GB573147A - Improvements in or relating to explosives - Google Patents

Abstract

573,147. Ammonium nitrate compositions. ROFFEY, F., POOLE, H. J., ALLMAND, A. J., STYLE, D. W. G., and DRAKE, C. F. Nov. 6, 1942, No. 15734. [Class 1 (ii)] [Also in Group XXI] Ammonium nitrate explosive or propellant compositions showing relatively small density changes when exposed to temperature cycles are obtained by (1) fuzing together in the presence of added water a mixture containing ammonium nitrate and a minor proportion of potassium nitrate or magnesium nitrate or both or (2) evaporating to dryness an aqueous solution of such a mixture, and subjecting the resultant product in either case to such thorough drying conditions that (a) the water content is reduced to 0.1 per cent. or less in the case where potassium nitrate is employed or (b) in the case when magnesium nitrate is used with or without potassium nitrate, the water content including water of crystallization is reduced to correspond to about 1 mol. or less per mol. of magnesium nitrate. When using potassium nitrate the ratio NH4NO3: KNO, is not less than 4: 1 and is preferably from 9 : 1 to 8.5 : 1.5, whilst with the magnesium nitrate the ratio NH4NO3 : Mg(NO3)2 is not less than 9: 1 and is preferably 95 : 5. When using both nitrates the ratio NH,NO,: KNO3:Mg(NO3)2 may be 92.5: 2.5: 5. Drying of the product containing potassium nitrate may be effected by repeated heating to 100‹C. and cold grinding, and of the product containing magnesium nitrate with or without potassium nitrate by heating to 100‹C. in a current of air. Products containing magnesium nitrate are improved by annealing for 5-8 hours at 55-70‹C. According to the Provisional Spedfication metallic nitrates other than potassium and magnesium nitrates may be used in carrying out the invention, the nitrates of calcium, strontium and zinc being referred to.