Analysis of the regularities of basalt open-pit fissility for energy efficiency of ore preparation

Abstract

Purpose. To identify dependence of specific rock mass fissility upon the bench height of basalt open pits based upon the analysis of basalt open-pit bench fissility. Methods. Fractural tectonics of basalt open pits was studied experimentally. In addition to the specific fissility, the studies determined both shape and quantity of natural blocks within each bench meter; their geometry in terms of fissure frequency; and nature of changes in the fissure number as well as geometry of the blocks depending upon a bench height. Graphical analysis of the obtained results has helped determine the typical dependencies of fissure number upon the changes in the open-pit bench height. Findings. It has been defined that the specific fissility of basalt benches is distributed irregularly in terms of an open-pit bench height. Field studies, involved three basalt open pits, have made it possible to identify that the 3rd degree polynomial is the most adequate approximation of the specific fissility dependence upon the bench height. Originality. For the first time, the experiments have helped define that rock mass joints a share downward from the smaller to the larger ones following a parabolic law (according to a cubic expression). The obtained regularities help identify the percentage of shares of three sizes for each bench height meter. Practical implications. Estimate of share percentage will make it possible to schedule rationally the drilling and blasting operations while selecting energy efficient parameters of production facilities for further basalt processing.