Vol 335, No 11 (2024)
Articles
Justification and implementation of the layer thickness control method in ultrasonic spraying
Abstract
Relevance. The need for the development and widespread use of the ultrasonic spraying method, which has unique advantages, to solve the most pressing problems of modern industry. In particular: minimal, of all known methods, energy consumption for the implementation of the process, the possibility of forming fine droplets without the use of gas under pressure, regulating the dispersion of the formed aerosol by the parameters of the emitter, etc. However, for widespread practical use of the ultrasonic spraying method, it is necessary to ensure spraying conditions with a specified dispersion and productivity. In this regard, there is a need to develop a method for controlling and maintaining the necessary and sufficient thickness of the liquid layer on the surface of the piezoelectric transducer of the atomizer, the spraying of which will ensure, at a given spraying performance, the formation of an aerosol with the smallest deviation in the size of the formed droplets relative to the average value. It is proposed to control the thickness of the liquid layer by identifying the dependence of the resonant frequency of the piezoelectric transducer of the atomizer on the thickness of the liquid film on the oscillating surface of the atomizer.
Aim. To develop a method and means for controlling the thickness of the layer of sprayed liquid by changing the resonant frequency of the ultrasonic oscillatory system and maintaining the optimal value of the layer thickness by changing the amplitude of vibrations of the surface of the ultrasonic sprayer.
Objects. Liquid atomizing with ultrasonic high-amplitude vibrations.
Methods. Obtaining the frequency characteristics of ultrasonic oscillatory systems, analyzing changes in the amplitude-frequency characteristics of oscillating systems and identifying criteria that allow monitoring and managing the ultrasonic spraying.
Results. The authors have proposed and developed the method for indirectly monitoring the thickness of a sprayed liquid layer on the oscillating surface of an ultrasonic atomizer, based on measuring the resonant frequency of an ultrasonic oscillating system. The possibility of implementing the method and its practical application is caused by the fact that in the working range of layer thicknesses of the sprayed liquid, the change in the resonant frequency can reach 100 Hz, and with a frequency measurement accuracy of 1 Hz, the accuracy of determining the layer thickness will be no more than 2% of the working layer thickness. The identified dependencies and certain values of possible ranges of changes in the controlled parameter made it possible for the first time to develop a method for automatically controlling ultrasonic spraying, ensuring the maintenance of optimal modes of ultrasonic influence (amplitude of vibrations of the spray surface) and the thickness of the layer of sprayed liquid.
7-18
Increasing the operating time of pumping units of water-reducing wells through the use of self-cleaning filters
Abstract
Relevance. At enterprises engaged in open-pit mining, water-reducing wells equipped with submersible installations of electric submersible pumps are widely used in drainage systems. A significant content of particles of mechanical impurities in the pumped-out well fluid causes intense hydro-abrasive wear of the working stages of the electric submersible pumps. Among the existing methods of combating hydro-abrasive wear of submersible pumps in water-reducing wells, the simplest, most economical and effective is the use of filters of various designs. An urgent task is to increase the operating time of submersible electric submersible pumps while reducing the time and costs for cleaning or replacing filters.
Aim. Justification of the designs and operating parameters of a self-cleaning filter and tubing string extension included in the electric submersible pump assembly of a dewatering well.
Methods. Static calculations of deformation of the tubing column and the tubing column extension under the influence of overpressure.
Results and conclusions. The authors have carried out the analysis of an electric submersible pump functioning in the dewatering wells of quarries during the development of mineral deposits by the open method. It was revealed that the main reason for the failure of the electric submersible pumps is the hydro-abrasive wear of the working stages of the submersible pump. The authors propose a method to increase the operating time of the electric submersible pumps in dewatering wells complicated by intensive removal of particles of mechanical impurities by using a self-cleaning filter of the original design. It is noted that a promising direction of development of the drive for self-cleaning filters is the use of deformation of the tubing column. Based on the calculations carried out, it was concluded that the small depths of dewatering wells cause an insufficient amount of deformation of the tubing string to clean the filter element. To increase the length of the reciprocating movement of the electric submersible pumps relative to the production string of a dewatering well, it is proposed to use a tubing string extension of an original design. The operating parameters of the tubing string extension were calculated, which showed the possibility of providing the required amount of controlled reciprocating movement of the electric submersible pumps in the well to restore the throughput of a self-cleaning filter.
