Rational strategy of transition processes in the formation of the quarry transport system to increase the effective depth of its development

Relevance. The need to increase the degree of development of the geo-resources of deep-lying deposits of solid minerals requires the search for methodological approaches to increase the economically achievable depth of the open-pit mining method as safer and more productive in comparison with the underground one. One of the options is to reduce the cost of transporting rock mass, which in the cost of commercial ore for deep quarries reach 50 % or more. The article examines the impact of the moments and nature of the implementation of transients in the formation of the transport system and the corresponding transformation of the field opening scheme on the economically achievable depth of the quarry. Aim. Development of methodological principles for choosing the moments of transition in the development of the deep pit transport system (as an element of the mining system) based on their impact on the final technical and economic indicators. Objects. A quarry at a deep-lying deposit and its transport system. Methods. Mining and geometric analysis, enlarged technical and economic calculations of economic indicators of field development, taking into account the type of transport and the depth of mining operations. Results. The paper introduces the results of calculations of the difference between income and expenses according to the variants of a theoretical quarry depth. The paper shows the impact of the moment of implementation of transitional processes for the development of the quarry transport system (transition from automobile to combined transport) on the economically achievable depth of the quarry. The author presents the concept of step-by-step implementation of transitional processes for transport system transformation. The proposed approach ensures the search for rational moments in the implementation of transitional processes for the transformation of the quarry transport system and, accordingly, the opening scheme, providing technical and economic advantages and achieving the maximum effective depth of field development.