Blasting professionals from BME’s Indonesia office recently shared their research on preventing mud flows from contaminating emulsion explosives, and proposed paths for future research, at the International Society of Explosives Engineers annual conference.
Their research paper, written in collaboration with customer Adaro Energy Indonesia, was presented at the ISEE in January in North Carolina.
Entitled ‘Dynamic Mud Flow Effects on Emulsion Explosives in Indonesia’, the paper was a response to incidents of significant contamination of emulsion blend explosive at an Indonesian coal mine – due to mud and water flow resulting from exceptionally high rainfall. This intrusion into the explosive columns on the mining bench compromised the stability and efficiency of blasting operations and impacted negatively on overall mining productivity.
Authors of the paper were Garfiansyah Rayes and Ngisomuddin of Kemitraan MNK BME – a partnership of BME and Indonesian company MNK – and Zulham of Adaro Indonesia. In their research, they analysed the extent and impact of these contaminants on the stability and performance of the emulsion blend explosive. Their assessment methodology included field measurements and controlled laboratory experiments which were designed to replicate the challenging site conditions.
Using theoretical calculations and computational fluid dynamics (CFD) simulations, their study evaluated the kinetic interactions between dynamic mud flows and emulsion explosives within drill holes.
“The methodology integrates Torricelli’s theorem for velocity assessments and Darcy’s Law for understanding the penetration mechanics of mud into the emulsion blend,” the authors explained. “CFD simulations were further correlated with actual blast data to assess discrepancies between theoretical predictions and real-world outcomes.”
Practical mitigation
The results demonstrated a significant reduction in the velocity of detonation (VOD) of the explosives, traced directly to mud contamination levels, which align with the quantified penetration rates in the study. The authors were then able to propose practical measures for mitigating such contamination; these included the reinforcement of waterways, culverts and bund walls at drilling locations – based on validated simulation data.
This study underscored the multifaceted challenges posed by heavy rainfall and high groundwater flow in the South Kalimantan mining context, illustrating the intricate balance between emulsion explosive formulations and site-specific hydrological pressures.
“The convergence of dynamic mud and water inflow with the intrinsic limitations of current emulsion blends reveals that even products engineered with robust water-resistance features can exhibit declining performance beyond certain operational thresholds,” the authors explained. “Such performance degradation, typified by the observed reductions in VOD, highlights the susceptibility of emulsions to contamination under turbulent and pressurised environments.”
Operational changes
They also made recommendations for operational adjustments during high rainfall events, aimed at enhancing blasting safety and efficiency. In their advice, they highlight that it is crucial to adjust the charging procedures for high-intensity rainfall events by implementing robust pre-charging protocols; these must be designed to protect the integrity of the emulsion blend. It may even be necessary to suspend charging operations during peak rainfall to prevent emulsion dilution.
“Monitoring weather conditions closely is also recommended,” they said. “Systems should be set up to accurately track rainfall intensity and link to weather apps that can automatically trigger adaptive blasting protocols when critical thresholds are reached.”
They added that there is also a need to continuously develop improved emulsion formulations. The ongoing refinement of emulsion chemistry – encompassing enhanced emulsifiers, advanced gassing or sensitising agents and optimised micro-balloon or hollow microsphere systems – was indispensable for raising the resilience of these products.
Deeper understanding
The authors pointed out that assessments using theoretical and computational fluid dynamics confirm the need for a deeper understanding of water-penetration mechanisms – and these can pave the way for predictive design strategies.
“However, it is evident that even the most advanced emulsion formulations will invariably require complementary site-level interventions,” they explained. “Holistic water management – including effective dewatering protocols, real-time monitoring of hydrogeological fluctuations, and adaptive blasting schedules – must form an integral component of strategic planning to mitigate the deleterious effects of excessive moisture.”
Future research
The paper concluded by suggesting directions for future research. Among the recommended focus areas were to develop more resilient emulsion formulations, and to enhance predictive modelling techniques. The latter could help to improve the forecasts of how environmental variables could impact on the performance of explosives in mining operations.
“Ultimately, the findings suggest that a purely chemical or material-based solution may be insufficient when operational conditions push the boundaries of engineered tolerances,” the authors said. “Instead, a synergistic approach that couples cutting-edge product innovation with comprehensive environmental control measures offers the most promising path forward.”
They highlighted that, by embracing iterative design improvements and proactive water management, the industry can more effectively maintain explosive efficacy. This will help to ensure safer, more predictable blasting outcomes in the face of intensifying climate variability.