Research of the economic indicator of costs under the cyclic-flow technology in ore pits
Introduction. The present article of dedicated to the estimation of technological parameters and conditions of rock mass transportation from deep horizons of ore open pit where the use of more expensive cyclic-flow technology (CFT) is the most efficient compared to the widespread use of excavating-automobile complex (EAC). The choice of the system of cyclic-flow technology and corresponding parameters is made according to an economic criterion towards lower costs. Research aim is to discover the regularities in transport costs change under different mining-technological parameters of CFT complexes and, based on this, by an economic criterion, estimate their permissible intervals where the use of these complexes would be the most efficient. Methodology. In order to discover regularities in transport costs change, the calculations of their experimental and discrete values has been carried out together with the further simulation of costs connections with the parameters of the complexes applied with the method of curvilinear functional-factor regression. The costs of excavating-automobile complexes for ore and overburden rocks transportation application have been experimentally calculated, together with the cyclic-flow technology in open pits with opencast and not opencast edges. The costs have been calculated with the account of reduction to one instant and their transfer to the relative units. Among the multitude of technological parameters influencing the expenses, two most significant ones have been singled out - production rate of transport complexes by rock weight and the height of its rise from the working horizon. Parameters were set by the corresponding values 5, 10, 20, 30 million tons/year and 180, 280, 380, 480, 580, 680 m. Based on the experimental calculations, the regression models have been created which, with high reliability by the coefficient of determination 0.986-0.998, display regularities in costs change and the features of their connections with technological parameters of complexes. The comparison of model costs has been carried out under the use of the transport complexes under consideration and, according to the accepted criterion, quantitative estimate of their parameters has been given where the use of the cyclic-flow technology is effective. Results. The application of the cyclic-flow technology in open pits without opencast edges during ore transportation is not limited by mining and technological parameters of complexes, whereas during overburden rocks transportation it is partially limited. The most significant restrictions of technological parameters are observed in open pits with opencast edges. These restrictions are expressed mathematically by the corresponding inequalities.