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Publikasjoner (10 av 80) Visa alla publikasjoner
Navarro, J., Schunnesson, H., Ghosh, R., Segarra, P., Johansson, D. & Sanchidrián, J. Á. (2019). Application of drill-monitoring for chargeability assessment in sublevel caving. International Journal of Rock Mechanics And Mining Sciences, 119, 180-192
Åpne denne publikasjonen i ny fane eller vindu >>Application of drill-monitoring for chargeability assessment in sublevel caving
Vise andre…
2019 (engelsk)Inngår i: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 119, s. 180-192Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Currently, the charging procedure for sublevel caving mining is carried out with no prior information of the rock mass condition. Thus, engineers are blindsided to unexpected rock conditions and ill-prepared to address issues associated with collapsing boreholes. This results on charging problems and, as consequence, bad fragmentation of the rock after blasting which difficult ore loading and transportation as the gravity flow of the rock is reduced.

This paper builds up the work done by Ghosh et al. (IJRMMS, 2018), to classify the geotechnical rock condition into five classes (solid rock, fractured rock, cave-in, minor and major cavity). From it, two applications based on the Measure While Drilling (MWD) technique have been developed: one for geotechnical rock condition of orebodies and the other for predicting the risk of collapse in boreholes. The work of Ghosh et al. has been improved into a geotechnical rock condition block model to simplify the quantitative assessment and automatic recognition of rock trends. A thorough correction of the MWD parameters has been also applied to minimize external influences other than the rock mass. From it, the risk of borehole collapses model has been developed by comparing different combinations of the geotechnical rock condition block-model with the charging length of 102 production fan-holes. The assessment of the number of collapsed and non-collapsed blastholes and the charging length/blasthole length ratio has been used to assign high, medium or low risk of collapse to each combination. The results predict collapses in the first half of the fan-holes for the high risk, collapses in the second half of the fan-hole for the medium risk and no collapses along the hole for the non-risk holes. The two models have been applied in large scale for two orebodies in the Malmberget mine, Sweden, which comprises 20 drifts and 5060 fan shape long-holes.

sted, utgiver, år, opplag, sider
Elsevier, 2019
Emneord
Rock mass condition, Underground blasting, Measurement while drilling (MWD), Block model, Explosives
HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-74969 (URN)10.1016/j.ijrmms.2019.03.026 (DOI)000472023100018 ()2-s2.0-85065716586 (Scopus ID)
Merknad

Validerad;2019;Nivå 2;2019-06-25 (johcin)

Tilgjengelig fra: 2019-06-25 Laget: 2019-06-25 Sist oppdatert: 2019-07-10bibliografisk kontrollert
Shekhar, G., Gustafson, A., Hersinger, A., Jonsson, K. & Schunnesson, H. (2019). Development of a model for economic control of loading in sublevel caving mines. Mining Technology:Transactions of the Institutions of Mining and Metallurgy, 128(2), 118-128
Åpne denne publikasjonen i ny fane eller vindu >>Development of a model for economic control of loading in sublevel caving mines
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2019 (engelsk)Inngår i: Mining Technology:Transactions of the Institutions of Mining and Metallurgy, ISSN 2572-6668, Vol. 128, nr 2, s. 118-128Artikkel i tidsskrift (Fagfellevurdert) Published
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.

sted, utgiver, år, opplag, sider
Taylor & Francis, 2019
Emneord
Draw control, mine economics, sublevel caving (SLC), draw point performance, Load Haul Dump (LHD)
HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik; Redovisning och styrning
Identifikatorer
urn:nbn:se:ltu:diva-73175 (URN)10.1080/25726668.2019.1586371 (DOI)000471557200005 ()2-s2.0-85064570087 (Scopus ID)
Forskningsfinansiär
Vinnova, 1832144
Merknad

Validerad;2019;Nivå 2;2019-05-03 (johcin)

