Non-Explosive Rock Fragmentation Techniques

Non-explosive fragmentation comprises physical, chemical and thermal approaches to break hard rock masses without conventional blasting. It spans expansive agents, thermal spalling, high-pressure fluids and gas-based fracturing. These strategies aim to mitigate vibration, noise, dust and toxic emissions, enhancing safety, environmental compliance and operational efficiency in mining, tunnelling and excavation. Chemical demolition agents, notably soundless cracking demolition agents, exploit expansive hydration reactions to generate controlled tensile stresses. Thermal fragmentation induces spalling via rapid temperature gradients, while plasma blasting employs ionised gas to impart mechanical and thermal loads. Controlled foams, supercritical fluids and mechanical splitters further extend the toolkit, offering targeted, sequenced or automated fragmentation. Recent advances integrate numerical simulation, real-time monitoring and optimised delivery systems to tailor fracture networks, minimise energy consumption and accommodate geological variability. These innovations underpin sustainable excavation, enabling continuous operation, reduced support requirements and improved resource recovery on a global scale.

Research from Nature Portfolio

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Research from all publishers

Recent work has introduced advanced numerical models to simulate the initiation and propagation of SCDA-induced fractures. By incorporating strain energy density rather than peak expansive pressure, three-dimensional distinct element analyses accurately replicate the expansion behaviour of cementitious demolition agents in intact rock and across joints. Laboratory validation under varying joint roughness and confining pressures demonstrated the model’s capacity to predict fracture nucleation, shear damage and energy release without additional calibration, supporting design optimisation for underground and surface applications.

A critical review of explosives-free methods has synthesised developments in thermal fragmentation, plasma blasting, controlled foam injection, radial-axial splitters and supercritical carbon dioxide fracturing. It highlights thermal spalling’s rapid cycle times balanced against high energy demand, plasma technology’s safe, fume-free performance tempered by equipment constraints, and foam-based systems’ versatility alongside dynamic safety considerations. Mechanically driven radial-axial devices offer hole-by-hole precision, while supercritical carbon dioxide jets produce high-pressure streams capable of fracturing without water use. The review underlines the promise of chemical demolition agents for in-situ mining and tunnelling, calling for further work on reaction kinetics, delivery methods and scalability in complex geological settings.

Non-Explosive Rock Fragmentation Techniques publication trend

The graph below shows the total number of articles in non-explosive rock fragmentation techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Soundless Cracking Demolition Agent (SCDA): A cementitious compound that expands upon hydration within boreholes to induce tensile stresses and controlled fracturing in rock.

Thermal fragmentation: A method using rapid heating to create steep temperature gradients, causing surface spalling and tensile failure in rock.

Plasma blasting: The application of high-temperature, high-pressure ionised gas pulses to generate shock waves and thermal stresses for rock breakage.

Radial-axial splitter: A mechanical device inserted into drilled holes that expands radially and axially to induce controlled fracturing.

Supercritical carbon dioxide fracturing: The use of carbon dioxide at supercritical conditions to produce high-pressure jets, exploiting fluid penetration and tensile stress development for fragmentation.

References

1. Strain energy dependent numerical simulation of rock fracture initiation and propagation using soundless cracking demolition agents (SCDA): Effects of SCDA-filled rock joints. International Journal of Rock Mechanics and Mining Sciences (2024).