Ignition temperature lead styphnate

Fig. 55. Variation of the minimum light energy for ignition of lead styphnate with ambient temperature, according to McAuslan [53]. x — ignition o—no ignition.

Fig 21 Variation of the Minimum Light Energy for Ignition of Lead Styphnate with Ambient Temperature (Ref 56)... 

Evans and Yuill [51] showed that lead styphnate may be ignited by adiabatic compression of air, the calculated temperature amounting to 660°C, whereas Bryan... 

Lead styphnate. Lead styphnate, 13, also known as 2,4,6-trinitro-soreinate, is an explosive compound used to start the ignition-to-detonation process in the explosive sequence. It is stable at elevated temperatures and non-corrosive. The addition of graphite enhances its electrical conductivity in systems designed for electrical initiation. Dry lead styphnate is the most sensitive of the primary explosives to electrostatic discharge [6]. 

Lead styphnate and mercuiy fulminate can be initiated by light but show two requirements for propagation. They either bum with a velocity of a few meters per second or detonate. The minimum critical ignition energy for lead styphnate monohydrate crystals covered with a quartz plate is 29 J [32]. If a water filter was used, the value was 31 J, showing that infrared radiation plays little part in the initiation, the temperature rise being produced by absorption of the blue or ultraviolet light emitted by the flash. 

Lead picrate is considered highly sensitive to mechanical impact and thermal stimuli [6]. The anhydride is more sensitive to mechanical stimuli than the hydrates. Impact sensitivity of anhydride is significantly higher than the sensitivity of mercury fulminate (4 cm/0.5 kg vs. 24 cm for MF) [7,8]. Handling of lead picrate anhydride represents the same level of risk as handling of lead styphnate. The ignition temperature is 281 °C (explosion takes place instantaneously or within 1 s) [7]. The formation of lead picrate by reaction of tetryl (which decomposes to picric acid) with lead azide is reported as a possible reason for the higher sensitivity of this mixture compared to pure LA [6]. 

The five second explosion temperature is 315°C to 345°C for pure lead azide and 275°C for dextrinated lead azide. These temperatures are much greater than the corresponding values for mercury fulminate, lead styphnate, diazodinitrophenol, and tetracene and reflect the greater difficulty in igniting lead azide in practical use. The maximum static discharge for which no ignition takes place is 0.01 joules. 

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