Tilgjengelig fra: 2019-03-12 Laget: 2019-03-12 Sist oppdatert: 2019-07-10bibliografisk kontrollert
Ittner, H., Olsson, M., Johansson, D. & Schunnesson, H. (2019). Multivariate evaluation of blast damage from emulsion explosives in tunnels excavated in crystalline rock. Tunnelling and Underground Space Technology, 85, 331-339
Åpne denne publikasjonen i ny fane eller vindu >>Multivariate evaluation of blast damage from emulsion explosives in tunnels excavated in crystalline rock
2019 (engelsk)Inngår i: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 85, s. 331-339Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Blast damage in tunnels is usually regulated in Swedish infrastructure contracts as it can influence the quality and lifecycle cost for tunneling projects. The topic is important for underground constructions with a long operation period such as tunnels for public transport, permanent access tunnels in mines or underground repositories for nuclear waste. This paper aims to evaluate the influence of design and geology variables on the resulting blast fracture length and frequency by means of multivariate data analysis. The analysis was based on data from five field investigations carried out at tunnel sites in Sweden and Finland where emulsion explosives were used. Data was compiled and analyzed using Principal Component Analysis (PCA). Charge concentration was found to be the most influential design variable and hole spacing had limited influence on blast fracturing. Results from the PCA suggest that blast fractures length could be dependent also on geology and natural fractures. Three main groups of fracture patterns were identified, one group with relatively few and short blast fractures, a group with several longer blast fractures and a group with few or a single long blast fracture. The result shows differences in fracture length between the column and bottom charge part of the contour holes, with blast fracture lengths up to approx. 40 cm for the column charge and up to approx. 60 cm for the bottom charge.

sted, utgiver, år, opplag, sider
Elsevier, 2019
Emneord
Blasting, Blast damage, Emulsion explosives, Mechanized charging, Principal Component Analysis
HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-67454 (URN)10.1016/j.tust.2018.12.021 (DOI)000457512000031 ()2-s2.0-85059473074 (Scopus ID)
Forskningsfinansiär
Rock Engineering Research Foundation (BeFo)
Merknad

Validerad;2019;Nivå 2;2019-01-10 (svasva)

Tilgjengelig fra: 2018-02-01 Laget: 2018-02-01 Sist oppdatert: 2019-04-23bibliografisk kontrollert
Ghosh, R., Gustafson, A. & Schunnesson, H. (2018). Development of a geological model for chargeability assessment of borehole using drill monitoring technique. International Journal of Rock Mechanics And Mining Sciences, 109, 9-18
Åpne denne publikasjonen i ny fane eller vindu >>Development of a geological model for chargeability assessment of borehole using drill monitoring technique
2018 (engelsk)Inngår i: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 109, s. 9-18Artikkel i tidsskrift (Fagfellevurdert) Published
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.

sted, utgiver, år, opplag, sider
Elsevier, 2018
HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-70266 (URN)10.1016/j.ijrmms.2018.06.015 (DOI)000440458000002 ()2-s2.0-85049528017 (Scopus ID)
Merknad

Validerad;2018;Nivå 2;2018-08-08 (andbra)

Tilgjengelig fra: 2018-08-08 Laget: 2018-08-08 Sist oppdatert: 2018-08-21bibliografisk kontrollert
Shekhar, G., Gustafson, A., Boeg-Jensen, P., Malmgren, L. & Schunnesson, H. (2018). Draw control strategies in sublevel caving mines: A baseline mapping of LKAB's Malmberget and Kiirunavaara mines. The Southern African Journal of Mining and Metallurgy, 118(7), 723-733
Åpne denne publikasjonen i ny fane eller vindu >>Draw control strategies in sublevel caving mines: A baseline mapping of LKAB's Malmberget and Kiirunavaara mines
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2018 (engelsk)Inngår i: The Southern African Journal of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 1543-9518, Vol. 118, nr 7, s. 723-733Artikkel i tidsskrift (Fagfellevurdert) Published
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.

