Purpose. The solution to one of the important problems of the underground mining method is to substantiate cost-effective, technologically feasible and safe variants for mining steeply dipping low-thickness ore bodies. Methods. Mining systems are substantiated on the basis of a detailed analysis of the developed and existing experiential variants for mining steeply dipping ore bodies, identifying production and economic disadvantages, as well as their causes. Findings.As a result of the research, the pillar raise performance in the mining system with ore shrinkage has been substantiated. The main parameters of the proposed variants for mining systems with ore shrinkage, intended for expansion-type supports and borehole breaking, have been substantiated. A design has been developed of fastening the material-running raises (MRR) and ventilating raises (VR) on the working and ventilation horizons to ensure their performance in the mining system with ore shrinkage. Originality. For the first time, dependences of dilution and labour productivity on the ore body thickness and the type of ore breaking for blast-hole stoping and borehole breaking for a single and “twinned block” have been obtained. In addition, a certain dependence of the loading and delivery performance on the average fractional composition, as well as on the delivery distance, has been obtained. Practical implications. The research is characterized by scientific innovations created for the first time, which are able to ensure the efficiency and safety of mining operations, while creating the ability to manage the loss of minerals and dilution in the block, as well as reaching their calculated optimal ratio in order to achieve the most cost-effective production rate.

Purpose. The research is aimed at increasing the useful component content in a pregnant solution during in-situ leaching (ISL) using a solid oxidizer and increasing the ferric iron concentration in the leaching solution based on laboratory research. Methods. Laboratory research is performed on a specially developed model electrolyzer for obtaining comparative data on divalent iron oxidation to trivalent iron and the change in the useful component content in a pregnant solution. Firstly, tests are conducted with a basic leaching solution, then on the oxidation of the leaching solution with a solid oxidizer in the form of a lead dioxide plate. Tests are conducted by changing sulphuric acid concentration within 5-50 g/l, amount of divalent iron ions in the solution from 0.5 up to 4.0 g, lead dioxide plate surface area from 19 to 76 cm2. The leaching time is up to 10 hours. Findings. The results of laboratory research on determining the oxidation degree of divalent iron ions and change in the oxidation-reduction potential (ORP) depending on the sulphuric acid concentration and on the initial concentration of divalent iron ions in the initial solution are presented. With a change in the sulphuric acid concentration from 5 to 50 g/l, the oxidation value of divalent iron ions increases from 26.5 to 96.5%, and with an increase in the initial solution concentration of divalent iron, the oxidation degree of divalent iron naturally decreases from 95.2 to 58.8%. In the initial leaching solution, the divalent solution concentration is 312 mg/l, and that of the trivalent solution is 288 mg/l. After oxidation with a solid oxidizer, the divalent and trivalent iron concentrations are 56 and 392 mg/l, respectively. In the course of further laboratory research using core materials from a uranium deposit, it has been revealed that when leaching with a basic solution, the uranium content in the pregnant solution is 19.36 mg/l, and when leaching with a solution after oxidation with a solid oxidizer, it is 27.9 mg/l, which is by 8.54 mg/l more. Originality. New dependences have been determined of the oxidation degree of divalent iron ions to trivalent one on the sulphuric acid concentration and on the initial concentration of divalent iron ions, as well as the useful component content in the pregnant solution on the leaching time when using a solid oxidizer. Practical implications. Using of a solid oxidizer, it is possible to increase the trivalent iron concentration in the leaching solution and the useful component content in the pregnant solution compared with the basic technology, thereby reducing the time of mining uranium reserves. Proposed technology is environmentally friendly, with low capital costs.

