The paper presents the findings of studying deformational changes in rocks connected with development of oil and gas fields and operation of underground gas storages (UGS) through the example of Garadag field/UGS in the South Caspian Basin (SCB). On the basis of repeated well-logging measurements, it was found that over relatively short monitoring period (from 8 months to 2.5 years), development of VII level of the productive stratum (Lower Pliocene) of Garadag gas condensate field in the South Caspian Basin led to decreasing permeability of rocks in the range from 1.2 to 4.9 mD, with pressure drop from 2.4 to 11.7 MPa. The relative decrease in permeability ranges from 41 to 56%, while the higher values are typical for highly porous rocks. It is shown that multiple cycles of changing loads on the stratum in the process of the field/UGS development also contribute to the development of deformational changes in the rock, which lead to disruption of the rock matrix. This conclusion is supported by precipitation of about 25 - 30 tons of sand in the separator and liquid tank at the Garadag UGS facility in the end of each season. The sand is a product of rupturing rocks of the underground reservoir. This leads to irreversible changes in permeability and porosity of the reservoir rocks, which are sharper reflected in the change in the rock permeability. Deformational changes in the stratum caused by exploitation of the field and UGS lead to decreasing well productivity and injectivity.

The Mae Moh basin is located in the Mae Moh District of Lampang Province, which is about 26 km east of Lampang City. The basin floor is about 320-340 m above mean sea level. The Mae Moh basin consists of three formations, namely the Huai King, Na Khaem, and Huai Luang formations, in ascending order. Their total thickness is nearly 1,000 m. The Na Khaem formation is a coal measure comprising three main coal zones, Q, K, and J. This study introduces preliminary approaches to determining minimum thickness suitable for extracting thin coal seams meeting coal quality requirements or maximum allowable thickness of diluting partings requirements. The approach considers heating value as the main parameter to be determined and considered in different scenarios of losses and dilution. The study findings indicate that high-quality coal-bearing diluting rock partings, such as BK and BK3, can be excavated with K3 coal seam, and the allowable diluting parting thickness ranges 1.68-5.3 m at the required heating value of 2,800 kcal/kg. These diluting parting thicknesses can constitute up to 20-50 % of excavation thickness of K3 coal seam. Low-quality coal-bearing diluting rock partings, such as TK1, TQ, and BQ4, cannot be excavated with K and Q coal seams at all. Coal-bearing partings should have heating value more than 1,000 kcal/kg for having potential to be excavated with coal seams.

The findings of the review of available information on geological conditions of the Drugoretskoye gabbro-diabase deposit are presented. Special attention is paid to the characteristics of fracture sets, since it is this factor that largely determines the deposit development process environment and profitability. Information on dimensional stone quarrying productivity is presented in the form of graphs. Based on these data, the problem of gradual decreasing the quality indicators of the deposit development was revealed. Taking into account the fact that the main factors determining yield of commercial blocks are natural and induced fracturing, it was assumed that this problem is caused by insufficient knowledge of the deposit and excessive impact of blasting operations on the gabbro-diabase rock mass during mining.
 The insufficient knowledge does not allow reasonable planning mining and blasting operations, and the existing blasting method has a number of disadvantages that prevent from limiting disruptive impact on the rock mass. The findings of the review of domestic and foreign methods of controlling the action of blasting in the process of dimensional stone quarrying, detailed exploration of a rock mass fracturing, and modeling of jointing bounded by fractures are presented. Conclusions are drawn about the inapplicability of most of available quarrying methods in the considered case due to too high fracturing of the gabbro-diabase rock mass and the need to develop fundamentally new methods to increase the quarrying productivity. As a result, the lines of research were determined for development of methods and techniques allowing to quickly respond to changes in mining and geological conditions and control disruptive blasting effect in the process of dimensional stone quarrying in intensively fractured rock masses.

In connection with development of underground mining method and the need to combine the principles of resource saving and natural environment protection, the indicators of the cost/environmentally-effective ore mining techniques need to be understood. It becomes necessary to rank the development indicators for a particular deposit. The mining effectiveness criterion in terms of completeness of subsoil resource use becomes the research objective, with ranking indicators of underground mining effectiveness. The problem solution includes modeling of a method parameters using mathematical programming methods with target functions to find a compromise optimum of mining performance indicators in the framework of a dynamic model for managing production processes. The experimentally obtained dependences of profit on dilution, operating costs, and ore losses at all mining stages are given. The quantitative indicators of ore losses and dilution by hosting rocks, rocks inside an ore body, a stoping worker labor productivity, a block productivity, and labor productivity of a worker in mining shop are given. The results of economic and mathematical modeling of development method options with different proportions of technological void backfilling are presented. An assessment of the development options for specific metal deposit is given by comparing the optimum values of the target functions. Compensation of dilution in the ore beneficiation stage has been proven to have the most significant effect on costs. It is concluded that the main condition for increasing ore deposit development efficiency is reducing losses and dilution of ores, including through optimization based on mathematical modeling with balancing quantitative and qualitative performance indicators of a deposit development.

