Authors: Yi, C; Johansson, D; Wimmer, M; Nordqvist, A; San Miguel, CR

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DOI https://doi.org/10.36487/ACG_repo/2205_66

Cite As:
Yi, C, Johansson, D, Wimmer, M, Nordqvist, A & San Miguel, CR 2022, 'Numerical modelling of fragmentation by blasting and gravity flow in sublevel caving mines', in Y Potvin (ed.), Caving 2022: Fifth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 963-974, https://doi.org/10.36487/ACG_repo/2205_66

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Abstract:
The sublevel caving (SLC) mining method is based on the utilisation of gravity flow of blasted ore and caved waste rock. Blasting is the initial and the major impact upon primary fragmentation and later material flow characteristics. A coupled numerical model was employed to investigate the fragmentation due to blasting and the gravity flow using the LS-DYNA code. In the coupled model, a loose discrete element model (DEM) was used to represent caved waste rock and a bonded DEM model was used to represent the orebody to be blasted, a particle blast method (PBM) was used to describe the detonation of explosive and a finite element model (FEM) was used to model the remaining orebody. The cumulative dilution of the ore by waste during extraction was evaluated. The results showed that the fragments at the upper part of the ring are coarse while the fragments at the lower part of the ring are fine. The change of the cumulative dilution along with the extraction is reasonable.

Keywords: sublevel caving, fragmentation by blasting, gravity flow, numerical modelling

