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  • 1.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Dumping oversize rock fragments in orepasses: the impact on the production cycle of a sublevel caving operation2023Ingår i: Mining Technology, ISSN 2572-6668, Vol. 132, nr 3, s. 215-224Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Oversize rock fragments are highly undesired in a sublevel caving (SLC) operation as they affectthe production cycle, equipment, and infrastructure. In this study, afield test was carried out inMalmberget mine to analyse the impact of oversize fragments on the production cycle and thecosts of different procedures for handling such fragments. The tests involved monitoring ofdumping oversize fragments in two orepasses, one with a grizzly and the other one withouta grizzly, using cameras. The cycle times of load-haul-dump (LHD) machines weredetermined for both orepasses. The results indicate that the grizzly increased the availabilityand productivity of the orepass despite increasing the cycle time of the LHD machines.Moreover, installation of a boulder breaker system along with the grizzly can furtherincrease the productivity and the cost of such a system will be paid offin a shorter time interms of enhanced productivity.

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  • 2.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Modelling the relationship between oversize fragments and nature of rock mass for a sublevel caving operation2023Ingår i: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 169, artikel-id 105433Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rock fragmentation is vital in a sublevel caving operation. The oversize fragments are the most undesiredfragmentation category because of their challenges; as such, they require special attention. This study carried outa field test in one of the LKAB’s iron ore mines in northern Sweden to analyse the occurrence of oversizefragments. The analysis involved correlation and regression tests and was performed for different types of rockmasses. The results showed that an increase in the percentage of solid rock mass caused an increase in thepercentage of oversize fragments. The other rock types, including slightly fractured, highly fractured, and rockmass with minor and major cavities, tended to have a reduced percentage of oversize fragments. The resultsindicate that oversize fragments can be predicted using linear regression or partial least square regression modelswith R2 values of 0.78 and 0.73, respectively. 

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  • 3.
    Tariq, Muhammad
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Training of load haul dump (LHD) machine operators: a case study at LKAB’s Kiirunavaara mine2023Ingår i: Mining Technology, ISSN 2572-6668, Vol. 132, nr 4, s. 237-252Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mining is a high-risk industry, so efficiency and safety are key priorities. Technological advancements, such as digitisation, digitalisation, and automation have made mines safer. These developments have also highlighted the need for operators with updated skills and improved education programs. This study analysed the training of semi-autonomous and manual Load Haul Dump (LHD) operators’ at LKAB’s Kiirunavaara mine, focusing on operators’ training, perspective and integration of more recent tool such as simulator training. The survey questionnaire was sent to all 120 LHD operators. 86 answers were received, giving response rate of 70%. Results showed that operators generally were satisfied with how the training was structured, organised, and delivered. However, they wanted to add more topics, including practical loading, spending time with departments of other sub-processes, etc. In addition, 36% of the operators, including 20% of those operating semi-autonomous LHDs, and 80% of those operating manual LHDs, found simulator training difficult.

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  • 4.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Challenges with Density-Based Grade Estimation at LKAB’s Underground Iron Ore Mines2022Ingår i: Mining, Metallurgy & Exploration, ISSN 2524-3462, Vol. 39, nr 6, s. 2301-2310Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Sublevel caving operation relies on the estimation of ore grade at drawpoints, as the mine management uses grade to decide whether the material at a certain ring should be loaded or abandoned. Grade is estimated in various ways, including visual estimation, density-based calculation, and sampling and assay methods. The grade estimation at the world’s two largest underground iron ore mines owned by LKAB in northern Sweden is based on the density difference between ore and waste. The calculations assume a constant swell factor, a theoretical fill of 100%, and a linear relationship between bucket weight and material grade. This study evaluated these assumptions in detail based on the loading data for 12,237 buckets and concluded that the method has some shortcomings which render the assumptions invalid. Further research is required to deal with these shortcomings to improve estimation of the material grade.

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  • 5.
    Hoeft, Madeleine
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Kronsell, Susanna
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Manzoor, Sohail
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Johansson, Fredrik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering. KTH.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    von Haslingen, Tobias
    ConcretePrint.
    Eriksson, Kent
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Real Estate Business and Financial Systems.
    Construction Automation and Robotics in Infrastructure2022Rapport (Övrigt vetenskapligt)
    Abstract [en]

    In Sweden, as in many other countries, the construction andinfrastructure sector are of large and growing importance for the economyand society. For instance, the construction industry’s turnover equals 11% ofthe Swedish gross domestic product (GDP) (Byggföretagen 2021), and theSwedish Transport Administration plans to invest SEK 799 billion during theperiod 2022-2033 (Regeringen 2021). At the same time, the cost ofinfrastructure projects has increased more than the consumer price index(CPI) (Trafikverket (2021)), partly due to a poorer development of theproductivity compared to other industries. An improved productivity andefficiency in the transport infrastructure and construction industry istherefore necessary. One way to increase productivity, improve theoccupational health and safety, and sustainability is through automation anddigitalization of the construction industry.The aim of the present report has been to identify ongoing initiatives andexisting research trends in construction automation with a focus on civilengineering, both nationally and internationally; and to identify potentialsand challenges that exist for the development of construction automation.Furthermore, the prerequisites for the implementation of automation in theconstruction industry have been studied. The research questions were studiedthrough a literature study and two thematic days on the subject.The results from the literature study shows that a clear increasing trendexists, both nationally and internationally, in automation, digitization androbotisation in the construction industry. The same trend can also be seen incivil engineering for roads, bridges, tunnels, as well as in the mining industry.With the mining industry as a role model, construction companies,universities, suppliers and clients together with small and medium-sizedenterprises (SMEs) should come together to develop a common vision and astrategic roadmap to enforce automation and digitization of the constructionindustry. A development of both technical, organizational and financialstructures is required, where an attractive business ecosystem can bedeveloped, enabling the upscaling of construction automation.Interdisciplinary collaborations, test-beds at an early stage, competencedevelopment, new financing infrastructure and a common vision are crucialto create conditions for construction automation.

  • 6.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Danielsson, M.
    Ramböll, Sweden.
    Söderström, E.
    AFRY, Sweden.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Fredriksson, H.
    AFRY, Sweden.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Predicting rock fragmentation based on drill monitoring: A case study from Malmberget mine, Sweden2022Ingår i: Journal of the Southern African Institute of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 2411-9717, Vol. 122, nr 3, s. 155-165Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fragmentation analysis is an essential part of the optimization process in any mining operation. The costs of loading, hauling, and crushing the rock are strongly influenced by the size distribution of the blasted rock. Several direct and indirect methods are used to analyse or predict fragmentation, but none is entirely applicable to fragmentation assessment in sublevel caving mines, mainly because of the limitations imposed by the underground environment and the lack of all the required data to adequately describe the rock mass. Over the past few years, measurement while drilling (MWD) data has emerged as a potential tool to provide more information about the in-situ rock mass. This research investigated if MWD can be used to predict rock fragmentation in sublevel caving. The MWD data obtained from a sublevel caving mine in northern Sweden were used to find the relationship between rock fragmentation and the nature of the rock mass. The loading operation of the mine was filmed for more than 12 months to capture images of loaded load-haul-dump (LHD) buckets. The blasted material in those buckets was classified into four categories based on the median particle size (X50). The results showed a strongercorrelation for fine and medium fragmented material with rock type (MWD data) than coarser material. The paper presents a model for prediction of fragmentation, which concludes that it is possible to use MWD data for fragmentation predict ion.

