Campbell, AD 2020, 'Recovery and flow in cave mining: current knowledge gaps and the role of technology in the future', in J Wesseloo (ed.), UMT 2020: Proceedings of the Second International Conference on Underground Mining Technology, Australian Centre for Geomechanics, Perth, pp. 77-104, https://doi.org/10.36487/ACG_repo/2035_0.04 (https://papers.acg.uwa.edu.au/p/2035_0.04_Campbell/) Abstract: Gravity flow of granular material in a caving mine is complex. Ore recovery and cave flow is impacted by wide particle size distributions, particle interlocking, an evolving cave geometry, and the mine draw strategy. However, these factors are rarely quantified in forecasts of cave performance at key stages in the planning process. Reliable tools for simulating cave flow and the technology to measure cave flow and footprint deformation have only emerged in the last 10 years. This includes technology such as electronic cave markers and tracker systems, 3D laser scanning for tunnel deformation and fragmentation measurement as well as coupled cave flow-deformation numerical simulations. This paper provides an overview of how the current state of cave flow knowledge has evolved and the knowledge gaps that still exist. The impact of these knowledge gaps is described in context with mine design and current design guidelines. A series of experiments to address these knowledge gaps have been conceptualised for future trials in existing and future caving mines. A methodology including instrumentation, monitoring requirements and operational practices is outlined for each experiment. Keywords: block caving, sublevel caving, granular flow, fragmentation