19-31
Electrical resistivity variations as a result of natural-technogenic seismicity in the Gorlovka depression of the Altai-Sayan folded region according to electrical tomography data
Abstract
Relevance. In the last decade, the intensity of development of the Gorlovka coal deposit in Novosibirsk region has significantly increased, which leads to the formation of seismic activation of the subsoil of the Gorlovka depression in response to technogenic impact. Since 2019, earthquakes with a magnitude of more than 4 have been recorded in the field area, felt in Novosibirsk and its suburbs. Currently, damage from natural disasters has been rapidly growing. This happens due to many reasons, such as urbanization, population growth, man-made changes in the geological environment, construction of high-risk facilities that contribute to the activation of negative processes. Therefore, the development of trustworthy criteria for the assessment, forecast and consequences of natural and man-made hazardous phenomena is an urgent task. Timely identification of dangerous geological processes will make it possible to develop and implement measures to prevent and eliminate emergencies of a natural and man-made nature.
Aim. Analysis of the results of regular observations by electrical tomography along a profile crossing the fault zone at the study site in the Gorlovka trough for further development of measurement techniques and software for automated processing and interpretation of monitoring data.
Methods. Field works, quantitative interpretation
Results and conclusions. The authors have obtained the first results of regular observations using electrical tomography along a profile crossing the fault zone at the study site in the Gorlovka trough, interpreting field data using the modernized DiInSo software package. It was found that the identified variations in geoelectric parameters reflect the response of the geological environment both to earthquakes occurring during the observation period and to man-made impacts (explosions). Furthermore, it is demonstrated that the fluctuations magnitude is influenced by the earthquake magnitude.
32-43
Analysis of the effect of the heat stabilizer outer surface finning on soil cooling efficiency
Abstract
Relevance. The construction of buildings and structures in permafrost conditions is associated with the problem of soil thawing. To prevent this phenomenon, heat stabilizer have proven themselves good in practice. Their successful use is difficult without preliminary modeling of heat flows in the soil–heat stabilizer system. The most effective design of a passive heat stabilizer is an installation with two-phase of refrigerant. An additional increase in the efficiency of using a two-phase heat stabilizer is possible due to the finning of the outer surface of the outer pipe of it.
Aim. To calculate the efficiency of using a heat stabilizer with and without finning of the outer surface.
Objects. Heat stabilizer, refrigerant, heat transfer, frozen soil.
Methods. The mathematical model for describing the processes of heat and mass transfer in the heat stabilizer–frozen soil system is considered in an axisymmetric formulation. There are three subtasks: the movement of liquid refrigerant in the inner tube of the heat stabilizer, the two-phase convective flow of refrigerant in the gap between the inner and outer tubes and conductive heat exchange in the system of the heat stabilizer–frozen soil. The influence of the finning of the outer surface of the heat stabilizer is considered within the framework of the modified concept of the skin factor.
Results and conclusions. The authors have obtained the pressure and temperature distributions along the length of the heat stabilizer. It was found that the presence of fins on the outer surface of the external pipe of the heat stabilizer increases the heat flow from the soil by 10%. It is determined that the soil is effectively cooled within 1 m from the heat stabilizer; this distance is recommended as optimal for the placement of an adjacent heat stabilizer.
44-53
Modern technologies for remediation of bottom sediments contaminated with heavy metals
Abstract
Relevance. The need for timely control of the state of water basins and prevention of their catastrophic pollution due to the processes of handling bottom sediments.
Aim. To generalize normative and published data devoted to the problem of assessment of bottom sediments pollution and application of modern technologies of remediation of sediments contaminated with heavy metals.
Results and conclusions. The article shows that the most significant transformations in the composition and properties of bottom sediments naturally occur in the conditions of the highest load, typical for historically industrialized and urbanized regions. The authors have carried out a review of regulatory support for the assessment and remediation of contaminated bottom sediments. The paper highlights the gaps in the existing regulatory framework applied in Russia related to the lack of requirements for safe concentrations of toxic metals in bottom sediments. Systematization and analysis of applied technologies for bottom sediments remediation are carried out. The main directions of such works include application of physical, physico-chemical, chemical and biological methods of bottom sediments remediation and purification. These methods can be implemented either in situ or ex situ. The advantage of the first option is the lower cost of the works, while the remediation of sediments outside the water body allows achieving a higher degree of purification from heavy metals. The review shown the prospect of using hybrid remediation technologies with the selection of a set of methods that meet the requirements for treatment efficiency and economic feasibility, as well as the possibility of using contaminated sludge for the production of marketable products.
54-68
Atmospheric air pollution from the Ermakovskoe fluorite-beryllium deposit development waste
Abstract
Relevance. Negative impact of waste from mining enterprises on the ecological state of the surrounding areas.