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  • 7.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Tariq, Muhammad
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Wettainen, T.
    LKAB, Sweden.
    Rock fragmentation measurements in sublevel caving: Field tests at LKAB’s Malmberget mine2022Ingår i: Caving 2022: Fifth International Conference on Block and Sublevel Caving Volume One / [ed] Y. Potvin, Australian Centre for Geomechanics , 2022, s. 381-392Konferensbidrag (Refereegranskat)
    Abstract [en]

    Ground vibrations from blasting are one of the main challenges faced by mines located near populated areas. To confront this challenge, Luossavaara-Kiirunavaara Aktiebolag’s Malmberget underground iron ore mine in Sweden tested a change in blast design. Specifically, it tested production holes with smaller diameter to decrease the explosive detonated per delay and thereby lower the ground vibrations. However, smaller holes normally increase hole deviation and may also influence the chargeability of the holes, both of which have a negative effect on fragmentation. Therefore, a detailed evaluation was required before a final decision could be made. To evaluate the fragmentation, field tests were carried out in two drifts of an ore body in the mine. Cameras were mounted in both drifts to record the fragmentation in every loaded bucket. The recording was configured to start by a motion detection parameter; consequently, every movement underneath the cameras was captured. The recording process continued for over a year and resulted in more than 15,000 videos. To analyse such an enormous data for fragmentation, an internally developed quick rating system (QRS) was used to evaluate a total of 7,258 loaded buckets. Blasted rock in the load–haul–dump buckets was classified as fine, medium, coarse, or oversize based on the median fragment size (X50). This paper explains the experimental setup of the test and the analysis procedures. The test results showed that smaller diameter boreholes tend to reduce the median fragment size slightly, and therefore favour the reduction of borehole diameter to deal with the ground vibration problem. The influence of borehole deviation and chargeability was not specifically investigated in this test and need further research to better understand subsequent fragmentation variations.

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  • 8.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Rock fragmentation variations with increasing extraction ratio in sublevel caving: a case study2022Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 36, nr 3, s. 159-173Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Variations in rock fragmentation are very likely to occur in a sublevel-caving operation. This study conducted a comprehensive test in an iron ore mine to monitor rock fragmentation. The results show a clear trend in fragmentation variations from start to end of production from a ring. These variations suggest an increase in coarse and oversized fragments with increasing material extraction from the rings that can be linked to increased overburden and drill hole deviations in the upper part of the rings. These problems can be addressed by shortening the drill hole length or directional drilling but need further investigations.

  • 9.
    Castaño Arranz, Miguel
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Chalabi, Hussan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    A generic framework for data quality analytics2020Ingår i: International Journal of COMADEM, ISSN 1363-7681, Vol. 23, nr 1, s. 31-38Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The challenge of generalizing Data Quality assessment is hindered by the fact that Data Quality requisites depend on the purpose for which the data will be used and on the subjectivity of the data consumer. The approach proposed in this paper to address this challenge is to employ a semi-automated user-guided Data Quality assessment. This paper introduces a generic framework for data quality analytics which is mainly composed by a set of software units to perform semi-automated Data Quality analytics and a set of Graphical User Interfaces to enable the user to guide the Data Quality assessment. The framework has been implemented and can be customized according to the needs of the purpose and of the consumer. The framework has been instantiated in a case study on Long-hole drill rigs, where several Data Quality issues have been discovered and their root cause investigated.

  • 10.
    Shekhar, Gurmeet
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jonsson, Kristina
    Luossavaara- Kiirunavaara AB, Luleå, Sweden.
    Martinsson, Jesper
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Development of an optimal draw control strategy for a sublevel caving operation at Malmberget mine2020Ingår i: Mining Technology, ISSN 2572-6668, Vol. 129, nr 2, s. 104-112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper addresses the identification of the optimal draw control strategy for a sublevel caving (SLC) operation at Malmberget mine in Sweden. Two mathematical models, a probability model and an economic model, were created using five datasets: bucket weights, bucket grades, extraction ratio, mine economics parameters and production constraints. The probability model was used to generate a set of simulated bucket weights and corresponding bucket grades which acts as a ‘virtual mine’ environment. The economic model assesses the economic impact of loading at the draw point. Two approaches to draw control were tested using the ‘virtual mine’ created by the probability model. Based on the results of the simulation tests, an optimal draw control strategy is suggested for a field test at the mine. The new draw control strategy optimises further the loading operation at Malmberget mine. The paper shows a roadmap for optimising draw control strategy for SLC operations.

  • 11.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Liaghat, Samaneh
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Establishing relationships between structural data from close-range terrestrial digital photogrammetry and measurement while drilling data2020Ingår i: Engineering Geology, ISSN 0013-7952, E-ISSN 1872-6917, Vol. 267, artikel-id 105480Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Geologists, mine planners, geotechnical, and mining engineers always strive for maximum information to get a better insight of the rock mass before interacting with it. Over the recent decades, close-range terrestrial digital photogrammetry (CRTDP) has been increasingly used for data acquisition and to support the conventional methods for rock mass characterization. It provides a safe, time-saving and contact-free way to gather enough data to minimize user dependent biases. However, it requires an expensive camera, fieldwork and some software to extract the information from images. In addition, it can over-estimate the rock fracturing sometimes due to weathering of the rock face or poor blasting practices. Measurement while drilling (MWD) data include the responses of different drilling parameters to the variations in the rock mass. MWD data are produced in large quantity, as they come from every hole drilled. These data correspond to the inside variations of rock rather than the surface ones counted in photogrammetry.

    In this paper, structural data are obtained from different bench faces of an open pit mine using a commercial software package, ShapeMetriX3D (by 3GSM). These data are compared to the MWD data of the boreholes that were blasted to produce these bench faces to establish certain relationships between drilling parameters and rock mass structures. Half casts of the boreholes with MWD data were visible on the bench faces of the pre-split wall that allowed a better correlation. The results show abrupt changes in MWD parameters for open joints or cavities with some infilling material and overall increases or decreases in parameters for closely spaced bedding planes, fractures or foliations. The results are promising and suggest the method can be used to characterize the rock mass, modify the charging of explosives in blasting operations and facilitate the geological modeling of the rock mass.

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  • 12.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Paraszczak, Jacek
    Université Laval, Quebec City, Canada.
    Shekhar, Gurmeet
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Bergström, Stefan
    Luossavaara Kiirunavaara AB, Sweden.
    Brännman, Pär
    Luossavaara Kiirunavaara AB, Sweden.
    Operator influence on the loading process at LKAB's Iron ore mines2020Ingår i: Journal of the Southern African Institute of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 2411-9717, Vol. 120, nr 3, s. 191-202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The loading process in sublevel caving mines entails loading material from the drawpoint using load haul dump machines that transport the material to orepasses or trucks, depending on the mine conditions. When each bucket is drawn from the drawpoint, a decision must be made as to whether loading should continue or be stopped and the next ring blasted. The decision to abandon the drawpoint is irrevocable, as it is followed by the blasting of the next ring. Abandonment of the drawpoint too early leads to ore losses and inefficient use of ore resources. Loading beyond the optimal point increases dilution as well as mining costs.The experience of the LHD operators is an important basis for manual drawpoint control. However, it has been difficult to establish which specific factors manual drawpoint control is based on. To try to shed more light on these factors we analysed the operators' experiences at LKAB's Kiirunavaara and Malmberget iron ore mines. The operators in the two mines completed a questionnaire on the current loading practices and the process of deciding to abandon 'normal' rings, opening rings, and rings with loading issues.It was found that in both case study mines, most decisions on the abandonment of drawpoints are made by the operators. The more experienced operators tend to make more decisions themselves rather than rely on support from the existing support functions.

