Given the critically important role of haul trucks in the overall mineral extraction process chain, the suspension system — the component with the highest failure frequency — was selected as the research object. The authors propose a method for quantitatively assessing a group of parameters of a technological transportation route due to challenging mining operating conditions. Using data from two mining enterprises over a three-year period, dependence was established between the reduction in the service life of dump truck suspensions and each of the identified factors in the route parameter groups. The assessment was carried out using data from remote monitoring systems installed on the vehicles. Based on the derived dependence, a criterion for optimizing the overhaul interval of haul truck suspensions was developed, incorporating a set of planning and economic factors. This criterion allows decisions to be made on the advisability of implementing measures aimed at achieving a target reliability level for the suspension system within the framework of the maintenance strategy adopted by mining enterprises, which combines scheduled and emergency repairs of machine components and assemblies. Using the proposed criterion, an optimal ratio between grading equipment and haulage equipment was determined when forming the vehicle fleet. Furthermore, an algorithm for determining a rational overhaul interval for haul truck suspensions was developed based on this criterion. Implementation of the algorithm at the mining enterprises under study has significantly reduced both the duration of unplanned downtime caused by suspension failures and the time required for repair activities.

Destruction of rocks and artificial composites is carried out in various ways. One of the most common methods is the impact fracture. The conical pick of JCB HM380 hydraulic breaker was used as the impact tool. The experimental study of rock fracture was carried out on an artificial composite—concrete. The depth of penetration of the pick into concrete was used as the test parameter. The model was based on the model of Professor V. B. Sokolinsky. The model developed in this work takes into account the degree of bluntness of the tool insingle and multiple impact. The system was considered as a two-component system due to the high stiffness of the pick–granite contact (as against the hammer piston–pick stiffness). The wave processes in the pick were disregarded because of the small length of the pick. The pick penetration depth in rocks was calculated theoretically, using the developed mathematical model, at each impact of the pick, and then was compared with the experimental data. The fracture tests also used JCB HM380 breaker and concrete. The penetration depth was determined from the step-frame analysis of video filming of the process. It is found that the pick blunting causes a monotonic increase in the rock resistance to the pick penetration, both in single and multiple impact, while the depth of the tool penetration and the blow time decrease (as compared with the initial state of the tool, by 28% and 20%, respectively).

The hydrotransport system of Mikhailovsky GOK PJSC used for iron ore processing tailings was studied with the aim of establishing its performance in slurry pipelines with and without polyurethane coatings of their internal surfaces under mass concentration variations of 10 to 70 %, as well as for preparing related recommendations for the enterprise. Theoretical and laboratory studies were completed with the development of a methodology for recalculating the experimental laboratory data for the specific head loss in industrial pipelines. It has been established that the use of internal polyurethane coatings significantly reduces the specific head losses in hydraulic transportation of thickened tailings slurry for iron ore processing tailings. The respective feasibility calculations confirm the economic efficiency of using steel pipes with internal polyurethane coating in hydrotransport slurry pipelines. The calculated specific head losses for the pipelines with a polyurethane coating in the hydraulic transportation of processing tailings slurry with the mass concentration of the solid phase of 6.95 % are almost 1.8 times lower than in steel pipelines without such coating. It is proposed to use the results obtained in the reconstruction of the tailings slurry hydrotransport system at Mikhailovsky GOK PJSC with a conversion to hydraulic transportation of bulk concentration tailings thickened to 35–40 % in slurry pipelines with an internal polyurethane coating, which will ensure energy savings in the hydrotransport process.