Authors: Paredes, P

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DOI https://doi.org/10.36487/ACG_repo/2205_27

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Paredes, P 2022, 'Evaluation of the effect of wider-spaced layouts in recovery for high column block caves', in Y Potvin (ed.), Caving 2022: Fifth International Conference on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 393-416, https://doi.org/10.36487/ACG_repo/2205_27

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Abstract:
Block caving has historically been the preferred underground solution to mine large, low-grade deposits (Laubscher 1994; Brown 2007; Chitombo 2010; Flores 2014). However, the caving industry has entered a less certain environment where some of the caving options are showing not to be fully suitable to achieving the envisaged low cost and high productivity (Flores 2019). This environment includes extreme conditions, i.e. deeper and blind deposits (>1,400 m from surface), lower grade, harder and heterogeneous rock masses, and higher in situ stress regimes (Flores 2019). It is well understood that the major drawback of block caving is the high upfront capital cost and long lead time required to establish the cave. Establishment time and cost is exacerbated by increasingly complex orebodies at depth, including depth related issues such as low grades, strength/stress ratios, material handling costs and heat, among others (Flores 2014; Chitombo 2018; Ferguson et al. 2018; Flores 2019). The underground materials handling system and the footprint development and setup can represent above 50% of the direct capital cost for a new block (Paredes 2021). In this context, cave layout and materials handling system design are key levers to reduce tunnelling and timing requirements to establish a block caving operation. By reducing the overall tunnelling scope to establish a cave, the total exposure to risk of people and equipment, and establishment cost and timing can be consequently reduced. Based on a critical literature review, one of the main gaps identified to enable the implementation of wider-spaced layouts (i.e. layouts that have wider spacing of extraction and drawpoint drives) that can be less intensive in development, is that: current methods to assess the gravity flow outcomes of block cave layouts in early engineering stages are based on physical experiments and empirical methods developed for low column heights in the 1990s and early 2000s. However, since then there has been significant progress in physical and numerical modelling of gravity flow, which can be used to quantify recovery and interaction for high column caves using wider-spaced layouts. Thus, this work aims to quantify the effect in recovery of widespaced layouts for deep and high-column caves based on mine data and the current state-of-the-art in flow modelling. This consisted of conducting a back-analysis of the Cadia East Mine data to understand the gravity flow behaviour and main flow parameters of a high column cave mine, with the aim to use these as the basis to quantify the effect in recovery of wide-spaced layouts using numerical and physical modelling. Subsequently, physical and numerical modelling (using both Cellular Automata and Kinematic approaches) was conducted to understand the effect on interaction and recovery of wider-spaced layouts and identify any potential fatal flaws. Results show that no fatal flaw in terms of interaction and recovery was identified by increasing drawpoint spacing beyond current industry practices, which presents an opportunity to evaluate wider-spaced layouts that are less intensive in development for deep and high column caves.

Keywords: block caving, mine design, drawpoint spacing

References:
Albanese, T & McGagh J 2011, ‘Future trends in mining’, Mining Engineering Handbook, Society for Mining, Metallurgy, and Exploration, Chapter 1.3, pp. 21–36.
Bridgwater, J, Cooke, MH & Scott AM 1978, ‘Inter-particle percolation: Equipment development and mean percolation velocities’, Transactions of the Institution of Chemical Engineers, vol. 56, 157 p.
Bridgwater, J, Utsumi, R, Zhang, Z & Tuladhar, T 2003, ‘Particle attrition due to shearing – The effects of stress, strain and particle shape’, Chemical Engineering Science, vol. 58, pp. 4649–4665.
Brown, ET 2007, ‘Block Caving Geomechanics’, JKMRC Monograph Series in Mining and Mineral Processing 3, Julius Kruttschnitt Mineral Research Centre, The University of Queensland, Brisbane.
Brunton, I, Sharrock, G & Lett, J 2012, ‘Full scale near field flow behaviour at the Ridgeway Deeps Block Cave Mine’, MassMin 2012: Proceedings of the 6th International Conference & Exhibition on Mass Mining, Sudbury, Ontario, Canada.
Brunton, I, Lett, J, Sharrock, G, Thornhill, T & Mobilio, B 2016, ‘Full-scale flow marker experiments at the Ridgeway Deeps and Cadia East Cave Operations’, MassMin 2016: Proceedings of the 7th International Conference & Exhibition on Mass Mining, Sydney, Australia, pp. 141–150.
Callahan, M & Gillon J 2012, ‘An Update on Henderson's 7210 Production Level’, MassMin 2012: Proceedings of the 6th International Conference & Exhibition on Mass Mining, Sudbury, Ontario, Canada.