References:
Brunton, I 2009, The Impact of Blasting on Sublevel Caving Material Flow Behaviour and Recovery, PhD thesis, University of Queensland, Brisbane.
Brunton, ID & Chitombo, GP 2010, ‘Modelling the impact of sublevel caving blast design and performance on material recovery’,
in JA Sanchidrián (ed.), Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting, Granada,
pp. 353–362.
Brunton, ID, Fraser, SJ, Hodgkinson, JH & Stewart, PC 2010, ‘Parameters influencing full scale sublevel caving material recovery at the Ridgeway gold mine’, International Journal of Rock Mechanics & Mining Sciences, vol. 47, pp. 647–656.
Campbell, AD & Power, GR 2017, ‘Improving calibration of flow models against SLC marker trials by linking blasting effects to particle mobility’, Proceedings of the 13th AusIMM Underground Operators’ Conference, The Australasian Institute of Mining and Metallurgy, Melbourne, pp. 11–22.
Campbell, AD 2018, ‘Full-scale experiments to measure the effect of crosscut height on recovery in sublevel cave mines’, in Y Potvin & J Jakubec (eds), Caving 2018: Proceedings of the Fourth International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 443–456.
Castro, R, Gonzalez, F & Arancibia, E 2009, ‘Development of a gravity flow numerical model for the evaluation of draw point spacing for block/panel caving’, Journal of the Southern African Institution of Mining and Metallurgy, vol. 109, no. 7, pp. 393–400.
DeGagne, D & McKinnon, S 2005, ‘The influence of blasting fragmentation on ore recovery in sublevel cave mines’, Proceedings of the 40th U.S. Rock Mechanics Symposium, American Rock Mechanics Association, Alexandria, pp. 1352–1361.
DeGagne, D & McKinnon, S 2006, ‘The influence of cave mass properties on discrete sublevel cave models’, in Proceedings of the 41st U.S. Rock Mechanics Symposium, American Rock Mechanics Association, Alexandria, pp. 1997–2004.
Furtney, J, Cundall, PA & Chitombo, G 2009, ‘Developments in numerical modeling of blast induced rock fragmentation: Updates from the HSBM project’, in JA Sanchidrián (ed.), Proceedings of the 9th International Symposium on Rock Fragmentation by Blasting, Granada.
Hallquist, J 2016, ‘LS-DYNA keyword user’s manual’, Liver-more Software Technology Corporation, vol. 1 & 2.
Itasca Consulting Group 2015, PFC3D, Particle Flow Code in 3 Dimensions. Users Guide, Itasca Consulting Group: Minneapolis.
Karajan, N, Han, Z, Teng, H & Wang, J 2013, ‘Interaction possibilities of bonded and loose particles in ls-dyna’, 9th European LS-DYNA Conference. Manchester, UK.
Kvapil, R 1998, ‘The mechanics and design of sublevel caving systems’, in RE Gertsch & RL Bullock (eds.), Techniques in underground mining, Selections from underground mining methods handbook. Littleton, USA: Society for Mining. Metallurgy, and Exploration, Inc.
Lapcevic, V & Torbica, S 2017, ‘Numerical Investigation of Caved Rock Mass Friction and Fragmentation Change Influence on Gravity Flow Formation in Sublevel Caving’, Minerals, vol. 7, no. 4, p. 56.
Newman, T 1996, ‘Blasting of Intact Ore Against Caved Waste Rock at Kiruna’, LKAB internal report, LKAB, Kiruna.
Nordqvist, A & Wimmer, M 2016, ‘Holistic approach to study gravity flow at the Kiruna Sublevel Caving mine’, in Proceedings of the Seventh International Conference & Exhibition on Mass Mining (MassMin 2016), The Australian Institute of Mining and Metallurgy, Melbourne, pp. 401–414.
Petropoulos, N, Wimmer, M, Johansson, D & Nordlund, E 2018, ‘Compaction of confining materials in pillar blast tests’, Rock Mechanics and Rock Engineering, vol. 51, no. 6, pp. 1907–1919.
Power, GR 2004, Modelling Granular Flow in Caving Mines: Large Scale Physical Modelling and Full Scale Experiments, PhD thesis, The University of Queensland, Brisbane.
Selldén, H & Pierce, M 2004, ‘PFC3D modelling of flow behavior in sublevel caving’, in A Karzulovic & MA Alafaro (Eds.), in Proceedings of the 4th International Conference and Exhibition on Mass Mining, Santiago, pp. 201–214.
Sharrock, G, Beck, D, Booth, G & Sandy, M 2004, ‘Simulating gravity flow in sub-level caving with cellular automata’, in A Karzulovic & MA Alafaro (Eds.), in Proceedings of the 4th International Conference and Exhibition on Mass Mining, MassMin 2004, Santiago, pp. 189–194.
Šmilauer, V 2020, Yade User’s Manual,
Susaeta, A 2004, ‘Theory of gravity flow (part 1)’, in Proceedings of the 4th International Conference and Exhibition on Mass Mining, MassMin 2004, Santiago, pp 167–172.
Teng, H & Wang, J 2014, ‘Particle blast method (PBM) for the simulation of blast loading’, in Proceedings of the 13th International LSDYNA Users Conference, 7 p.
Wimmer, M 2010, ‘Gravity flow of broken rock in sublevel caving (SLC) – State-of-the art’, Swebrec report 2010: P1, ISSN 1653–5006.
Wimmer, M 2012, Towards Understanding Breakage and Flow in Sublevel Caving (SLC) – Development of new measurement techniques and results from full-scale tests. Doctoral thesis, Luleå University of Technology, Luleå.
Wimmer, M, Nordqvist, A, Righetti, E, Petropoulos, N & Thurley, MJ 2015, ‘Analysis of rock fragmentation and its effect on gravity flow at the Kiruna sublevel caving mine’, Proceedings of the 11th International Symposium on Rock Fragmentation By Blasting, The Australasian Institute of Mining and Metallurgy, Melbourne, pp. 715–791.
Yi, CP & Johansson, D 2014, ‘Numerical comparison for blast-induced fragmentation of curved-hole and standard SLC rings’, LKAB report.
Yi, CP, Sjöberg, J & Johansson, D 2017, ‘Numerical modelling for blast-induced fragmentation in sublevel caving mines’, Tunnelling and Underground Space Technology, vol. 68, pp. 167–173.




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