Developing a Safer Underground Explosive

Underground mines resort to the use of explosives to break extremely hard materials that intrude into coal seams. Since there is no longer P5 explosive available for delay firing, mines resort to using type 1 explosive. Confusion arises as to how these explosives can be safely used. Currently permitted explosives are being used outside the recommended guidelines as published by the Buxton Testing Authority in the UK. In order that they can be used safely, mines are conducting risk assessments to manage the incendive hazard that possibly could be created by a cut off shot and additionally managing the deflagration hazard with the same risk assessment when using P1 explosives.  

The outcomes achieved in this project include:

• being able to benchmark an explosive before sending it to be tested against the requirements of Testing Memorandum -2 (TM-2);
• solving the riddle of the invisible receptor after testing in the Type II Cannon;
• developing an explosive that meet the requirements for a P5 explosive which is fully compliant with TM-2.

This project developed an alternate test regime that adequately assesses the deflagration risk of an explosive. The information gained from this testing provides additional data to change the testing regime for permitted explosives.