At the underground mining works performed in coal, rock and mixed coal & rocks, the process applied almost exclusively is by drilling & blasting. Given that the mines in the Jiu Valley are classified as methane mines, this involves the use of explosives and means of initiation that are safe from methane gas and coal dust. To date, permissible powdered explosives have been widely used. The drilling & blasting patterns were established according to the physical - mechanical and geological characteristics of the rocks in the massif, the type and section of the mining works as well as the restrictions imposed by the methane regime of the mines. In recent years, the widespread use of emulsion explosives has led to the development of permissible types of emulsion explosives. In order to use the permissible emulsion in the coal mines in the Jiu Valley, it was necessary to test in the INSEMEX landfill the safety and functioning parameters as well as to perform underground blasts, in the specific conditions of the methane coal mines. The paper describes the underground experimental blasting works performed, as well as technical and safety recommendations for the use of this type of explosive - permissible emulsion.
Coal dust, Lycopodium and niacin used in hybrid mixtures with methane and hydrogen in 1 m3 and 20 l chambers