Aim. To determine the migration ability of toxic chemical elements from waste storage sites of the Ermakovskoe beryllium deposit in the air.
Object. Ermakovskoe fluorite-bertrandite-phenacite deposit and the surrounding area.
Methods. Inductively coupled plasma mass spectrometry, laser diffraction, inductively coupled plasma atomic emission spectrometry.
Results and conclusions. The paper introduces the experimental studies of surface was used atmospheric pollution by mining waste from the Ermakovskoe fluorite-bertrandite-phenakite deposit. Аn installation for collecting aerosols above the sand surface has used. It was established that toxic components formed during the decomposition of residual sulfide mineralization and products of the interaction of acidic waters with rocks move from the sand thickness to the surface along with water vapor. The moisture condensed over the sand contains high contents of aluminum, iron, manganese, zinc, and phosphorus. These elements form a halo of air pollution over mining waste and are then dispersed by air currents into the surrounding area. In winter, due to wind dispersion of aerosols, the snow cover becomes contaminated over a vast area. Among the toxic elements found were beryllium, lead, cadmium, and molybdenum, which belong to the second hazard class. The solid residue of the snow cover contains a fine fraction of dust, the size of which is less than 10 microns. The halo of snow contamination with toxic chemical elements and dust extends several kilometers away from the disturbed lands.
69-86
Porous aggregate developed with the use of coal-containing clays of the Angren field
Abstract
Relevance. One of the ways to solve the issues of resource and energy conservation is the production and use of porous aggregates. Porous aggregates allow obtaining effective lightweight concrete for thermal insulation, wall panels, monolithic walls and other load-bearing structures, contribute to the increase of energy efficiency, improvement of thermal insulation, reliability, increase of fire resistance, frost resistance and seismic resistance of buildings, reduction of their weight. Therefore, in the production of porous aggregates, the primary task is the use of industrial waste and products of their processing. Solving these problems leads not only to saving valuable natural resources, but also to solution of environmental problems.
Aim. Development of compositions and study of properties of porous aggregate based on bentonite clay of Navbakhar deposit and coal-containing clay of Angren brown coal deposit.
Object. Coal-containing clay of Angren brown coal deposit, bentonite clay of Navbakhar deposit and artificial porous aggregate based on them.
Methods. Chemical, energy-dispersive X-ray, X-ray phase and infrared spectroscopic analysis, scanning electron microscopy, mathematical modeling, etc.
Results. The authors have determined chemical and mineralogical compositions of the clays used. Using the mathematical modeling method they developed the regression equations describing the effects of the amount of bentonite clay in the batch, firing temperature and isothermal holding time on the bulk density and water absorption of the porous aggregates. The resulting porous aggregates with a bulk density of 395 to 690 kg/m3 have a compressive strength in a cylinder of 2.74 to 6.46 MPa, respectively. It was found that the aggregates obtained meet the requirements of regulatory documents.
87-103
Monsoonal effect on sediment grain distribution along the subaqueous Mekong Delta coastal, Vietnam
Abstract
Relevance. Annually, the coastal areas of the Mekong Delta receive approximately 50% of the total sediment load from the Mekong River, primarily during the southwest monsoon. During the northeast monsoon, this coastal sediment undergoes reworking and is transported southwestward along the coastal areas of the Mekong delta.
Aim. Analyzing the grain-size distribution of sea-bed surface sediment helps improve our understanding of sediment redistribution along the coastal areas of the Mekong Delta.
Methods. In order to illustrate changes in sea-bed surface sediment grain size between the two monsoons, we focused on the median grain size, a widely used parameter for sediment transport calculation, and created spatial maps of median grain size along the coastal areas of the Mekong Delta. The analysis was based on sediment samples collected along the coastal areas of the Mekong Delta during field excursions in the southwest and northeast seasons.
Results. The results reveal that median grain size during northeast (mainly ranging from 0.005 to 0.01 mm) are larger than those during southwest (primarily ranging from 0.01 to 0.05 mm). These changes in median grain size and spatial distributions are most prominent along the east coast, specifically from Soc Trang to Bac Lieu. In contrast, median grain size along the west side does not exhibit significant differences between the southwest and northeast monsoons. These observations imply a more significant sediment transport along the east coastal areas of the Mekong Delta during the northeast monsoon and provide evidence for the transportation of sediment from the east coast to the west coast during the monsoons.
104-111
Highly efficient purification of the process solution when producing lithium hydroxide by caustification
Abstract
Relevance. The need to develop highly effective methods for purifying the process solution from impurity calcium and aluminum ions for the industrial production of lithium hydroxide at the Chemical Metallurgical Plant JSC in Krasnoyarsk.
