Kleshchov A. Improving technology of plasma-mechanical rock fracture

The thesis is aimed at improving technology of plasma-mechanical rock fracture by adding artificial flaws to the existing natural ones. As a result, it was determined that I type elastic modulus changes in accordance with quadratic dependence on energy of molecular bonds of crystalline structures. That allowed to assess rock energy potential. Furthermore, there were determined dependencies of plasma-mechanical rock fracture energy density on inductance in accordance with unimodal distribution with positive skewness, as well as on current intensity of combined load in accordance with unimodal distribution with negative skewness. That allowed to select an efficient mode of rock combined loading. There was achieved a decrease of energy density as to fracturing granites at "Pyniazevytskyi Quarry" using modernized drilling machine Copco ROC L8 - by 11%, from 61.38 kW*h/m^3 to 54.69 kW*h/m^3. There was also recorded a physical effect expressed by preliminary weakening of aleurolits and sandstones at DP "Volynvuhillia" of VP "Shakhta Buzhanska". Using plasma fracturing unit, I type elastic modulus of aleurolits decreased from 30.5 GPa to 11.7 GPa, of sandstones - from 15.0 GPa to 4.5 GPa. Annual economic effect coming from introducing plasma-mechanical rock fracture within "Pyniazevytskyi Quarry" may reach UAH 1,577,800. Calculated period of repayment as to introducing improved technology of plasma-mechanical rock fracture is 7 months.