sted, utgiver, år, opplag, sider
The Southern African Institute of Mining and Metallurgy, 2018
Emneord
Sublevel caving, draw control, optimization, draw point monitoring
HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-71770 (URN)10.17159/2411-9717/2018/v118n7a6 (DOI)000442393900006 ()2-s2.0-85053623244 (Scopus ID)
Prosjekter
SIP-STRIM
Forskningsfinansiär
VINNOVA, 1832144
Merknad

Validerad;2018;Nivå 2;2018-12-07 (johcin)

Tilgjengelig fra: 2018-11-27 Laget: 2018-11-27 Sist oppdatert: 2018-12-07bibliografisk kontrollert
Danielsson, M., Johansson, D. & Schunnesson, H. (2018). The Influence of Blast Fragmentation on Loadability in Sublevel Caving. In: Kevin Hachmeister (Ed.), Proceedings of the forty-forurth annual conference on explosives and blasting technique: . Paper presented at 44th Annual Conference on Explosives and Blasting Technique, San Antonio, Texas, Jan. 28–31 2018.
Åpne denne publikasjonen i ny fane eller vindu >>The Influence of Blast Fragmentation on Loadability in Sublevel Caving
2018 (engelsk)Inngår i: Proceedings of the forty-forurth annual conference on explosives and blasting technique / [ed] Kevin Hachmeister, 2018Konferansepaper, Publicerat paper (Fagfellevurdert)
Abstract [en]

In sublevel caving, blasted material flows gravitationally into the drawpoint from above in a periodical manner. This type of flow behavior entails muck pile conditions that are variable along the course of extraction. The effect of this variability on the LHD (Load-Haul-Dump) operation in terms of loading efficiency and ability to undermine the blasted ring is not fully understood as of today. This paper presents results from a field test in LKABs Malmberget mine in Sweden, where the influence of fragmentation on the loading operation has been studied in detail. Drawpoint filming was conducted for extraction of two rings equivalent of roughly 10000 metric tons (~9842 long tons) of material each. The analysis includes fragmentation measurements, muck pile classification, and general estimations in terms of loadability. Further, an evaluation of LHD machines from two different manufacturers was conducted to identify and highlight differences. The results show that fragmentation, muck pile compactness, and flow characteristics are all interdependent. Flow disturbances and the subsequent loading of compacted fine material in the back of the ring have been identified as the main reason for occurring problems and prolonged digging times. However, the ability to sufficiently undermine the blasted ring has been identified to primarily depend on digging depth which is only observed to be high during flow disturbances. An absence of flow disturbances seem to promote high loading efficiency but simultaneously limit the maximum digging depth. A mid-range particle size distribution with a low amount of fines has proven beneficial for overall loading efficiency. The various LHDs employed showed significant variations in terms of ability to handle difficult loading situations (e.g. compactness, boulders, etc.).

HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-70536 (URN)
Konferanse
44th Annual Conference on Explosives and Blasting Technique, San Antonio, Texas, Jan. 28–31 2018
Tilgjengelig fra: 2018-08-22 Laget: 2018-08-22 Sist oppdatert: 2018-08-28
Johansson, D. & Schunnesson, H. (Eds.). (2018). Twelfth International Symposium on Rock Fragmentation by Blasting: Fragblast 12. Paper presented at Twelfth International Symposium on Rock Fragmentation by Blasting; Luleå,Sweden on June 9-15, 2018. Luleå University of Technology
Åpne denne publikasjonen i ny fane eller vindu >>Twelfth International Symposium on Rock Fragmentation by Blasting: Fragblast 12
2018 (engelsk)Konferanseproceedings (Fagfellevurdert)
sted, utgiver, år, opplag, sider
Luleå University of Technology, 2018
HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-68578 (URN)978-91-7790-134-1 (ISBN)978-91-7790-135-8 (ISBN)
Konferanse
Twelfth International Symposium on Rock Fragmentation by Blasting; Luleå,Sweden on June 9-15, 2018
Tilgjengelig fra: 2018-05-02 Laget: 2018-05-02 Sist oppdatert: 2019-05-28bibliografisk kontrollert
Ghosh, R., Danielsson, M., Gustafson, A., Falksund, H. & Schunnesson, H. (2017). Assessment of rock mass quality using drill monitoring technique of Hydraulic ITH drills (ed.). International Journal of Mining and Mineral Engineering, 8(3), 169-186
Åpne denne publikasjonen i ny fane eller vindu >>Assessment of rock mass quality using drill monitoring technique of Hydraulic ITH drills
Vise andre…
2017 (engelsk)Inngår i: International Journal of Mining and Mineral Engineering, ISSN 1754-890X, Vol. 8, nr 3, s. 169-186Artikkel i tidsskrift (Fagfellevurdert) Published
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.