Aim. Development of methods for reducing the content of impurity calcium and aluminum ions in the process solution of lithium hydroxide after caustification to a concentration of 5–10 mg/l.
Methods. Evaporation and crystallization, precipitation of colloidal sediments of aluminum and calcium with an ammonia buffer solution, chemical precipitation with 8-hydroxyquinoline.
Results and conclusions. The effectiveness of the applied methods for purifying a process solution of lithium hydroxide from calcium and aluminum ions was shown: evaporation followed by crystallization, precipitation with an ammonia buffer solution, precipitation in the form of hydroxyquinolates. It was experimentally established that when using the evaporation method followed by crystallization, the degree of extraction of impurity aluminum ions Al3+ is achieved 29%; and calcium ions Ca2+ – 56%. When cleaning the process solution by precipitation of aluminum hydroxide colloid with an ammonia buffer solution, the degree of extraction for aluminum ions Al3+ was 96%; for calcium ions Ca2+ – 67%. The use of the chemical precipitation method with 8-hydroxyquinoline in an alkaline solution showed the degree of extraction of aluminum ions Al3+ 20%; and calcium ions Ca2+ – 76%. It was established that the method of evaporation and crystallization of the process solution does not require the use of special reagents. A method using an ammonia buffer solution to remove impurity calcium and aluminum ions shown to be simple and effective. For the first time, a method was proposed for cleaning the process solution after caustification using an aqueous-alkaline solution of 8-hydroxyquinoline, excluding the use of organic, flammable and toxic solvents.
112-118
Intelligent control system for technological complexes of aluminum industry enterprises
Abstract
Relevance. Aluminum production is one of the most important industries all over the world. It has a high environmental load, resource and energy intensity. To reduce the negative impact of aluminum production, efforts are underway to improve its technological processes, aimed at increasing aluminum recovery rates, reducing waste volumes, and lowering energy consumption. The reduction of energy consumption can be achieved, among others, through implementing control systems that provide energy management. Due to the complexity and multiplicity of technological processes in aluminum production, the use of traditional linear approaches for such control systems is ineffective, and adequate mathematical models are required. At the same time, for the production level, the use of mathematical models based on a phenomenological description of the ongoing physical processes overly complicates the control task. As a result, the use of intelligent and adaptive approaches to both the mathematical description of technological processes and the optimal energy consumption management is relevant.
Objects. Technological complexes of aluminum production, which have the properties of inertia, nonlinearity, and closedness; and the control system based on artificial intelligence methods. Alumina production is chosen as an illustration.
Aim. To develop mathematical models capable of adequately describing the interrelated processes in the technological complexes under consideration, as well as the control system that allows optimal energy consumption management.
Methods. For the mathematical model based on balance equations under uncertainty, the fuzzy-set theory was used along with the gradient descent method to identify the model parameters; for the optimization task, the genetic algorithm method was used.
Results. The mass balance model and the process conditions changing model have been developed to determine the energy consumption for the technological complexes of aluminum production with continuous inertial nonlinear closed production. Based on these models, the dynamic characteristics of energy consumption and the parameters of technological processes were determined depending on the main controlled parameters, allowing us to predict emergencies. Considering technological parameters and cost factors, the optimization task for energy consumption management was solved.
119-132
Rheological properties of water-oil emulsions of Archinskoe oil deposit
Abstract
Relevance. The development of new methods for regulating the rheological properties of water-oil emulsion using thermal and chemical methods will allow reducing the viscosity of oil well products and energy consumption for pumping hydrocarbon mixtures.
Aim. To determine the activation energy of viscous flow and particle sizes of the internal phase of the initial emulsion of the Archinskoe deposit and the emulsion with an introduced demulsifier.
Methods. All experiments required to investigate the rheological properties of colloidal disperse systems were performed using HAAKE Viscotester iQ rotational viscometer.
Results. Comparative experimental studies were carried out on the effect of the introduced demulsifier on the effective viscosity of the water-oil emulsion of the Archinskoe deposit. Laboratory-scale experiments were performed using the rotational viscometry, which allows one to evaluate the dependence of viscosity on shear rate and temperature. It was established that the studied samples are liquids with pronounced non-Newtonian properties, which are a consequence of the paraffinic nature of oil and its water-oil emulsion. The structure of nanoparticles of the dispersed phase of dehydrated oil and its emulsion is discussed and justified. Using the analytical Arrhenius–Frenkel–Eyring expression, which describes the dependence of viscosity on temperature and the physical and chemical nature of the liquid system, the results of viscometrical experiments were processed and the activation energies of viscous flow and the particle size of the inverse emulsion were calculated in the absence of a demulsifier and in its presence. Laboratory experiments have confirmed that for complete dehydration of oil well products, it is not enough to introduce only a demulsifier, but it also requires heating the emulsion to a temperature sufficient to melt and dissolve paraffin particles, which form a structural and mechanical barrier situated on the surface of the emulsion droplets.