Callahan, M, Keskimaki, K & Fronapfel L, 2008, ‘Constructing and operating Henderson’s new 7210 production level’, MassMin 2008: Proceedings of the 5th International Conference & Exhibition on Mass Mining, H Schunnesson & E Nordlund (eds), Luleå University of Technology, Luleå, Sweden, pp. 15‐24.
Casten, T, Priatna, A & Rumbino H, 2016, ‘Deep Mill Level Zone – from Feasibility to Production’, MassMin 2016: Proceedings of the 7th International Conference & Exhibition on Mass Mining, Sydney, Australia.
Castro, R 2006, The Study of the Mechanism of Gravity Flow for Block Caving, PhD thesis, University of Queensland, Brisbane, Australia.
Castro, R & Paredes, P 2012, ‘Comparison of REBOP to Large Panel Caving at Codelco’s Operations’, Technical Report for the Mass Mining Technology Project II.
Castro, R & Paredes, P, 2014 ‘Empirical observations of dilution in panel caving’, The Journal of the Southern African Institute of Mining and Metallurgy, vol. 114, pp. 455–462.
Castro, R, Trueman, R & Halim, A 2007, ‘A study of isolated draw zones in block caving mines by means of a large 3D physical model’, International Journal of Rock Mechanics and Mining Sciences, pp. 860–870.
Castro, R, González, F & Arancibia, E 2009, ‘Development of a gravity flow numerical model for the evaluation of drawpoint spacing for block/panel caving’, Journal of the South African Institute of Mining and Metallurgy, vol. 109, no. 7, pp. 393–400.
Castro, R, Vargas, R & De La Huerta, F 2012, ‘Determination of drawpoint spacing in panel caving: a case study at the El Teniente Mine’, The Journal of The Southern African Institute of Mining and Metallurgy, vol. 112, pp. 871–876.
Castro, R, Arancibia, L, Guzman, D & Henriquez JP 2018, ‘Experiments and simulation of gravity flow in block caving through FlowSim’, in Y Potvin & J Jakubec (eds), Proceedings of the Fourth International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 313–322.
Cavieres, P, Contreras, E & Arce, J 2005, Dimensionamiento de mallas de extracción, bateas recolectoras y pilar corona para método panel caving en roca primaria (Sizing of extraction meshes, collecting troughs and crown pillar for panel caving method in primary rock), El Teniente, Universidad de Santiago de Chile, Santiago, Chile [in Spanish].
Chadwick, J 2010, ‘Operation Focus – DOZ mine’, International Mining, January, p. 12.
Chitombo, G 2010, 'Cave mining — 16 years’ after Laubscher’s 1994 paper ‘Cave mining – state of the art’, in Y Potvin (ed.), Caving 2010: Proceedings of the Second International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 45–61, 
Chitombo, G 2018, Cave mining 2040: advancing cave mining to meet future needs,
Codelco, 2018, ‘Evolution of Mining Methods at El Teniente Mine’, Presentation for 2018 Caving Knowledge Workshop, Phoenix, USA.
Cuello, D & Newcombe, G 2018, ‘Key geotechnical knowledge and practical mine planning guidelines in deep, high-stress, hard rock conditions for block and panel cave mining’, in Y Potvin & J Jakubec (eds), Proceedings of the Fourth International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 17–36.
DeWolfe, V 1981, ‘Draw control in principle and practice at Henderson Mine’, Design and Operation of Caving and Sublevel Stoping Mines, DR Stewart (ed.), Society of Mining Engineers, USA.
Ferguson, GA, Cuello, D, Gandara, P, Potvin, Y & Rojas, E 2018, ‘Strategy for research and development in the cave mining industry’, in Y Potvin & J Jakubec (eds), Proceedings of the Fourth International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 487–498.
Flores, G, 2014, ‘Future challenges and why cave mining must change’, in R Castro (ed.), Proceedings of Caving 2014, Third International Symposium on Block and Sublevel Caving, Universidad de Chile, Santiago, Chile, pp. 23–52.
Flores, G, 2019, ‘Major hazards associated with cave mining: are they manageable?’, in J Wesseloo (ed.), Proceedings of the First International Conference on Mining Geomechanical Risk, Australian Centre for Geomechanics, Perth, pp. 31–46.
Flores, G & Catalan, A, 2019, ‘A transition from a large open pit into a novel “macroblock variant” block caving geometry at Chuquicamata mine, Codelco Chile’, Journal of Rock Mechanics and Geotechnical Engineering 11.3, pp. 549–561.
Flores, G & Karzulovic, A 2002, Benchmarking Report, prepared for ICS-II, JKMRC and Itasca Consulting Group, Inc., Brisbane.
Freeport, 2018, ‘Grasberg Block Cave Update’, Presentation for 2018 Caving Knowledge Workshop, Phoenix, USA.
Fuenzalida, MA & Ghazvinian, E 2021, ‘Gravity Flow Analysis at Cadia East Mine’, Internal report prepared for Newcrest Mining Limited, Itasca Consulting Group.
