A long-hole open-stope blast in hot ground.

A project is described involving the drilling and blasting of a 200 000 t stope enclosed between stopes filled with oxidising waste sulphide material at the Brunswick Pb-Zn mine in New Brunswick, Canada. The rock temperatures were up to 83 degrees C and there was a constant risk of SO2 exposure. The stope was drilled off from two different platforms and required a combination of down, side and up holes. The rock temperature was monitored and tests carried out to investigate the reactivity of the ore with the explosive. On the basis of the results, a bulk emulsion explosive with a reaction inhibitor for sulphide ore suitable for up-hole application was selected. Two sticks of a cap-sensitive emulsion explosive containing the same inhibiting agent were used for priming. The blast was successfully and safely conducted without any incidents.
A project is described involving the drilling and blasting of a 200 000 t stope enclosed between stopes filled with oxidising waste sulphide material at the Brunswick Pb-Zn mine in New Brunswick, Canada. The rock temperatures were up to 83 degrees C and there was a constant risk of SO2 exposure. The stope was drilled off from two different platforms and required a combination of down, side and up holes. The rock temperature was monitored and tests carried out to investigate the reactivity of the ore with the explosive. On the basis of the results, a bulk emulsion explosive with a reaction inhibitor for sulphide ore suitable for up-hole application was selected. Two sticks of a cap-sensitive emulsion explosive containing the same inhibiting agent were used for priming. The blast was successfully and safely conducted without any incidents.