The presented research is focused on two issues. The first one is finding additional parameters that characterize the technical condition of an electric machine according to the current consumption. The second one is increasing of the informativeness of diagnostic methods in conditions of limited access to equipment and incomplete information. The paper discusses a method for diagnosing low and medium power asynchronous electric motors by electrical parameters. It is shown that asynchronous electric motors powered from a self-commutated voltage inverter have contained higher harmonic components in addition to the main harmonic. The non-sinusoidal voltage leads to the emerging of the highest current components in the stator winding of the motor. This is the reason for occurring of a pulsating component of the torque on the motor shaft. Therefore, there are two types of ripple: the one caused by the power supply from the self-commutated inverter and the one caused by defects. The moments’ coincidence of these ripples leads to increasing in the amplitude of oscillations. However, significant noise due to the presence of an autonomous inverter does not allow using the current spectrum to diagnose damage. Analysis of the hodographs of the Park’s vector of the stator current and voltage allows one to exclude harmonic components that were formed by the carrier frequency (and multiple of it). At the same time, analyzing the modulus of the Park’s vector and its spectrum, one can note pulsations of the amplitude values of the vector modulus corresponding to certain damage.

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.

The most important task of the production of the mineral raw materials industry is to increase the efficiency of the equipment and infrastructure in operation. In particular, this also applies to the need to create transport systems with high productivity while reducing the cost of transporting mineral raw materials and waste from its processing. Particular attention is paid to the use of hydraulic filling systems as a measure to prevent man-made tectonic earthquakes during prolonged and continuous development of deposits. In this paper, we consider the problem aimed at solving the fundamental problems of developing effective methods for controlling the flow of pasty substances in pipelines of variable cross-section, intended for the production of pumping equipment and used in such industries as mining, chemical, food, etc.