1964 The test methodology was designed to qualify such new products on a site-specific basis. When deploying the 90-day product sleep time at a particular mine, samples of that mine’s ore can be tested as per the new protocol. In the rare case a mine has an extremely reactive area that could overwhelm the inhibitor system, the test will identify it and flag that additional controls or an alternate approach is needed for that site. Given that several factors on site introduce uncertainty, for instance: the small number of samples tested and limited access to sampling areas means the most reactive rock on site may not be sampled; heat is not easily dissipated from bulk explosive products or some reactive ores; the level of oxidation and weathering is variable across space and time - large safety factors were included, which are justified given the consequences of failure (potential unplanned detonation). With the combination of the: new test methodology; 90-day sleep time product range and WebGen™ wireless initiating system, mines can plan entirely new mining strategies. For example, an underground mine can pre-charge stopes months in advance and initiate blasts on demand to match logistical schedules or improve recovery by bogging to grade, vastly improving mining cycle efficiency and reducing personal exposure to the hazardous areas like rills. Surface mines can preload multiple shots and reduce downtime. Importantly, all this can be done while maintaining the safety of reactive ground management on sites by identifying reactive zones proactively, using the qualified product in those zones, and adhering to the defined sleep limit (90 days) backed by test data and applied consistently. Both the time-to-reaction studies and the modeling scenarios demonstrated the importance of understanding the ground temperature because even modest self-heating can escalate dangerously over time. Some additional precautions are proposed: regular monitoring of blast hole temperatures at long sleep time sites to identify self-heating if it occurs, clear tracking of all loaded holes and integration with mine planning (to avoid exceeding the allowed time), and having an emergency response plan (for example, the ability to evacuate personnel to safety if any sign of reaction is detected). These are consistent with existing codes and good practices but must be maintained over a longer time. The mining team must remain vigilant when managing all blasting hazards, including hot and reactive ground. The ability to proactively manage reactive ground for long durations has benefits beyond the immediate use-case of wireless blasting. It enhances general mine safety – reducing the “load-and-shoot” requirement in reactive areas allows greater flexibility and reduces operational disruption by allowing larger, less frequent firings. Finally, our methodology and findings contribute to the broader advancement of mining science and blasting practice, as noted in the abstract. This study combines chemistry, calorimetry, and engineering modelling to address a real-world mining problem, demonstrating how multidisciplinary research can yield practical safety solutions. REFERENCES AEISG. ( 2020). Code of Practice Elevated temperature and Reactive Ground Edition 5. Australasian Explosives Industry Safety Group (AEISG). ASTM. (2022). Assessing Thermal Stability of Matarialsby Methodsof Accelerating Rate Calorimetry. ASTM. Bustamante Rúa, M. O. (2019). A study of fire propagation in coal seam with numerical simulation of heat transfer and chemical reaction rate in mining field. International Journal of Mining Science and Technolog. Cadiou S, C. M. (2020). 3D heat transfer, fluid flowand electromagnetic modelfor cold metal transfer wire arc addaptive manufacturing. Additive Manufacturing. doi:https://doi.org/10.1016/j.addma.2020.101541
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