133-141
Voltammetric method for determining hydrazine at a composite polymer-carbon electrode modified with gold particles
Abstract
Relevance. Hydrazine and its derivatives are used in the production of corrosion inhibitors, medicines, pesticides, dyes, polymers, components of energy production and storage systems, rocket fuels. The prospect of replacing carbon fuels with hydrazine is associated with its high calorific value and the formation of environmentally friendly oxidation end produ-cts (nitrogen, water). A serious disadvantage limiting the widespread use of hydrazine is its high toxicity. When exposed to the human and animal body, hydrazine and its compounds have carcinogenic and mutagenic effects, affect the central nervous system, and cause anemia. In this regard, the development of new and improvement of existing methods for the determination of hydrazine and its compounds in environmental objects, technological and biological environments is an urgent task.
Aim. To establish the possibility of voltammetric determining hydrazine in solutions using a composite polymer-carbon electrode modified with gold particles.
Objects. Solutions of hydrazine salts; aqueous solutions of acids, alkalis and salts.
Methods. DC voltammetry, scanning electron microscopy, X-ray spectral microanalysis, computational modeling of ion-molecular equilibria.
Results. The oxidation of hydrazine in solutions of N2H4×H2SO4+0.1 М KNO3 on a polymer-carbon electrode modified with gold particles under conditions of voltammetry with linear potential sweep proceeds at potentials E>0.3 V (vs. Ag/AgCl/KCl electrode) with a pronounced maximum current of anodic oxidation in the range of 0.5...0.9 V. Hydrazine oxidation on a modified electrode proceeds at low potentials due to the manifestation of the effect of electrocatalysis. It is established that the delayed stage of the electrode process is single-electron transfer. The reaction is of the first order in terms of hydrazine, is irreversible and is controlled by the diffusion of the substrate to the electrode surface. Based on the results of the analysis of the dependence of the maximum value of the hydrazine oxidation current on the modified electrode on the conditions of voltammetry (solution concentration, potential sweep rate, pH), a method for determining hydrazine in solutions is proposed. The following conditions for recording voltammograms are optimal: nitrogen deaerated background electrolyte 0.1 M KNO3, pH=5...7, the potential range for recording an analytical signal is 0.2...1.0 V, the potential sweep rate is 50 mV/s. Under these conditions, the dependence of the maximum value of the anodic oxidation current on the hydrazine concentration is described by linear regression equations in the ranges of 1×10–5…1×10–4 and 1×10–4…1.5×10–3 M N2H4 (the detection limit is 2.1×10–6 M). In comparison with the electrodes known from the literature, the modified electrode used in the work does not require a costly preparation and storage procedure, according to its analytical characteristics, the proposed method is not inferior to the most highly sensitive electrochemical methods for determining hydrazine.
142-156
External electric grid impact on mode parameters at a load node
Abstract
Relevance. A passive experiment is one of the advanced techniques for a static load voltage characteristic identification. External electric grid impact on mode parameters at a load node – a grid response – sophisticates the statistical processing of passive experiment results significantly. For this reason, the analysis of a grid response impact and detection of its reduction are relevant problems.
Aim. Quantitative evaluation of a grid response impact is produced by grid response active and reactive power coefficients; therefore the aim of this paper is to analyze the variance of grid response coefficients in relation on scheme and mode parameters. This allows finding techniques of reducing a grid response impact.
Methods. Transformations of the Jacobi matrix, when scheme and mode parameters are formed as complex numbers.
Results. The authors have proposed the analytic expressions, reproducing dependences of grid response coefficients on scheme and mode parameters in general variants.
Conclusions. Based on the analytic and schematic dependencies the authors determined the measures for reducing a grid response impact. It is demonstrated that with increase in the impedance among power and load nodes, a grid response impact grows as well by active and reactive power. The authors proposed the practical technique for calculating a grid response impact. The perspective trends for improving accuracy in identifying a grid response impact using current mode and scheme parameters are defined.
