Patent ID: 9557149
Date: 2017-01-31
CPC Classifications: A62D,C06B,F42B

Claim:
1. A method of deactivating an explosive cartridge in a blasting operation during mining, quarrying, or seismic exploration in which an explosive composition provided in an explosive cartridge is rendered insensitive to detonation after a predetermined amount of time, comprising the following steps: (a) positioning the explosive cartridge in a borehole and priming the explosive cartridge with an initiating device; (b) contacting the explosive composition with a chemical deactivating agent that is contained in the explosive cartridge and that is capable of reacting with the explosive composition to render the explosive composition insensitive to detonation; and (c) allowing the chemical deactivating agent to react with the explosive composition so that the explosive composition is rendered insensitive to detonation by the initiation device, wherein the explosive composition remains sensitive to detonation by the initiating device for a controlled amount of time after the explosive cartridge has been positioned in the borehole and primed with the initiation device, the controlled amount of time being less than the predetermined amount of time, and wherein steps (b) and (c) take place so that the explosive composition is rendered insensitive to detonation following the predetermined amount of time, and wherein the chemical deactivating agent and explosive composition are separated by a barrier element and wherein the barrier element is ruptured or removed by (i) insertion of the initiating device into the cartridge, thereby causing the chemical deactivating agent and explosive composition to come into contact with each other, or (ii) connecting one of the explosive cartridges to another of the explosive cartridges.