Vol 335, No 1 (2024)

Relevance. Related to the need to carry out environmental protection measures in potash mining areas exposed to the environmental consequences of the impact of multi-tonnage salt waste.

Aim. To summarise and analyse the geography of potash mining operations, the environmental impact of these operations, and potash waste management practices.

Object. Potash mining waste.

Methods. Theoretical and logical analysis of the data.

Results. The research considers the geographical distribution of potash deposits and presents the characteristics of potash mining waste using the example of the Verkhnekamskoe Potash Deposit. The paper provides both domestic and foreign analyses of ecological consequences of waste storage on the day surface. Several options for potash mining waste management are analysed. For the management of clay-salt slurry, the most effective approach is its injection into underground horizons, which includes the use of saturated solutions as a fertiliser component, as a part of a product in construction, and in the oil industry. A more comprehensive approach to halite waste management is needed. Waste disposal to waste dumps is relevant due to the presence of mined-out areas on the territory of long-operating enterprises. Reclamation of the salt dump will help to isolate it from atmospheric precipitation, thereby reducing the inflow of saturated water into the environment. Utilising waste for production of construction materials is the most economically and environmentally favourable option. Extracting valuable components, producing fertilisers, concentrates, etc. from waste is the least practical approach due to the ecological and economic expenses involved in acquiring extraction equipment and the repeated generation of waste. The most challenging aspect of reducing waste generation in terms of technology lies in improving mining operations and implementing selective mining.

Relevance. Statistical studies of water discharge in river systems conducted by various authors have shown that forms of distribution of river discharge probability density are polymodal. There are various hypotheses for the origin of this polymodal distribution. For example, in dynamic systems the formation of attractors is possible, or under conditions of perturbation of the initial data singular numbers can be transformed into a polymodal structure. However, the proposed hypotheses of formation of polymodal distribution of transformation intensity of elements of an open system are not always applicable to specific objects and are limited to certain conditions. Therefore, it is proposed to apply the universal theory of formation of polymodal distribution of transformation intensity of open systems to study water discharge distribution in river systems.

Aim. To confirm the compliance of river flow modes with universal transformation principles in unifying the polymodal statistical probability distribution of water discharge in river systems.

Object. Samples of water discharge intensity of hydrographic open systems of the Velikaya and Oka rivers in different seasonal period.

Method. Determined on the basis of the derived universal equation of modes of unified polymodal probability density distributions for transformation of any open systems. Each mode in the unified polymodal distribution of river runoff corresponds to a certain universal principle of transformation of an open system under external influence. Its universality is based on the constants of the ratio of time parameters (internal time of transformation of system elements and external time of impact on the system) associated with the "golden" proportion. Soil evaporation and moistening reduce the flow rate and is an internal transforming process depending on atmospheric temperature, and precipitation is an external factor that increases river runoff.

Results. Certain modes of polymodal distribution of water discharge fully correspond to universal states of transformation of open systems under external influence. For each seasonal period, the modes correspond to different, previously established principles of systems transformation.

Conclusions. Based on a sample of water discharge in river systems, using the unification equation of polymodal distribution, it is possible to determine the state of the river system transformation in the present time and, knowing the parameters of external influence, to predict its future development.

Relevance. Phosphate raw materials processing at the Gomel chemical plant over a period of more than 50 years has led to accumulation of millions of tons of phosphogypsum dumps. They are a source of subterranean water contamination by sulfates, phosphates and other chemical compounds. Therefore, there is the need in current estimation of the scale and extent of aquifers contamination, taking into account the geological and hydrogeological conditions that influence the migration of contaminants.

Aim. Assessment of hydrogeological parameters affecting distribution of contaminants in subterranean water and the degree of aquifers contamination.

Objects. Aquifers and impermeable horizons.

Methods. Methods for assessment of hydrogeological parameters, methods for determining the chemical composition of subterranean water.

Results. The paper assesses a technogenic effect, produced by dumps of Gomel chemical plant. It reviews a subterranean water monitoring local network within the Gomel chemical plant influence area. The hydrogeological parameters of aquifers of the upper hydrodynamic zone are quantitatively assessed, given that this zone undergoes the strongest anthropogenic impact. The study of subterranean water quality ends up with three classes of contamination: high, moderate and insignificant. Major contaminants include sulphates, nitrogen ammonium, and phosphorus phosphate. The authors find a spatial pattern of subterranean water contaminants differentiation that tends to develop both horizontally and vertically. As a result of the study, areas and sources of high groundwater contamination are determined and mapped. A conclusion is drawn on the necessity of further control over the subterranean water conditions and contamination development in time and space.

