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Date submitted2024-06-04
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Date accepted2025-01-28
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Date published2025-04-04
Impact of dry and wet magnetic separator process parameters on iron oxide removal from Egyptian feldspar ore
The demand for feldspar as a raw material in the ceramic industry is continuously increasing. Feldspar is abundant in the Earth's crust and typically found alongside other silicate minerals, as well as titanium and iron oxides. This study aims to reduce the iron oxide content in feldspar ore from the Wadi Zirib region and achieve an optimal grade of feldspar concentrate for various industrial uses. The research involved dry and wet magnetic separation techniques followed by leaching with oxalic and citric acids to minimize iron impurities and enhance optical properties. The factors affecting the dry magnetic separation, for feldspar size of –250+45 µm, were optimized using the Box – Behnken factorial design and a non-magnetic concentrate with 0.29 % Fe2O3 and an 92.19 % feldspar yield was obtained. The wet magnetic separation for feldspar fines of size –45µm was optimized and a concentrate with 0.27 % Fe2O3 was achieved. The acid leaching was conducted on the non-magnetic feldspar concentrates using oxalic and citric acid. Oxalic acid was more successful in reducing iron oxide of dry (to 0.19 %) and wet (to 0.12 %) non-magnetic feldspar concentrates. The optical properties of the leached concentrates were improved compared to the original sample, as the whiteness improved up to 90 %.
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Date submitted2024-03-20
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Date accepted2024-11-07
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Date published2025-02-27
Analysis of the stress state of rocks transformation near a horizontal well during acid treatment based on numerical simulation
The article presents an overview of the assessment and modelling of the stress state of rocks in the near-wellbore zone of horizontal wells during acid stimulation of the formation for improving the efficiency of oil and gas field development. A numerical finite element model of near-wellbore zone of the reservoir drilled by a horizontal section was compiled using one of oil fields in the Perm Territory as an example. The distribution of physical and mechanical properties of the terrigenous reservoir near the well was determined considering transformation under the action of mud acid for different time periods of its injection. Multivariate numerical simulation was performed and the distribution of horizontal and vertical stresses in near-wellbore zone was determined with regard for different values of pressure drawdown and changes in stress-strain properties depending on the area of mud acid infiltration. It was found that a change in elastic modulus and Poisson's ratio under the influence of acid led to a decrease in stresses in near-wellbore zone. Analysis of the stress distribution field based on the Coulomb – Mohr criterion showed that the minimum safety factor of rock even after the effect of mud acid was 1.5; thus, under the considered conditions of horizontal well modelling, the reservoir rock remained stable, and no zones of rock destruction appeared.
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Date submitted2022-09-30
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Date accepted2024-11-07
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Date published2025-02-25
Carbon dioxide corrosion inhibitors: current state of research and development
Among the methods of corrosion control in the oil and gas production industry the leading place belongs to inhibitor protection, since there is no need for technological and technical changes in the existing equipment. The combination of high variability of inhibitor composition with changing conditions of its application and low capital investments makes it an indispensable reagent at oil and gas fields. The main classes of compounds used as active bases of carbonic acid corrosion inhibitors for the protection of oil and gas equipment are described. Classical organic active bases containing heteroatoms (oxygen, sulfur, nitrogen) are examined. Special attention was paid to alkylimidazolines and other nitrogen-containing compounds as the most frequently used as active bases of carbonic acid corrosion inhibitors in Russia and abroad. A wide range of possibilities to achieve the desired properties of corrosion inhibitors by varying the substitutes has been demonstrated. Nowadays, in addition to the traditional requirements for corrosion inhibitors, their safety for the environment is equally important. The information on prospective research and development aimed at improving the environmental characteristics of the reagents used is given. Plant extracts, synthetic and biological polymers involved in traditional corrosion inhibitors or used as new independent compounds are considered. It is shown that the effectiveness of corrosion inhibitors significantly depends on the pH of the medium, temperature, partial pressure of СО2, flow rate, and other factors.
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Date submitted2023-06-25
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Date accepted2024-11-07
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Date published2025-02-25
Study of wormhole channel formation resulting from hydrochloric acid treatment in complex-type reservoirs using filtration and X-ray computed tomography methods
- Authors:
- Andrei A. Аbrosimov
The primary function of hydrochloric acid treatment (HAT) is to create the maximum number of high-conductivity channels in the near-wellbore zone of the reservoir to restore its permeability and enhance hydraulic connectivity between the undisturbed part of the formation and the well. The objective of this study is to physically model HAT on core samples from the Orenburg oil and gas condensate field and to research the impact of such treatment on the structure of the pore space of rocks related to complex-type reservoirs. The complexity of the rock's pore space and the low permeability of the formations are distinguishing features of the study object. For this reason, HAT is a widely applied method for production intensification, necessitating the verification of acid injection rates, where the success criterion is the formation of high-conductivity filtration channels (wormholes) in the near-wellbore zone. These channels significantly expand the drainage area of wells, thereby bringing additional reservoir sections into development. The study examined the characteristics of filtration channel development resulting from acid treatment. Their structure was characterized and analyzed using X-ray computed tomography. The complex study confirmed the accuracy of the selected injection rate and provided practical recommendations for enhancing the efficiency of HAT.
