The article discusses the requirements for propellers of bottom mining machines for the development of deep-sea deposits of such unique minerals as ferromanganese nodules, deep-sea polymetallic sulfides, cobalt-manganese crusts. The main factor is the minimal impact on the underwater ecosystem. Based on existing prototypes of mining machines and patents, an analysis of the advantages and disadvantages of existing conceptual mechanisms for the movement of mining machines was carried out, as a result of which it was determined that the most promising machines are those that do not contact the surface of the seabed, but such machines have a number of disadvantages. No less promising today are walking and tracked vehicles. The paper presents simplified formulas for determining the required minimum traction force when moving underwater mining machines, and simplified formulas for determining the speed of movement were obtained, which also clearly indicates the advantage of floating mining machines. According to the obtained graphical dependencies, a set of parameters plays an important role in the productivity of mining machines, including the speed of movement, overall dimensions, weight, and shape of the machine. The article also describes a complex for the extraction of minerals dispersed along the seabed, developed by the staff of the Department of Mechanical Engineering of St. Petersburg State University with various configuration options for the complex depending on the type of mineral, as well as the density of its distribution.

Project risk management in the mining industry is necessary to identify, analyze and reduce uncertainty. The engineering features of mining enterprises, by their nature, require improved risk management tools. This article proves the relevance of creating a simulation model of the production process to reduce uncertainty when making investment decisions. The purpose of the study is to develop an algorithm for deciding on the economic feasibility of creating a simulation experiment. At the same time, the features and patterns of the cases for which the simulation experiment was carried out were studied. Criteria for feasibility assessment of the model introduction based on a qualitative parameters became the central idea for algorithm. The relevance of the formulated algorithm was verified by creating a simulation model of a potassium salt deposit with subsequent optimization of the production process parameters. According to the results of the experiment, the damage from the occurrence of a risk situations was estimated as a decrease in conveyor productivity by 32.6%. The proposed methods made it possible to minimize this risk of stops in the conveyor network and assess the lack of income due to the risk occurrences.

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).