawpoint control strategy practiced at LKAB and presents the variation of drawpoint performance parameters along the production drifts. It uses automatically generated data from a bucket weighing system that measures tonnage drawn per bucket, and it classifies the blasted rings into four zones based on their relative position along the production drift. It considers the loading procedure for blasted rings at Kiirunavaara mine and analyses the variations in drawpoint performance along the production drift. The paper finds that although the current draw control strategy is sensitive to ring position along the drift, it could be modified to optimise the final extraction ratio.

  • 73.
    Shekhar, Gurmeet
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Gustafson, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Hersinger, Anders
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Jonsson, Kristina
    Luossavaara-Kiirunavaara AB, Kiruna, Sweden.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Development of a model for economic control of loading in sublevel caving mines2019In: Mining Technology:Transactions of the Institutions of Mining and Metallurgy, ISSN 2572-6668, Vol. 128, no 2, p. 118-128Article in journal (Refereed)
    Abstract [en]

    This paper presents an economic model for optimizing loading at the draw point in sublevel caving (SLC) operations. The input data consist of estimated bucket grades based on bucket weights from Load Haul Dump machines. This information, together with average operational mining costs, was used to create an economic model providing a real-time economic assessment of the draw point performance for SLC rings. The results demonstrate the importance of continuous draw point monitoring to optimize SLC operations. The proposed model provides an economic assessment of operating draw points and will help mine personnel to decide when to stop loading from a blasted ring. It can also help mine management understand the complexity of material flow in SLC operations. Finally, it provides operational flexibility for the mine to optimize loading at the draw point by increasing ore recovery while maintaining operational control of draw point performance.

  • 74.
    Shekhar, Gurmeet
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Gustafson, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Draw Control Strategy and Resource Efficiency in Sublevel Caving: State-Of-the-Art2016Report (Other academic)
    Abstract [en]

    Sublevel caving is an underground mass mining method used for extracting different types of ores from the earth crust. Mines using sublevel caving (SLC) as the primary mining method are generally highly mechanized with standardized and independent unit operations. Mine development for caving operations are similar to other underground mining methods, however, the scale of production drilling and blasting performed in caving operations including SLC are larger than many other underground mining methods (such as room and pillar or cut and fill). Loading of the material from the production face in sublevel caving is facilitated by the flow of material under gravity into the production face. A large amount of material is loaded from a limited opening termed as the draw point. Different unit operations (drilling, blasting, loading and transportation) are performed in isolation with each other which leads to standardized procedures and safe operation. The mine design allows for operational agility with respect to ore geometry and inclination. These features give SLC an advantage over other mining methods. However, SLC demands a caving conducive geology along with a large ore footprint. The mining method also registers higher percentage of dilution and ore loss compared to non-caving mining methods. Material flow in SLC has been studied extensively in the past five decades and different methods have been used to simulate material flow in caving operations. Physical models of different scales has been designed for simulating material flow by using sand, gravel or rocks and studying the movement of material inside the model. Initial physical models showed an ellipsoidal zone above the draw point from which material flowed into the draw point. However, subsequent modelling results disagreed with this notion of material flow. Numerical modelling techniques have also been applied to simulate material flow. The models were calibrated against mine or mill production data for optimization. Currently, marker trials are being used to understand material flow in SLC. Markers (numbered steel rods, RFID enabled markers) are installed in boreholes drilled inside the burden of a production ring and based on the recovery sequence of markers, material flow is predicted. Results from physical models, numerical models and marker trials along with mine experience have been used in the past to design draw control strategy for SLC operation. Initial draw control techniques were based on the assumption of uniform flow of material. But with the advancement in modelling techniques, draw control strategies have also changed. Ore flow simulation techniques developed to simulate material flow are being applied to predict the ore grade at draw point and hence help in draw control during the loading process. Recent draw control strategies in some mines have evolved to include production data and metal prices to optimize the loading process in SLC. Monitoring of the ore grade at the draw point is crucial in controlling dilution and increasing ore recovery. Present draw point monitoring technique predicts ore grade by exploiting the differences between ore and waste. The difference between ore and waste can be detected through visual observations, assay sampling or weight measurements. Draw point monitoring gives data for both regulation and calibration of draw control strategies, and provides important information regarding dilution and ore recovery during the loading process. Understanding material flow is vital for improving different aspects of SLC operation but draw control for SLC is an operational activity which regulates the loading process for a given mine design and material flow conditions. Therefore, an effective draw control requires a constant monitoring system and a constant calibration of the loading criteria’s through draw point monitoring for reducing dilution and improving ore recovery.