Fuenzalida, MA, Pierce, ME, Gresham, J & Loring, D 2016, ‘Case Study: Mechanisms of Dilution at Henderson’, in 50th U.S. Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Asociation (ARMA), Houston, Texas.
Gaete, S, Dunlop, R, Parraguez, R, Parra, J & Rodriguez, F 2007, ‘Estimation of cave back using gravity measurements at the El Teniente Mine.k-2, El Teniente’, Proceedings 1st International Symposium on Block and Sub-Level Caving, The Southern African Institute of Mining and Metallurgy, Cape Town, South Africa.
Garces, D, Viera, E, Castro, R & Melendez, M 2016, ‘Gravity Flow full-scale tests at Esmeralda Mine’s Block-2, El Teniente’, MassMin 2016: Proceedings of the 7th International Conference & Exhibition on Mass Mining, Sydney, Australia, pp. 349–358.
Gómez, R 2015 Experimental Assessment of Hang Up and Secondary Fragmentation for Block Caving, Master’s thesis, Universidad de Chile, Chile. [in Spanish]
Guest A, 2007, ‘The difference between interaction and interactive draw’, Proceedings 1st International Symposium on Block and Sub-Level Caving, The Southern African Institute of Mining and Metallurgy, Cape Town, South Africa
Guest, A & Cundall, P 1995, ‘A three dimensional particles flow code for block cave modelling’, Group Mining Symposium, Anglo American and De Beers, vol. 2, paper 7.
Halim, A 2006, Study of the Influence of Interactive Draw Upon Drawpoint Spacing in Block and Sublevel Caving Mines, PhD thesis, The University of Queensland, Brisbane (ICS 2 and MMT).
Hancock, WR & Weatherley, DK 2008, '3D Simulations of Block Caving Flow Using ESyS-Particle', in Y Potvin, J Carter, A Dyskin & R Jeffrey (eds), SHIRMS 2008: Proceedings of the First Southern Hemisphere International Rock Mechanics Symposium, Australian Centre for Geomechanics, Perth, pp. 221–229, 
Hancock, WR, Weatherley, DK & Chitombo, GP 2010, 'Large-scale simulations of gravity flow in block caving', in Y Potvin (ed.), Caving 2010: Proceedings of the Second International Symposium on Block and Sublevel Caving, Australian Centre for Geomechanics, Perth, pp. 553–566, 
Hancock, WR, Weatherley, DK & Chitombo, GP 2012, Modeling the Gravity Flow of rock using the Discrete Element Method, MassMin 2012: 6th International Conference and Exhibition on Mass Mining, Sudbury, Ontario, Canada, Canadian Institute of Mining, Metallurgy and Petroleum, Westmount, Canada.
Heslop, T & Laubscher, D 1981, ‘Draw control in caving operations on Southern African Chrysotile asbestos mines’, International Conference on Caving and Sublevel Stoping, SME-AIME, Denver, pp. 755–774.
Itasca 2016, Fragmentation and Flow Study Cadia Valley Operations Update August 2016, Technical Report.
Julin, D 1992, Block Caving, H Hartman (editor), SME Mining Engineering Handbook, Littentlon, Society for Mining Metallurgy and Exploration, pp. 1815–1836.
Kvapil R, 1965 ‘Gravity flow of granular materials in Hoppers and Bins, Part ll, coarse material’, International Journal of Rock Mechanics Mining Science, vol. 2, pp. 277–304.
Kvapil, R 1992, ‘Sublevel caving’, in HL Hartman (ed), SME Mining Engineering Handbook, pp. 1789–1814, Society for Mining, Metallurgy & Exploration, Englewood.
Kvapil R, 2004, Gravity Flow in Sublevel and Panel Caving – A Common Sense Approach, Book/CD published with very limited circulation.
Laubscher, DH 1994, Cave mining – the state of the art, Journal of the Southern African Institute of Mining and Metallurgy, 94(10), pp. 279–293.
Laubscher, DH 2000, Block Caving Manual, prepared for International Caving Study, JKMRC and Itasca Consulting Group, Inc, Brisbane.
Lett, J, Brunton, I, Capes, G, Jager, A, Mobilio, B, Rachocki, J, Sharrock, G & Secheny, M 2016, ‘Undercutting to surface breakthrough – Cadia East panel cave (Stage 1)’, MassMin 2016: Proceedings of the 7th International Conference & Exhibition on Mass Mining, Sydney, Australia.
Lorig, L & Cundall, P 2000, ‘A rapid gravity flow simulator’, Final Report, International Caving Study, ET Brown (ed), Brisbane, JKMRC and Itasca Consulting Group, Inc.
Macquarie Research 2016, Metals and Mining: A Chip Off the New Block, Macquarie Group, Sydney.