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Date submitted2023-06-21
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Date accepted2023-10-25
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Date published2024-08-26
Specific action of collector from phosphoric acid alkyl esters class in flotation of apatite-nepheline ores
Increasing amount of apatite-nepheline ores with complex mineral composition involved in processing, growing content of the associated minerals in ore which are similar in their floatability to apatite lead to the necessity of using highly selective collectors. Non-frothing flotation method gave a comparative assessment of floatability of pure minerals and demonstrated a high selectivity of the action of phosphoric acid esters in relation to apatite. The effect of four reagent modes differing in the number of selective synthetic collectors was studied using the example of flotation of an apatite-nepheline ore sample containing 17.27 % apatite and 40.18 % nepheline. Mineralogical analysis of crushed ore showed that it contained two apatite varieties – coarse-grained free and finer poikilitic as inclusions in rock-forming minerals. Free apatite opens and occurs as open grains even in coarse-grained (+0.16 mm) grades. Poikilitic apatite occurs as intergrowths with different minerals, mainly with nepheline and its alteration products (natrolite, spreustein, sodalite, etc.), and pyroxene. Optical microscopy demonstrated that a growing share of reagent from the phosphoric acid oxyethylated esters class in the composition of the collector mixture allows improving the quality of the produced apatite concentrates by reducing the number of apatite intergrowths with nepheline and pyroxenes in the concentrates. In the concentrate obtained in the most selective reagent mode, the intergrowths are characterized by a 50/50 and higher ratio in favour of apatite. Concentrates of lower quality comprised intergrowths with lower apatite content, to 20/80 or less.
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Date submitted2024-04-10
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Date accepted2024-06-03
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Date published2024-07-19
Combined method for processing spent acid etching solution obtained during manufacturing of titanium products
Possessing high strength, low density and significant chemical resistance, titanium has found wide application in various fields of the national economy – the chemical industry, aviation and rocket technology, mechanical engineering, medicine, etc. The production of titanium products is hampered by a fairly strong oxide film covering its surface. Removal of the oxide film from the surface of titanium workpieces is carried out by etching in solutions of mineral acids of various compositions. A spent acid etching solution (SAES) is formed, containing titanium salt and the remainder of unreacted acids. Almost all etching solutions contain HF and one of the strong acids. This is H2SO4, HCl or HNO3. Thus, the SAES includes ions of titanium, fluorine or chlorine, orsulfate, or nitrate. SAES is quite toxic and must be diluted or cleaned several times before being discharged into a reservoir. Most of the methods used to extract impurities contained in SAES lead to a decrease in their content. As a result of such purification, there is a loss of substances contained in SAES in significant quantities and of interest for further use. The work presents experimental results obtained from the combined processing of SAES containing titanium fluoride, hydrofluoric and hydrochloric acids. At the first stage, SAES is treated with sodium hydroxide. The resulting titanium hydroxide precipitate is filtered off. At the second stage, the filtrate containing sodium fluoride and chloride is processed in a membrane electrolyzer. In this case, not only the extraction of sodium salts from the filtrate occurs, but also the production of sodium hydroxide and a mixture of hydrofluoric and hydrochloric acids. Sodium hydroxide can be used for processing SAES, and a mixture of acids for etching titanium workpieces.