  • 75.
    Shekhar, Gurmeet
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Gustafson, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Loading Procedure and Draw Control in LKAB’s Sublevel Caving Mines: Baseline Mapping Report2017Report (Other academic)
    Abstract [en]

    Sublevel caving (SLC) is an underground mass mining method used to extract iron ore from the Kiirunavaara and Malmberget mines. Although both mines use SLC as the mining method, their implementation varies in terms of mine design, ring design and draw control strategy. The Kiirunavaara mine has a continuous and massive ore deposit which allows a standard mine design layout, while the Malmberget mine has scattered ore bodies with varying mine design parameters. The two mines also employ different opening techniques for production drifts.

    Luossavaara-Kiirunavaara AB (LKAB) uses different information systems to run these highly mechanized mines. The information generated by the various systems is transferred between the different unit operations and is used to optimize the mining process. The mines use GIRON to create, store and display different information related to the mining operation. Information on all unit operations is stored in a number of databases inside GIRON. The two loading related information systems which support the loading operation are the Wireless Loader Information System (WOLIS) and the Loadrite system. The Loadrite system measures the bucket weights being loaded by the Load Haul Dump (LHD) machines at the draw point. This information, along with information on planned ring tonnage etc., is displayed to the LHD operator inside the LHD machine using WOLIS. WOLIS provides online data on the ring performance such as grades, tonnage extracted etc. to the LHD operators and the production team.

    In SLC, the different aspects of loading at the draw point include loading procedures, loading issues, loading criteria and loading constraints. Loading procedures include the practices and precautions taken during loading at the draw point. Loading issues include events observed at both mines, such as brow failure, ring freeze, hang-ups etc. Although most loading issues are handled in a similar manner, hang-up handling techniques are different at the Kiirunavaara and Malmberget mines. Loading criteria and constraints along with the nature of material flow collectively provide a complete understanding of the draw control strategy. Loading criteria comprise a set of rules or guidelines for loading and closing a draw point. LKAB uses WOLIS to enforce the loading criteria for its SLC operations. Loading constraints include production constraints, grade control and mining constraints which must be followed for a safe and sustainable mining operation.

    A baseline analysis of the draw control and loading operations at the Kiirunavaara and Malmberget mines is summarized in this report using information collected through internal documents, meetings, e-mails and manuals.  

  • 76.
    Skawina, Bartlomiej
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Greberg, Jenny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Salama, Abubakary
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Mechanical excavation and drilling and blasting: a comparison using discrete event simulation2014In: Mine Planning and Equipment Selection: Proceedings of the 22nd MPES Conference, Dresden, Germany, 14th – 19th October 2013 / [ed] Carsten Drebenstedt; Raj Singhal, Springer-Verlag GmbH , 2014, Vol. 1, p. 367-378Conference paper (Refereed)
    Abstract [en]

    Mine development is often a bottleneck in mining operations and is strongly influenced by the choice of excavation method. In this paper, the two well-recognized methods, conventional drill and blast and mechanical excavation, are compared and discussed. The former method is the continuation of a long tradition in mining, while the latter method started to be used in 1960s, when mechanical excavators such as roadheaders, continuous miners or tunnel boring machines were developed. The rate at which the tunnel advances is one of the most important factors for mine development. By evaluating and selecting the right technique, the speed and effectiveness of the development could be improved. This paper aims to estimate and compare the advancement rate between the mechanical excavator and drill and blast method using simulation with AutoMod. This study has been done for one of Boliden Mineral AB’s mines in Sweden. For the drill and blast method, the study shows increased performance for two simultaneously drilled tunnels when compared with a single one. Furthermore, the simulation runs have estimated the total tunnel development times for the specified development lengths. The study is concluded by sketching an interesting picture of mine development using the mechanical excavator.

  • 77.
    Skawina, Bartlomiej
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Salama, Abubakary
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Greberg, Jenny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Production rate comparison using different Load-Haul-Dump fleet configurations: Case study from Kiirunavaara Mine2015Conference paper (Refereed)
  • 78.
    Song, Zhen
    et al.
    Department of Civil and Environmental Engineering, School of Engineering, Aalto.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Rinne, Mikael
    Department of Civil and Environmental Engineering, School of Engineering, Aalto.
    Sturgul, John
    School of Civil, Environmental and Mining Engineering, University of Adelaide.
    An Approach to Realizing Process Control for Underground Mining Operations of Mobile Machines2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 6, article id e0129572Article in journal (Refereed)
    Abstract [en]

    The excavation and production in underground mines are complicated processes which consist of many different operations. The process of underground mining is considerably constrained by the geometry and geology of the mine. The various mining operations are normally performed in series at each working face. The delay of a single operation will lead to a domino effect, thus delay the starting time for the next process and the completion time of the entire process. This paper presents a new approach to the process control for underground mining operations, e.g. drilling, bolting, mucking. This approach can estimate the working time and its probability for each operation more efficiently and objectively by improving the existing PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method). If the delay of the critical operation (which is on a critical path) inevitably affects the productivity of mined ore, the approach can rapidly assign mucking machines new jobs to increase this amount at a maximum level by using a new mucking algorithm under external constraints.

