Justification of the rational scope and technology for the use of hydraulic excavators in surface mining

The constrained conditions of deep-pit mining and the rigid technological interdependence between operations on lower and upper horizons significantly complicate the performance of loading and haulage systems and, in particular, hinder the efficient use of large rope shovels. At the same time, due to a limited service life and a sharp decline in reliability after 7–10 years of operation, mobile hydraulic excavators cannot compete with mechanical shovels when excavating hard rock formations. Based on research and industrial experiments, combined solutions have been developed and tested for the use of rope and hydraulic excavators within their respective optimal application areas to improve the efficiency of mining operations. The proposed priority application zone for hydraulic excavators is defined in areas with a planned low concentration of drilling-and-blasting operations, where the utilisation factor of rope shovels is below 0.5, while that of mobile hydraulic excavators – with appropriate geomechanical support – is at least 0.7. At the same time, hydraulic excavators cannot directly compete with large mechanical shovels in the development of hard rock. Therefore, a specialised technology for within-block differentiation of drilling and blasting parameters is proposed to ensure the geomechanical conditions necessary for the effective integration of hydraulic excavators into mining operations.