Relevance. The conditions of complex structural and tectonic setting, insufficiency and uneven geological and hydrogeological exploration of mineral deposits in Eastern Siberia determine the relevance of the issues of optimization of hydrogeological works and reduction of their implementation costs.

Aim. Identification of a number of readily defined, indirect indicators that predetermine the selection of sites promising for drilling hydrogeological wells.

Methods. The two-stage method of system-model analysis was used to improve the efficiency of the project work. The first stage is training. It involves the use of the principal component analysis and ends with the compilation of a classification table of standard objects (thoroughly studied in geological and hydrogeological terms) in accordance with the earlier identified most significant indirect indicators but easily accessible ones. The second stage is recognition or forecast. It includes attribution of analogous objects (with poorly or unstudied geological and hydrogeological conditions) to certain classes determined at the first stage. When solving this problem, the programs implementing cluster and multiple regression analyses are used. As a result, the analogous objects are classified in accordance with the task set.

Results. The developed methodology is used for various purposes: for structural hydrogeological zoning of the Ilim-Lena plateau with associated main iron ore deposits of Eastern Siberia, for typification of alluvial deposits of the Lena gold ore region according to the complexity degree of engineering hydrogeological conditions, for identification of sites featuring increased water abundance in the fields of the oil and gas complex of Eastern Siberia. The results obtained make it possible to recommend the method to be widely introduced into the practice of hydrogeological research. It is necessary for optimizing the types and volumes of special works at mineral deposits in order to identify the most water-abundant zones when developing dewatering and water supply systems under different-scale structural hydrogeological zoning. In addition, the method of system-model analysis provisioned with additional processing methods has a potential and is already widely used when dealing with databases and object typification according to environmental and hydrogeological indicators.

Relevance. The need for geotechnical monitoring in the areas of distribution of permafrost soils for underground pipelines. The geotechnical system “permafrost soil – underground pipeline” is subject to the influence of exogenous geological processes during operation, cyclical changes in the state of soils of the seasonal layer of thawing and freezing, thawing of permafrost soils from the thermal effect of the pipeline, changing the plan-altitude position. The variety of schemes for interaction of the pipeline body with varieties of lithological structure of permafrost soils along the route should be worked out in detail at the design stage and also assessed in detail during geotechnical monitoring of the pipeline. The lack of regulatory requirements for the monitored parameters of underground pipelines leads to the use of non-standardized and varied monitoring networks from project to project. The lack of standard values ​​for the maximum deformations of an underground pipeline leads to the need to use calculation methods for determining the maximum deformations of the base and pipeline. The authors proposed the use of a comprehensive methodology for calculating underground pipelines, developed by employees of JSC TomskNIPIneft to determine the maximum permissible deformations of the pipeline at each point of the route with the presence of permafrost soils at the design stage, with further use of the results obtained as a controlled criterion when conducting geotechnical monitoring.

Aim. To determine the controlled parameters for geotechnical monitoring of underground pipelines in the cryolithozone at the operational stage based on the application of a comprehensive methodology for calculating underground pipelines, as well as the formation of requirements for the system of information points.

Methods. Review of the regulatory framework for geotechnical monitoring, analysis and evaluation of the applied methods and designs for monitoring underground pipelines, analysis of a comprehensive methodology for calculating underground pipelines in relation to the purposes of geotechnical monitoring.

Results. Based on the results of the review of regulatory and technical documentation, the authors have revealed a lack of specification of methods, equipment, volume of the geotechnical monitoring network and frequency of pipeline monitoring, as well as the requirement for the use of the calculation method of limiting deformations and the lack of description of possible methods. A detailed analysis of the complex methodology for pipeline calculations, developed at JSC TomskNIPIneft, substantiates its use for geotechnical monitoring purposes, and notes the advantage of the methodology in the detail of the obtained limit values ​​of deformation with an accuracy of one meter along the axis of the pipeline route. The authors studied the methods and designs used for monitoring deformations of underground pipelines and established the compatibility of using a complex methodology with any design and method of monitoring. The paper introduces the list of the main monitored parameters and justification for the scope of the geotechnical monitoring network for underground pipelines.