  • 13.
    Schunnesson, Håkan
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Shekhar, Gurmeet
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    A review of mining practices for surface support: an international survey2019Ingår i: Ground Support 2019: Proceedings of the Ninth International Symposium on Ground Support in Mining and Underground Construction / [ed] John Hadjigeorgiou; Marty Hudyma, Australian Centre for Geomechanics (ACG), , 2019, s. 283-293Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper reviews mining practices for surface support and identifies four key areas that need attention. An international survey was conducted as part of the Mining Initiative on Ground Support Systems and Equipment III project from 2017 to 2018. The survey used a standardised, web-based questionnaire adapted for personal computers and smartphones. The survey was distributed globally, with data collected from 58 underground mines with different mining conditions and challenges. The results highlight the challenges with regard to safety and automation of surface support for different rock conditions and the advantages and disadvantages of various machines (face drills versus mechanised dedicated bolters versus semi-mechanised bolters) used to install surface support. The survey also shows the ambiguity in the mining community with regard to productivity of mine support. This paper presents an approach for collecting technical data through an online tool, which is inexpensive and effective.

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    Shekhar_ground support_2019
  • 14.
    Shekhar, Gurmeet
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hersinger, Anders
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Jonsson, Kristina
    Luossavaara-Kiirunavaara AB, Kiruna, Sweden.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Development of a model for economic control of loading in sublevel caving mines2019Ingår i: Mining Technology:Transactions of the Institutions of Mining and Metallurgy, ISSN 2572-6668, Vol. 128, nr 2, s. 118-128Artikel i tidskrift (Refereegranskat)
    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.

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  • 15.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jonsson, K.
    Luossavaara Kiirunavaara AB, Malmberget, Sweden.
    Draw point behavior in LKAB’s SLC mines2019Ingår i: Rock Mechanics for Natural Resources and Infrastructure Development - Full Papers: Proceedings of the 14th International Congress on Rock Mechanics and Rock Engineering (ISRM 2019), September 13-18, 2019, Foz do Iguassu, Brazil / [ed] Sergio A.B. da Fontoura; Ricardo Jose Rocca; José Pavón Mendoza, Taylor & Francis, 2019, s. 211-218Konferensbidrag (Refereegranskat)
    Abstract [en]

    In a sublevel caving mine, the ore recovery, side rock dilution and the total ore extraction rate are determined and controlled at the draw point. The decision to stop loading at a drawpoint and continue blasting the next fan is critical. Abandonment of the draw point too early leads to ore losses and inefficient use of ore resources. On the other hand, closing a draw point too late leads to increased side rock dilution and increased production costs. The purpose of this paper is to evaluate the used technique for draw control and the potential for increasing the loading level efficiency using available data sources as well as other types of information from the Luossavaara Kiirunavaara AB (LKAB) mines.

  • 16.
    Liaghat, Samaneh
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ore grade prediction using informative features of MWD data2019Ingår i: Mining Goes Digital: Proceedings of the 39th International Symposium 'Application of Computers and Operations Research in the Mineral Industry' (APCOM 2019), June 4-6, 2019, Wroclaw, Poland / [ed] Christoph Mueller; Winfred Assibey-Bonsu; Ernest Baafi; Christoph Dauber; Chris Doran; Marek Jerzy Jaszczuk; Oleg Nagovitsyn, Taylor & Francis, 2019, s. 226-234Konferensbidrag (Refereegranskat)
    Abstract [en]

    Detailed knowledge of the content and geometrical variation of ore grade is essential in mining operations for production planning and economic analysis. Common ore grade specification methods, sampling and analysis are costly and time consuming. Measurement While Drilling (MWD) technique can directly extract grade information from the drilling process increasing data resolution and reducing cost.

    This study introduces a supervised feature selection method based on the Hilbert-Schmidt independence criterion to increase the accuracy of the results and decrease processing time. Potential of the method for recognizing the most effective and non-repetitive dimensions of input data has also been investigated. By exploiting the lower dimension data, a classification model is developed to map the parameter values to ore grade levels.

    Evaluation of the model using MWD data from LKAB’s Leveäniemi mine proved the effectiveness of the proposed feature selection and classification method.

  • 17.
    Manzoor, Sohail
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Liaghat, Samaneh
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Rock mass characterization using MWD data and photogrammetry2019Ingår i: Mining goes Digital: Proceedings of the 39th International Symposium 'Application of Computers and Operations Research in the Mineral Industry' (APCOM 2019), June 4-6, 2019, Wroclaw, Poland / [ed] Christoph Mueller, Winfred Assibey-Bonsu, Ernest Baafi, Christoph Dauber, Chris Doran, Marek Jerzy Jaszczuk, Oleg Nagovitsyn, London: Taylor & Francis Group, 2019, s. 217-225Konferensbidrag (Refereegranskat)
    Abstract [en]

    Measurement while drilling data are produced in enormous quantity in underground and surface mines across the world. The data comprise parameters recorded during the drilling process, including penetration rate, rotation pressure, feed pressure, percussive pressure, damping pressure and flush pressure. MWD data are shown to be very useful for rock mass characterization, blasting applications and geological modelling of the rock mass. In this study, an open pit mine in Austria was selected for data collection as a part of SLIM project. The MWD data collected from drilling rigs were processed to identify different zones of rock mass, i.e. weak, fractured or competent rock. The results were compared to 3D images obtained by close-range terrestrial digital photogrammetry for validation; which showed a close agreement with each other. The method can be used to characterize the rock and to modify the charging of explosives in the boreholes for improved blasting results.

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  • 18.
    Ghosh, Rajib
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Development of a geological model for chargeability assessment of borehole using drill monitoring technique2018Ingår i: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 109, s. 9-18Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the mining industry, the ability to charge and blast a production borehole is fundamental. However, if rock mass conditions are challenging, with cavities, fracture zones or even unstable boreholes, the charging crew may fail to insert the required amount of explosives, resulting in bad fragmentation and significant production disturbances in the downstream process. Prior detailed knowledge of the chargeability of each production fan or ring will improve both the planning and execution of the charging work in a mine. The paper describes a study using the drill monitoring technique to assess the chargeability of production boreholes. For the study, data were collected on four drill parameters, penetration rate, rotation pressure, feed pressure and percussive pressure, from 23 drill fans with a total of 186 boreholes. A parameter called fracturing was calculated based on penetration rate variability and rotation pressure variability. Sixty-three boreholes were filmed to establish different rock mass conditions: solid rock, cavities, fractured zones and cave-ins. Principal Component Analysis (PCA) was performed to model the relationship between drill monitoring data and the geological features. The developed model shows high potential by identifying charging problems directly from drill monitoring data, and has been verified and validated in a real charging operation in an operating mine.

