GELATION OF GALACTOMANNAN CONTAINING WATER-BEARING EXPLOSIVES

1,205,972. Explosive compositions. E.I. DU PONT DE NEMOURS & CO. 31 May, 1968 [2 June, 1967], No. 26232/68. Heading C1D. A water-containing blasting composition is prepared by forming a hydrosal comprising water, galactomannan, a fuel, an inorganic oxidizing salt other than a chromium compound, and a water-soluble reducing agent, and adding to the hydrosol a water-soluble chromate or dichromate, which is reduced and effects rapid cross-linking of the galactomannan. The chromate may be added just prior to packaging or pumping into a bore-hole. Self-explosive fuels specified include TNT, PETN, RDX, HMX, tetryl, nitrostarch, nitrocellulose, and mixtures thereof; several non-explosive fuels are listed, including dinitrotoluene, sulphur, coal, vegetable products, hydrocarbons, Al, Mg, Zn, B, Si, ferrophosphorus, and ferrosilicon. The inorganic oxidizing salt may be an alkali metal, alkaline earth metal, or ammonium nitrate or perchlorate. The galactomannan is preferably guar gum, but several other gums are listed. Suitable reducing agents are alkali metal, alkaline earth metal, and ammonium sulphites and bisulphites, and soluble antimony and bismuth compounds, several such compounds being specified. Chromates specified are sodium and potassium chromates and dichromates, and barium and zinc chromates. In examples, the following ingredients are used: aqueous ammonium nitrate liquor, sodium nitrate, TNT, sulphur, aluminium particles coated with a fatty acid and a high viscosity oil, guar gum, potassium antimonyl tartrate or sodium sulphite, and sodium dichromate. - Reference has been directed by the Comptroller to Specification 1,002,672.