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negative master mold making

Geotechnical Engineering and Engineering Geology
  • Date submitted
    2023-05-17
  • Date accepted
    2023-08-17
  • Date published
    2023-10-27

Scientific and technical substantiation of the possibility for the organization of needle coke production in Russia

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Russia is one of the world's leading steel producers, while about 33 % of production comes from the scrap remelted in arc steelmaking furnaces. The graphitized electrodes of SHP and UHP grades, mainly consisting of needle coke, are used for high current loads and temperatures in furnaces. USA, Japan, Korea, and China are focused on needle coke production, where coal (tar and pitch) and petroleum (decantoil), by-products of metallurgical factories and oil refineries, are used as raw materials. Russia's annual demand for needle coke is approximately 100 thousand tons, but all of it is covered by imports. Russia's raw material potential, established by the authors of the article, is more than 5 million tons per year and includes decantoil, coal tar and pitch, and heavy pyrolysis tar. The results of obtaining needle coke from decantoil and heavy pyrolysis tar are given below. The prototypes of needle coke were produced on specially designed delayed coking laboratory units (loading up to 0.25 and 80 kg). Raw materials were modified according to the original technology of Saint Petersburg Mining University, the convergence of target properties of which is confirmed by the results of quality analysis of the obtained needle coke, including after 100-fold scaling. The electrodes were molded from the obtained coke. After standardized stages of firing, mechanical processing and graphitization at 2,800-3,000 °C, the coefficient of linear thermal expansion was less than 1 × 10–6 К–1, and the value of specific electrical resistance was 7.1-7.4 μOhm, which proves that the obtained carbon material corresponds in quality to Japanese analogues and Super Premium needle coke.

How to cite: Rudko V.А., Gabdulkhakov R.R., Pyagai I.N. Scientific and technical substantiation of the possibility for the organization of needle coke production in Russia // Journal of Mining Institute. 2023. Vol. 263 . p. 795-809. EDN KYNHWL
Geotechnical Engineering and Engineering Geology
  • Date submitted
    2021-09-16
  • Date accepted
    2022-02-24
  • Date published
    2022-04-29

Production of microfluidic chips from polydimethylsiloxane with a milled channeled surface for modeling oil recovery during porous rock waterflooding

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Microfluidic chips with porous structures are used to study the flow of oil-containing emulsion in the rock. Such chips can be made from polydimethylsiloxane by casting into a master mold. At the initial stages of research, fast and cheap prototyping of a large number of different master molds is often required. It is proposed to use milling to make a channeled surface on a polymethyl methacrylate plate, from which a negative image should be taken, which is the master mold for casting positive polydimethylsiloxane chips in it. Several epoxy compositions have been tested to make this master mold. The main requirement in the search for the material was the exact replication of the geometry and sufficiently low adhesion to polymethyl methacrylate and polydimethylsiloxane for removing the product with minimal damage to the mold. It was possible to make master molds from all the materials used, but with defects and various degrees of damage. One of the epoxy compositions was found suitable for making a master mold with many elements simulating the grains of a porous medium (height to width ratio 2:3). The developed method makes it possible to use polydimethylsiloxane for prototyping chips simulating the porous structure of an oil rock.

How to cite: Yakimov A.S., Pryazhikov A.I., Pryazhikov M.I., Minakov A.V. Production of microfluidic chips from polydimethylsiloxane with a milled channeled surface for modeling oil recovery during porous rock waterflooding // Journal of Mining Institute. 2022. Vol. 253 . p. 105-114. DOI: 10.31897/PMI.2022.9
Geoeconomics and Management
  • Date submitted
    2021-02-05
  • Date accepted
    2021-03-30
  • Date published
    2021-04-26

Assessment of negative infrastructural externalities when determining the land value

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The work forms and substantiates the concept of land value, based on a new institutional theory. The infrastructural component of the cost of land in the presented concept determines, on the one hand, the efficiency of the use of natural resources, properties, demand for land on the market, on the other hand, the costs, which are determined not only by capital investments in construction of engineering infrastructure, but also by losses associated with restrictions on activities within zones with special conditions for territory use, creation of unfavorable conditions for economic activity, small contours, irregularities and others on a specific land plot, which are external negative infrastructural externalities that create losses of rights holders of land plots that are not compensated by the market, falling within the boundaries of these zones. Methods for assessing the impact of such negative infrastructural externalities on the cost of land encumbered by zones in different conditions of land market activity have been developed and tested, based on an expert-analytical approach (depressed market); the ratio of market values of land plots encumbered and unencumbered by a specific zone, and qualimetric modeling (inactive market); modeling by introducing into the model the factor of presence of zones with special conditions for territory use, based on the grouping of zones according to similar regulations for use, or by introducing the parameters of this factor (active market). Methods for taking into account spatial deficiencies and compensating for restrictions and prohibitions on activities on the territory of land plots with an individual market assessment are proposed.