  • 19.
    Shekhar, Gurmeet
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Boeg-Jensen, Patricia
    Luossave-Kiirunavaara AB, Kiruna, Sweden.
    Malmgren, Lars
    Luossave-Kiirunavaara AB, Kiruna, Sweden.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Draw control strategies in sublevel caving mines: A baseline mapping of LKAB's Malmberget and Kiirunavaara mines2018Ingår i: Journal of the Southern African Institute of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 2411-9717, Vol. 118, nr 7, s. 723-733Artikel i tidskrift (Refereegranskat)
    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.

  • 20.
    Skawina, Bartlomiej
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Greberg, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Salama, Abubakary
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    The effects of orepass loss on loading, hauling, and dumping operations and production rates in a sublevel caving mine2018Ingår i: Journal of the Southern African Institute of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 2411-9717, Vol. 118, nr 4, s. 409-418Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Orepass failure is a well-known problem in deep mines, and the risk of losing an orepass is associated with severe production disturbances. In the near future, one possible scenario in the Loussavaara Kiirunavaara Aktiebolag (LKAB) Malmberget mine is to concentrate the mining operation in fewer, but larger, production areas. In this paper we evaluate the effects of orepass loss on loading, hauling, and dumping operations and production rates using discrete event simulation, by simulating part of the Malmberget mine loading and hauling system under different environmental and operational constraints.

  • 21.
    Ghosh, Rajib
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Danielsson, Markus
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Falksund, Hanna
    Luossavaara-Kiirunavaara Aktiebolag (LKAB), Malmberget.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Assessment of rock mass quality using drill monitoring technique of Hydraulic ITH drills2017Ingår i: International Journal of Mining and Mineral Engineering, ISSN 1754-890X, Vol. 8, nr 3, s. 169-186Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A rock drilling system always responds to variations in the mechanical properties of the penetrated rock mass. Combining the drill response with a detailed understanding of the drill system has the potential to give a detailed and high-resolution characterisation of the penetrated rock mass along the borehole. This paper analyses 186 boreholes, drilled using a water powered in-the-hole (ITH) drilling technique considering drill parameters; penetration rate, rotation pressure, feed pressure and percussive pressure. In addition, it suggests, calculates and uses a parameter reflecting rock fracturing. Sixty-three of the holes were filmed with a borehole camera to reveal the geo-mechanical features. The results show that the responses from the drill monitoring system can distinguish between solid rock, fracture zones, cavities and damaged rock. The ability to extract this information directly from the drilling operation provides unique prior information and can be useful to adjust production planning before charging and blasting boreholes.

  • 22.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Paraszczak, Jacek
    Department of Mining, Metallurgical and Materials Engineering, Université Laval, Quebec City.
    Tuleau, Jocelyn
    Department of Mining, Metallurgical and Materials Engineering, Université Laval, Quebec City.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Impact of technical and operational factors on effectiveness of automatic load-haul-dump machines2017Ingår i: Mining Technology, ISSN 1474-9009, E-ISSN 1743-2863, Vol. 126, nr 4, s. 185-190Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of automatic load-haul-dump (LHD) machines in underground metal mines is a promising way to overcome some of the challenges now facing mining companies. They offer several potential benefits over man-operated units, mostly in terms of safety and health of the workers, but also in terms of higher availability, increased productivity, and reduced mining cost. That said, using such systems at their full capacity is a challenging and complex task. In this context, after describing some commercially available equipment and systems, the paper examines factors affecting reliability, availability and productivity of automatic LHDs and notes several technical and operational concerns.

  • 23.
    Shekhar, Gurmeet
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Loading Procedure and Draw Control in LKAB’s Sublevel Caving Mines: Baseline Mapping Report2017Rapport (Övrigt vetenskapligt)
    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.  

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  • 24.
    Ghosh, Rajib
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Monitoring of Drill System Behavior for Water-Powered in-the-hole (ITH) drilling2017Ingår i: Minerals, E-ISSN 2075-163X, Vol. 7, nr 7, artikel-id 121Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A detailed understanding of the drilling system and the drilling control is required to correctly interpret rock mass conditions based on monitored drilling data. This paper analyses data from hydraulic in-the-hole (ITH) drills used in LKAB’s Malmberget mine in Sweden. Drill parameters, including penetration rate, percussive pressure, feed pressure, and rotation pressure, are monitored in underground production holes. Calculated parameters, penetration rate variability, rotation pressure variability, and fracturing are included in the analysis to improve the opportunity to predict rock mass conditions. Principal component analysis (PCA) is used to address non-linearity and variable interactions. The results show that the data contain pronounced hole length-dependent trends, both linear and step-wise linear, for most parameters. It is also suggested that monitoring can be an efficient way to optimize target values for drill parameters, as demonstrated for feed force. Finally, principal component analysis can be used to transfer a number of drill parameters into single components with a more straightforward geomechanical meaning

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  • 25.
    Morant, Amparo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Larsson-Kråik, Per-Olof
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Safety and availability evaluation of railway operation based on the state of signalling systems2017Ingår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 231, nr 2, s. 226-238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A framework is presented to evaluate the safety and availability of the railway operation, and quantifying the probability of the signalling system not to supervise the railway traffic. Since a failure of the signalling systems still allows operation of the railway, it is not sufficient to study their effect on the railway operation by considering only the failures and delays. The safety and availability are evaluated, handling both repairs and replacements by using a Markov model. The model is verified with a case study of Swedish railway signalling systems with different scenarios. The results show that the probability of being in a state where operation is possible in a degraded mode is greater than the probability of not being operative at all, which reduces delays but requires other risk mitigation measures to ensure safe operation. The effects that different improvements can have on the safety and availability of the railway operation are simulated. The results show that combining maintenance improvements to reduce the failure rate and increase the repair rate is more efficient at increasing the probability of being in an operative state and reducing the probability of operating in a degraded state.

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  • 26.
    Greberg, Jenny
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Salama, Abubakary
    Department of Chemical and Mining, College of Engineering and Technology, The University of Dar es Salaam, Dar es Salaam P.O. Box 35901, Tanzania.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Skawina, Bartlomiej
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Alternative Process Flow for Underground Mining Operations: Analysis of Conceptual Transport Methods Using Discrete Event Simulation2016Ingår i: Minerals, E-ISSN 2075-163X, Vol. 6, nr 3, artikel-id 65Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    As the near surface deposits are being mined out, underground mines will increasingly operate at greater depths. This will increase the challenges related to transporting materials from deeper levels to the surface. For many years, the ore and waste transportation from most deep underground mines has depended on some or all of the following: truck haulage, conveyor belts, shafts, rails, and ore pass systems. In sub-level caving, and where ore passes are used, trains operating on the main lower level transport the ore from ore passes to a crusher, for subsequent hoisting to the surface through the shaft system. In many mines, the use of the ore pass system has led to several problems related to the ore pass availability, causing production disturbances and incurred cost and time for ore pass rehabilitation. These production disturbances have an impact on the mining activities since they increase the operational costs, and lower the mine throughput. A continued dependency on rock mass transportation using ore passes will generate high capital costs for various supporting structures such as rail tracks, shaft extensions, and crushers for every new main level. This study was conducted at an existing underground mine and analyzed the transport of ore from loading areas at the lower levels up to the existing shaft points using trucks without employing ore passes. The results show that, when the costs of extending ore passes to lower levels become too great or ore passes cannot be used for production, haul trucks can be a feasible alternative method for transport of ore and waste up the ramp to the existing crusher located at the previous main level. The use of trucks will avoid installing infrastructure at the next main level and extending the ore passes to lower levels, hence reducing costs.

