Ammonium nitrate explosive substances

AMMONIUM NITRATE EXPLOSIVE SUBSTANCES (EN: ammonal, ammonium nitrate explosives; DE: Ammonsalpetersprengstoffe, Ammonnitrat-sprengstoffe, ANC-Sprengstoffe; FR: explosifs nitres; ES: explosivos de nitrato amonico; RU: аммиачно-селитренные взрывчатые вещества) are the explosive mixtures, the main component of which is the ammonium nitrate. They have been proposed for the first time in 1867 by I.Norbin and J.Olsen, who were the Swedish scientists, as the mixtures with the non-explosive combustible materials or nitro compounds. They have got the first practical usage within the 80-ies of the 19 century within France in the form of the mixtures with dinitronaphthalene (the compositions by Favier), with nitroglycerin (12-29%), namely, grizu-dynamites (within Russia, grizutines), as the safety improver of the explosive substances for the blasting works within the coal mines, which are dangerous because of gas or dust.

Modern ammonium nitrate explosive substances are sub-divided into the ammonites (nitro compounds), ammonals (aluminium and other metallic powders), simplest and dynammons (non-explosive combustibles of the organic origin), water-containing (plasticized by the aqueous gelatin), nitroglycerine explosive substances.

For the addition of the special properties, they introduce into the ammonium nitrate explosive substances the flame retardants, for example, the salts of the alkali metals (explosive substances with improved safety), the hydrophobic additives, namely, salts of the fatty acids, paraffin wax (waterproof ammonium nitrate explosive substances), the plasticizers, namely, aqueous gelatin (water-containing ones, namely, aquanites, aquatols, ifzanites (slurries)), and others.

For the prevention of the caking, for the increase of the flowability, and for the decrease of the dusting, they produce ammonium nitrate explosive substances in granular form. Unlike the individual brisant explosive substances, the process of the explosive transformation of the ammonium nitrate explosive substances is two-staged: during the 1st stage there proceed the decomposition of the ammonium nitrate with the release of oxygen, the decay or gasification of the fuels; during the 2nd stage there proceed the oxidation of the products of the decay, and the gasification of the solid particles of aluminium by oxygen.

The detonative ability of the ammonium nitrate explosive substances depends on the sizes of the particles, composition, and density of the charge. The ammonium nitrate explosive substances are significantly safer during the handling, and more economical, than dynamites and powerful individual explosive substances, and because of this are the major type of the industrial explosive substances. The sensitivity of the ammonium nitrate explosive substances to the mechanical impacts increases with the increase of the dispersion of the mixture and after the introduction of the sensitizers. There are most safe during the handling the granular and water-containing ammonium nitrate explosive substances, which tolerate the mechanized methods of charging.

The ammonium nitrate explosive substances are used during the development on the daylight surface and underground, including within the mines, which are dangerous because of the gas or dust, within the dry and watered stopes, during the manual and mechanized methods of charging. The ammonium nitrate explosive substances, which are assigned for the underground works, have the oxygen balance, which is near to the zero one, which ensures during the explosion the minimal release of the toxic gases (carbon monoxide, nitrogen oxides).