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Date submitted2023-12-15
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Date accepted2024-06-13
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Date published2025-02-25
Development of equipment and improvement of technology for inertial thickening of backfill hydraulic mixtures at the final stages of transportation
The results of the study of the functioning of the developed thickening equipment as part of the stowing complex for the formation of a flow of high-concentration hydromixture are presented. To explain the operation of the hydrotransport system of the stowing complex, equipped with a thickener of the developed design, its basic diagram is presented. A mathematical model has been created that describes the mechanism of inertial sedimentation of a solid component of a hydraulic mixture in a working chamber equipped with hydrodynamic profiles. Interaction with the profile leads to flow stratification due to a change in the trajectory of movement and a decrease in speed. The interval of rational velocity of primary pulp entering the input of the working chamber of the inertial thickener is substantiated. The synthesis of solutions of the thickening process model is performed in the COMSOL Multiphysics and Ansys Fluent programs. This made it possible to eliminate physical contradictions in the operation of the equipment and justify the overall dimensions of its main elements, ensuring the implementation of the mechanism of inertial sedimentation of the slurry. It was found that the concentration of the thickened flow at the outlet branch pipe of the thickener working chamber is determined by the level of the primary hydraulic fluid velocity, the characteristic length of the section of interaction with the deflecting profile, and the ratio of the flow and attack angles. A nomogram of the dynamics of the change in the hydraulic fluid concentration in the section of the outlet branch pipe depending on the ratios of the overall dimensions of the deflecting profile of the working chamber was compiled. The results of the study allowed formulating recommendations for selecting the dimensions of the thickener's deflecting hydrodynamic profile to form a flow of hydraulic mixture with a concentration of about 50 % by weight. The developed equipment can be used in a stowage complex and will increase the range of supply of the stowage mixture. This is due to the fact that a flow of primary slurry with a low concentration, due to lower pressure losses, can be moved in a pipeline system over a greater distance than a flow with a high filler content. The use of a thickener at the final stage of transportation is intended to increase the concentration of the hydraulic mixture immediately before production.
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Date submitted2023-07-25
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Date accepted2024-05-02
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Date published2024-08-26
Finite element analysis of slope failure in Ouenza open-pit iron mine, NE Algeria: causes and lessons for stability control
Slope failures in mining engineering pose significant risks to slope stability control, necessitating a thorough investigation into their root causes. This paper focuses on a back analysis of a slope failure in the Zerga section of the Ouenza – Algeria open-pit iron mine. The primary objectives are to identify the causes of slope failure, propose preventive measures, and suggest techniques to enhance stability, thereby providing crucial insights for monitoring slope stability during mining operations. The study commenced with a reconstruction of the slopes in the affected zones, followed by a numerical analysis utilizing the Shear strength reduction method within the Finite element method (SSR-FE). This approach enables the examination of slope stability under both static and dynamic loads. The dynamic load assessment incorporated an evaluation of the vibrations induced by the blasting process during excavation, introducing seismic loading into the finite element analysis. The findings reveal that the primary triggering factor for the landslide was the vibration generated by the blasting process. Furthermore, the slope stability was found to be critically compromised under static loads, highlighting a failure to adhere to exploitation operation norms. The challenging geology, particularly the presence of marl layers where maximum shear strain occurs, contributed to the formation of the landslide surface. The study not only identifies the causes of slope failure but also provides valuable lessons for effective slope stability management in mining operations.
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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 submitted2022-05-20
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Date accepted2023-04-03
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Date published2024-02-29
Impact of carbon dioxide on the main geotechnical quality criteria and preparation cost of cemented paste backfill
There is a global upsurge in the use of cemented paste backfill (CPB) for various mining functions. However, the cost of the Portland cement binder is prohibitive, thus warranting strategies to reduce cement usage without overly diminishing the CPB quality. Since carbon dioxide is used for patented sand moulding processes, this study is premised on that physicochemical ability of CO2 to enhance the curing of consolidated inorganic materials. It evaluated the impact of carbon dioxide on the uniaxial compressive strength UCS and preparation cost of CPB standard samples (ASTM C109). The preparation cost was delimited to the purchase cost of the Portland cement. The backfill material was silica sand tailings with 4.5 wt.% Portland cement binder and a water-cement ratio of 7.6. Distilled water of pH 5.4 was used for the control samples while variable amounts of carbon dioxide were dissolved in distilled water to generate carbonated mixing water with pH values of 3.8; 4 and 4.2. The lower the carbonated water pH, the higher is the CO2 concentration. UCS tests were conducted on the samples after curing for 3, 7, 28, and 90 days. There was an observable increase in the UCSs and reduction in curing time with increasing carbon dioxide. Samples prepared with carbonated water of pH 3.8 had almost double the strength of those prepared with pure distilled water of pH 5.4, implying that more dissolved CO2 corresponds to higher CPB strength. This is supported by the trendline equations for the graphical simulation of strength on curing time. Thus, CPB with much less binder can be expected to attain the requisite UCS if carbon dioxide is incorporated. The average reduction in Portland cement consumption was 0.61 %, which translates to a cost saving of the same percentage points. If calculated over the operational life of a mine, this is a massive saving of millions of dollars.