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Date submitted2024-04-11
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Date accepted2024-06-03
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Date published2024-07-04
Assessment of the efficiency of acid mine drainage purification (using the example of copper-pyrite mines in the Middle Urals)
According to the results of the anti-rating of regions with extreme pollution of watercourses in the Sverdlovsk region, the largest number of polluted rivers has been recorded in recent years – more than a quarter of all high and extremely high pollution. One of the sources of pollution of natural water bodies in the Middle Urals are closed and flooded copper-pyrite mines, where acidic mine drainage continue to form and unload to the surface. Several of them have organized collection and a two-stage acidic drainage purification system, including neutralization with lime milk and settling in a clarifier pond. Despite the identical schemes, different indicators of pollutants are recorded during discharge into water bodies. The aim of the work is to evaluate the effectiveness of the applied acid mine drainage purification system and identify the parameters affecting the quality of treated mine water. Laboratory studies were performed using methods of flame emission spectrometry, flame atomic absorption, atomic absorption spectrometry, mass spectrometry with ionization in inductively coupled plasma, potentiometric, etc. It has been established that the existing mine drainage purification system at the Degtyarskii mine makes it possible to significantly reduce the concentrations of most toxic components of mine waters to almost standard values. At the Levikhinskii mine, the multiplicity of exceeding the maximum permissible concentrations reaches hundreds and thousands of times. To achieve a higher degree of purification, it is necessary that the duration of passive purification is sufficient for the reactant to interact with acidic waters. However, to ensure this possibility, it will require the creation of a cascade of ponds with an area of several thousand hectares. If the current two-stage system is quite effective for the Degtyarskii mine, then for Levikhinskii it is necessary to switch to the use of more modern systems, including three stages of purification.
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Date submitted2024-05-06
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Date accepted2024-06-14
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Date published2024-07-04
Natural carbon matrices based on brown coal, humic acids and humine extracted from it for purification of aqueous solutions from low molecular weight organic impurities
Heterogeneous systems including natural carbon matrices in the solid phase and aqueous solutions of low molecular weight organic compounds with positive and negative variations from ideality in the liquid phase are considered. The technical characterization of the considered supramolecular ensembles on the basis of brown coal of the Kara-Keche deposit (Kyrgyzstan), humic acids and humine extracted from it is given. Functional analysis of the samples was carried out using FTIR spectroscopy. The morphology of the surface of the considered carbon matrices has been investigated, in different points of which the local microelement composition has been established. An X-ray phase analysis of Kara-Keche brown coal and humic acids and humine extracted from it was carried out. The isothermal adsorption of bipolar molecules of glycine and urea, neutral D-glucose from aqueous solutions on solid carbon sorbents has been studied. An assumption has been made about the adsorption of low molecular weight organic compounds from aqueous solutions on humine and Kara-Keche coal in irregularities and pores of the carbon matrix of sorbents, for humic acids – on surface reaction centers. Due to its developed pore structure and resistance to acids and alkalis, humine from Kara-Keche coal is recommended for the purification of industrial wastewater from low molecular weight organic ecotoxicants.
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Date submitted2024-05-02
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Date accepted2024-06-03
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Date published2024-07-04
Iron ore tailings as a raw material for Fe-Al coagulant production
The paper presents the results of experimental research into the recovery of Fe-Al coagulant from iron ore tailings (IOTs). The variables investigated in the laboratory tests included sulphuric acid concentration, temperature, leaching time, solid/liquid phase ratio (S:L) and the presence of stirring. The experiment determined the composition of the coagulant and the solid residue after leaching. The maximum iron content in the solution after leaching was obtained using 40 % H2SO4 at a temperature of 100 °C (or with stirring at 75 °C) and a contact time of 60 minutes. In this case, the iron yield was at the level of 25 % of the total content in the iron ore tailings. Chemical analysis of the solution obtained after leaching showed Fe and Al sulphate contents of 11 and 2 % respectively. In the next step, the efficiency of the coagulant was evaluated on model solutions of colour. The experimental results showed that the coagulant obtained from the iron ore tailings can be used for wastewater treatment in a wide pH range from 4 to 12 pH units. The solid residue after leaching is a fine-grained powder rich in silica, which can potentially be used as an artificial raw material in the construction industry. The research carried out in this thesis has shown that the extraction of coagulants from iron ore tailings can be considered as a way to extend the production chain of iron ore mining and to minimise the amount of tailings to be stored in tailing ponds. The technical solution presented in this work allows to comprehensively solve the problem of environmental protection by creating new target products for wastewater treatment from IOTs.