The requirements for the quality of steel products dictate the need to increase the share of evacuated steel. In addition, the growing cost of fuel, as well as the desire of society and the state to decarbonize various industries, including ferrous metallurgy, requires companies to reduce fuel costs and switch to more modern and cleaner technologies. Reducing the specific fuel consumption, and, accordingly, emissions, is possible due to the transition to continuous production, minimizing the cost of heating the equipment and maintaining the set temperature in the degasser during technological downtime. The article deals with the issues of steel melt degassing in U-type continuous degassers in continuous steel making units.

Aim. To consider the influence of rarefaction of a gas bubble on the characteristic size over the melt, speed and time of its surfacing in a U-type degassing unit. Based on the obtained dependences, to determine the characteristic size of a vacuum chamber and energy effect of switching to a continuous vacuumization.

Methods. Analytical methods.

Results. The authors have determined a bubble characteristic size in a steel melt under vacuum of different degrees. They studied the effect of vacuum on vacuumization speed and the degassing unit dimensions. The energy effect of switching to continuous vacuumization was determined. The proposed methodology is valid for liquid media, the calculations are presented on the example of molten steel. Based on the conducted calculations, the depression influence on molten steel vacuumization was determined. The vacuum chamber dimensions, comparable with RH-vacuum cleaners presented at the market of similar productivity and quality of finished products, as well as reducing energy consumption for steel degassing in a continuous vacuum degasser, compared with the existing circulating installation, were determined.

Relevance. The need to increase the level of comprehensive use of phosphorites during their electrothermal processing and to reduce the amount of slag waste generated during phosphorus production, polluting the environment.

Aim. To conduct computer thermodynamic modeling of the effect of temperature and amount of iron on technological parameters of interaction of a Karatau and Aktobe phosphorites mixture with carbon and iron to produce phosphorus, calcium carbide and ferrosilicon.

Objects. Phosphorites of the Karatau and Aktobe phosphorite-bearing basins.

Methods. Thermodynamic computer modeling using the HSC Chemistry 6.0 software; rotatable second-order experiment planning technique; geometric optimization of technological parameters.

Results. It has been established that depending on temperature in the mixture of Karatau and Aktobe phosphorites with carbon and iron, they participate in interaction: CaSiO₃, SiO₂, Si, SiC, SiO_(g), MgSiO₃, Al₂SiO₅, Na₂SiO₃ , Ca_(g), CaO, CaC₂, CaF₂, CaS, Fe, FeSi, FeSiO₃, FeP, Fe₂P, Fe₃P, FeP₂, FeO, Fe₃Si; Ca₃(PO₄)₂, P_2(g), P_4(g). An increase in iron amount leads to an increase in the degree of silicon extraction into the alloy, and at 2000°C reduces the extraction degree of calcium in CaC₂ and the silicon concentration in the alloy. Branded calcium carbide with a volume of more than 230 dm³/kg and ferrosilicon FeSi25 are formed from a mixture of phosphorites, carbon and iron at 2077...2088°C in the presence of 20...21.4% iron and 43% carbon (in this case, phosphorus is completely distilled off into the gas phase). Using our proposed method of electric smelting of phosphorites with phosphorus distillation and associated production of ferroalloy, in comparison with the traditional method, the indicator of integrated use of raw materials increases from 43.9 to 62.7...73.6%, that is 1.43...1,67 times. The proposed processing technology helps to increase active reserves of phosphorites and bring low-grade phosphorites of the Aktobe basin into production.

Soil massif fracturing has a significant impact on change in engineering and geological conditions and, as a result, on stability of structures. Development of tectonic fracturing of local structures, taking into account the history of the process, its mechanism, resulting stresses in the massif and subsequent deformations of the rocks, led to a change in their structure, composition and strength characteristics, activation of hypergenesis and exogenous processes. The above circumstances require careful attention to identification of areas of increased fracturing, as the most dangerous in terms of risks during the construction of engineering structures. Field methods for assessing the fracturing of rock masses are laborious. It is not always possible to conduct instrumental surveys that allow solving the final problem – establishing patterns and sizes of damaged areas within local structures. The existing mathematical models for assessing fracturing, as a rule, are used to solve local problems: assessing the stability of developed pits, water content of rock masses, degree of fragmentation of individual blocks, etc. This information is not sufficient when assessing the areal distribution of weakened zones and clarifying their boundaries, since it does not take into account the history of the development of the structure, its parameters (dimensions, amplitude of the foundation block uplift, deformation properties of rocks).