Manca, L & Flores G, 2013, ‘Modern planning practices for cave mining’, MinePlanning 2013: Proceedings of the 3rd International Seminar on Mine Planning, GECAMIN, Santiago, Chapter 3.
Marano, G 1980, ‘The interaction between adjoining draw points in free-flowing materials and its application to mining’, Chamber of Mines Journal, Zimbabwe, vol. 22, pp. 25–32.
Nedderman, R 1995 ‘The use of the kinematic model to predict the development of the stagnant zone boundary in the batch discharge of a bunker’, Chemical Engineering Science, vol. 50, pp. 959–965.
Newcrest Mining 2018, Cadia East Expansion Prefeasibilty Study Findings, Market Release.
Newcrest Mining 2019, Cadia Expansion Feasibility Study, internal report.
Newcrest Mining 2020, Red-Chris Block Cave Concept Study, internal report.
Paredes, P & Pineda M 2014, ‘An analysis of the lateral dilution entry mechanism in Panel Caving’, in R Castro (ed), Proceedings of the 3rd International Symposium on Block and Sublevel Caving, Santiago, Chile.
Paredes, P, Leano, T & Jauriat, L 2018, 'Chuquicamata underground mine design: the simplification of the ore handling system of Lift 1', 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. 385–398, 
Paredes, P 2021, Design Step Changes to Achieve Safer, Faster and Lower-Cost Establishment in Block Cave Mining Under Extreme Conditions, mid-candidature review report, The University of Queensland.
Pierce, M 2010, A Model for Gravity Flow of Fragmented Rock in Block Caving Mines, PhD thesis, The University of Queensland.
Pierce, M, Cundall, P, Van Hout, G & Lorig, L 2003, ‘PFC3D modeling of caved rock under draw, in numerical modeling in micromechanics via particle methods’, in H Konietzky (ed), Proceedings 1st International PFC Symposium, Gelsenkirchen, Germany, Balkema, pp. 211–218.
Power, G 2004, Modelling Granular Flow in Caving Mines: Large Scale Physical Model and Full-scale Experiments, PhD thesis, University of Queensland, Brisbane, Australia.
Resolution Copper 2018, ‘Resolution Copper project update’, Presentation for 2018 Caving Knowledge Workshop, Phoenix, USA.
Rio Tinto 2018, Oyu Tolgoi project overview, Presentation for 2018 Caving Knowledge Workshop, Phoenix, USA.
S&P Global Market Intelligence 2020, Oyu Tolgoi Capex Blowout, S&P Global, New York.
Sainsbury, D, Sainsbury, B, Paetzol, H, Lourens, P & Vakili, A 2016, ‘Caving-induced subsidence behaviour of Lift 1 at the Palabora Block Cave Mine’, MassMin 2016: Proceedings of the 7th International Conference & Exhibition on Mass Mining, Sydney, Australia.
Sharrock, G, Beck, D, Booth, G & Sandy M 2004, ‘Simulating gravity flow in sub-level caving with cellular automata’, MassMin 2004: Proceedings of the 4th International Conference & Exhibition on Mass Mining, SA Karzulovic & M Alfaro (eds), Chilean Engineering Institute, Santiago, Chile, pp. 189–194.
Sharrock, G & Hashim, M 2009, ‘Disturbed gravity flow in block caving’, Proceedings 43rd US Rock Mechanics Symposium and 4th U.S.-Canada Rock Mechanics Symposium, American Rock Mechanics Association (ARMA), Asheville, NC.
Susaeta, A, Rubio, E, Pais, G & Henriquez, J 2008, ‘Dilution behaviour at Codelco panel cave mines’, MassMin 2008: Proceedings of the 5th International Conference & Exhibition on Mass Mining, H Schunnesson & E Nordlund (eds), Luleå University of Technology, Luleå, Sweden.
Trueman, R, Castro, R, Halim & A 2008, Study of multiple draw-zone interaction in block caving mines by means of a large 3D physical model, International Journal of Rock Mechanics and Mining Sciences, pp. 1044–1051.
Van As, A & Van Hout, G 2008, ‘Implications of widely spaced drawpoints’, MassMin 2008: Proceedings of the 5th International Conference & Exhibition on Mass Mining, H Schunnesson & E Nordlund (eds), Luleå University of Technology, Luleå, Sweden.
Van As, A, Power, G & Van Hout, G 2011, ‘The implication of high block heights on cave flow and recoveries’, Proceedings 45th US Rock Mechanics/Geomechanics Symposium, American Rock Mechanics Association, San Francisco, CA.
Vargas, R 2010, Metodología de diseño de malla de extracción en block y panel caving incorporando back-análisis (Methodology of design of extraction mesh in block and panel caving incorporating back-analysis), MSc thesis, Universidad de Chile. [in Spanish]




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