157-169
Chemical and mineral composition of altered volcanic ash in coals of the Kharanorskoe Deposit, Eastern Siberia
Abstract
Relevance. The necessity to assess the role of altered volcanic ash on the formation of mineral and geochemical characteristics of coal-bearing deposits. Traces of volcanic material in coals are diagnosed mainly in the form of clay horizons – tonsteins. The study of the chemical and mineral composition of clay tuffaceous horizons and the host coals allows us to answer a number of questions concerning volcanic material impact on coal accumulation. Tonsteins are known in Paleozoic, Mesozoic and Cenozoic coal-bearing deposits. Finds of Mesozoic tonsteins are relatively rare. In this regard, the Kharanorskoe brown coal deposit is a unique object for the study of altered layers of volcanic ash in Cretaceous coal-bearing deposits.
Aim. Comprehensive study of altered volcanic ash in Cretaceous coals of the Zabaikalsky Krai.
Methods. Field stu-dies; the mineral composition was studied by optical microscopy, scanning electron microscopy, X-ray diffractometry; chemical composition was determined by inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectrometry, and instrumental neutron activation analysis.
Results and conclusions. The paper presents the data on the mineral and chemical composition of tonstein in the Early Cretaceous Novy-1a coal seam of the Kharanorskoe deposit located in the southeast of the Eastern Siberia (Russia). The mineral composition of the tonstein is represented by kaolinite, quartz, and feldspar. Accessory minerals are zircon, ilmenite, monazite-(Ce), and xenotime-(Y). The tonstein is characterized by high concentrations of Ga, Nb, Hf, Ta, Hg, Th and U. The highest concentrations of rare trace elements in the coal, and especially in the coal ash of the Novy-1a seam, are localized in the areas of contact between the tonstein and the coal. The enrichment with REE, Zr, Nb, Y, Ta, Hf, Th and U is the most significant. Mineralogical and geochemical characteristics of the studied tonstein indicate its formation from volcanic ash of alkaline composition.
170-184
Synthesis of Magnéli phases in a high-speed electric discharge plasma jet
Abstract
Relevance. Currently, there is an active search for photocatalytic materials suitable for water decomposition and hydrogen production that exhibit activity when exposed to visible light, and are also accessible, chemically stable and safe. In this regard, a number of materials with the general formula TinO2n-1 (n=2–10) are distinguished, they are called Magnéli phases. Despite the fact that Magnéli phases exhibit significantly higher photocatalytic activity compared to traditional titanium oxides (rutile, anatase, brookite), their practical application is currently extremely difficult due to the complexity of their synthesis. Promising approaches are those that provide well-controlled conditions with the possibility of rapid stabilization of the system, among which plasma synthesis methods stand out.
Aim. To develop a method for synthesizing a product containing Magnéli phases in a high-speed jet of electric discharge plasma.
Objects. Dispersed materials obtained in the Ti-O system.
Methods. Plasma dynamic synthesis, X-ray diffractometry (X-ray phase analysis), scanning electron microscopy, transmission electron microscopy.
Results. Using a high-speed jet of electric discharge plasma generated by a coaxial magnetoplasma accelerator, experimental studies were performed on the synthesis of non-stoichiometric titanium oxides in a carbon dioxide environment. The composition and microstructure of the obtained dispersed products were studied. It was revealed that the materials contain Magnéli phases TinO2n−1, as well as traditional stoichiometric rutile and anatase. From the point of view of the efficiency of obtaining Magnéli phases, the single-pulse mode of operation is more attractive (content over 50%), while the efficiency of CO2 conversion is higher in the multi-pulse mode (up to 10% of CO2 is converted into CO). A distinctive feature of the synthesized materials at both the micro- and nanolevels is the tendency to form particles with a high degree of sphericity. The nanofraction of the products mainly consists of rounded particles with sizes up to hundreds of nanometers, of which the Magnéli phases primarily include nanoparticles with a characteristic highly defective crystalline structure with dislocation shifts.
185-196
Chemical composition of natural waters of the eastern rim of the Siberian platform (Predverkhoyansk foredeep)
Abstract
Relevance. Foothill (foredeep, pericratonic) deflections play a significant role generation and localization of hydrocarbon accumulations and are promising objects of oil and gas exploration. Numerous studies of such structures are focused mainly on the geological structure, formation and prospects of oil and gas potential of these territories. Issues related to the geochemistry of natural waters are either not covered at all, or are presented in an extremely limited form. Studying the chemical composition of the natural waters of the Predverkhoyansk foredeep at the modern analytical level will make it possible to assess the hydrogeochemical background and emphasize the peculiarities of the behavior of the main components of the aquatic environment in conditions of a sharp change in the tectonic situation.
