GB1205971A - Blasting agent - Google Patents

Abstract

1,205,971. Explosive compositions. E.I. DU PONT DE NEMOURS & CO. 13 Sept., 1967, No. 41800/67. Heading C1D. A thickened slurry blasting agent which will detonate reliably at 40‹ F., consists essentially of water, an inorganic oxidizing salt at least partially dissolved in the water, a surfaceactive agent as a crystal modifier for the salt, a non-explosive fuel including at least 3% by weight, based on the total composition, of a carbonaceous fuel dissolved in the water, and from 5-60% by volume of small gas-filled cavities dispersed throughout the composition. Suitable inorganic oxidizing salts are alkali metal, alkaline earth metal, and ammonium nitrates, perchlorates, and dichromates. The surfaceactive agent may be anionic or amphoteric. Soluble carbonaceous fuels referred to are mono- and di-saccharides, alcohols, aldehydes, ketones, aliphatic acids, nitriles, amides, and lignin sulphonates. Insoluble fuels may also be present, for example, finely-divided coal, sulphur, iron pyrites, ferrophosphorus, and ferrosilicon. Thickening agents which may be used include tree exudates, seaweed colloids, seed extracts, starches and modified starches, and cellulose derivatives. A liquid organic compound may be added to act as an anti-freezing agent. Many specific examples of the above ingredients are given in the Specification. The gas-filled cavities may be produced by incorporating air, nitrogen, or carbon dioxide during the preparation of the composition, using a turbine or aerating mixer or a Venturi eductor, or by the generation of gas by the action of carbonates or bicarbonates on acid ammonium nitrate solutions. Alternatively, the composition may include a porous fuel such as a closed cell polymeric foam, a cellular carbonaceous material, or an expanded cereal, mineral or siliceous product; many of such materials are specified. In examples, the oxidizing salt is ammonium nitrate, together with sodium nitrate, the crystal modifier is sodium methylnaphthalene sulphonate or sodium lauryl sulphate, the soluble fuel is sucrose, dextrose, ethylene glycol, or formamide, the thickening agent is guar gum with potassium dichromate as a cross-linking agent, and the cavities are provided by agitation and aeration, or by the addition of bagasse pith, vermicu@ie, expanded cornflakes, or polyethylene foam. Reference has been directed by the Comptroller to Specification 1,156,596.