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Date submitted2024-04-25
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Date accepted2024-06-13
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Date published2024-07-11
Evaluation of the effectiveness of neutralization and purification of acidic waters from metals with ash when using alternative fuels from municipal waste
- Authors:
- Polina A. Kharko
- Aleksandr S. Danilov
The problem of pollution of natural water objects with heavy metals is extremely relevant for the areas where industrial enterprises are located. Unauthorized discharge of contaminated wastewater, inefficient operation of sewage treatment plants, as well as leakage of drainage waters from man-made massifs lead to changes in the hydrological system affecting living objects. The article studies the composition of ash from the combustion of alternative fuels from municipal waste, and also considers the possibility of using it to neutralize sulfuric acid drainage waters and extract metal ions (Cu, Cd, Fe, Mn, Zn) from them. It has been established that the efficiency of water purification from metals depends on the pH value achieved during the purification process. The pH value is regulated by the dose of the introduced ash, the contact time and depends on the initial concentration of metal ions and sulfates in the solution. Studies on the neutralization and purification of a model solution of sulfuric acid drainage waters of a tailings farm of known composition have shown that in order to achieve a pH of 8-9, optimal for precipitation of metal hydroxides Cu, Cd, Fe, Mn, Zn and Al washed out of ash, and water purification with an efficiency of 96.60 to 99.99 %, it is necessary to add 15 g/l of ash and stir the suspension continuously for 35 minutes. It was revealed that exposure to ash with sulfuric acid waters leads to the transition of water-soluble forms of metals into insoluble ones and their “cementation” with calcium sulfate. The amount of Zn and Fe ions washed out of the ash decreases by 82 and 77 %, Al, Cd, Cu, Mn – by 25 %. This reduces the toxicity of ash, which is proved by a decrease in the toxic multiplicity of dilution of the water extract by 14 times.
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Date submitted2023-04-11
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Date accepted2023-10-25
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Date published2024-07-04
Acid mine water treatment using neutralizer with adsorbent material
One of the biggest issues in the mining sector is due to acid mine drainage, especially in those abandoned mining operations and active ones that fail to adequately control the quality of their water discharge. The removal degree of copper, iron, lead, and zinc dissolved metals in acid mine drainage was investigated by applying different proportions of mixtures based on neutralizing reagent hydrated lime at 67 % calcium oxide (CaO), with adsorbent material – natural sodium bentonite, compared to the application of neutralizing reagent without mixing, commonly used in the neutralization of acid mining drainage. The obtained results show that the removal degree of dissolved metals in acid mine drainage when treated with a mixture of neutralizing reagent and adsorbent material in a certain proportion, reaches discharge quality, complying with the environmental standard (Maximum Permissible Limit), at a lower pH than when neutralizing material is applied without mixing, registering a net decrease in the consumption unit of neutralizing agent express on 1 kg/m3 of acid mine drainage. Furthermore, the sludge produced in the treatment with a mixture of the neutralizing reagent with adsorbent material has better characteristics than common sludge without bentonite, since it is more suitable for use as cover material, reducing the surface infiltration degree of water into the applied deposit.
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Date submitted2023-07-04
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Date accepted2023-09-20
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Date published2023-10-27
Structure maintenance experience and the need to control the soils thermal regime in permafrost areas
- Authors:
- Anatolii V. Brushkov
- Andrei G. Alekseev
- Svetlana V. Badina
- Dmitrii S. Drozdov
- Vladimir A. Dubrovin
- Oleg V. Zhdaneev
- Mikhail N. Zheleznyak
- Vladimir P. Melnikov
- Sergei N. Okunev
- Aleksei B. Osokin
- Nikolai A. Ostarkov
- Marat R. Sadurtinov
- Dmitrii O. Sergeev
- Roman Yu. Fedorov
- Konstantin N. Frolov
The risks of reducing the stability of buildings and structures are increasing in conditions of climate change and the active development of the territories under the influence of natural and anthropogenic factors. The main causes include: loss of the bearing capacity of frozen soils, various geocryological processes, errors at the stages of design, construction and operation of facilities. Main actual task when conducting research and industrial operations in the cryolithozone is monitoring and, if necessary, managing thermal processes in the permafrost layers interacting with facilities. In this article the obtained positive experience of various technologies applying at various stages of the life cycle of civil and industrial facilities was analyzed. It helps to eliminate or prevent the structure deformation or destruction under the influence of climate change. The methods of permafrost stabilization used in the oil and gas industry in process of industrial infrastructure development of the fields have been studied – freezing (cooling) of foundation soils during construction on heterogeneous foundations. The solution to the problems of minimizing accidents when locating production wells in the permafrost zone of the Yamal Peninsula is considered using the example of an oil and gas condensate field and restoring of the temperature regime of perennial unfrozen soils in areas of valve units of main gas pipelines. An assessment of methods used to maintain the industrial and residential infrastructure within the northern municipalities that ensure the functioning of the fuel and energy complex of the Russian Federation in the Arctic was made. The systems of thermal stabilization in the foundations of buildings and industrial facilities built and operated on permafrost soils allow to fully use the high strength and low deformability of frozen grounds. It ensures the state's long-term plans of the industrial development in the Arctic.
