busting procedure, composite explosive charge, and booster charge therefor

摘要

1,195,461. Blasting accessories. IMPERIAL CHEMICAL INDUSTRIES Ltd. 16 Dec., 1968 [1 Jan., 1968], No. 118/68. Heading F3A. An explosive blasting accessory comprises a column 13 of powdered metal or metalloid free from oxidizing material packed in a container 14 and, surrounded by the column, a charge of explosive 12 having a higher velocity of detonation than ANFO and in sufficient amount to dispense at least part of the powdered metal or metalloid in the after detonation gases of a blasting explosive charge 16 detonated in contact with the accessory in a method of blasting. The container is formed of polyethylene or P.V.C. and the metal or metalloid is present as a dry powder or a liquid suspension comprising aluminium, magnesium, iron, silicon or boron. The suspending liquid may be water thickened with guar gum, ground psyllium seed or cellulose ether. The charge 12 can be detonating fusecord and the charge 16 is ANFO or slurried explosive. In the method of blasting a gelatinous nitroglycerine explosive 11 is used as a primer. Quarry grit is employed as stemming 17.