Granular Flow Mechanics in Underground Mining Systems

Granular flow mechanics in underground mining addresses the movement and interaction of fragmented rock as it drains through voids created by caving, drawing or blasting. These flows exhibit complex behaviour that bridges solid- and fluid-like regimes, governed by particle size distribution, moisture content, interparticle friction and confinement geometry. Effective management of granular flow underpins ore-recovery efficiency, ground stability and safety in mass-mining methods such as block caving, sublevel caving and draw-point extraction. Advances in numerical simulation—particularly the discrete element method—have enabled particle-scale resolution of stress transmission, dilation and arching phenomena that lead to flow instabilities or hang-ups. Continuum approaches, incorporating non-Newtonian rheologies and constitutive laws, now inform large-scale mine design, while in situ monitoring with tilt meters, acoustic sensors and 3D imaging validates model predictions. Practical applications include optimisation of draw schedules to minimise dilution, design of hopper and funnel geometries to prevent jamming, and controlled induction of arch collapse to enhance drawpoint performance. Globally, improved understanding of granular flow mechanics is catalysing more sustainable extraction, reducing ore loss and enhancing worker safety as mines extend to greater depths and span more challenging geomechanical conditions.

Research from Nature Portfolio

Recent studies have employed high-resolution X-ray and neutron imaging to observe internal flow structures in analogue rock aggregates under realistic stress states. Particle-scale insights reveal how micro-jamming events nucleate shear bands that propagate and reorganise the bulk flow field. Complementary discrete element simulations demonstrate that slight variations in particle shape or moisture lead to pronounced segregation and layer formation, affecting drawpoint stability. Further work has integrated machine-learning algorithms with real-time sensor data to predict impending flow blockages by recognising precursory patterns in acoustic emissions and strain signals. Together, this body of research has refined constitutive models for granular rheology under confining pressures typical of deep block-caving operations and informed feedback-controlled draw schedules to sustain steady flow.

Granular Flow Mechanics in Underground Mining Systems publication trend

The graph below shows the total number of articles in granular flow mechanics in underground mining systems across all publications each year (not limited to Nature Index journals).

Technical terms

Granular flow: Movement of discrete particles interacting via friction and collisions under external loading in confined spaces.

Jamming: Transition from fluid-like to solid-like behaviour when particle packing or stress exceeds a threshold, halting flow.

Shear band: Localised zone of intense deformation in a granular assembly, often leading to flow channeling or blockages.

Block caving: Mass-mining method where an undercut induces fragmentation and gravity-driven flow of broken ore towards drawpoints.

References

1. Modelling of primary fragmentation in block caving mines using a finite-element based fracture mechanics approach. Geomechanics and Geophysics for Geo-Energy and Geo-Resources (2017).
2. Study on the Rock Mass Caving and Surface Subsidence Mechanism Based on an In Situ Geological Investigation and Numerical Analysis. Mathematical Problems in Engineering (2018).
3. Prediction of the caved rock zones’ scope induced by caving mining method. PLOS ONE (2018).