This paper carries out the research on the continental mining of solid minerals and on the search of the alternative solutions of raw material’s procurement for leading industries. A value of conducting underwater operations for extraction of shelf zone’s ferromanganese nodules is specified. Schematic diagram of conducting mining operations is submitted. The construction of a mining complex for mining ferromanganese nodules of the Baltic Sea with the possibility of its separation partial enrichment on the seabed during the process of production is proposed. An analytical model of the system with bottom device and flexible traction element is given. The interaction between a flexible traction element and a bottom-mining unit allows to define the character of relative motion and also to describe the position of the flexible traction element as it moves in the aquatic environment. Specific conditions for steady operation of the complex for its inseparable moving on a seabed are presented.

The causes of failure of the tangential rotary cutter bits of the road header during stonedrift in rocks of medium strength are analyzed in the article. It was revealed that the most typical cause of failure of cutter bits is premature wear of the toolholder (body) of the cutter bit. It is well known that the most effective way to improve the wear resistance is to increase hardness. The influence of the thermomechanical treatment of the material of the cutter bit toolholder on its hardness is studied. It was established that the thermomechanical treatment of the cutter bit toolholder material results in the increase of its hardness. It was found that the increase of material hardness is proportional to the increase of material strain intensity during thermomechanical treatment. It was concluded that the use of thermomechanical treatment can lead to the increase of both the hardness and wear resistance of the cutter bit material.

DEM parameters calibration is the most important step in preparing a DEM model. At the same time, the lack of a universal approach to DEM parameters calibration complicates this process. The paper presents the author’s approach to creating a universal calibration approach based on the physical meaning of the friction coefficients and conducting symmetrical experiments at full scale and in a simulation, as well as the implementation of the approach in the form of a physical test rig. Several experiments were carried out to determine the DEM parameters of six material–boundary pairs. The resulting parameters were adjusted using a refinement experiment. The results confirmed the adequacy of the developed approach, as well as its applicability in various conditions. The limitations of both the approach itself and its specific implementation in the form of a test rig were identified.