METHOD OF EFFECTING UNDERGROUND BLASTING OPERATIONS

摘要

1,237,193. Generating foam. DYNAMIT NOBEL A.G. 30 Jan., 1969 [31 Jan., 1968], No. 5098/69. Heading B1C. [Also in Divisions Cl, E1 and F3] A method of suppressing dust formation and ignition of fire damp in underground blasting operations comprises displacing the gases present in a borehole by filling it with a foam obtained from a foam-forming agent, water and a gas the foam being kept in the borehole during insertion therein of an explosive charge and until ignition of the latter. The gas may be air, carbon dioxide or inert gases. Foam forming agents may be anionic, cationic and non-ionic soaps and surface-active substances and saponin and proteins. Inorganic foam forming agents may be colloidal aluminium oxide and aliphatic carboxylic or phosphoric acids or their salts. There may also be used sulphonation products of mineral oils and alcohols, and horse-chestnut extracts. Foam stabilizers which may be used are condensation products of fatty acids with alkanolamines, polyacrylic acids, urea, thiourea or guanidine. The foam also forms a tamping medium.