sted, utgiver, år, opplag, sider
InderScience Publishers, 2017
HSV kategori
Forskningsprogram
Gruv- och berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-14546 (URN)10.1504/IJMME.2017.10006862 (DOI)2-s2.0-85027419669 (Scopus ID)deb3ea8d-3a3b-4f92-a89c-67863f4661bf (Lokal ID)deb3ea8d-3a3b-4f92-a89c-67863f4661bf (Arkivnummer)deb3ea8d-3a3b-4f92-a89c-67863f4661bf (OAI)
Merknad

Validerad;2017;Nivå 1;2017-08-16 (rokbeg)

Tilgjengelig fra: 2016-09-29 Laget: 2016-09-29 Sist oppdatert: 2018-11-20bibliografisk kontrollert
Gustafson, A., Paraszczak, J., Tuleau, J. & Schunnesson, H. (2017). Impact of technical and operational factors on effectiveness of automatic load-haul-dump machines. Mining Technology, 126(4), 185-190
Åpne denne publikasjonen i ny fane eller vindu >>Impact of technical and operational factors on effectiveness of automatic load-haul-dump machines
2017 (engelsk)Inngår i: Mining Technology, ISSN 1474-9009, E-ISSN 1743-2863, Vol. 126, nr 4, s. 185-190Artikkel i tidsskrift (Fagfellevurdert) Published
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.

sted, utgiver, år, opplag, sider
Taylor & Francis, 2017
HSV kategori
Forskningsprogram
Gruv- och Berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-62122 (URN)10.1080/14749009.2017.1285980 (DOI)2-s2.0-85038357365 (Scopus ID)
Merknad

Validerad;2018;Nivå 1;2017-12-21 (andbra)

Tilgjengelig fra: 2017-02-22 Laget: 2017-02-22 Sist oppdatert: 2018-04-16bibliografisk kontrollert
Shekhar, G., Gustafson, A. & Schunnesson, H. (2017). Loading Procedure and Draw Control in LKAB’s Sublevel Caving Mines: Baseline Mapping Report. Luleå: Luleå tekniska universitet
Åpne denne publikasjonen i ny fane eller vindu >>Loading Procedure and Draw Control in LKAB’s Sublevel Caving Mines: Baseline Mapping Report
2017 (engelsk)Rapport (Annet vitenskapelig)
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.  

sted, utgiver, år, opplag, sider
Luleå: Luleå tekniska universitet, 2017. s. 60
Serie
Forskningsrapport / Luleå tekniska universitet, ISSN 1402-1528
Emneord
Draw control, Kiirunavaara, Kiruna, Malmberget, Sublevel caving, SLC, LHD, Loading, Drawpoint, loading constraints, Drill design, mining, underground mining, Information systems in Mining
HSV kategori
Forskningsprogram
Gruv- och Berganläggningsteknik
Identifikatorer
urn:nbn:se:ltu:diva-61938 (URN)978-91-7583-807-6 (ISBN)978-91-7583-943-1 (ISBN)
Prosjekter
Improved Resource Efficiency through Dynamic Loading Control
Forskningsfinansiär
VINNOVA, 1832144
Tilgjengelig fra: 2017-02-10 Laget: 2017-02-10 Sist oppdatert: 2018-04-16bibliografisk kontrollert
Organisasjoner