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Date submitted2021-10-27
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Date accepted2023-06-20
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Date published2023-12-25
Geomechanical analysis of the impact of the new tunnels construction in the vicinity of existing underground subway structures on the state of the soil massif
The specificity of the behavior of the soil massif near the tunnel under construction in difficult mining conditions is considered. It was revealed through the joint interpretation of the results of geophysical measurements in the tunnel and computer simulation. The results of field geophysical studies to identify areas of decompacted soil behind the lining in two existing tunnels during successive drilling of two new tunnels under them are described. A method to analyze the response of the lining to impact was used providing for the calculation of its energy. It has been established that the decompaction zones are mainly located in the lateral lower areas of the tunnel. To substantiate the mechanism of formation of cavities, computer simulations were carried out using the finite element method with the COMSOL Multiphysics software. The finite element model is built on the Drucker – Prager criterion in the variant of a two-dimensional problem statement. It is shown that at the initial position of two old tunnels, the areas of decompaction can develop mainly on the sides. The position of the zones changes significantly when excavating two new tunnels. Soil decompaction zones appear between the tunnels and there is a tendency for the areas to spread to the upper point of the tunnel. According to geophysical data time delays in the impact of new tunnels on the existing line are noted, as well as a decrease in the size of decompacted soil areas over time. There is a satisfactory agreement between the positions of the decompaction areas and voids obtained by the geophysical method and the results of numerical simulation.
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Date submitted2022-10-23
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Date accepted2023-02-13
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Date published2023-12-25
Sorption purification of acid storage facility water from iron and titanium on organic polymeric materials
Obtaining and production of metals from natural raw materials causes a large amount of liquid, solid, and gaseous wastes of various hazard classes that have a negative impact on the environment. In the production of titanium dioxide from ilmenite concentrate, hydrolytic sulphuric acid is formed, which includes various metal cations, their main part is iron (III) and titanium (IV) cations. Hydrolytic acid waste is sent to acid storage facilities, which have a high environmental load. The article describes the technology of ion exchange wastewater treatment of acid storage facility from iron (III) and titanium (IV) cations, which form compounds with sulphate ions and components of organic waste in acidic environments. These compounds are subjected to dispersion and dust loss during the evaporation of a water technogenic facility, especially in summer season. Sorption of complex iron (III) cations [FeSO4]+ and titanyl cations TiO2+ from sulphuric acid solutions on cation exchange resins KU-2-8, Puromet MTS9580, and Puromet MTS9560 was studied. Sorption isotherms were obtained both for individual [FeSO4]+ and TiO2+ cations and in the joint presence. The values of the equilibrium constants at a temperature of 298 K and the changes in the Gibbs energy are estimated. The capacitive characteristics of the sorbent were determined for individual cations and in the joint presence.
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Date submitted2022-11-04
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Date accepted2023-03-03
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Date published2023-04-25
Efficiency of acid sulphate soils reclamation in coal mining areas
During the development of coal deposits, acid mine waters flowing to the surface cause the formation of acid sulphate soils. We study the effectiveness of soil reclamation by agrochemical and geochemical methods at the site of acid mine water discharge in the Kizel Coal Basin, carried out in 2005 using alkaline waste from soda production and activated sludge. A technosol with a stable phytocenosis was detected on the reclaimed site, and soddy-podzolic soil buried under the technogenic soil layer with no vegetation on the non-reclaimed site. The buried soddy-podzolic soil retains a strong acid рН concentration Н 2 О = 3. A high content of organic matter (8-1.5 %) is caused by carbonaceous particles; the presence of sulphide minerals reaches a depth of 40 cm. Technosol has a slightly acid pH reaction H 2 O = 5.5, the content of organic matter due to the use of activated sludge is 19-65 %, the presence of sulphide minerals reaches a depth of 20-40 cm. The total iron content in the upper layers of the technosol did not change (190-200 g/kg), the excess over the background reaches 15 times. There is no contamination with heavy metals and trace elements, single elevated concentrations of Li, Se, B and V are found.
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Date submitted2022-10-19
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Date accepted2023-02-14
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Date published2023-04-25
Electric steelmaking dust as a raw material for coagulant production
The paper describes the issues associated with waste generated during steel production and processing, in particular the dust from electric arc furnaces (EAF). An effective solution for the disposal of such waste is its involvement in processing to obtain valuable products. This paper studies the physical and chemical properties of EAF dust produced during the smelting of metallized pellets and captured by the dust and gas cleaning system of the steel-smelting shop at the Oskol Electrometallurgical Combine, Belgorod Region. The results obtained in the study of the chemical and disperse compositions of dust, the microstructure of the surface made it possible to propose the use of dust as a raw material for coagulant production. The conditions of acid-thermal treatment of dust are determined, contributing to the partial dissolution of iron (II), (III), and aluminium compounds, which ensure the coagulation processes during wastewater treatment. Model solutions show high efficiency (> 95 %) of water treatment from heavy metal ions by modified EAF dust.