  • 27.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sundqvist, Fredrik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sjödin, Erik
    Greberg, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Conceptual models for mining at greater depths: Automated bolt rigs and scaling rigs2016Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    One of the challenges that underground mines face today is the deepening of the mines. This, together with lower grades of the deposits, makes the mines strive for higher productivity and lower costs. By introducing autonomous vehicles, the operators will be removed from the face, and thus safety for operators will be improved. Since autonomous vehicles are scheduled to operate during breaks, there is a potential for a productivity increase. The goal with this study was to determine if and to which degree autonomous bolt rigs and scaling rigs can improve the productivity in a deep underground mine.The research is based on data collected during 2013 from New Boliden AB’s Kristineberg mine in Sweden. A simulation tool, SimMine, was used for analyzing the effects of operational changes and for simulation of parameters that are difficult to estimate, such as traffic congestions. A number of scenarios were simulated and compared to the base case with focus on productivity.It can be concluded that the simulation scenarios using faster, manually operated vehicles shows a productivity increase, and that the automated vehicles further improved the productivity increase. The largest productivity increase comes however from faster vehicles, and not from the automation itself.

  • 28.
    Shekhar, Gurmeet
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Boeg-Jensen, Patricia
    LKAB.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Draw control optimization along the production drift in sublevel caving mines2016Ingår i: Seventh International Conference & Exhibition on Mass Mining : (MassMin 2016), Sydney: The Australian Institute of Mining and Metallurgy , 2016, s. 241-249Konferensbidrag (Refereegranskat)
    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.

  • 29.
    Shekhar, Gurmeet
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Draw Control Strategy and Resource Efficiency in Sublevel Caving: State-Of-the-Art2016Rapport (Övrigt vetenskapligt)
    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.

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  • 30.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Face to Surface: a fragmentation study2016Rapport (Refereegranskat)
    Abstract [en]

    As ore grades have decreased and the mining depth has increased over the past few decades, other characteristics than ore grade and tonnage are becoming important. The underground mining process, from in-situ rock mass characteristics to the final mill product with fully liberated minerals, consists of a chain of unit operations that impact, and are influenced by, fragmentation. This report presents the baseline mapping of the project “From Face to Surface”, studying the effects of fragmentation on the process flow in an underground SLC mine. It analyses the underground unit operations in detail, from mine planning to shafts, and maps the blast fragmentation’s effect on the process flow. The goal is to provide a deeper understanding of fragmentation´s effect on different unit operations. The objective is to describe the mining operation at Luossavaara-Kiirunavaara AB (LKAB) and identify key areas for improving fragmentation. To understand how fragmentation influences different operations in the mine, the project conducted a literature study, collected data and interviewed mine personnel in LKAB’s Malmberget mine. Data were collected from the mine’s internal systems, such as GIRON, WOLIS, IP21 and a local drilling data system. The interviews were conducted in cooperation with research personnel from the mine.This baseline mapping shows that the mining operation in Malmberget is affected by fragmentation in several ways. For some unit operations, the fragmentation has a large impact, while for others, it has none at all. The influence of fragmentation starts with the loading operation after the initial blasting and ends with the crushing operation. For the former, boulders are the largest problem, as they cause a great deal of idle time, either when they have to be moved to a separate drift for secondary blasting or when they create hang-ups in the ore passes. When boulders are dumped into the ore passes, they risk damaging the ore pass walls. If boulders create a hang-up, it has to be removed. If the hang-up must be removed with explosives, there is a risk of further damaging the ore pass. In addition, the toxic fumes created by the explosives hinder production until the pass is ventilated. Finally, hang-ups affect the transportation operation as the trucks cannot use an ore pass blocked by a hang-up or closed for ventilation of toxic fumes. There is also a slight possibility that a boulder which does not get stuck in the ore pass will get stuck on a truck. The last operation affected by fragmentation is crushing; boulders and large fragments risk creating a hang-up in the crusher. There are no reports of problems related to fragmentation after this point.The results suggest that further work and mine trials are required in the following areas: drilling, loading, ore passes and crushers.

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  • 31.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jonsson, Kristina
    LKAB.
    Johansson, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    From Face to Surface: a Fragmentation Study2016Ingår i: Seventh International Conference & Exhibition on Mass Mining : (MassMin 2016), Sydney: The Australian Institute of Mining and Metallurgy , 2016, s. 555-562Konferensbidrag (Refereegranskat)
    Abstract [en]

    The underground mining process, from in-situ characteristics of the unmined rock mass to the final mill product with fully liberated minerals, consists of a chain of unit operations. Some of them influence fragmentation while fragmentation impacts others. From a production point of view, fragmentation is a key parameter for the proper functioning of many unit operations and affects total production; it influences the ability to load, haul and crush the rock later in the process. Fragmentation varies because of rock mass strength, the presence of joints, the chosen explosive, specific charge (kg/m3) and quality of drill holes. The efficiency and result of unit operations such as drilling, blasting, loading and crushing depend on the rock properties which vary throughout a mine. Generally speaking, operations are not well adapted to the actual rock properties, leading to a non-optimised flow in production. This paper presents the initial part of a project that will build knowledge on the impact of fragmentation on each step of the production chain in an underground mine. It identifies the key parameters of fragmentation which influence the overall energy consumption and productivity in a mining operation through interviews, mine visits and a literature review. In the subsequent stages of the project, a number of field tests in the case study mine will address important segments of the production process where fragmentation is a major obstacle to improvements. Optimising the entire process, rather than isolated unit operations, will lead to increased productivity, decreased amount of interruptions and lower energy consumption.

     

  • 32.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Timusk, Markus A.
    Division of Engineering, Laurentian University, Sudbury.
    Hauta, Rebecca
    Division of Engineering, Laurentian University, Sudbury.
    Productivity of rock reinforcement: Methodology development2016Ingår i: Journal of the Southern African Institute of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 2411-9717, Vol. 116, nr 12, s. 1127-1134Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The working environment for ground support installation in mines has improved during the last 20-30 years, with more mechanized equipment for installation of ground support elements such as bolts, cable bolts, and screens. Ground support installation productivity has, however, not followed the same development curve, remaining more or less constant. In some cases, for example the mechanized installation of bolts, productivity has even dropped. One reason for this is that modern mechanized bolt rigs are complex. In this paper we evaluate manual and mechanized ground support systems, propose a way to measure the productivity of bolt rigs, and make relevant comparisons between different mines and equipment. Some productivity measures for rock reinforcement are suggested, using productivity results from eight case study mines

  • 33.
    Morant, Amparo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Söderholm, Peter
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Industriell Ekonomi.
    Safety and Availability Evaluation of Railway Signalling Systems2016Ingår i: Current Trends in Reliability, Availability, Maintainability and Safety: An Industry Perspective / [ed] Uday Kumar; Alireza Ahmadi; Ajit Kumar Verma; Prabhakar Varde, Encyclopedia of Global Archaeology/Springer Verlag, 2016, s. 303-316Konferensbidrag (Refereegranskat)
    Abstract [en]

    The purpose of this paper is to evaluate the safety and availability of railway signalling systems using Markov models. Since a failure of the signalling systems still allows operation of the railway, it is not sufficient to study their safety and availability by considering only the failures and delays. The safety and availability are evaluated, handling both repairs and replacements by using a Markov model. The model is validated with a case study of Swedish railway signalling systems with different scenarios. The results obtained show that the probability of being in a state where operation is possible in a degraded mode is greater than the probability of not being operative at all, which reduces delays but requires other risk mitigation measures to ensure safe operation.

