| The occurrence of blast malfunctions is investigated for deep underground production stopes at Vale's Creighton mine. Over the course of six years, multiple stope blasts were recorded throughout Creighton with triaxial accelerometers and borehole camera surveys to detect the frequency of blast malfunctions. The variety in stope and blast design parameters have allowed for a detailed comparison to be made regarding the frequency of malfunctions related to the size of the blasts, the type of detonators used, the type of explosive used, the relative in-situ stress of the stope, and the number of explosive decks used in the blast designs. The investigations into the malfunctions have found that the sequence of explosive performance typically is initiated by successful charges, followed by partial energy charges, followed again by failed charges. It was also discovered that single charge boreholes have a greater explosive performance success rate than multi-decked blast designs. |