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Date submitted2023-03-12
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Date accepted2023-06-20
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Date published2023-07-19
Increasing the energy efficiency of an autonomous power supply system of a drilling rig in case of voltage dips
The article discusses the emergency modes of operation of an autonomous electrical complex of a drilling rig. The concept of voltage failure and its influence on the technological process of industrial enterprises is revealed. A description of the methods used in the power supply of industrial enterprises to overcome voltage dips and load surges in autonomous power systems is presented, from which it is possible to single out the accelerated lifting of critical equipment to prevent emergency conditions, as well as the use of backup storage, usually batteries. An algorithm has been developed for the interaction of the battery and the diesel generator set as backup power sources during various modes of operation of the electric motor, taking into account load surges, which allows successfully overcoming voltage dips in the system both in transient and in steady state. It is proposed to use a combined method to eliminate the voltage dip, a feature of which is the use of a combined structure of backup power sources as part of a diesel generator set and a battery, acting on the base of the proposed interaction algorithm in autonomous electrical complexes. The method makes it possible to overcome sudden load surges and voltage dips caused by a shortage of reserve power in the electrical system. The use of a rechargeable battery as a transitional element makes it possible to switch between the main and backup power sources without stopping the technological one and to expand the overload threshold of an autonomous electrical complex up to 60 %. The use of the combined method increases the energy efficiency of the autonomous complex due to a reduction in the number of emergency shutdowns of equipment, process interruptions and additional power consumption.
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Date submitted2022-10-17
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Date accepted2023-02-13
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Date published2023-04-25
Environmental geotechnology for low-grade ore mining with the creation of conditions for the concurrent disposal of mining waste
Due to the constantly deteriorating environmental situation in the regions with mining enterprises, the article considers the topical issue of disposing the maximum possible volume of waste from the mining and processing of low-grade ferrous ores through the creation of an effective underground environmental geotechnology. Traditional procedure with descending mining of reserves with a caving system does not allow waste to be disposed of in a gob. The idea is to use geotechnology based on the ascending order of mining the ore body, room excavation, leaving truncated pillars, and staggered arrangement of adjacent rooms in height, which makes it possible to form containers for waste disposal in the form of a cementless backfill. The main characteristics of the proposed procedure are investigated and compared with the traditional procedure of low-grade iron ores mining. It was established that from the point of view of the complete extraction of reserves and the unit costs for the preparatory-development operations, the processes are comparable, while in terms of the mining quality, the proposed option is much more efficient. Evaluation of environmental geotechnology by the criterion of waste disposal, performed according to the proposed methodology, showed that the combination of these technical solutions ensures the placement in the formed gob from 80 to 140% of all waste generated during the mining and beneficiation of low-grade iron ores.
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Date submitted2020-10-13
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Date accepted2021-03-02
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Date published2021-04-26
Trace element accumulation by soils and plants in the North Caucasian geochemical province
Long-term studies of the North Caucasian geochemical province allowed to establish regional abundances and calculate accumulation (dispersion) factors for chemical elements in rocks, soils, and plants. Certain natural regional patterns characterize the province. Associations of elements in high and low concentrations are often determined by the predominant composition of rocks: carbonate-terrigenous, terrigenous, and igneous. The study of the average contents of several chemical elements in the soils of the province showed that the association of accumulated elements includes metals with different migration characteristics. Thus, despite the rather close values of the ionic radii, Pb, Zn, Cu, and Li (judging by the ionic potential) are characterized by the formation of cations, while Mn, Mo, and Zr form complex ions. Such elements as Zn, Cu, and Pb are mainly accumulated on hydrosulfuric barriers, while Mo, Co, and Mn are stopped by oxygenous barriers. For Cu, Zn, Mo, and Co, biogenic accumulation plays a significant role, while for Pb and Ni it is practically absent. The absolute dispersion of the elements did not reach environmentally hazardous values, although it indicates a fairly intensive migration. In woody plants, Ba, Nb, Sc, Sr, and Zn are accumulated most intensively.
