Manufacture ammonium nitrate mining explosives

The density of nitropolystyrene is very low, due to its fluffiness . Medard suggested its use in the manufacture of ammonium nitrate mining explosives of low density, hence of a relatively low power. The following figures give some idea of such mixtures ... 

The preparation of infusible (loose powder) ammonium nitrate mixtures is usually carried out in the same way as the manufacture of composite mining explosives. Since the military explosives are not very sensitive to mechanical stimulants, and it is important to obtain a high density, mixing is usually performed by edge runner mills. 

According to the U.S. Standards ammonium nitrate for production of military explosives should contain 99.0% of NH4N03, no more than 0.02% free nitric acid, 0.18% of water-insoluble material, 0.50% of ammonium sulphate and 0.5% of ammonium chloride. The product should be free from alkalis and metal nitrates. A substance of similar purity is used for the manufacture of mining explosives. 

Methods of manufacture ammonium nitrate are described in specialist books on inorganic technology and technology of nitric acid and ammonium salts. However, the method of manufacture of low density prilled ammonium nitrate merits special attention as it can be used to manufacture low density coal mine explosives. 

During the 1914-1918 War trinitroanisole was manufactured in Germany under the names of Nitrolit, Trinol and An. It was used alone or in admixture with ammonium nitrate, hexyl, or hexanitrodiphenyl sulphide, for filling high explosive shells and for submarine and land mines. Eventually it had to take the place of TNT. 

Most of the nitric acid is utilized in the form of 50 to 70% acid for the manufacture of nitrogen-containing fertilizer, particularly ammonium nitrate. Ammonium nitrate is also used as an explosive e.g. in mining, due to its low explosion temperature (safety explosive). Other industrially important nitrates are sodium nitrate, a speciality fertilizer and oxidizing agent in the glass and enamel industries, and calcium and potassium nitrates, which are also used as fertilizers. Nitric acid is also utilized in the digestion of raw phosphate (Odda process, which is not operated in the USA, see Section 2.1.2.4) ... 

Ammonium nitrate is used commonly in fertilizers in pyrotechniques, herbicides, and insecticides, as well in the manufacture of nitrous oxide. It is used as an absorbent for nitrogen oxides, an ingredient of freezing mixtures, an oxidizer in rocket propellants, and a nutrient for yeast and antibiotics. It is also used in explosives (especially as an oil mixture) for blasting rocks and in types of mining. 

Faversham Powder.—One of the explosives on the permitted list (coal mines) is extensively used, and is manufactured by the Cotton Powder Co. Ltd. at Faversham. It is composed of tri-nitro-toluol 11 parts, ammonium nitrate 93 parts, and moisture 1 part. This explosive must be used only when contained in a case of an alloy of lead, tin, zinc, and antimony thoroughly waterproof it must be used only with a detonator or electric detonator of not less strength than that known as No. 6. 

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