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This study focuses on the process of the COVID-19 pandemic spread across Siberia in 2020-2021, using the case study of 15 constituent entities of the Russian Federation. Its purpose has been to explain the mechanism of coronavirus penetration into Siberia and the resulting excess mortality proceeding from the distinctive features of Siberian regions’ space. The novelty of our approach consists in using the most reliable monthly excess mortality statistics for characterizing the demographic impact of the pandemic, regional regulatory legal acts of antiviral nature, and the concept of spatial diffusion of innovations to characterize pandemic waves in the regions of Greater Siberia. The main findings are as follows. First, five types of Siberian regions have been singled out in terms of integral demographic damage from the pandemic in 2020-2021: Khanty-Mansi Autonomous Okrug and Yamalo-Nenets Autonomous Okrug for the highest excess mortality; Omsk, Novosibirsk, and Tyumen Oblasts for moderately high; Tomsk Oblast, Altai and Krasnoyarsk Krais for relatively high; Irkutsk and Kemerovo Oblasts, Altai Republic, Republics of Khakassia and Buryatia, and Zabaykalsky Krai for below the national average; Republic of Tuva for extremely low excess mortality throughout the entire pandemic. Second, four types of regional spatial systems in Siberia have been identified according to the degree of vulnerability to coronavirus diffusion: most vulnerable open polycentric; highly vulnerable open centralized; moderately vulnerable closed centralized; least vulnerable closed polycentric. Third, it has been found that for the first type, crucial for pandemic spread was relocation spatial diffusion (and its particular characteristic case of rotational migration); the second type had relocation (by plane) and horizontal (within the local labor market); the third and fourth types had horizontal spatial diffusion as the most prominent factor. Conventional factors, such as industry specialization, population density, and Siberian-specific transport infrastructure, had little effect on coronavirus incidence. Much more important was the (contact-intensive) communication slice of these factors, which determined the potential and rate of pandemic spread in Siberian regions.

The literature review discloses preferability of using the time of induction rather than the wetting angle as a criterion of coal floatability. The authors analyze kinetics of coal flotation as function of surface properties of heteropolar collectors relative to the gas-liquid interface. The correlation between the spreading velocity of collectors on water surface and the coal flotation kinetics is determined as a case-study of fat coal slurries. Justification is given for using the time of displacement of the boundary between three states of aggregation as the time of induction. From the correlation of the spreading velocity of a collector, displacement time of the contact line (induction time) and the flotation velocity, it is found that flotation activity of the collector is governed by its properties relative to the gas-liquid interface.

The article proves the promising nature of joint roasting of rebellious oxidized and sulfide lead-and-zinc ore from Ozerny deposit at the stage of ore preparation for flotation. The joint roasting of lead-and-zinc ore and sulfide ore initiates generation of sulfur-containing agents and sulfidation of rebellious oxidized lead and zinc. It is experimentally proved that selective oxidation of pyrite proceeds together with disintegration of lead and zinc along the interphase boundaries. The main products of such interaction are ZnS, PbS, Fe₃O₄ and Fe₂O₃, which can greatly facilitate flotation later on. This method of complex ore processing can potentiate commercialization of oxidized lead-and-zinc ore and rebellious sulfide ore, can prolong service life of mines and mitigate the environmental impact of the industry. The produced samples are analyzed and described using the X-ray phase analysis, differential scanning calorimetry, optical microscopy, chemical analysis, Rietveld refinement and program TOPAS.

Consumable supplies in mines (explosives and explosive devices, oil, lubricants, rubber, protective devices, spare parts for machinery and equipment, flotation reagents, etc.) should be sufficient for stable production. However, for mining operations, supplies are burden costs, as storing supplies increases operating costs. The logical question is how to achieve the balance between mine production stability and minimization of costs of supplies, that is, how to optimize supplies. The paper presents a quantitative model of stochastic supplies optimization as a possible answer to this question. The application was demonstrated in the specific case of polymetallic ore lead, zinc, copper, and silver mine flotation with value indicators.

The authors discuss the mineral resources and mineral reserves of the Russian Far East in terms of their volume and production of certain minerals. The key challenges of subsoil use, which complicate advancement in the mining sector at the present time, are identified. The growth prospects of the mining sector can build on the processing industry and on the transition from mineral extraction to mineral production at high degree of conversion. The economic efficiency of subsoil use depends on the professional corporate management, transportation and power generation infrastructure, sound scientific grounding and on the development of the processing industry which uses products of the mining industry. The main trends of the spatial development in subsoil use are proposed. The large infrastructural projects are described, which can promote social and economic progress in the Far East Federal District of Russia. Emphasis is laid on improvement of personnel potential and on introduction of scientific supervision in the mining and processing industry in the region.

The authors present a multi-factor algorithm for making provisions for geological/geotechnical constraints and operation timing criteria subject to availability of resources. The algorithm enables embracing a variety of possible combinations of heading or stoping conditions at each specific underground mine facility. The algorithm is a part of the digital tool of automated underground mine production planning in geological and mining information system MINEFRAME.

The authors examine the present-day hydrogeological situation and its post-mining phase forecast in the Chelyabinsk Coal Field. Geotechnical facilities in the areas of Krasnaya Gornyachka Mine and Kopeisk and Korkino Open Pit Mines are discussed. The problems to arise during flooding are identified. The hydrological forecasts and an action plan to prevent underflooding in the study areas are presented.

The article presents the case-study of properties of domestic binders in dust suppression at tailing storage facilities at a mining and processing plant in the Murmansk Region. The strength development dynamics of the binder-formed blankets and the change in the strength in the wetting-drying mode are determined, the impact of chemical agents on water permeability of treated tailings is estimated, and leaching of polymerized concentrates in weakly acid and alkaline media is carried out. The authors emphasize essentiality of an integrated research for the well-founded choice of a binder.

In the study, the particulate matter (PM) measurements were carried out during several blasting operations using a portable Cascade Impactor with eight particle size fractions. The particle mass size distribution was characterized for each blast shot. The PM dispersion trend equations were established for using the measurements collected from various distances in the downwind direction and classified for different fractions (respirable, thoracic, and inhalable) to assess the health risks. As an outcome of the study, the amount of dust generated in the blasting source was specified according to the blasting theory. The PM dispersion trends were established by evaluating measurement results. It was concluded that, PM decreases from gram to milligram grades in the first 100 m distance. All of the PM fractions ultimately settles at an approximate distance of 535m and not spread out of the quarry pit. Regarding particle mass size distribution studies, blast-induced PM is classified as fine particles. The study has preceded features regarding both PM sampling during a blasting event and revealing PM fractions close to the blasting point. The context also provides a detailed comparison of the amount and characteristics of dust caused by blasting with other activities.

The authors investigate geophysical parameters of water-saturated and frozen rock samples, and compare the results with the data of natural rocks. The samples were subjected to dynamic loading, an acceleration signal was recorded and a spectral density was calculated. On this basis, later on, the authors determined the longitudinal vibration velocity, the logarithmic decrement of damping, the internal friction factor and the acoustic Q-factor. The water-saturated and frozen rock samples demonstrated the increased velocities of longitudinal vibrations. The samples, which had the high acoustic Q-factors in the frozen conditions, fractured under much higher loads. The degree of water saturation affected the strength of the test samples: their strength reduced with the higher water saturation. Freezing of the samples generated microseismic vibrations in the region of high frequencies. In the uniaxial compression tests to failure of the samples under critical loading, a high frequency signal was recorded during initiation of an extension fracture, and the signal spectrum shifted toward lower frequencies as the fracture grew.