Thermal decomposition characteristics and spontaneous combustion phenomenon of emulsion explosive containing FeS2 impurity

Abstract

AbstractIn the process of pyrite blasting mining, emulsion explosives in blast holes can sometimes spontaneously detonate prematurely. In order to reveal its accidental explosion mechanism, the effects of different content of FeS2 impurity on the thermal decomposition characteristics and thermal spontaneous combustion parameters of emulsion explosives were studied in detail. The experimental results of thermal analysis showed that pure emulsion explosive had a strong stability, but when it was doped with FeS2 impurity, its initial temperature of thermal decomposition reaction reduced and the decomposition rate accelerated. With the increase of FeS2 impurity content, the average activation energy of emulsion explosives decomposition decreased from 110.84 to 63.78 kJ/mol, resulting in an increasing risk of thermal runaway. The results of thermal spontaneous combustion experiments showed that FeS2 impurity would significantly shorten the ignition delay period and combustion flame duration of emulsion explosive, and increase the combustion flame temperature. With the increase of FeS2 impurity content in emulsion explosive, the ignition delay period and the duration of the flame continued to decrease and increase, respectively, and the maximum average temperature of the flame showed a trend of rising at first and then decreasing. The research results were of great significance to the accident identification of emulsion explosive accidental explosion in pyrite blasting operations.