  • 34.
    Salama, Abubakary
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Greberg, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Skawina, Bartlomiej
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Analyzing energy consumption and gas emissions of loading equipment in underground mining2015Ingår i: CIM Journal, ISSN 1923-6026, Vol. 6, nr 4, s. 179-188Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In an environment of rising energy prices and mining at greater depths, cost-efficient loading and hauling equipment is essential. Conducted at an underground mining operation, this study analyzes the energy consumption and gas emissions of diesel and electric load-haul-dump machines (LHDs) with similar bucket capacities. Based on energy prices from the first quarter of 2014, results of discrete event simulation show that energy costs for diesel and electric LHDs are US$0.24/t and US$0.07/t, respectively. Also, diesel LHDs emit 2.68 kg CO2 per litre of diesel fuel, whereas using electric machines reduces the need for ventilation to mitigate engine heat and emissions and reduces energy costs.

  • 35.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Reliability analysis and comparison between automatic and manual load haul dump machines2015Ingår i: Quality and Reliability Engineering International, ISSN 0748-8017, E-ISSN 1099-1638, Vol. 31, nr 3, s. 523-531Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Today's trend of replacing manually operated vehicles with automated ones will have an impact not only on machine design, working environment and procedures but also on machine breakdown and maintenance procedures. In the harsh environment of underground mines, the transition from manual to automatic operation is believed to fundamentally change the basis for break downs, maintenance and machine design. In this paper, differences and similarities between manual and automatic underground loading equipment is analysed from a reliability point of view. The analysis is based on a case study performed at a Swedish underground mine. In the contrary of common thoughts, this paper proves that there is a difference between the manual and semi-automatic machines and in particular for the transmission, in favour of the manual one. This paper also shows a path for detailed reliability analysis, and the results may be used for improving maintenance programmes for other types of mobile equipment

  • 36.
    Paraszczak, Jacek Jack
    et al.
    Department of Mining, Metallurgical and Materials Engineering, Université Laval, Quebec City.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Technical and operational aspects of autonomous LHD application in metal mines2015Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 29, nr 5, s. 391-403Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Due to safety concerns, automation of load-haul-dump (LHD) machines receives considerable attention from the mining industry. This paper analyses and discusses the issues and problems related to implementation and use of autonomous LHDs in underground metal mines. It presents the need for safety measures, infrastructure and discusses technical problems encountered. The paper looks also into technical and operational issues (reliability, maintainability, utilisation, production rate, etc.) as compared to conventional manually operated machines. Conclusions focus mostly on the aspects requiring attention before and after the implementation of autonomous loading systems in order to maximise the chances that they deliver expected benefits

  • 37.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ghosh, Rajib
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Bolting Procedures in Outokumpu’s Kemi Mine2014Ingår i: Mine Planning and Equipment Selection: Proceedings of the 22nd MPES Conference, Dresden, Germany, 14th – 19th October 2013 / [ed] Raj Singhal ; Carsten Drebenstedt, Encyclopedia of Global Archaeology/Springer Verlag, 2014, Vol. 3, s. 411-420Konferensbidrag (Refereegranskat)
    Abstract [en]

    The working environment for ground support installation in mines has improved a lot during the last 20-30 years, with more and more mechanized installations of the different ground support elements such as bolts, cable bolts and screen. However ground support installation productivity has not followed the same development curve. In fact, its productivity has more or less remained constant and in some cases has even fallen if, as an example, comparisons are made between the manual and mechanized installations of bolts. One reason for this is that modern mechanised bolt rigs are very complex, capable to perform many tasks. To be able to fully utilize this equipment’s capability a different level of maintenance and product support is required. This paper describes the bolting process in Outokumpu’s Kemi mine that has a very interesting procedure for bolt installation and has also paid an unsurpassed attention to the maintenance procedures to improve productivity.

  • 38.
    Salama, Abubakary
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Greberg, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Conceptual models regarding mine layout/infrastructure and process flow at greater depths: A literature review on haulage systems2014Rapport (Övrigt vetenskapligt)
    Abstract [en]

    This report is part of the work done by Luleå University of Technology within the EU 7th framework project I2Mine, Innovative Technologies and Concepts for the Sustainable and Intelligent Deep Mine of the Future. The work is performed within work package 2 Novel mining and underground processing methods, subtask 2.1.1 Novel mining methods and processes for deep, steeply dipping orebodies. This subtask aims at identifying new conceptual methods and processes for mining of deep, steeply dipping orebodies. The literature review presented in this report is aiming at identifying haulage systems that might be applicable for the given conditions, and serves as input for the future work within subtask 2.1.1 which is carried out by the research subject Mining and Rock Engineering at LTU together with LKAB and Boliden from November 2011 to November 2015.

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  • 39.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Lipsett, Michael
    Mechanical Engineering, University of Alberta, Edmonton.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Development of a Markov model for production performance optimisation: Application for semi-automatic and manual LHD machines in underground mines2014Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 28, nr 5, s. 342-355Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper compares three ways to operate a load haul dump (LHD) machine, manual operation, automatic operation (fleet operation) and semi-automatic operation, to find the best operating mode. In a fault tree analysis, different failures are classified and analysed, but the way to recover from certain states is not accounted for, which is something a Markov model can handle. The paper is based on the analysis of real data from an underground mine. A Markov model has been built for mining application and it is shown that a semi-automatic LHD has the highest probability of being in a productive state since it has the advantage of changing operating modes (manual and automatic) depending on the need and situation. Hence, the semi-automatic LHD is the best choice from an operational point of view. The paper fills a gap in the literature on manual vs. automatically operated LHDs by providing a new way of evaluating the operating mode of LHDs using Markov modelling, while considering the operating environment.

  • 40.
    Hassan, Syed Alley
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Greberg, Jenny
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Transition from surface to underground mining in the Arctic region: A case study from Svartliden Gold Mine, Sweden.2014Ingår i: Mine Planning and Equipment Selection: Proceedings of the 22nd MPES Conference, Dresden, Germany, 14th – 19th October 2013 / [ed] Carsten Drebenstedt; Raj Singhal, Germany: Encyclopedia of Global Archaeology/Springer Verlag, 2014, Vol. X, s. 1397-1408Konferensbidrag (Refereegranskat)
    Abstract [en]

    Gold ores often consist of nuggets associated with quartz veins. In other ore types gold can be found as a by-product to pyrite. For both types, mine planning of scattered veins type deposits is often complicated regarding both mine design and production scheduling. Despite the cold climate in the Arctic region, near surface deposits are initially mined with open pit mining. As the mine goes deeper, the stripping ratio and the transportation cost increases which economically limit the possibility to continue the project with open pit mining. The transition to underground mining, with gradually decreasing production from an open pit, near its final depth, and with gradually increasing production from newly developed underground production areas, require detailed planning and production scheduling to avoid production delays and maintaining a high cash flow. This paper high-lights the main operational aspects of the Svartliden gold mine in Sweden and in particular how a scattered gold deposit during harsh cold weather conditions was dealt with. The on-going transition from surface to underground mining and the applied concept of minimizing own personnel in favour of national and local contractors for production purposes are also discussed.

