Hot-hole blasting in coal mines: Reference Explosives Formulations
Sub-surface fires due to smoldering coal deposits are challenges to drilling, charging, and blasting mining operations.
Such holes, apparently looking cool and safe can undergo sudden escalations in temperature resulting in the explosion of explosives. This is because of the ample availability of oxygen (for burning coal) in hitherto oxygen-deficient situations.
Such auto-ignition of explosives inside the hot hole may be life-threatening if there are personnel within range of the blast or its flyrock. In a worst-case scenario, this can result in premature and uncontrolled detonation of the explosives column. Such an event could occur while the operators still work on the bench.
Most mines follow operating procedures for blasting in hot areas, however, there have been several incidents where primed but not charged holes have detonated prematurely.
We have developed "explosive formulations" that can withstand higher temperatures.
We have studied the physico-chemical parameters of the input materials and the final products that can withstand the high temperatures inside the hot holes and can delay the process of auto-ignition for a reasonable amount of time.