Initiation by flame

Initiation by flame and heat will be described in sections VIII and IX... 

Eizember, R. F. et al., J. Org. Chem., 1974, 39, 1792-1793 During oven-drying, kg quantities of the salt exploded violently. Investigation showed that self-propagating and extremely rapid decomposition of a cold sample can be initiated by local heating to over 200° C by a flint spark, prolonged static spark or flame. The sodium salt could only be initiated by flame, and the free acid is much less sensitive. 

Detonators are used to detonate high explosives. Stab detonators are initiated by sharp firing pins and are used in explosive trains of different types of fuses. Flash detonators are initiated by flames produced by safety fuses, primers, or delay elements. A special type of flash detonator ignited by the flame of a safety fuse is called a blasting cap. Detonators are primarily composed of three types of explosives including sinoxid mixtures, lead azide-based mixtures, and mercury fulminate-based mixtures. 

M.A. Cook etal, TrFaradSoc 56, 1028-38(1960 Promotion of shock initiation of detonation by metallic surfaces) 36a) Andreev Belyaev (i960), 265-68 (Starting impulse and mechanism of initiation) 268-70 (Initiation by heat) 270-73 (Initiation by flame) 273-86 (Initiation by shock or friction) 287-89 (Initiation of expln in projectiles on hitting a target) 36b) J. Favier C. Fauquignon, MP 42, 65-81(1960) (Initiation of expls. and transmission of detonation) 37) D.B. Moore J.C. Rice, Detonation of Secondary Explosives by Lead Azide , SRI (Stanford Research Institute), Poulter Laboratories, Technical Report 004-60(1960) 37a) S.J. Jacobs, AmRocket-... 

Initiation by Flame. Various aspects of this process were described under Burning and Combustion, Vol 2, pp B343-346 Dead-Pressed Explosives, Vol 3, p D20 Ignition in this Vol Thermal Explosion in a future Vol... 

In OrdnSergeant (Ref 4a, p 18) is described a WWII Instantaneous Fuse for Initiation of Demolition Charges which contd a core of MF 79.4 with wax 20.6%. When initiated by a cap, the fuse functioned at the rate of about 20000ft/s (6100m/s). If initiated by flame it will burn but its use as slow burning fuse was not recommended... 

Initiated by flame, sparks, friction, shock, high temps Cannot be initiated in the wet state Oxygen present in formulation... 

If the expi chge cannot be initiated by flame, it is pressed without insertion of the reinforcing cap. Then a 0.300 g chge of LA is placed on top of the expl, followed by the reinforcing cap and another compression at 3000 psi. Then the fuse is insetted and the chge initiated as above. After detg the amt of sand ctushed by these caps, subtract the wt of sand ctushed by 0.300 g LA, when loaded alone in No 6 caps... 

If the espl chge cannot be initiated by flame, it is pressed without insertion of the reinforcing cap. Then a... 

OSHA PEL TWA 2 mg(Sn)/m3 ACGIH TLV IW A 2 mg(SnVm3 SAFETY PROFILE Poison by ingestion, intraperitoneal, intravenous, and subcutaneous routes. Experimental reproductive effects. Human mutation data reported. Potentially explosive reaction with metal nitrates. Violent reactions with hydrogen peroxide, ethylene oxide, hydra2ine hydrate, nitrates, K, Na. Ignition on contact with bromine trifluoride. A vigorous reaction with calcium acetylide is initiated by flame. When heated to decomposition it emits toxic fumes of Cl. See also TIN COMPOUNDS. 

Detonators (Figure 1.2) are used to detonate high explosives. They are classified according to their external initiation mechanism into stab and flash detonators. Stab detonators are initiated by a sharp firing pin and used in the explosive train of different types of fuses, viiile flash detonators are initiated by flame produced by a safety fose, primer, delay elements, etc. 

Primary explosives differ in the way they respond when subjected to flame and, based on this type of response, may be divided into two groups. The explosives in the first group bum when initiated by flame and may, but do not have to, undergo transition to detonation. The detonation then propagates further with stable detonation velocity if such transition occurs. The typical substances in this group are MF, HMTD, TATP, and DDNP. This group is sometimes called a merctuy fulminate group. ... 

The second group, the so-called lead azide group, does not exhibit a predetonation zone under normal conditions. Initiation by flame results in practically instantaneous detonation. The typical members of this group include, besides lead azide, also silver fulminate and silver azide. Explosives of both groups—MF group as well as LA group—detonate when initiated by shock wave [24]. 

As opposed to alkaline azides which do not have properties of explosives, alkaline fulminates are mostly reported as highly sensitive and explosive substances [8,107, 108] even though one source mentioned sodium fulminate as not so sensitive (impact sensitivity for NaCNO to be 32 cm with 0.5 kg hammer compared to 7.5-10 cm MF under the same conditions) [27]. Sensitivity of these fulminates is reported as extreme and handling a hazardous operation [8, 107, 108]. Extreme sensitivity is further reported for the rubidium and cesium salts. Alkaline fulminates undergo explosion when initiated by flame, even in small amounts, whereas mercury fulminate only deflagrates. The exact sensitivity data are, however, not reported in this work [107]. Sensitivity of cadmium fulminate to impact is about the same as that of MF sensitivity of thallium fulminate is higher [15, 57]. 

LA has relatively low sensitivity to flame which is one of its biggest drawbacks. This low sensitivity is further lowered by formation of basic lead carbonate on its surface. This layer of carbonate isolates LA and makes the initiation by flame difficult, and as mentioned earlier, the formation of carbonate is favored in a humid and C02-rich atmosphere (e.g., in mines). In order to introduce and maintain good ignitability by flame, LA is mixed with some other primary explosive sensitive to flame (particularly lead salts of di- or trinitroresorcine). 

Initiated by flame, Initiated by flame, Most explosives are capable... 

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