How to cite: Bykova E.N. Assessment of negative infrastructural externalities when determining the land value // Journal of Mining Institute. 2021. Vol. 247 . p. 154-170. DOI: 10.31897/PMI.2021.1.16
Electromechanics and mechanical engineering
  • Date submitted
    2018-10-28
  • Date accepted
    2018-12-30
  • Date published
    2019-04-23

Development and research of formation technologies on specialized presses with subsequent sintering of high-density details from iron-based powders

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Creating shifts of the lyaers in a deforming workpieces improves the quality of the product produced by pressure treatment. qual-channel angular pressing and precipitations of a cylindrical billet with a rotating turnaround were developed by specialists earlier and became basic for scientists engaged in nanotechnology. One of the most modern schemes for creating nanostructures by processing on presses is the «Cyclic Extrusion Compression» scheme (in Russia – «Hourglass»), which has significant drawbacks. To date, research on the creation of layer shifts in compacted metal powders is substantially less than in compaction of compact blanks. The article developed compaction schemes for presses of blanks from iron-based powders that have a certain analogy with the «Hourglass», while lacking the disadvantages inherent in the named scheme and implemented on the created samples of specialized hydraulic presses. The results of the studies of density, strength and microhardness before sintering the samples molded from a number of domestic and imported powders on iron base, including those doped with carbon and other alloying components, are described. It has been established that with the use of the formation schemes for powders providing large shifts between particles, the density of the preforms increases on average by 10-12 %. With an average stress (16.32 MPa) of the transverse section of the molded specimen prior to its sintering, molding with shifts between particles increases this stress by 78 %. The strength after sintering of samples made using the compaction schemes developed by the authors of the article increases approximately by 2 times. Magnetic pulse treatment (MPT) of a molded sample prior to its sintering increases its resistance to shearing before sintering, regardless of the molding pattern. When MPT of both the powder and the molded sample is executed, the most uniform distribution of microhardness in the sample is achieved, and after subsequent sintering, the most uniform distribution of the mechanical characteristics of the product. The results of all studies are described by regression equations.

How to cite: Dmitriev A.M., Korobov N.V., Badalyan A.Z. Development and research of formation technologies on specialized presses with subsequent sintering of high-density details from iron-based powders // Journal of Mining Institute. 2019. Vol. 236 . p. 216-228. DOI: 10.31897/PMI.2019.2.216
Electromechanics and mechanical engineering
  • Date submitted
    2017-08-30
  • Date accepted
    2017-11-21
  • Date published
    2018-02-22

Simulation of operation of pneumatic compensator with quasi-zero stiffness in the electric centrifugal submersible pump unit

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The ECSPU pneumatic compensators with quasi-zero stiffness are proposed. The pneumatic compensator with quasi-zero stiffness is suggested to be made in the form of pneumatic spring assemblies having a power characteristic with a positive stiffness working area and a set of successively connected Belleville springs and a power characteristic with a working area of negative stiffness. Structurally, a set of Belleville springs is located inside the air spring and supports pneumatic compensator piston. As a result of adding the negative stiffness of the disc spring washers set and the positive stiffness of the pneumatic spring, the resulting system (the proposed pneumatic compensator) acquires a quasi-zero or specified low stiffness. The efficiency of the suggested pneumatic compensator was determined by the possibility of moving its piston from the effects of various pressure drops. It was assumed that the greater the distance the piston can move under a given action, the more effective the pneumatic compensator is. The effect of various forces acting on the piston in the case of pressure drops on the discharge line of the electric centrifugal submersible pump units (ECSPU) is simulated: a rapidly decreasing load; a sudden increase in the force acting on the piston and vibration impact. In all the considered examples, the displacement of the piston was several meters, which corresponds to the length of the working area of the power characteristic of the considered pneumatic compensator with quasi-zero stiffness. It is shown that existing pneumatic compensators, which are like gas caps, are in principle unable to provide the same displacement of the piston under the same effects on it. For their effective operation, the size of the gas cap should be several tens of meters, which is impossible in the conditions of the well. In the calculations, it is shown that it is possible to manufacture the necessary disk spring washers from various materials: steel; fiberglass FGM; beryllium bronze. Of particular interest are disk spring washers made of beryllium bronze, which are capable of withstanding up to 20 billion load cycles.

How to cite: Zotov A.N., Urazakov K.R., Dumler E.B. Simulation of operation of pneumatic compensator with quasi-zero stiffness in the electric centrifugal submersible pump unit // Journal of Mining Institute. 2018. Vol. 229 . p. 70-76. DOI: 10.25515/PMI.2018.1.70
Economical aspects in the developments оf fuel & energy complex
  • Date submitted
    2008-11-23
  • Date accepted
    2009-01-05
  • Date published
    2009-12-11

The economic mechanism of project risk management in development of oil and gas resources

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Management decisions efficiency in well construction projects depends on the control of the worked out planning taking into consideration expected risks, rapid reaction on plan vs fact deviations and adjustment to course of works. Economic assessment of well construction risks offers an opportunity to find adequate managerial decisions for prevention of possible design deviations and to submit respective recommendations for construction of new wells to be placed in operation.

How to cite: Krainova E.A. The economic mechanism of project risk management in development of oil and gas resources // Journal of Mining Institute. 2009. Vol. 184 . p. 144-149.
Economical aspects in the developments оf fuel & energy complex
  • Date submitted
    2008-11-26
  • Date accepted
    2009-01-01
  • Date published
    2009-12-11

Strategy modelling of jaking decisions at ecological and economic evaluation of oil project

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The supposed methodological approach to the evaluation of oil investment project is based on the principle of correlation of profits and expenses, nature protection expenses included at their early stage. The advantage of this analysis is the possibility of making project analysis of ecological risks based on the method analysis of taking decisions and the analysis of the economical results. The account of the ecological factor of the oil project model of evaluation is based on the developed interaction of the technological, ecological and economic information. It’s basis is project documentation, project influence materials, evaluation upon the environment and accountants report.

How to cite: Markhasina M.V. Strategy modelling of jaking decisions at ecological and economic evaluation of oil project // Journal of Mining Institute. 2009. Vol. 184 . p. 156-159.