In connection with a gradual extraction of ore areas in a valley, with the aim of support of annual output of the Koashva open-pit mine, a necessity arises in involving in the mining of near-ore bank reserves, located in the north-west bench of open-pit mine. For uncovering and mining of near-ore bank reserves it is necessary to assess the geodynamic and geomechanical conditions for support of the safe mining operations. The article describes the solution of this problem by means of software product 3DEC of Itasca firm.
The choice of mining methods is one of the most important phases at the designing stage and it has an influence on the economic efficiency of mineral deposit mining. Consideration is given to the order of selection of mining methods on the example of near-ore bank reserves of the Koashva deposit. Upon selecting a mining method by constant and variable factors, the selected mining methods are compared by their technical and economic indices, and so the field of application of each mining method is identified.
The influence of the duration of the explosive pulse on the size of the resulting crater is investigated. Various factors affecting its size are considered. For this purpose, experiments were carried out at the mines of AO Sevuralboksitruda. It is established that the radius of the explosive funnel is equal to the radius of distribution of a wave of stresses for the duration of an explosive load, defined depending on the point of initiation of a charge, and cannot exceed the size of the radius of a cracking zone at influence on a monolithic rock massif by energy of explosion of an elongated charge. The minimum length of the charge, providing the maximum possible size of the blast funnel radius, depends on the initiation scheme, the detonation rate of the explosive used, physical and mechanical properties of rocks of the blasted massif and is determined by the obtained formulas.
