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Date submitted2024-04-27
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Date accepted2024-11-07
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Date published2025-03-05
Comprehensive studies of the snow-firn layer in the area of the Russian Antarctic Vostok Station
The article presents the findings from research conducted at Vostok Station during the 69th Russian Antarctic expedition. The primary goal of the research is to perform a thorough investigation of the snow-firn layer using both direct (drilling and core analysis) and indirect (georadiolocation and seismic exploration) methods. As part of the research, fundamental tasks related to the study of the structure and dynamics of the upper part of the ice sheet were addressed, as well as applied tasks aimed at justifying the depth of explosive charge placement for seismic work with the goal of conducting a detailed study of Lake Vostok and selecting the point for drilling access to the lake. Data on the microstructure and physical properties of the snow-firn layer were collected. The findings will allow for future improvements to the firn densification model, which is required to understand the evolution of ice grains during the early stages of metamorphism. The study's findings aided in the understanding of the structural features of the ice sheet's surface layer, allowing for more precise determination of the structural and physical characteristics of the snow-firn layer and ice, potentially leading to a better understanding of climatic and geological processes in Antarctica.
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Date submitted2022-10-24
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Date accepted2023-03-03
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Date published2023-04-25
Use of clay-containing waste as pozzolanic additives
Growing productivity of mining and processing enterprises entails an increase in the volumes of liquid tailings impoundments and upstream impoundments of ore processing waste. Enterprises face the challenge of minimizing the environmental impact of waste and guaranteeing the sanitary and epidemiological safety of population. The article presents a possibility of recycling one type of such waste (clay-containing concentration tailings of apatite-nepheline and sylvinite ores, coal beneficiation tailings) by using them after preliminary thermochemical treatment as pozzolanic additives to cements and concretes, including concrete mixtures used for soil stabilization, development of territories, reclamation of mine workings, as a component of the insulating layer of landfills for the disposal of municipal solid waste. An analysis of the phase changes of kaolinite, one of the main minerals that make up clay-containing waste, in the temperature range of 200-1,000 °С showed that a change in its mineral form during heat treatment is the main factor in changing its pozzolanic activity. The effect of heat treatment of clay minerals at temperature of 700-800 °C on their pozzolanic activity, estimated by the ability to absorb calcium hydroxide (0.7 g Ca(OH) 2 per 1 g of modified kaolinite), is considered. It is shown that the addition of heat-treated samples (20 % by weight) improves the quality of cement increasing its activity by 15 %, in comparison with the use of unmodified clay minerals. It was proved experimentally that partial replacement of Portland cement with thermally modified kaolinite increases the strength of consolidating stowing mixture by up to 15 %. This approach to processing of ores containing layered silicates, which provides for thermochemical modification of run-of-mine ore, intensifies the processes of tailings thickening and filtering.
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Date submitted2021-05-31
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Date accepted2021-10-18
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Date published2021-12-16
Experimental evaluation of compressibility coefficients for fractures and intergranular pores of an oil and gas reservoir
- Authors:
- Vitaly S. Zhukov
- Yuri O. Kuzmin
The paper is devoted to studies of the volumetric response of rocks caused by changes in their stress state. Changes in the volume of fracture and intergranular components of the pore space based on measurements of the volume of pore fluid extruded from a rock sample with an increase in its all-round compression have been experimentally obtained and analyzed. Determination of the fracture and intergranular porosity components is based on the authors' earlier proposed method of their calculation using the values of longitudinal wave velocity and total porosity. The results of experimental and analytical studies of changes in porosity and its two components (intergranular and fractured) under the action of effective stresses are considered. This approach allowed the authors to estimate the magnitude of the range of changes in the volumetric compressibility of both intergranular pores and fractures in a representative collection of 37 samples of the Vendian-age sand reservoir of the Chayanda field. The method of separate estimation of the compressibility coefficients of fractures and intergranular pores is proposed, their values and dependence on the effective pressure are experimentally obtained. It is determined that the knowledge of the values of fracture and intergranular porosity volumetric compressibility will increase the reliability of estimates of changes in petrophysical parameters of oil and gas reservoirs caused by changes in the stress state during the development of hydrocarbon fields.
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Date submitted2017-12-29
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Date accepted2018-03-26
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Date published2018-06-22
Methods to enhance oil recovery in the process of complex field development of the Yarega oil and titanium deposit
- Authors:
- I. E. Dolgii
Yarega oil and titanium deposit is a unique facility due to a combination of two mineral resources – oil and titanium ore – in one geologic structure. The paper describes mining and geologic conditions of the field, as well as engineering solutions to enhance oil recovery and the efficiency of heat transfer. The author focuses on the issues of deposit opening and preparation for development, and provides recommendations regarding the exploitation procedure of the oil and titanium parts of the field, which take into account field data on the extraction rates of high viscosity oil and titanium ore from the start of deposit development. The paper contains analysis of existing technological schemes of high viscosity oil extraction and steam heating of the oil bed, as well as assessment of their feasibility. Issues of field preparation for development are reviewed from the position of accumulated practical experience, and recommendations on the feasibility of combined underground and open-pit mining are supported with evidence. The main advantages of the proposed system are explained; key technical and economic indicators are calculated.
