St. Petersburg Mining University (St. Petersburg, Russia):

Bolobov V. I., Professor, Doctor of Engineering Sciences, Senior Researcher, boloboff@mail.ru
Plashchinsky V. A., Assistant, Candidate of Engineering Sciences, SlavaPlash@yandex.ru

Energy consumption for rock fracturing is one of the key indicators used for assessing the overall mining efficiency. It is, therefore, critical to develop methods aimed to ensure the proper measurement accuracy for this value. In the current research, the energy consumed for rock fracturing, regardless of the method, is generally viewed as a function of the linear size of the sample, its cross-sectional area, or its volume. There is, however, no single substantiated approach to what indicators should be used for various fracturing methods, including when splitting large rock fragments. A clarification for this issue is, therefore, quite relevant. This paper presents the methodology and experimental results for the splitting of sandstone in the form of cube-shaped samples and plates. It has been established that no satisfactory convergence is observed when the splitting energy is regarded as a function of the splitting surface area or the sample volume: respective energy consumption ratios for the cubic form and plates are widely scattered (between the factors of 2 and 240). By contrast, the ratio of the energy to the thickness of the sample being fractured takes on an almost constant value. It has been experimentally confirmed that the use of a composite impact tool with extended impact times reduces energy consumption in rock fracturing, which is also consistent with the statements of V. B. Sokolinsky on the preconditions for the splitting process.

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