Basic trends in development of drilling equipment for ore mining with block caving method

The authors have determined the causes of drop in performance of induced block caving using fans of blastholes 105 mm in diameter and single blastholes 250 mm in diameter, as well as the sources of increased drilling cost and expansion of start-up time of production blocks in Abakan underground mine. Alternatives of improvement in drilling efficiency under current conditions are discussed.     

Microseismic Monitoring of Geodynamic Phenomena in Rockburst-Hazardous Mining Conditions

Journal of Mining Science - The stress–strain behavior patterns in rockburst-hazardous rock mass are described as a case-study of mineral deposits in Gornaya Shoria. The microseismic research...     

Influence Exerted by Construction of Vertical Cylindrical Explosive Charges Increased in Diameter on the Degree of Ore Shattering

The results are presented for the laboratory and in-situ investigations into influence exerted by construction of the vertical cylindrical explosive charges on the degree of rock-mass shattering. The necessity is shown for creating the ascending workings with a cross-section up to 1m ². For the vertical concentrated charges with inert gaps, the drilling-and-blasting parameters ensuring a decrease in specific consumption of explosive for the secondary shattering are given.     

Bimetallic catalysts for the hydrogenation of aromatic nitro compounds

The catalytic activity of bimetallic Pd-Ni, Pd-Cu, and Pd-Ag catalysts in the reaction of nitrobenzene hydrogenation was studied. It was found that the rate of hydrogenation on the bimetallic catalysts was higher than that on palladium metal (palladium black), and it depended on catalyst preparation pro cedures. The catalytic activity of the bimetallic systems increased in the order Pd-Cu< Pd-Ag ? Pd-Ni.     

Utilization of elastic energy of rock mass as a source of renewable energy

The authors investigate modes and parameters of mining operations with a view to create conditions for transmission of geotechnologically produced kinetic energy of rocks to electric generators. The features of application of energy-harvesting equipment in underground mining of hard minerals are discussed. The low-frequency energy trap designed to entrap elastic energy of rock mass oscillations operates in a wide range of amplitudes and frequencies of rock mass vibration, and is composed of three nonlinear oscillators having preset mass and elastic characteristics.     

Using hybrid neural networks in a problem of adaptive testing

In the paper, we studied specific features of adaptive testing implementation by means of different methods for the purpose of increasing an objective character of results of such tests and decreasing labor-intensiveness of their creation. We chosen an optimal structure for a hybrid neural network.     

Fission time for the U + α reaction measured by the crystal blocking technique

The crystal blocking technique has been used to measure the total time of the induced fission process for the ²³⁵U + α reaction in the energy range of bombarding α-particles from 25.9 to 31.2 MeV. Experimental fission times observed in this reaction vary from 10⁻¹⁷ to 10⁻¹⁶ s, depending on the projectile energy. Together with the corresponding experimental data on angular anisotropy in the same reaction they were analyzed within the dynamic-statistical approach with allowance for the nuclear dissipation phenomenon and the double-humped fission barrier model. It was demonstrated that the time of induced fission at low excitation energies is sensitive to the nuclear dissipation magnitude.     

Electromagnetic Emission of Rocks after Large-Scale Blasts

Journal of Mining Science - Physical modeling results on electromagnetic response of rock mass to low-energy impacts in the Tashtagol iron ore deposit are presented. It is found that multiple...