  • 41.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Automation of Load Haul Dump machines: comparative performance analysis and maintenance modeling2013Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The Load Haul Dump (LHD) machine and its operating environment create a complex system. Mine productivity depends on the operation of the LHDs and on the mining environment, including fragmentation, size of boulders, navigation techniques etc. Traditional navigation techniques require a lot of infrastructure to accommodate automatic operation. From fully automated fleets of vehicles, the focus of automation has gradually widened to include more flexible solutions, such as semi-automatic LHD machines, with safety as a main goal. The automatic system used for semi-automation is different from that used for fleet automation in that less infrastructure is needed, and the operator controls only one vehicle at a time. A semi-automatic LHD machine can operate in either manual or automatic mode depending on the need and situation. Several issues must be resolved to maximise the benefits of automation. One is to improve the maintenance strategy, especially preventive maintenance, as it is crucial to avoid the loss of time incurred by unplanned breakdowns. Another issue is the complexity of the mining environment; external disturbances such as oversized boulders, road maintenance etc. can throw the entire investment in automation into question.The purpose of this thesis is to explore the maintenance actions connected to automated LHDs as well as the factors influencing the operation of the machine. Research methods include a literature review, unstructured interviews, and data collection and integration. Reliability analysis, fault tree analysis and Markov modeling were performed to comparatively analyse manual and automatic LHDs.This thesis presents an approach to evaluate the performance of manual and semi-automatic LHD machines. It describes the maintenance procedures of automatic LHD machines. It includes a study of the reliability of LHD machines with special attention to automatic operation. It studies the operating environment’s effect on automatically operated LHDs compared to manually operated LHD machines, identifies the external disturbances affecting the automatic operation of LHD machines, and introduces a new way of modeling the maintenance and environmental disturbances to determine the best operation mode for the LHD machine.The analysis shows that the production performance of manual and semi-automatic LHD machines is similar. When it comes to the maintenance performance, hydraulic and electric systems are still the biggest reason for machine downtime but the stops are usually short, which means that LHD machines can start producing relatively soon after failure. However, the automatic LHD machine has more time spent in the workshop for the transmission and engine than the manual LHD machine. The difference in reliability between the machines regarding the engine is not significant. But for the transmission there is a verified difference. One possible reason for the difference in transmission reliability could be engaging/disengaging gears when the machine is in automatic mode.The analysis of the operating environment shows that LHDs suffer from mining related, machine related and/or automatic system related disturbances. Seventy-five percent of the stops causing idle time for LHD machines are related to the operating environment. Better fragmentation of rock to avoid big boulders, better constructed roads to minimise the need for road maintenance etc. are keys to the successful operation of automated LHDs.Fault tree models and reliability block diagrams are effective tools for evaluating the reliability of a system but it can be difficult to include mining related disturbances. Therefore, in this thesis, Markov models are introduced to describe disturbances affecting LHD machines and to identify possible differences between manual and semi-automatic LHDs. A fault tree model can classify and analyse failures but cannot show changes between states; this is something a Markov model can handle. The proposed Markov model built for the application shows that the best mode, from an operational point of view, is semi-automatic operation due to its flexibility handling disturbances of different kinds, especially those that are mining related.

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  • 42.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Production and maintenance performance analysis: manual versus semi-automatic LHDs2013Ingår i: Journal of Quality in Maintenance Engineering, ISSN 1355-2511, E-ISSN 1758-7832, Vol. 19, nr 1, s. 74-88Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose – The purpose of this paper is to evaluate and analyse the production and maintenance performance of a manual and a semi-automatic Load Haul Dump (LHD machine to find similarities and differences.Design/methodology/approach – Real time process-, operational- and maintenance data, from an underground mine in Sweden, have been refined and aggregated into KPIs in order to make the comparison between the LHDs.Findings – The main finding is the demonstration of how production and maintenance data can be improved through information fusion, showing some unexpected result for maintenance of automatic and semi-automatic LHDs in the mining industry. It was found that up to one third of the manually entered workshop data are not consistent with the automatically recorded production times. It is found that there are similarities in utilization and filling rate but differences in produced tonnes/machine hour between the two machines.Originality/value – The originality in this paper is the information fusion between automatically produced production data and maintenance data which increases the accuracy of reliability analysis data. Combining the production indicator and the maintenance indicator gives a common tool to the production and maintenance departments. This paper shows the difference in both maintenance and production performance between a manual and semi-automatic LHD.

  • 43.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Kumar, Uday
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    The influence of the operating environment on manual and automated load-haul-dump machines: a fault tree analysis2013Ingår i: International Journal of Mining, Reclamation and Environment, ISSN 1748-0930, E-ISSN 1748-0949, Vol. 27, nr 2, s. 75-87Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The automated load-haul-dump (LHD) machines have the potential to increaseproductivity and improve safety, but there are many issues to be considered when optimising the operation of LHDs. Today’s focus on improved equipment reliability is part of the problem, and another difficult issue is the special conditions and constraints of the operating environment. For automated LHDs, the latter issue is even more important, as humans have been removed from the production area and are not close by to solve the problems. The purpose of this paper is to find the causes of LHD idle time and to study their impact on the operation of LHDs. In this study, real-time process data and maintenance data from an underground mine in Sweden have been refined and integrated. The study takes into account the complexity of the mine environment, discusses the factors to be considered when optimising and automating the operation and uses fault tree analysis (FTA) to analyse the idle time.

  • 44.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Heyns, Stephan
    Division of Structural Mechanics, Pretoria.
    Fusion of production, operation and maintenance data for underground mobile mining equipment2012Ingår i: The Ninth International Conference on Condition Monitoring and Machinery Failure Prevention Technologies, 2012, Vol. 2, s. 783-791Konferensbidrag (Refereegranskat)
    Abstract [en]

    For integration purposes, a data collection and distribution system based on the concept of cloud computing could be possible to use for collection of data or information pertaining from various sources of data. From a maintenance point of view, the benefit of cloud computing is that information or data may be collected on the health, variability, performance or utilization of the asset. It is especially useful in data mining where different types of data of different quality must be integrated. This paper discusses the concept and presents one example from the underground mining industry.

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  • 45.
    Galar, Diego
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Tormos, Bernardo
    Berges, Luis
    Maintenance Decision Making based on different types of data fusion: [Podejmowanie decyzji eksploatacyjnych w oparciu o fuzję różnego typu danych]2012Ingår i: Eksploatacja i Niezawodność – Maintenance and Reliability, ISSN 1507-2711, E-ISSN 2956-3860, Vol. 14, nr 2, s. 135-144Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Over the last decade, system integration is applied more as it allows organizations to streamline business processes. A recent development in the asset engineering management is to leverage the investment already made in process control systems. This allows the operations, maintenance, and process control teams to monitor and determine new alarm level based on the physical condition data of the critical machines. Condition-based maintenance (CBM) is a maintenance philosophy based on this massive data collection, wherein equipment repair or replacement decisions depend on the current and projected future health of the equipment. Since, past research has been dominated by condition monitoring techniques for specific applications; the maintenance community lacks a generic CBM implementation method based on data mining of such vast amount of collected data. The methodology would be relevant across different domains. It is necessary to integrate Condition Monitoring (CM) data with management data from CMMS (Computer Maintenance Management Systems) which contains information, such as: component failures, failure information related data, servicing or repairs, and inventory control and so on. These systems are the core of traditional scheduled maintenance practices and rely on bulk observations from historical data to make modifications to regulated maintenance actions. The most obvious obstacle in the integration of CMMS, process and CM data is the disparate nature of the data types involved, and there have benn several attempts to remedy this problem. Although, there have been many recent efforts to collect and maintain large repositories of these types of data, there have been relatively few studies to identify the ways these to datasets could be related. This paper attempts to fulfill that need by proposing a combined data mining-based methodology for CBM considering CM data and Historical Maintenance Management data. It shows a system integration of physical and management data that also supports business intelligence and data mining where data sets can be combined in non-traditional ways.