Aim. To study and identify the hydrogeochemical features of the composition of natural waters in the area of the eastern framing of the Siberian platform in the region of its junction with the scaly-thrust dislocations of the Verkhoyano-Kolyma folded zone.
Methods. Measurements of ra-pidly changing parameters of natural waters (pH, Eh, temperature) were carried out directly at the sampling site with a portable HQ-40D analyzer from Hach Lange (USA). The analysis of the chemical composition of waters was carried out in the Problematic Research Laboratory of Hydrogeochemistry of Tomsk Polytechnic University using ion chromatography methods on a two-channel reagentless ionochromatographic complex ICS-5000 with conductometric detection manufactured by Dionex-Thegmo Scientific (USA). The content of CO32– and HCO3– anions in the studied waters was determined by the traditional titrimetry method for these indicators. The Si concentration was determined by inductively coupled plasma mass spectrometry on a NeXION 300D device, Perkin Elmer (USA).
Results. The paper presents the data on the chemical composition of the natural waters of the Tompo, Lyapiske, Sobolokh-Mayan (Sobopol) river basins in the inner part of the Predverkhoyansk foredeep in front of the cutting edge of the advanced thrust of the western slope of the Verkhoyansk anticlinorium. The patterns of the distribution of basic ions are shown, common features and differences between the studied sites are revealed.
197-209
Approaches to the method of granulation of fly ash of power plants
Abstract
Relevance. The research is aimed at reducing the impact of deficiencies (dusting) when involving in circulation fly ash, which prevents the wider use of valuable secondary raw materials in the production of demanded products. The direction of work corresponds to the Comprehensive Waste Disposal Plan for coal-fired power plants and boiler houses, approved by the Decree of the Government of the Russian Federation dated 06/15/2022 No. 1557-R.
Aim. Development of an optimal technology for the production of granules from fly ash of Kemerovo Urban District Power Plant using two types of substances of a similar nature as a binder, depending on the concentration of the binder in an aqueous solution and the delay time of strength gain and abrasion index.
Object. A granulate or pellet made of fly ash based on a binder of experimental aluminosilicate glue and liquid sodium glass "Diola-53".
Methods. Strength tests were carried out on a hydraulic press according to SS 8929-2020 and the abrasion index of a large filler in a shelf drum was determined out according to SS 9758-2012. Two methods of granulation of fly ash were used: 1) two-stage – preparation (cooking) of aluminosilicate glue from fly ash and granulation; 2) one-stage – granulation using market liquid glass. Liquid aluminosilicate glue was produced experimentally in a container using a flask heater and a mixing device.
Results and conclusions. The authors have established the differences in the delay time of strength gain and the abrasion index of granules obtained by two methods based on fly ash from Kemerovo Urban District Power Plant using aluminosilicate glue and liquid sodium glass "Diola-53" as a binder. They found the dependences of the delay time of strength gain and the abrasion index of granules on the concentration (fraction) of an aqueous solution of the binder. The specific costs for the production of granules for each binder and its proportion in an aqueous solution are determined. Granulate from fly ash based on a binder: experimental aluminosilicate glue and liquid sodium glass "Diola-53", can be transported without dusting by any type of transport and serve as a potential raw material for cement production and a component in concrete production.
210-218
Mathematical model of the system performance mode for simultaneous separate well operation
Abstract
Relevance. The trend of oil production technology development is related to many relevant topics. One of such actual directions is the technology of simultaneous separate well operation, in particular, including two electric centrifugal pumps and double-sided submersible electric motor. The presence of two formations at the bottomhole implies the selection of the optimal layout, technological parameters of pumps pumping oil. Considering production from two independent formations in the well according to the mentioned technology, there is a high need in selection of correct parameters of installations at the design stage. In the absence of correct selection of technological parameters of units at the design stage, further operation of a well with two independent formations can be economically inexpedient, and in some cases unrealizable, which is due to a number of reasons. First, if the necessary underbalance is not provided for each particular formation, counterflow of fluid may occur and one of the pumps will not participate in the production process. Secondly, when operating an arrangement, which capacity significantly exceeds the capacity (fluid flow from the reservoir) of the well, there is a possibility of pumping failure and, as a consequence, there is a risk of potential failure. In this regard, an extremely urgent task at the moment is to ensure correct selection of technological parameters of electric centrifugal pump units used in simultaneous separate operation of wells with two independent formations.