Aim. To develop a mathematical model of formation of the red-colored strata tectonic fracturing zones based on deformation criterion of destruction and mechanism of development of local structures.

Results. The authors have developed a new mathematical model for predicting damage (fracturing) of terrigenous rocks of the red-colored strata that make up local structures, based on the mechanism of formation of local tectonic structures of the 3^rd order and the deformation criterion of destruction. The paper introduces the mathematical dependencies that make it possible to predict the size (area) of taxa based on the data on the uplift amplitude of local structures. The results of the research can be used in assessing the fracturing of massifs composed of terrigenous rocks, and make it possible to judge the regularities in distribution of weakened zones within the entire massif being assessed.

Relevance. The need to increase production of light olefins. The use of advanced process control systems and Real–Time Optimization makes it possible to increase the efficiency of steam cracking plants, but requires a high-speed mathematical model of the process.

Aim. To select a method for numerical solution of systems of ordinary differential equations, which provides the highest speed when calculating the reaction coil of a steam cracking furnace. Reducing the time spent on calculating each scenario will allow the proposed model to be used for real-time process optimization tasks.

Object. Mathematical model of ethane steam cracking, numerical methods for ordinary differential equations systems solution.

Methods. System analysis, mathematical modeling. To solve the ordinary differential equations systems, various explicit numerical methods were used, differing in approach to integration step determination.

Results. The authors have developed and tested a steady-state model of ethane steam cracking. The developed model was used to compare the calculation time required for solving ordinary differential equations systems using different numerical methods. It was demonstrated, that the use of an adaptive integration step reduces calculation time by more than 20 times (from more than 11 hours to 34 minutes) while maintaining the accuracy of calculations. This is due to different reaction rates through the length of the reaction coil – in areas of high temperatures and high concentrations of reagents, a reduction in the integration step is required to obtain the desired accuracy. And in low reaction rates areas an increase in the step and reduction in the total calculated iterations are acceptable. 

Relevance. Azerbaijan water and soil resources are limited and subject to technogenic impacts more and more every year. Use of water and demand for water in the republic are growing at a higher rate every year. On the other hand, global climate changes have a serious impact on formation of hydrogeological processes. In such circumstances, it is very important to study the formation situations of hydrogeological conditions under the influence of natural and anthropogenic factors, to use the available water resources efficiently and economically, and to take preventive measures against negative processes.

Aim. To study the regularity of formation of the hydrogeological conditions of the Shirvan steppe of the Kura-Araz lowland in the Republic of Azerbaijan under the influence of natural and anthropogenic processes over a long period of time.

Object. Subsoil waters of the Shirvan steppe of the Kura-Araz Lowland in the Republic of Azerbaijan.

Methods. Based on the results of the studies (1977 to 2020) of perennial average level of groundwater and degree of mineralization, the rate of soil salinization, the regime of groundwater and based on the materials collected in this direction, the regime types of groundwater were separated and correlative dependence was found by the method of least squares between regime types and regime-shaping factors – atmospheric sediments, river networks, irrigation water, irrigation canals, drainage, etc. The genetic types of the regime were selected according to the factors creating the regime and the synchronicity of the groundwater level change.

Results. Under the influence of natural and anthropogenic factors, the level of groundwater, degree of mineralization, chemical composition, salinity and chemical composition of soils have changed. From 1958 to 2020, due to the irrigation melioration, the groundwater level of the area rose by 4.1 m, due to the infiltration of surface water and removal of mineralized water through drainage, their mineralization rate decreased by 16.2 g/l. Due to the synchronicity of regime-creating factors and groundwater level changes, the genetic types of the regime were selected – climate, hydrological, irrigation, irrigation-watering, drainage, irrigation-watering and the fields of their distribution areas were determined.