Explosive substances perchlorates, 339

It is assumed that fluorine with perchloric acid at 72% forms the following highly explosive substance ... 

Reputedly the most explosive substance known, it is very sensitive to impact, friction and heat. It is readily formed from ethanol and perchloric acid. 

Explosives that contain a chlorate along with an ammonium salt or an acidic substance, including a salt of a weak base and a strong acid, are forbidden in transportation, e.g., ammonium chlorate, which is shock-sensitive, can detonate when exposed to heat or vibration. It is used in the production of explosives. Ammonium perchlorate is also shock-sensitive, and may explode when exposed to heat or by spontaneous chemical reaction. This is the material that was involved in the explosion at the Pepcon plant in Henderson, Nevada. It is also used in the production of explosives, pyrotechnics, etching and engraving, and jet and rocket propellants. 

Perchlorates are powerful oxidizing substances. These compounds explode when mixed with combustible, organic, or other easily oxidizable compounds and subjected to heat or friction. Perchlorates explode violently at ambient temperatures when mixed with mineral acids, finely divided metals, phosphorus, trimethylphosphite, ammonia, or ethylenediamine. Explosions may occur when perchlorates are mixed with sulfur, or hydride of calcium, strontium, or barium and are subjected to impact or ground in a mortar. Perchlorates react with fluorine to form fluorine perchlorate, an unstable gas that explodes spontaneously. Heating perchlorates to about 200°C (392°F) with charcoal or hydrocarbons can produce violent explosions. Metal perchlorates from complexes with many organic solvents, which include benzene, toluene, xylenes, aniline, diozane, pyridine, and acetonitrile. These complexes are unstable and explode when dry. Many metal perchlorates explode spontaneously when recrystaUized from ethanol. Saturated solution of lead perchlorate in mathanol is shock sensitive. 

It should be noted that the incorporation of substances such as TNT increased the sensitivity to initiation, and the addition of AN increased the quantity of expln gases, while at the same time diminishing the sensitivity of the perchlorate expl to open flame Refs See below under Inorganic Perchlorate Military Explosives... 

Before nitrates and particularly ammonium nitrate were readily available commercially, explosives were developed based on chlorates and perchlorates. These also are still used in some countries. In general perchlorates are considered less dangerous than chlorates and therefore preferred. They are easily sensitised, so that in addition to explosives of this type based on nitroglycerine, others have been based on various organic liquids, particularly nitrobodies. History shows that chlorates and perchlorates must be regarded as temperamental substances, liable in bulk to lead to inexplicable accidents. Particularly when mixtures of chlorates and oxidising materials are allowed to become wet and then dry out, conditions can arise in which there is an appreciable sensitiveness to friction and impact. Explosives of this type have an unfortunate record of accidents. They are used, therefore, to a limited extent only, now that safer compositions are available. 

The diazonium perchlorates are extremely explosive, shock-sensitive materials when dry, some even when damp [1,2], The salt derived from diazotised p-phenylendiamine was considered to be more explosive than any other substance known in 1910 [3], Individually indexed compounds are 4-Aminobenzenediazonium perchlorate, 2304 Benzene-l,4-bis(diazonium perchlorate), 2160 Benzenediazonium perchlorate, 2232 4,4/-Biphenylenebis(diazonium) perchlorate, 3457... 

Yet another important feature of inorganic oxidisers such as potassium nitrate rests with the nature of the atoms forming the chemical bonds. Many pyrotechnic compositions rely on chlorates, perchlorates or nitrates as high-energy oxidisers whilst high explosives commonly are based on nitrated organic substances. The reason for this lies with the electronegativity of the atoms concerned. 

Explosive Properties of Mixtures of Organic Substances with Nitric and Perchloric Acids... 

This substance forms salts with acids. The nitrate, perchlorate and picrate of (IV) have explosive but not initiating properties. 

These substances have a variable composition depending upon the reaction conditions, chiefly the concentration of the reagents used. Salvadori [119] called attention to the interesting explosive properties of the chlorates and perchlorates of complex ammines of the type ... 

Friedrich and Vervoorst found that the substance [Cu(NH3)4](C103)2 has initiating properties. It is however of no practical use, losing ammonia fairly rapidly in air. In damp air it is easily hydrolysed. Nickel ammino perchlorate [Ni(NH3)6] (C104)2 is a fairly strong explosive with the rate of detonation 5300 m/sec at the density 1.39. 

Perchlorate explosives, like chlorate explosives, can be compressed to a high density, but the detonation at a high density is difficult. This is illustrated by a graph published by the French Commission on Explosives (Commission des Substances Explosives) (Fig. 75) [80] which shows how the rate of detonation and the amount of mercury fulminate required for detonation varies with density. 

Elliot and Brown [62] made extensive studies of the inflammability of mixtures of perchloric acid with oxidizable substances. Most of the mixtures of 60% perchloric acid when ignited in a confined space burned to detonation. The mixtures with 70% perchloric acid and some of them with 60% perchloric acid could be ignited by impact. Explosion was induced under action of No. 6 detonator on mixtures with 60% perchloric acid with wood meal or cotton and the rate of explosion was found to be 3000 m/sec. 

It is well known that anhydrous perchloric acid must never be allowed to come into contact with oxidizable organic substances such as alcohols, wood, cotton, paper, cork and most plastics otherwise ignition or explosion will result. 

Anhydrous perchloric acid is liable to explosive decomposition even when free of organic substances. On storage it gradually becomes coloured due to the formation of decomposition products, even in the dark, and in this condition it may explode spontaneously. Anhydrous acid which has become amber coloured (or darker) should therefore be diluted with water immediately and discarded. 

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