Oltenia Coal Basin occupies the area of 4500 km² and encloses the most important deposits of lignite in Romania, many of which are exploited by open-pit mining. Open-pit lignite mining involves long-term occupancy of large areas and considerable negative impact on physical, chemical and structural characteristics of the lands that define the regional terrain, resulting in full degradation of previously existed landscape. The degraded lands require great efforts on their reclamation for recultivation of soils, recovering landscape and overall mitigation of mining environmental impact. Selecting post-mining use of remaining mined-out pit space is performed taking into account such criteria as climate, geomorphology, pit slope stability conditions, regional development strategy, local community requirements, financial resources, etc.

The purpose of the paper is to solve the scientific and practical problem of the rational use of technogenic resources in open-pit mining as exemplified by deep Muruntau open pit. Overview of the studies in this area is given. Their main results are summarized, and the methods and approaches used are described. The research method used is based on reviewing lines of use and functional purpose of a technogenic mass formation in the course of open-pit mining: rock storage, ensuring work safety, stabilizing production processes, forming structural elements of an open pit. Based on the analysis of applying the method of external and internal dumping while developing deposits of complicated structure, it has been established that the formation of external and internal dumps should be coordinated with the development of mined-out space of open pits. Implementation of the results obtained makes it possible to increase efficiency of deposit development with increasing output of high-saleable products both for domestic and world market and improving mining performance indicators.

The problem of underground ore mining in Siberian lies in developing deposits in permafrost conditions – cryolithic zone, which covers 64% of the territory of Russia. The difficulty of completeness of mineral extraction with ensuring environmental safety in the permafrost zone lies primarily in the extremely high sensitivity of this zone to any technogenic impact. Mining industry has a great impact on the entire biosphere: atmosphere, lithosphere, hydrosphere, and, first of all, causes air pollution. To manage air pollution during subsoil use, improving mining methods and techniques, decreasing emission of toxic gases, dust and capturing them in mined-out space to prevent their release into the atmosphere is required. The question of national security of Russia is selective mining of only rich ore areas, which leads to premature closure of mining enterprises and losses of strategic raw materials. The situation can be corrected by applying methods to avoid large losses of valuable ores in the subsoil. In this paper, the methods are considered that ensure high-performance mining, environmental safety and national security in the conditions of permafrost zone of Siberia.

Egypt belongs to states developing its mineral resource base. Gold-bearing territory of Egypt is located within the Nubian-Arabian shield in the Neoproterozoic collision zone of transverse thrusts. Granitoid massifs are widely developed within this tectonic zone. The massifs of postorogenic granite (540−435 Ma) are confined to the tectonic collision zones of the Late Riphean and characterized by elevated alkalinity. Spatial relationship has been established between metasomatic halos of ultramafic rock carbonatization, granite intrusions in them, and gold mineralization. The gold mineralization is associated with quartz veins in the granite. In all these quartz gold-bearing veins, gold is associated with pyrite or aggregates of pyrite and arsenopyrite. The veining zones consist of massive quartz with impregnated gold and sulfide minerals. Thus, predominant type of the Precambrian gold mineralization is gold-quartz and gold-sulfide-quartz ore veins associated with zones of increased tectonic permeability of the crust and magmatic rocks – derivatives of granitic magmas and sulfide fluid systems.

Applying scientific-research findings in practice requires systematic studying characteristics, parameters, and physical and chemical properties of materials. The paper is devoted to the study of vaporization using tensimetry method with diaphragmatic manometer in temperature range of 370-600 K (using the example of M-10G₂ diesel oil). Based on the dependence of vapor pressure on temperature, barogram of diesel oil vaporization was built, showing a complicated scheme of vaporization and stepping in the desired temperature range, as well as the corresponding dynamics in each stage. Thermodynamic parameters characterizing enthalpy, entropy and Gibbs energy of M-10G₂ diesel oil have been obtained.

The paper provides a brief overview of researches on automation of flotation beneficiation. The main disadvantages of existing systems and methods for regulating parameters of this process have been revealed, which consist in low speed, errors in determining control action, and incapability of stabilizing pulp density in a mixer. In this connection, a conclusion is made about the relevance of development of an ACS for the process of pulp mixing before flotation, which will allow maintaining the specified density at a given level. Modeling using Matlab Simulink software package was chosen as the research method. At the same time, mathematical description of such elements of the ACS model as the valve, the mixer, the pump, the PID controller is given. The modeling provided time diagrams reflecting the principle of the pulp density stabilization by manipulating the flow of water into the mixer with abrupt change in the pulp solid phase density and flow. Conclusions are given on the possibility of using the ACS as part of an automated process control system at mining enterprises, since the system model operation showed satisfactory results in density control with small readjustment and low control time.