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Date submitted2022-05-12
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Date accepted2022-11-17
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Date published2023-04-25
Microbiological remediation of oil-contaminated soils
- Authors:
- Irina D. Sozina
- Aleksandr S. Danilov
Microbiological remediation is a promising technology for the elimination of environmental contamination by oil and petroleum products, based on the use of the metabolic potential of microorganisms. The issue of environmental contamination by crude oil and its refined products is relevant in the Russian Federation since the oil industry is one of the leading sectors of the country. Mechanical and physico-chemical methods of treatment are widely used to clean oil-contaminated soils. However, the methods belonging to these groups have a number of significant drawbacks, which actualizes the development of new methods (mainly biological), since they are more environmentally friendly, cost-effective, less labor-intensive, and do not require the use of technical capacities. Various bio-based products based on strains and consortia of microorganisms have been developed that have proven effectiveness. They include certain genera of bacteria, microscopic fungi, and microalgae, substances or materials acting as sorbents of biological agents and designed to retain them in the soil and increase the efficiency of bioremediation, as well as some nutrients. Statistical data, the most effective methods, and technologies, as well as cases of using microorganisms to restore oil-contaminated soils in various climatic conditions are presented.
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Date submitted2022-05-10
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Date accepted2022-09-06
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Date published2022-11-03
Flotation separation of titanite concentrate from apatite-nepheline-titanite ores of anomalous zones of the Khibiny deposits
Titanium raw materials are widely used for the synthesis of various functional materials – sorbents of radionuclides and rare earth elements, various additives, filler pigments, etc. Since most of titanium concentrates are imported, in line with the import substitution program, production of titanite concentrate from apatite-nepheline ores of the Khibiny deposits is a promising trend for supplying national industry with titanium raw materials. The article presents the results of laboratory studies of flotation separation of titanite concentrate from apatite-nepheline-titanite ores extracted from the upper ore horizon of the Koashvinskoye deposit, where titanite-enriched ores are concentrated. Recovery of titanite concentrate was accomplished using two reagent modes – a mixture of alkyl hydroxamic and carboxylic acids with the addition of distilled tall oil and a mixture of tall oils with the addition of polyalkyl benzene sulfonic acids. The results of the research showed that the first flotation mode, which allows a selective recovery of titanite into the concentrate (titanite content in the concentrate was 93.5 %) is the most efficient. It was shown that flotation separation of titanite concentrate is preferable compared to the chemical method based on sulfuric acid leaching.
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Date submitted2022-02-22
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Date accepted2022-05-11
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Date published2022-11-03
Scientific substantiation and development of innovative processes for the extraction of zirconium and rare earth elements in the deep and comprehensive treatment of eudialyte concentrate
- Authors:
- Valentin A. Chanturiya
Based on a package of modern analysis methods, the influence of various acids and energy effects on the morphology, elemental composition, structural and chemical transformations of the mineral surface, and the efficiency of eudialyte concentrate leaching was studied. The mechanism and the optimal conditions and specific features of the destruction of eudialyte and rock minerals and the extraction of zirconium and REE under the influence of various acids, powerful nanosecond pulses, dielectric barrier discharge, electrochemical processing, mechanochemical activation and ultrasound were revealed. The mechanism of formation and the optimal conditions for the dispersion of silica gel, depending on the methods and parameters of energy effects, was theoretically and experimentally substantiated. A combined three-stage circuit of nitric acid leaching of eudialyte concentrate with ultrasonic treatment of the suspension, providing 97.1 % extraction of zirconium and 94.5 % REE, were scientifically substantiated and tested. The conditions for the selective deposition of zirconium and REE were theoretically and experimentally substantiated.