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Date submitted2014-11-24
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Date accepted2015-01-02
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Date published2015-10-26
Complex processing of apatite-nepheline ores based on the creation of closed-loop process flow sheets
- Authors:
- A. I. Alekseev
The article presents the chemical and engineering fundamentals of processing apatite and nepheline concentrates directly on the Kola Peninsula. Implementation of the existing separate processing of nepheline and apatite concentrates demonstrates inefficiency of these technologies due to the formation of waste calcium sulfate and calcium silicate, which have so far not found a practical use and are wastes stored in sludge repositories of the Russian Federation. Suggested new scientific and technical solutions will allow enterprises to significantly increase the volume of production of new in-demand marketable products due to rational and complex use of mineral raw materials of the Kola Peninsula, reduce their costs while decreasing the volume of rock extraction and eliminate waste creating a closed-loop technological cycle of processing apatite and nepheline ores.
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Date submitted2014-10-15
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Date accepted2014-12-23
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Date published2015-08-25
Nickel electrolyte purification from ferrum (III) and copper (II) impurities by extraction using a mixture of oleic acid and triethanolamine
- Authors:
- L. A. Voropanova
- N. T. Kisiev
The conditions of the selective and joint extraction of copper and ferrum impurities from a nickel electrolyte by extraction using a mixture of oleic acid and trietanolamine in kerosene were determined: extraction Fe (III) at 3 < рН ≤ 4, 1 ≤ В:О ≤ 4 and t = 40 °C; extraction Cu (II) at 5 ≤ рН ≤ 6, 1 < В:О ≤ 4 and t = 40 °C; joint extraction of copper and ferrum at рН = 5-6, 1 ≤ В:О ≤ 4 and t = 40 °C. The process flow sheet of selective extraction of ferrum and copper from a nickel electrolyte by extraction using a mixture of oleic acid and triethanolamine in kerosene is given.
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Date submitted2009-09-03
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Date accepted2009-11-20
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Date published2010-06-25
Virtual and rational in anthropological horizons of consciousness
- Authors:
- A. I. Voronov
In work ambivalence of concept «a virtual reality» is considered. On the advantage, the given concept serves as the description of technics of a virtual reality, but on the other hand, it, more and more, becomes a symbol of new mythological concept of consciousness.
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Date submitted2009-08-29
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Date accepted2009-10-30
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Date published2010-02-01
The unit for gravity concentration of fine particles
- Authors:
- Ya. V. Kuskova
It was made new modification of device for allows increasing recovery, to increase productivity and to lower size of concentrated particles. The device has a deck executed as a circle, which divides into two sectors; each sector has circular rifles with progressively growing height from the centre to periphery of a deck. The table is equipped with the high-frequency step-by-step engine ensuring continuous rotation of a table and submission counter impulses for shear of particles in a direction, opposite to rotation of a table. The quantity of angle sectors can be various. Testing of prototype of a table has confirmed an opportunity of increase of recovery, decrease size of extracted dense minerals and increase of throughput.
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Date submitted2008-10-21
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Date accepted2008-12-25
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Date published2009-12-11
Comparative analysis of spiriferida complexes of the frasnian stage in the south of Novaya Zemlya and one-aged complexes of East-European platform and other districts
- Authors:
- D. V. Bezgodova
The Article contains a brief characteristic of spiriferida (brachiopod) complexes spread in the Frasnian sediments in the South of Novaya Zemlya, and their comparison with one-aged complexes of several regions of East-European platform, such as Main Devonian field, Central districts, the Volga-Urals region, South Timan, south-western districts and also outlying districts of the Kuznetsk coal basin and North-West of Russia.
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Date submitted2008-10-11
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Date accepted2008-12-21
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Date published2009-12-11
Cyclicity of the devonian and carboniferous deposits of Novaya Zemlya
- Authors:
- R. A. Schekoldin
Two structural-formational zones are recognized in the Devonian and Carboniferous deposits of Novaya Zemlya: the Barents zone and the Kara zone. The first one is characterized by thick, predominantly carbonate deposits, containing a rich complex of benthic fossils, and corresponds to the shelf paleoenvironments. The second one is characterized by thin hemipelagic argillaceous, lime and siliceous deposits, containing scarce pelagic fossils. This zone is suggested to represent bathyal paleoenvironments (slope and basin floor). The main control on sedimentation in both zones provided relative sea-level rises and falls, which repeated with mean periodicity equal to an age (third-order cycles). Sea-level highstands correspord to periods of low sedimentation rates and stagnation in deep-water zone. Sea-level lowstands were favourable to intensification of sediment gravity flows and better aeration of bottom waters.