Abstract: A method of blasting plural layers of material in a blastfield that reduces the amount of mechanical excavation required to expose a lower layer of material. The method includes using rows of equally spaced blastholes that pass through all of the layers and additional intermediate rows of blastholes that pass down only through the top layer. Each blasthole is capped with stemming material and includes one or more decks of explosive material and detonators, which air decks or inert stemming separating adjacent explosive decks. The detonators in layer are detonated first in order from row rearwards to throw a substantial amount of the blast material from the layer forwardly of free face onto the floor. In the same blasting cycle and within seconds of the throw blast, explosives materials in layers are detonated in a stand-up blast in which material in layers are broken up but otherwise are minimally displace or thrown forwardly.

Abstract: A method of blasting rock, in mining for recoverable material, comprising drilling blastholes in a blast zone, loading the blastholes with explosives and then firing the explosives in the blastholes in a single cycle of drilling, loading and blasting. The blast zone comprises a high energy blast zone in which blastholes are partially loaded with a first explosive to provide a high energy layer of the high energy blast zone having a powder factor of at least 1.75 kg of explosive per cubic meter of unblasted rock in the high energy layer and in which at least some of those blastholes are also loaded with a second explosive to provide a low energy layer of the high energy blast zone between the high energy layer and the adjacent end of those blastholes, said low energy layer having a powder factor that is at least a factor of two lower than the powder factor of said high energy layer.

Abstract: A method of blasting rock, in mining for recoverable material, comprising drilling blastholes in a blast zone, loading the blastholes with explosives and then firing the explosives in the blastholes in a single cycle of drilling, loading and blasting. The blast zone comprises a high energy blast zone in which blastholes are partially loaded with a first explosive to provide a high energy layer of the high energy blast zone having a powder factor of at least 1.75 kg of explosive per cubic metre of unblasted rock in the high energy layer and in which at least some of those blastholes are also loaded with a second explosive to provide a low energy layer of the high energy blast zone between the high energy layer and the adjacent end of those blastholes, said low energy layer having a powder factor that is at least a factor of two lower than the powder factor of said high energy layer.

Abstract: A method of blasting rock, in mining for recoverable material, comprising drilling blastholes in a blast zone loading the blastholes with explosives and then firing the explosives in the blastholes in a single cycle of drilling, loading and blasting. The blast zone comprises a high energy blast zone in which blastholes are partially loaded with a first explosive to provide a high energy layer of the high energy blast zone having a powder factor of at least 1.75 kg of explosive per cubic meter of unblasted rock in the high energy layer and in which at least some of those blastholes are also loaded with a second explosive to provide a low energy layer of the high energy blast zone between the high energy layer and the adjacent end of those blastholes, said low energy layer having a powder factor that is at least a factor of two lower than the powder factor of said high energy layer.

Abstract: A method of blasting plural layers of material (38, 40, 42, 44) in a blastfield (16) that reduces the amount of mechanical excavation required to expose a lower layer of material. The method includes using rows of equally spaced blastholes (18, 20, 22, 24) that pass through all of the layers and additional intermediate rows of blastholes (26, 28) that pass down only through top layer (40). Each blasthole is capped with stemming material and includes one or more decks of explosives material (46) and detonators (48), with air decks or inert stemming (45) separating adjacent explosives decks (46). The detonators in layer (40) are detonated first in order from row (18) rearwards to throw a substantial amount of the blast material from layer (40) forwardly of free face (12) onto floor (34).

Abstract: A method of blasting plural layers of material in a blastfield that reduces the amount of mechanical excavation required to expose a lower layer of material. The method includes using rows of equally spaced blastholes that pass through all of the layers and additional intermediate rows of blastholes that pass down only through the top layer. Each blasthole is capped with stemming material and includes one or more decks of explosive material and detonators, which air decks or inert stemming separating adjacent explosive decks. The detonators in layer are detonated first in order from row rearwards to throw a substantial amount of the blast material from the layer forwardly of free face onto the floor. In the same blasting cycle and within seconds of the throw blast, explosives materials in layers are detonated in a stand-up blast in which material in layers are broken up but otherwise are minimally displace or thrown forwardly.

Abstract: A method of blasting rock, in mining for recoverable material, comprising drilling blastholes in a blast zone loading the blastholes with explosives and then firing the explosives in the blastholes in a single cycle of drilling, loading and blasting. The blast zone comprises a high energy blast zone in which blastholes are partially loaded with a first explosive to provide a high energy layer of the high energy blast zone having a powder factor of at least 1.75 kg of explosive per cubic metre of unblasted rock in the high energy layer and in which at least some of those blastholes are also loaded with a second explosive to provide a low energy layer of the high energy blast zone between the high energy layer and the adjacent end of those blastholes, said low energy layer having a powder factor that is at least a factor of two lower than the powder factor of said high energy layer.

Abstract: A method of blasting plural layers of material (38, 40, 42, 44) in a blastfield (16) that reduces the amount of mechanical excavation required to expose a lower layer of material. The method includes using rows of equally spaced blastholes (18, 20, 22, 24) that pass through all of the layers and additional intermediate rows of blastholes (26, 28) that pass down only through top layer (40). Each blasthole is capped with stemming material and includes one or more decks of explosives material (46) and detonators (48), with air decks or inert stemming (45) separating adjacent explosives decks (46). The detonators in layer (40) are detonated first in order from row (18) rearwards to throw a substantial amount of the blast material from layer (40) forwardly of free face (12) onto floor (34).