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  • 46.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Automation of load haul dump machines2011Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Load Haul Dump (LHD) vehicles are used in underground mines to load and transport ore and minerals. They can be manually or automatically operated. With an automatic system, the operator can be taken out of the mine and simultaneously control up to three LHDs, thus increasing both productivity and security for the personnel. There are a number of operation modes available for Load Haul Dump (LHD) vehicles and there are many criteria to consider when choosing the best one. This report fills a gap in the literature by mapping and describing the experiences and present status of the operation and maintenance of both automatic and manual LHDs as well as the existing navigation systems and techniques associated with underground automated loading and transportation.The commercially systems available today for automation of LHDs are supplied by Sandvik, Caterpillar and Atlas Copco. Automation focus have over the years gradually shifted from having fully automated fleets of vehicles to more flexible solutions with semi-automatic LHDs gaining safety as one of the main goals. Several issues must be resolved to maximize the benefits of automation. One is to improve maintenance, as this is crucial for an operation to work smoothly without the waste incurred by unplanned breakdowns.

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  • 47.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Dependability assurance for automatic load haul dump machines2011Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Load Haul Dump (LHD) machines are used in underground mines to load and transport ore and minerals. Loading and hauling blasted ore from drawpoint to dumping point constitute a significant portion of the production costs for mining companies. There are a number of operation modes available for LHDs, and there are many criteria to consider when selecting the best one. The use of automated LHDs has been widely discussed due to the potential to increase productivity. The increasing focus on safety and ergonomics also gives an edge to automatically operated loaders over manually operated ones. Mine managers must decide when it is preferable to use manually operated loaders and when to complement or replace these with automatic ones. Automation focus has over the years gradually shifted from having automated fleets of vehicles to the more flexible solutions with semi-automatic LHDs gaining safety as one of the main goals. Several issues must be resolved to maximize the benefits of automation. One is to improve maintenance, and moving from operatorassisted “fail and fix” to planned maintenance. Since the operator is removed from the machine during automatic operation and maintenance staff is not always available on short notice, it is crucial to increase planned maintenance to maximize the investment in automation. Another issue is the complexity of the mining environment, including both the infrastructure and external disturbances like oversized boulders and road maintenance, as these can throw the entire investment in automation into question. The purpose of this thesis is to explore the maintenance actions connected to automated LHDs as well as the factors influencing the dependability of the machine. Research methods include a literature review, interviews, and data collection and analysis. Real time process data, operation and maintenance data have been refined, integrated and aggregated to make a comparative analysis of manual and automatic LHDs. The analysis show that 75% of the stop occasions causing idle time for LHDs relate to the operating environment, 21.5% pertain to machine related issues and 3.5% are related to the infrastructure of the automatic system installed in the mine. There is no difference in what kind of maintenance actions that are taken for manually and automatically operated LHDs, but there is a difference in what type of failures that occurs more frequently for the different operation modes. For automation of LHDs too much unplanned repairs and maintenance work significantly reduces the overall availability and can jeopardize the entire investment in automation. The difference between the semi-automatic and the manual LHD was found to be very small in terms of maintenance cost versus produced number of tons. However, a semi-automated LHD is an optimal machine regarding the ability to adapt to reconfiguring the operation mode to meet demands such as safety, flexibility and productivity.

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  • 48.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Maintenance indicators for underground mining equipment: a case study of automatically versus manually operated LHD machines2011Ingår i: Proceedings of the 24th International Congress on Condition Monitoring and Diagnosis Engineering Management: COMADEM 2011 / [ed] Maneesh Singh; Raj B.K.N. Rao; J.P. Liyanage, Stavanger: COMADEM International, 2011, s. 1205-1214Konferensbidrag (Refereegranskat)
    Abstract [en]

    Key Performance Indicators (KPIs) are performance measures directly related to the overall goals of the company and some of them depend on the maintenance function. In mining companies top managers use the maintenance cost per unit versus budget as one of the KPIs. However many other technical, organizational and economical parameters in a company can be helpful during the decision making process.In this paper the productivity of Load-Haul-Dump machines (LHDs), that is obtained when manual and/or automatic mode are used, are being analysed. The correlation between the productivity and the maintenance KPIs as well as the issues related to the acquisition of data will be shown in this paper highlighting the complexity of getting accurate decision process parameters. It is recognized that the data for some of the components and failure modes originating from different sources are not compatible. This situation must be considered when compiling the data, especially to permit comparison the data should be made compatible. The problem of incompatibility is most severe when dealing with demand related failures. The philosophy and mechanisms of demand related failures as well as the methods used to denote the time and demand related failures in common form have to be taken into account.

  • 49.
    Gustafson, Anna
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Schunnesson, Håkan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Galar, Diego
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    TPM framework for underground mobile mining equipment: a case study2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    In underground mines, mobile mining equipment is critical to the production system. Drill rigs for development and production, vehicles for charging holes, LHDs for loading and transportation, scaling rigs and rigs for reinforcement and cable bolting are all important units in the process to generate a continuous ore flow. For today’s mining companies, high equipment availability is essential to reduce operational and capital costs and to maintain high production. High and controllable reliability is also important especially in attempts to automate the production equipment. This paper compares existing maintenance work in a Swedish and a Tanzanian mine. The various maintenance procedures are identified and evaluated based on a TPM framework.

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  • 50.
    Galar, Diego
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Parida, Aditya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Gustafson, Anna
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Berges, Luis
    University of Zaragoza.
    Use of vibration monitoring and analysis as KPIs in paper industry2011Ingår i: Proceedings of the 24th International Congress on Condition Monitoring and Diagnosis Engineering Management: COMADEM 2011 / [ed] Maneesh Singh; Raj B.K.N. Rao; J.P. Liyanage, COMADEM International, 2011, s. 135-147Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of automated systems for monitoring or surveillance of the condition of machinery for an industrial plant is becoming more common. Variables or indicators are transmitted to a database connected "on line" with such systems, allowing us to correctly track the condition parameters included in the PdM (Predictive Maintenance) Program. A practical example of an installation of 500 measuring points in a paper mill is presented in this paper. Paper mill plants show a wide variety of defects and conditions related to problems in rotating machinery bearings, gears, low speed operation, variable speed machine due to harsh conditions in the environment for elements of the installation and other adverse factors. Therefore, the vibration analyses are presented as physical indicators of the technical system for this type of machinery, on which the maintenance performance metrics are built. The article concludes presenting the "state of the art in data transmission to remote facilities engineering, for predictive diagnostic in order to detect potential problems in machinery which facilitate decisionmaking process in maintenance departments. These systems allow the rapid construction of the KPIs at different hierarchical levels. Therefore an approach to decision making based on the Maintenance methodology has been developed as a result of technological advances in the collection of physical data

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