The authors conducted the analysis of the peculiarities on the destruction of rock formations by means of tunneling and mountain combine tools. They specify key criteria for choosing the rational parameters of cutting executive bodies in mountain combines. The article lists the factors influencing the efficiency of mine rock cutting. It is noted that the key drawback of mountain massif destruction with cutting is that consecutive elementary rock chips separation occurs under the influence of compression loads. The least energy-intensive way of destruction of rocks is a method that involves the destruction of mountain massifs chiefly under the influence of tensile loads, that is, by detachment. A design is proposed which is a combined executive body of the tunneling and cleaning unit including a bar executive and two-sided hydrocylinders-tractors installed inside the bar beam. The operation principle and procedure of the proposed executive body are described. The use of the proposed executive body will allow one to destroy the mountain massif in the most energy-efficient way ensuring high productivity and the lowest specific consumption of cutters.

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.

The article is devoted to the analysis of the composition and properties of the materials and liquids during transportation using pipeline and shows that in order to increase the efficiency of hydraulic transport systems in mining a transition to the transportation of slurries with a high concentration of solids in the slurry flow is necessary. Experimental studies have shown that slurry tailings of gold-containing ore with mass concentrations of more than 55 % are viscoplastic fluids. Experiments on a rotational viscometer allowed us to establish the main rheological characteristics of the studied slurries – shear stress and the dynamic effective viscosity. It has been established that over the entire range of concentrations from 55 to 65 %, the flow of slurries is described by the Bingham rheological equation. Experimental studies of hydraulic transport performed on a laboratory setup with a pipeline diameter of 50 mm confirmed the results obtained on a rotational viscometer. The curved of mixture stream is inclined straight lines that are cut off on the axis of the head in the sections, which determine the initial hydraulic slope corresponding to the yield shear stress on the rheological curves. According to the results of the experiments, a method has been developed for calculating the hydraulic transport of high concentrated slurries of tailings of gold-bearing ore. Calculations showed that in a given range the performance of the hydrotransport system and the mass concentration of the solid phase pressure losses vary from 11 to 84 m of water column/m. Head loss values increase with the increasing concentration. A sharp increase in the head loss occurs in the concentration range from 60 to 65 % and higher.