Zajtsev I. Working out of the methods for breaking rocks of different hardness under the thermal expansion in the open-pit minings

The thesis deals with the problems of boring and blasting operations in quarries under the thermal expansion of cutter holes bored in contact rocks of different harness by using the spontaneous regulation effect for the kettle-shaped hollows diameters. An operative method for determining of the kettle-shaped hollows volumes is proposed. The economical and mathematical model of specific expenditures for the whole technological circuit of the very hard rock mining is worked out and it permits to optimize these expenditures depending on the quality of mined bulk crushing. The results of investigation have been introduced into production and the real economic effect was reached. Key words: quarry, rocks of different hardness, hole, thermal expansion, kettle-shaped hollow, drilling and blasting operations.