Storchak A. Development and introduction of safe means and technologies for explosive dislodging of sulphide-containing rocks in open-cast mines.

The dissertation is devoted to the issues of development of safe means and technology for explosive dislodging of sulphide-containing rocks in open-cast mining of minerals. In the event of use of elementary and water-containing explosives, under certain conditions, there is a probability of occurrence of a spontaneous chemical reaction between components of an explosive material and natural sulfides. As a consequence, an exothermic reaction and premature detonation of charge of an explosive material is possible. The process of interaction between free nitric acid and sulfides (pyrite) is an initial impulse for ammonium nitrate decomposition. Reactions proceed under acid self-catalyzed mechanism with much heat release. It was determined that the process of activation and nature of behavior of exothermic reaction depends on pyrite concentration, temperature of ammonium nitrate solution, pieces of pyrite size, acidity of subsoil water etc. Chemical reaction prevention is achieved by introduction finely ground chalk into hot-flowing explosive materials structure. On this basis new modernized aquatol was worked out and introduced. But in view of the fact that in real conditions pyrite concentration considerably exceeds pyrite threshold value (4 %), it was made new method and technology of neutralization of exothermic reaction, which takes place at explosives operations in natural sulphides, namely: placing aquatols with chalk into polyethylene envelopes. This technology was introduced on Poltavskiy GZK open-pit mine. At the same time the problem of safety and efficiency of explosives operations has been solved.