The immediacy of the problem under study is due to the fact that the devices for extraction of solid mineral deposits from the offshore fields are not effective enough and do not meet modern requirements regarding safety, productivity, energy intensity and environmental friendliness nowadays. The purpose of the article is to analyze the influence of hydrostatical pressure, determined by the depth of the capsule location, on the operational and energy characteristics of the proposed mining equipment and the dependence of system performance on the type of a dredge head and its parameters. The leading approach to analyzing this problem was the theoretical study of the processes of hydraulic hoisting and separation of nodules from the bottom, as well as experimental studies of the applied hydraulic motor parameters on the laboratory bench with the processing of results via the mathematical statistics methods and verification of the adequacy of theoretical provisions. As a result, it was found that the energy intensity of the nodule production process depends on the capsule location depth and varies according to the parabolic law; in this case, there is a mode of effective work of the facility to be determined by the model proposed in the article. It was also substantiated that the achievement of the facility performance required level is ensured by the application of a special dredge head, which has an annular channel between the driven hydraulic motor and protective cover, which geometrical dimensions are being determined with consideration for the maximum nodule size and required engine power. It has been experimentally proven that local resistances at the output of the driven hydraulic motor depend on the release coefficient when draining the power fluid into the environment. The materials of the article are of practical value for further studies in the field of determining a high performance technology for extraction of sea-bed solid mineral deposits, as well as during development of technical facilities for the underwater mining of nodules and other solid mineral deposits.

This article examines the development of deep and extensive potash deposits, focusing on the mandatory preservation of the waterprotective layer and the implementation of measures to minimize surface subsidence, which significantly affects the mineral extraction ratio. These requirements, along with the need for disposal of processing plant waste, can be addressed through backfilling of mined-out spaces. The main types and methods of backfilling are reviewed. It is noted that backfill costs can be reduced by using technologies that employ hardening mixtures, which enable the subsequent extraction of inter-chamber pillars and increase overall mineral extraction. However, the production and complete filling of chambers with hardening mixtures substantially raises costs, limiting widespread adoption and necessitating the development of more economical solutions. A technology for layer-by-layer mechanized backfilling, developed by the Institute of Comprehensive Exploitation of Mineral Resources (IPKON) Russian Academy of Sciences, is presented. This approach involves two stages: the primary stage uses dry transport of processing waste, and the secondary stage backfills the upper part of the chamber with a hardening mixture prepared directly near the chamber, achieving high strength characteristics in the backfill mass. A proposed equipment set, designed to fit within the actual dimensions of mine workings, can be assembled into a single mobile system through technical modifications. The potential for using mobile systems to prepare backfill mixtures in underwater mining of solid minerals is also discussed.

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.