  • 79.
    Song, Zhen
    et al.
    Department of Civil and Environmental Engineering, School of Engineering, Aalto.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Rinne, Mikael
    Department of Civil and Environmental Engineering, School of Engineering, Aalto.
    Sturgul, John
    School of Civil, Environmental and Mining Engineering, University of Adelaide.
    Intelligent Scheduling for Underground Mobile Mining Equipment2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 6, article id e0131003Article in journal (Refereed)
    Abstract [en]

    Many studies have been carried out and many commercial software applications have been developed to improve the performances of surface mining operations, especially for the loader-trucks cycle of surface mining. However, there have been quite few studies aiming to improve the mining process of underground mines. In underground mines, mobile mining equipment is mostly scheduled instinctively, without theoretical support for these decisions. Furthermore, in case of unexpected events, it is hard for miners to rapidly find solutions to reschedule and to adapt the changes. This investigation first introduces the motivation, the technical background, and then the objective of the study. A decision support instrument (i.e. schedule optimizer for mobile mining equipment) is proposed and described to address this issue. The method and related algorithms which are used in this instrument are presented and discussed. The proposed method was tested by using a real case of Kittilä mine located in Finland. The result suggests that the proposed method can considerably improve the working efficiency and reduce the working time of the underground mine

  • 80.
    van Eldert, Jeroen
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Ittner, Henrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Johansson, Daniel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Evaluation of Alternative Techniques for Excavation Damage Characterization2016In: ITA-AITES World Tunnel Congress 2016, WTC 2016 / [ed] Society for Mining, Metallurgy & Exploration (SME), United States of America, 2016, Vol. 2, p. 1168-1177Conference paper (Refereed)
    Abstract [en]

    Numerous aspects of underground construction, from structural stability to construction costs, depended on the tunnel quality, including blast damage and the Excavation Damage Zone. Accurately quantifying the extent and severity of damaged rock is a problem. Recent technical developments in the field of Measurement While Drilling (MWD), including software for on-board logging and on-site analysis, have shown potential for rock-mass characterization. Ground Penetrating Radar (GPR) and P-wave velocity measurement have also improved and show similar potential. This paper explores the use of MWD, GPR and P-wave velocity measurements and uses them in techniques for excavation damage characterization and prediction. The paper is based on data collected from a small underground wastecollection site in central Stockholm, Sweden. The data is correlated against rock-mass characteristics and their responses are evaluated. Results indicate potential for excavation damage characterization for all tested techniques, which could minimize blasting damage and improve the over-all tunnel quality.

  • 81.
    van Eldert, Jeroen
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Johansson, Daniel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Saiang, David
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Application of Measurement While Drilling Technology to Predict Rock Mass Quality and Rock Support for Tunnelling2019In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453XArticle in journal (Refereed)
    Abstract [en]

    A tunnelling project is normally initiated with a site investigation to determine the in situ rock mass conditions and to generate the basis for the tunnel design and rock support. However, since site investigations often are based on limited information (surface mapping, geophysical profiles, few bore holes, etc.), the estimation of the rock mass conditions may contain inaccuracies, resulting in underestimating the required rock support. The study hypothesised that these inaccuracies could be reduced using Measurement While Drilling (MWD) technology to assist in the decision-making process. A case study of two tunnels in the Stockholm bypass found the rock mass quality was severely overestimated by the site investigation; more than 45% of the investigated sections had a lower rock mass quality than expected. MWD data were recorded in 25 m grout holes and 6 m blast holes. The MWD data were normalised so that the long grout holes with larger hole diameters and the shorter blast holes with smaller hole diameters gave similar results. With normalised MWD data, it was possible to mimic the tunnel contour mapping; results showed good correlation with mapped Q-value and installed rock support. MWD technology can improve the accuracy of forecasting the rock mass ahead of the face. It can bridge the information gap between the early, somewhat uncertain geotechnical site investigation and the geological mapping done after excavation to optimise rock support.

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