Mankind will always need metallic minerals. Despite of reduction of specific consumption, of increase both volumes of their reuse, and increase in strength qualities and wear resistance, of addition to metal alloys of synthetic materials, and also of transition to artificial atomic assembly of the necessary chemical elements from natural rocks and their constituent minerals and synthesis of metals from ocean water, offshore placers and bottom deposits in the future, extraction of ore from massif of earth crust will be the basic source of supply of demanded minerals. Based on these immutable postulates, we have made a comprehensive analysis of the existing geochemical patterns, the accumulation of mineral matter suitable for use as minerals. The origin of the planets of the Solar system with the condensation of the gas-dust cloud, which, in turn, as a result of adiabatic compression turned into planets of the Earth type and the asteroid belt with meteorites, was the reason for the same distribution of chemical elements in the Sun, in meteorites and in the Earth crust. We considered the anthropogenic-technical possibilities of mankind on the maximum depth of development of the continental part of the Earth's crust, the minimum industrial content (which will change over time towards reduction), the amount of minerals according to the clark in that part of the continental Earth's crust which is possible for industrial use with the objective restrictions, we determined the reserves of the demanded chemical elements. Calculations show their sufficiency for many years to come, but it will be the reserves in the deposits of a new type, created by objective geochemical regularities acting in nature, but not considered at present. Particular attention should be paid to the analytical generalization of mineral content at the micro- and nanoscale, which are currently not defined, being unaccounted reserves within well above the clark content at the minimum industrial level. The use of clarks and other geochemical patterns in the Earth's crust will require the creation of new analytical capabilities in exploration, new technological solutions for the extraction and processing of minerals from deposits of a new type, which are briefly described in the paper and are the subject of a more detailed and evidence-based description in the development of this article.

This article describes the prospects for use of man-made disturbed lands of mining regions, which for a number of reasons are not subject to recultivation, in the context of the effective use of renewable energy sources. The use of renewable energy sources is considered, first of all, to satisfy energy needs, but taking into account their environmental value and renewability. It is shown the importance of decentralization of power supply sources for consumers, which can be achieved through the use of renewable energy sources. The article provides a brief structure of Ukraine's energy consumption. The main obstacles that stand in the way of the development of renewable energy sources and improvement of energy efficiency in Ukraine are analyzed. As one of the perspective directions for the introduction of renewable energy sources, the use of wind power plants is considered. The main advantages of wind energy are listed. Formulas for calculating the power of a wind power plant are provided. The gross potential, technical potential and economic potential of the implementation of wind power plants are considered. The coefficient of wind energy utilization, which depends on the wind speed, is given. The paper gives a comparative assessment of existing types of wind turbines – with a horizontal and a vertical axis of rotation. It has been proved that vertical axis wind power plans are more effective for implementation. The vertical axis wind power plans have their advantages. It is recommended to use vertical axis wind power plans with using of a magnetic levitation. This makes vertical axis wind turbines the most efficient. Due to the use of wind generators with a vertical axis of rotation of a turbine with a magnetic-levitating bearing, in the conditions of Kryvbas, vertical wind power plants can produce electricity more than 7 times more than traditional (horizontal) ones. It has been proven that the amount of generated electricity increases with the height of the wind turbine location. The article examines the ecological advantages of placing wind power plans on man-made disturbed lands of mining regions.

It is advisable to conduct mining operations in the conditions of the ultimate state of the opened massif with an increase in the pit wall slope angles below the limit of effective use of combined motor-conveyor transport in the cleaning-up zone of deep and ultradeep open pit mines to the final depth. Such a design of the pit walls is achieved when mining benches from top to bottom within the boundaries of steep-slope layers with the use of in-bench loaders in the cleaning-up zone. The conditions for the occurrence of irreversible shear deformations in rock layers and the position of the potential sliding surface with an increase in the pit walls slope angle of steeply inclined layers in the conditions of the ultra-deep Kachar iron ore open pit mine to critical values are established. It is advisable to use skips as the load-carrying body of the in-bench loader, the design of the supports of which allows it to be built with a lifting height of more than 30 m with the possibility of moving along the pit wall with variable berm elevations. The main provisions on the selection and justification of the expediency of using a loading device for operation in the deep zone are formulated based on the differentiation of the application zones of cyclic (motor transport) and cyclic and continuous method (combined motor-conveyor transport). In particular, the total costs of transporting rock mass according to the new scheme of combined in-pit transport with the use of a loading device for operation in the deep zone should be less than the costs of transportation according to existing or traditional schemes.