GB1157303A - Improved Process for the Manufacture of Granulated Ammonium Nitrate - Google Patents

Abstract

1,157,303. Ammonium nitrate; explosive compositions. OFFICE NATIONAL INDUSTRIEL DE L'AZOTE. 15 July, 1966 [15 July, 1965], No. 31973/66. Headings C1A and C1D. Granular ammonium nitrate is crystallized from a solution the solute of which consists of ammonium nitrate and 0.01 to 10% by weight of the total weight of solute of a compound or compounds whose crystals are isomorphic with allotrope IV of ammonium nitrate. The solution may be prepared by adding the compound(s) to a nitric acid solution and neutralizing the acid with ammonia, or by adding the compounds) to an ammonium nitrate solution. Examples of compounds which may be used are ammonium sulphate, ammonium fluoborate, ammonium oxalate, the double carbonate of magnesium and ammonia, the double phosphate of magnesium and ammonium, magnesium orthophosphate, manganese orthophosphate, magnesium sulphate, potassium carbonate, potassium nitrate potassium sulphate and potassium orthophosphate. The ammonium salts mentioned may be prepared in situ by the addition of sulphuric acid, fluoroboric acid or oxalic acid to the nitric acid solution prior to the completion of the neutralization with ammonia. The granules prepared are found to have an impact strength 5 to 150 times greater than conventional granules, and may be used to prepare explosives, for example by mixing the granules with 6% by weight of fuel oil.