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Date submitted2015-10-23
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Date accepted2015-12-19
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Date published2016-08-22
Nondestructive techniques to control the quality and quantity of oil flows
- Authors:
- R. M. Proskuryakov
- A. V. Kopteva
The article considers the issue of improving the efficiency of exploiting the acting oil fields and transportation system on the basis of modern hi-tech technologies to control the extracted and transported material. Factors are studied that lower the reliability of oil flow measurements, both qualitatively and quantitatively, the main ambiguities are described of using current systems for metrological account of oil transported through the pipelines. The effect is studied of inclusions in the transported oil flow on measurement efficiency. A technique is suggested for selective measurements of separate phases in the complex multi-phase flows with isotropic radio emission, the principal relationships are presented to describe the intensity of direct and scattered gamma-radiation on flow parameters. Criteria are given for developing a measurement system that would control the actual component composition of the flow with time, hence the amount of oil transported; that would enable organizing a centralized open department to control the quality of oil and transportation conditions, upgrade the level of production and provide high measurement accuracy. Results are presented of testing the technique on an operating oil field; the relative error margin of measuring free gas content was 0.2 %. The range is reviewed of possible applications for the measurement system of multi-phase multi-component flows, developed in the Saint Petersburg Mining University.
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Date submitted2013-07-16
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Date accepted2013-09-16
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Date published2014-03-17
Stopes walls stabilization at the rich iron ore mining by the flat-back cut-and-fill method
- Authors:
- V. P. Zubov
- M. D. Morozov
- A. S. Malyutin
The most influencing the stopes walls stability factors have been determined. Physical-and-mechanical ore mass properties impact to the stopes height has been researched. Advanced ways to improve stopes walls stability have been considered.
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Date submitted2013-07-26
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Date accepted2013-09-22
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Date published2014-03-17
Parameters of removing the overburden for deposits complex structure of carbonate rocks
- Authors:
- V. V. Ivanov
The main features of the development of Open-complex structure of carbonate rocks. The dependence for the determination of dozing on the domestic heap career, moving overburden on bestransportnoy scheme in goaf. Found that the optimum length of excavator block executed by one parking dragline at quarries carbonate rocks is achieved with the minimum total cost of doing the work of overburden and waste associated with the removal of the overburden.
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Date submitted2010-07-21
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Date accepted2010-09-08
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Date published2011-03-21
Calculation methodology of physical parameters of the artificial pillar barrier
- Authors:
- M. N. Adreev
The article is devoted to the calculation methodology of physical parameters of the artificial barrier pillar needed when developing underquarry deposits of kimberlitic pipes in difficult hydrogeological conditions.
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Date submitted2010-07-15
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Date accepted2010-09-26
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Date published2011-03-21
Development of the stowing material and testing of its mechanical properties
- Authors:
- M. N. Andreev
- E. I. Boguslavskiy
Article is in touch with analysis of backfill materials applied on diamond mines, description of research of its mechanical properties to create the optimal compound in conditions of Yakutian kimberlitic tubes.
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Date submitted2009-09-14
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Date accepted2009-11-28
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Date published2010-06-25
Formаtion of a new type individuality under the conditions of generation of integration of interdependent communities
- Authors:
- A. I. Mikheev
This paper deals with the question of model generation of a new type individuality, that contemporary society demands for an advanced, deteriorative-free, balanced and creative development, which renders possible the elaboration of a system of formation of the given linguistic identity as a result of foreign language teaching.
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Date submitted2009-08-22
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Date accepted2009-10-19
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Date published2010-02-01
The substantiation of reinforcing support of preparation mines in the ore massive of the Yakovlevskiy deposit
- Authors:
- Yu. N. Antonov
- V. Yu. Sinegubov
The paper justifies a design of reinforcing mine support of the protective roof at the priority high-grade ore mining site of the Yakovlevskiy deposit. Experience of mine roadway support with the KMP-A3 standing support has been analyzed. A reinforcing support is offered consisting of rock bolts back bracing the ore exposure, which best fits with continuous miner roadheading and consolidating stowing (concrete).
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Date submitted2009-07-08
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Date accepted2009-09-19
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Date published2010-04-22
Geomechanical and hydrogeological problems оf the Yakovlevsky deposit development
- Authors:
- V. L. Trushko
- A. G. Protosenya
- R. E. Dashko
The article deals with geomechanical and hydrogeological problems under the Yakovlevsky ore deposit development including variations in strength properties. The estimation of feasible underground water inrush inside the mining excavation is done. In situ results of ore strata deformation around excavation are discussed. Numerical modeling of stress and strain in the waterproofing ore pillar due to partially backfilling of excavation is carried out.