Mercury fulminate density

Mercury fulminate is a pale brownish solid, insoluble in cold water, but dissolving slightly in hot water to a solution which does not give the normal mercury reactions. In cold conditions it is stable, but at higher temperatures gradually decomposes and loses strength as an explosive. It has a density of 4-45 g ml-1 and a velocity of detonation, when compressed to a practical density of 2-5, of about 3600 m s-1. 

The densities of loading for mercury fulminate obtainable by applying different pressures are tabulated below ... 

According to Kast and Haid [55] the rate of detonation against the density of mercury fulminate is related as follows ... 

A mixture of mercury fulminate containing 10% of KC103 detonates at a density of 3.16 with a rate of 4090 m/sec. 

Fig. 75. The relation between the density and the rate of detonation, and sensitiveness to initiation by mercury fulminate of chlorate explosive [80].

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. 

Medard [23a] examined the explosive properties of methyl-a-D-glucopyranoside tetranitrate prepared according to Fleury et al. [12]. The product requires a relatively weak initiator, e.g. 0.25 g of mercury fulminate suffised to detonate a sample of the substance of density 1.10. Only the cast product (density 1.65) requires a strong detonator (over 1.5 g fulminate). 

Mercury fulminate has a specific gravity of 4.45, but a mass of the crystals when merely shaken down has an apparent density (gravimetric density) of about 1.75. In detonators the material is usually compressed to a density of about 2.5, but densities as high as 4.0 have been obtained by vigorous compression. Mercury fulminate crystallizes from water in crystals which contain y.H20, from alcohol in crystals which arc anhydrous. One liter of water at 12° dissolves 0.71 gram, at 49° 1.74 grams, and at 100° 7.7 grams. 

Hexamethylenetriperoxidediamine is almost insoluble in water and in the common organic solvents at room temperature. It detonates when struck a sharp blow, but, when ignited, bums with a flash like nitrocellulose. Taylor and Rinkenbach 63 found its true density (20°/20°) to be 1.57, its apparent density after being placed in a tube and tapped 0.66, and its density after being compressed in a detonator capsule under a pressure of 2500 pounds per square inch only 0.91. They found that it required a 3-cm. drop of a 2-kilogram weight to make it explode, but that fulminate required a drop of only 0.25 cm. In the sand test it pulverized 21/ to 3 times as much sand as mercury fulminate, and slightly more sand than lead azide. It is not dead-pressed by a pressure of 11,000 pounds per square inch. It is considerably... 

Primary explosives include mercury fulminate [Hg(ONC)2, melting point 160°C with explosion, density 4.2], lead azide [Pb(N3)2, density 4.0], basic lead styphnate (lead trinitroresorcinate), diazodinitrophenol, and tetrazine (a complex conjugated nitrogen compound, melting point 140 to 160°C with explosion). Most priming compositions consist of mixtures of primary explosives, fuels, and oxidants. 

Mercury fulminate is the most sensitive among the initiating agents to impact and friction, although its sensitivity decreases as the density of the pressed mass increases. The sensitivity also decreases by the addition of water but increases in the presence of sunlight. Mercury fulminate decomposes when stored at elevated temperatures. 

However, when lead azide, lead styphnate, mercury fulminate, RDX, TNT, and PETN were subjected to bombardment with a negative pion beam, no explosions or decompositions were observed for any of the explosives. The analysis had predicted initiation only for RDX. Also it had indicated that nuclear fission events would produce higher energy densities and greater temperature increases than were actually observed. 

Fig. 2.1 Influence of density on detonation velocity top mercury fulminate [3-11] and bottom lead azide [4-9, 12-16). Two samples with specific surface 706 cm g and 5,802 cm were listed in [9]...

The mercury fulminate (MF) formula is HgCC N" —0 )2 with a covalent bond between the mercury and carbon atoms [20]. Its crystal density is reported to be 4.42-4.43 g cm [29, 30, 39, 40], but recent results of X-ray analysis updated it to 4,467 g cm [21]. Bulk density depends on crystal size and shape—it is reported to be between 1.35 and 1.55 g cm [38]. The heat of formation of MF is reported as being between —268 and —273 kJ moP [29, 41, 42]. The structure of the MF molecule and its crystal was published recently by Beck et al. [21]. Pure and ordinarily prepared mercury fulminate is, for all practical purposes, not hygroscopic, but its hygroscopicity rapidly increases in presence of impurities (e.g., mercury oxalate, calomel, mercuric chloride), which are generally present in the industrial... 

Dependence of detonation velocity on density is shown in Fig. 2.1. Mercury fulminate belongs to the group of primary explosives with a long predetonation zone. In other words, it means that it takes a long time, and uses significant amounts of charge, before the decomposition reaction accelerates from simple initial impulse to fully developed detonation (slow deflagration to detonation transition... 

Tiirker, L., Erko9, S. Density functional theory calculations for mercury fulminate. J. Mol. Struct. THEOCHEM 712, 139-142 (2004)... 

Table 3.1 The effect of density on the velocity of detonation for the primary explosive, mercury fulminate and secondary explosive, nitroguanidine...

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