In the process industry major accidents are still caused by fires and explosions caused by combustible dusts. Purpose of these investigations was to identify whether porous inert materials have an influence on dust explosibility and if so, whether this effect can be used to mitigate dust explosions. Commonly dry chemicals are used to minimize the impact and to prevent the occurrence of dust explosions in the process industry. Generally, two types of inerting are known. The first type, which is called thermal extinction, is the cooling effect caused by the partial evaporation of the inert material. The other type is based on the interaction of the radicals with the particle wall (i.e. the surface of the particle).
An influence on the explosibility of combustible dusts is expected due to the addition of porous inert material with a high surface area. Investigations were conducted to determine whether and in which way the addition of porous matter with a high surface area influences the dust explosibility. Therefore, investigations with a mixture of various inert materials and lycopodium powder as combustible dust have been carried out. Whereas commonly used extinguishing powders have a surface area of about 0.1 to 0.4 m²/g, the tested porous material has a 1000-fold higher specific surface area. Finally, investigations using samples with a lower surface area have been carried out to identify the difference between various surface area values.