Aim. Development of a mathematical model that allows selecting the optimal technological parameters of the arrangement consisting of two electric centrifugal pumps and a double-sided submersible motor, used for simultaneous separate operation of wells with two independent formations.
Methods. Numerical simulation methods for analyzing the operation mode of electric centrifugal pumps in conditions of oil production from two independent reservoirs.
Results and conclusions. It was obtained that the developed mathematical model of the system operation mode for simultaneous separate operation of wells allows estimating the potential of each individual selected pump during oil production (in time dynamics) by analyzing the depression on each individual reservoir, as well as modeling the process taking into account the potential backflow of liquid and supply failure.
219-227
Optimization of rheological characteristics of xanthan-based solutions for washing liquid treatment
Abstract
Relevance. Within the limits of the isolated concentrations of xanthan and salts, optimization of rheological parameters of a pseudoplastic liquid intended for thickening drilling mud is shown. For this purpose, it is proposed to isolate from the complete rheological curve the separation of the liquid liquefaction section, according to which the nonlinearity parameters are determined. The complete factorial experiment allows us to specify the dependence of rheological nonlinearity on the concentration of ingredients. The formulation of the complete factorial experiment makes it possible to qualitatively evaluate other brands of biopolymers. Based on the non-linearity indicators, an indicator for optimizing the carrying capacity of drilling fluids is proposed. The use of the above and characteristic viscosity of the solutions can serve as qualitative and quantitative estimates of the projected compositions of drilling fluids. The multiplicity of brands of xanthan gums determines their qualitative diversity. The choice of gum for thickening drilling fluids is not formalized. The article offers one of the options.
Aim. Using the Ostwald de Weil model to evaluate the rheological characteristics of aqueous solutions of DUO-VIS xanthan gum in the presence of Na and K chlorides at elevated concentrations of xanthan and salts, as well as to analyze the effect of the dispersed phase of the thickener solution on its rheological characteristics.
Methods. Instrumental methods for determining the parameters of drilling fluids according to SS 33213-2014, mathematical modeling using a complete factorial experiment.
Results and conclusions. Using the example of a DOU-VIS xanthan solution applied as a thickener for drilling fluids, the S-shape of the viscosity profiles of solutions of xanthan thickeners is shown. The paper considers the example of highlighting a section of the viscosity curve with decreasing viscosity and approximating it by a power dependence. The effect of biopolymer and potassium chloride (within the limits of their isolated concentrations) on the parameters of the power dependence used as an approximated viscosity curve is shown using a complete factorial experiment. The paper introduces the distribution of the optimization parameter, which is the ratio of the consistency coefficient to the nonlinearity indicator, within the range of changes in the concentrations of biopolymer and KCl. An example of calculating the volume fraction of biopolymer macromolecules in solution is shown and the application of the reduced and characteristic viscosities for estimating solutions at the scale of suspension particles is given.
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Development of an observer of rotor angular velocity and resistance moment on the shaft of an adjustable permanent magnet synchronous motor powered through long cable
Abstract
Relevance. Currently, when using submersible electric motors in centrifugal electric pump installations in cyclic operation mode, there is a reduction in the inter-repair period of submersible equipment, which is associated with a reduction in oil pumping periods to several minutes. As a result, there is a multiple increase in starting currents and torque, which leads to an increase in mechanical loads on the pump shaft and appearance of resonance phenomena during the electric motor acceleration, reducing the reliability of a seal protection. To solve these problems, it is necessary to synthesize closed-loop vector control systems with current and electromagnetic torque control in transient responses. Open-loop scalar control systems for electric drives of oil well production are used in operation, which is due to the complexity of obtaining feedback signals on the angular velocity of the rotor and the moment of resistance on the shaft by means of submersible telemetry. This problem determines the relevance and necessity of developing observers for rotor speed and load torque estimation, taking into account the features of the technological process of installing centrifugal electric pumps, in particular, the presence of a long cable for powering a submersible electric motor based on a synchronous machine with permanent magnets.
Aim. To develop a full-order observer rotor speed and load torque for the dynamic system "long supply cable – synchronous motor with permanent magnets".
Methods. System analysis and identification of dynamic systems, synthesis of Luenberger observers, mathematical modeling of dynamic systems, electric drives and electrical machines.
Result and conclusions. The authors have proposed the mathematical model of a rotor speed and load torque full-order observer for the dynamic system "long supply cable – synchronous motor with permanent magnets". The performance of the observer was investigated under varying load on the shaft, mismatch of non-zero initial conditions, deviation of the parameters of the equivalent circuit of the observer and the object in the range from –20 to +20% of the nominal values.
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