Patent ID: 7387071

Claim:
A method of blasting or breaking rock or other materials by means of pressure/shock waves generated in a tamped drill hole, the method including forming a stemming plug by holding a stemming material in a container at a predetermined spacing from a surface by a bottom of the drill hole by means of a frangible spacer abutting said surface and corresponding to said predetermined spacing and being connected to the container, the container and the spacer forming a sacrificial blasting accessory; locating a pressure generating or shock wave generating substance adjacent the container remote from the bottom; initiating said pressure generating or shock wave generating substance to cause the stemming material to be displaced at speed toward the bottom, characterized in that the container is of a defined volume and includes a openable and closable closure and by the initial method step of filling, in use, the container with a correspondingly defined volume of stemming material and closing the container by means of the openable and closable closure.