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Date submitted2021-03-18
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Date accepted2021-11-30
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Date published2021-12-27
Deformations assessment during subway escalator tunnels construction by the method of artificial freezing of soil for the stage of ice wall formation
- Authors:
- Evgenii M. Volokhov
- Diana Z. Mukminova
The work is devoted to the study of the processes of displacement and deformation of the surface during the escalator tunnels construction of the subway by the method of artificial freezing of soils. The features of the construction and freezing technology, the rocks characteristics in which the escalator tunnels made are considered. The data of specially organized, full-scale surveying observations of deformations on the earth surface are presented. The main factors influencing deformation processes in the frozen strata of a layered inhomogeneous rock mass with inclined tunneling are determined, the complexity of the predictive task and the need to simplify the design scheme are shown. The work is focused on the assessment of the least studied geomechanical processes of soil heaving-uplifts and deformations during the periods of active and passive freezing stages. When studying the displacements processes of the earth surface and rock mass, the finite element method and analysis of the obtained data using field observations of displacements were used. A simplified calculation scheme is proposed for modeling, which allows taking into account the uneven influence of frozen rocks of an inhomogeneous layered rock mass with a large inclined tunneling. The satisfactory convergence of the data of field surveying observations on the earth surface and the results of modeling geomechanical processes for the period of active and passive freezing stages is shown. The proposed calculation scheme is recommended for the prediction of deformation at the stages of underground construction, characterized by the development of the most dangerous tensile deformations of buildings and structures on the surface.
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Date submitted2021-06-24
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Date accepted2021-10-18
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Date published2021-12-16
Modeling the acid treatment of a polymictic reservoir
- Authors:
- Mars M. Khasanov
- Andrey А. Maltcev
Acid treatment of wells program is directly related to oil production efficiency. Investigations aimed at improving the efficiency of acid treatment in a terrigenous reservoir have mainly reviewed the changing and adapting the reagents to minimize bridging caused by acid-rock interaction. Under real conditions, application of new and unique acid compositions is a complex process from an organizational point of view and is therefore not widely used as compared with conventional compositions based on a mixture of hydrochloric and hydrofluoric acids. The paper is based on an approach to improve acid treatment efficiency through optimal design based on near-bottomhole zone treatment simulation. The aspects for practical application of the developed acid treatment simulator for terrigenous reservoirs based on a numerical model of hydrodynamic, physical and chemical processes in a porous medium on an unstructured PEBI-grid are described. The basic uncertainties of the model are identified and analyzed. Influence of empirical parameters within the system of equations on the calculation results and modeling of the mineralogical composition of rocks are considered. Algorithm for static modelling of near-bottomhole zone for acid treatment modelling is described, as well as an approach to optimizing the design of near-bottomhole zone treatment based on adapting the results of rock tests in the model. Using experimental data, the necessity of accounting for influence of secondary and tertiary reactions on the results of modeling physical and chemical processes during acid treatment of terrigenous reservoirs was proved. The distinctive features of West Siberian objects (polymictic reservoirs) with respect to the efficiency of near-bottomhole zone treatment with clay acid have been investigated. Series of calculations to determine the optimum volume of acid injection has been carried out. Experience of previously conducted measures under the considered conditions has been analyzed and recommendations to improve the efficiency of acid treatment have been given.
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Date submitted2021-02-09
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Date accepted2021-07-27
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Date published2021-10-21
Development of an algorithm for determining the technological parameters of acid composition injection during treatment of the near-bottomhole zone, taking into account economic efficiency
Relevance of the research is due to the low proportion of successful hydrochloric acid treatments of near-bottomhole zones of carbonate reservoirs in the Perm region caused by insufficiently careful design and implementation of measures to stimulate oil production. Within the framework of this article, the development of a program is presented, which is based on an algorithm that allows determining the volume and rate of injection for an acid composition into a productive formation corresponding to the maximum economic efficiency during hydrochloric acid treatment. Essence of the proposed algorithm is to find the greatest profit from measures to increase oil recovery, depending on the cost of its implementation and income from additionally produced oil. Operation of the algorithm is carried out on the principle of enumerating the values of the volume and rate of injection for the acid composition and their fixation when the maximum difference between income and costs, corresponding to the given technological parameters of injection, is reached. The methodology is based on Dupuis's investigations on the filtration of fluids in the formation and the results of the experiments by Duckord and Lenormand on the study of changes in the additional filtration resistance in the near-well zone of the formation when it is treated with an acid composition. When analyzing and including these investigations into the algorithm, it is noted that the developed technique takes into account a large number of factors, including the lithological and mineralogical composition of rocks, technological parameters of the injection of a working agent and its properties, well design, filtration properties of the formation, properties of well products. The article provides an algorithm that can be implemented without difficulty using any programming language, for example, Pascal. Selection of the optimal values for the volume and rate of injection is presented in this paper, using the example of a production well at the Chaikinskoye oil field, located within the Perm region. Introduction of the developed algorithm into the practice of petroleum engineering will allow competent and effective approach to the design of hydrochloric acid treatments in carbonate reservoirs without a significant investment of time and additional funds.
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Date submitted2020-06-14
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Date accepted2020-06-14
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Date published2020-06-30
Geochemical approach in assessing the technogenic impact on soils
- Authors:
- Galina I. Sarapulova
The soil assessment was carried out in the technogenically-affected area of Irkutsk Oblast with the geochemical approach as a key geoecological method using physical and chemical techniques of analysis and ecodiagnostics. Diagnostic signs of the disturbed natural properties of the soil were revealed up to a depth of 40 cm in the profile based on macro- and micromorphometric parameters. The content of heavy metals (HM) – Pb, Zn, Hg, and Cu with an excess of standards was determined, and empirical HM – pH correlations were obtained by statistical clustering of the data array. The contributions of additional factors affecting the chemical element distribution in the soil layer were investigated. Significant soil contamination with sulfates and the possibility of implementing the ion-exchange of HM andfor element immobilization were revealed. It was shown that reactions with sulfates and the influence of pH, HM exchange processes involving mobile K and P can determine the nature of the described chemical element distribution in the multi-factor-contaminated technogenic soil. However, the effectiveness of such types of interaction is different for each metal and also depends on the quantitative ratio of substances and soil characteristics, even under a minor change in pH. Two-parameter correlations of HM distribution in sulfate-contaminated soils confirmed the different degrees of involvement of chemical elements in these types of interactions. The results obtained and the identified factors are of applied significance and can be used as the basis for geoecological differentiation of the contaminated soil, as well as for determining local geochemical fields in the technogenesis zone. Areas of advanced research are related to three-dimensional modeling for a more complete study of the cause-and-effect relationships of geochemical parameters.
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Date submitted2019-04-03
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Date accepted2022-12-02
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Date published2020-02-25
Influence of parameters of delayed asphalt coking process on yield and quality of liquid and solid-phase products
Paper studies the effect of excess pressure during delayed coking of asphalt, obtained by propane deasphaltization of tar, on yield and physical and chemical properties of hydrocarbon fuels' components and solid-phase product – petroleum coke. Asphalt was coked at a temperature of 500 °C and excess pressure of 0.15-0.35 MPa in a laboratory unit for delayed coking of periodic action. Physical and chemical properties of raw materials and components of light (gasoline), medium (light gasoil), and heavy (heavy gasoil) distillates obtained during experimental study were determined: density, viscosity, coking ability, sulfur content, iodine number, pour points, flash points, fluidity loss and fractional composition. Quantitative group hydrocarbon and microelement compositions and properties of obtained samples of petroleum coke (humidity, ash content, volatiles' yield, sulfur content, etc.) were also studied. Comparative assessment of their quality is given in accordance with requirements of GOST 22898-78 “Low-sulfur petroleum coke. Specifications”. In addition, patterns of changes in excess coking pressure on yield and quality indicators of distillate products and petroleum coke were revealed. With an increase in excess pressure of coking process from 0.15 to 0.35 MPa, content of paraffin-naphthenic hydrocarbons in light and heavy gasoils of delayed coking decreases. Common pattern in asphalt coking is an increase in yield of coke and hydrocarbon gas with an increase in excess pressure from 0.15 to 0.35 MPa.
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Date submitted2019-03-11
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Date accepted2019-05-11
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Date published2019-08-23
Estimate of Radial Drilling Technology Efficiency for the Bashkir Operational Oilfields Objects of Perm Krai
- Authors:
- S. V. Galkin
- A. A. Kochnev
- V. I. Zotikov
The radial drilling technology efficiency for carbonate bashkir deposits of Perm Krai is considered. The geological structure of a productive part of bashkir layer is characterized by high degree of heterogeneity that promotes while drilling radial channels involvement in development additional interlayers that earlier was not drained. During the analysis the main geological process parameters affecting drilling technology efficiency were revealed. According to the dynamics of average daily oil production growth, palettes were built to forecast additional oil production as a result of radial drilling activities. Using the pallets, it is possible to predict the total additional oil production, well operating time with the effect of radial drilling and average daily oil production growth for each year. It was found that hydrochloric acid treatments performed on wells prior to radial drilling significantly reduce the effectiveness of radial drilling technology. For such wells, the value of the correction is statistically substantiated, which reduces the predictive estimate of the increase in oil production. A model was built to assess the increase in oil production in the first year after the event and an algorithm for calculating the total additional oil production was developed using linear discriminant analysis. For the resulting model, errors are calculated that are compared with the forecast efficiency of standard methods for oil-producing enterprises. This model shows a much more accurate correspondence of forecast results to actual technology application results. The probability of the event high efficiency increases significantly with a more detailed approach to the selection of wells for radial drilling. According to the forecast methodology, the technology’s efficiency was calculated and recommendations for its implementation for the wells of the Bashkir production objects were made in the interests of an oil-producing enterprise.