Purpose. To create the technology increasing the level of ecological safety of underground mining of iron ores by means of decreasing the number of harmful substances released into the atmosphere.methodology. Laboratory and industrial research studies of the condition of the atmospheric air around mine arrangement were conducted by means of a physical-and-chemical method and biological testing. The standard method for calculation of their concentration in the atmosphere was used for determination of features of harmful substance dispersion.findings. Regularities of ground concentration of total influence of harmful substances changing with taking into account a specific consumption of explosives and distance from an emission source are revealed. The dependence of conditional indicator of damageability of bioindicators changing with increase in distance from a source of emission and specific consumption of explosives is established. The method for calculation of ecological assessment of atmospheric air condition around an emission source is developed.originality. Dependence of influence of ground concentration of harmful substances on damageability of bioindicators at the cellular and organismal levels is established, which allows estimating an ecological state of atmospheric air on industrial territories.Practical value. Regularities of inluence of ground concentration of total impact of harmful substances on a condition of indicator systems are determined that allows estimating the state of the environment and increasing reliability of local environmental monitoring around an iron-ore mine. The technology of drilling-and-blasting operations conducting in which emulsion explosives are used during mining of iron ores by means of the chamber mining methods, which allows decreasing the hazard index of harmful substances influence on the atmosphere, is developed and implemented.
Представлені результати чисельних та експериментальних досліджень процесу нагріву алмазних бурових коронок під час буріння свердловин. Розглянуто температурні режими буріння в умовах стаціонарної і нетрадиційної технології імпульсної промивки свердловини. За результатами дослідження теплових процесів на вибою визначено параметри, які забезпечують ресурсо-та енергоефективний режим буріння при імпульсної подачі промивальної рідини Ключові слова: температурні режими, буріння, CFD моделювання, енергоефективність, імпульсне промивання Представлены результаты численных и экспериментальных исследований процесса нагрева буровых коронок при бурении скважин. Рассмотрены температурные режимы бурения в условиях стационарной и нетрадиционной импульсной промывки скважины. По результатам исследований тепловых процессов на забое определены параметры, которые обеспечивают энергоэффективный и ресурососберегающий режим буренияКлючевые слова: температурне режимы, бурение, CFD моделирование, энергоэффективность, импульсная промывка UDC 621.7:622.23
Purpose. To identify indicators of massif zonal structuring around underground working using numerical modeling techniques. Methods.Research into massif zonal structuring was performed using finite element method and thermodynamic method by which the size and number of zones formed around development workings and stopes have been simulated. Findings.The ratio of zones' vertical and horizontal semi axes in the massif has been established and reliability of the obtained results was determined. The prospects of new modeling techniques for the study of massif zonal structuring parameters around underground workings have been identified. Originality.The opportunities for wide application of numerical simulation methods to study the phenomenon of zonal encapsulation by the massif of underground workings have been revealed. Practical implications.The sizes and shapes of zones in the massif around workings were determined and requirements were formulated stating that synergetic research methods should allow to more accurately determine the number, size and shape of zones, as well as fading sinusoidal stress and massif strain domains.
ВплиВ Витрати промиВальної рідини на контактну температуру при бурінні сВердлоВинPurpose. To establish the influence of drilling fluid circulation rate onto the contact temperature during the rotation drilling using an impregnated diamond drill bit; to verify the mathematical model of the diamond drill bit heating process in the course of boreholes drilling.Methodology. Bench experiments and theoretical analysis using methods of mathematical modeling. Findings. In the course of the bench experiments the data of influence of the drilling fluid circulation rate on the contact temperature during drilling of granite rock with a 59-mm diameter drill bit were obtained. A relevant mathematical model of the drill bit heating under the variable rate of drilling fluid was represented on the basis of a system of the heat transfer differential equations. A comparative analysis of experimental and predicted data was carried out, and its findings positively confirm the reliability of the mathematical modeling of heat transfer processes in the downhole during bore-hole drilling.Originality. The methodology of experimental measuring of the contact temperature during the bench experiment borehole drilling using resistance sensors was proposed herein. New experimental data was obtained which allowed establishing a correlation between the contact temperature and the rate of drilling fluid in the downhole area. The proposed mathematical model of the process is found to be adequate; it allows predicting the temperature mode on the working face of borehole in the course of drilling. The findings of the research make it possible to substantiate the effect of the diamond core drilling performance gaining due to transition from the fixed time operation parameters to the variable ones.Practical value. The regularities of action of the drilling fluid circulation rate on the contact temperature of the "tool -working face" system in the course of borehole drilling were established. The performed research confirmed the possibility of managing the thermal mode of drilling by variation of the drilling fluid circulation rate. The diamond core drilling performance gains, therefore, are possible to achieve by way of increasing the thermal stimulation of the mining rock. The developed mathematical model allows forecasting the contact temperature in the course of borehole drilling for various values of the drilling fluid circulation rates. Using of this model makes it possible to define the permissible diminishing of the drilling fluid circulation rate in order to prevent any abnormal thermophysical wear of the drill bit.Keywords
Loss of drilling fluid in wells is one of the most important drilling challenges. To prevent this problem an insulation of borehole wall is requiring. The results of study of an innovative technology of isolation of borehole using a new thermomechanical plugging material are presented herein. The material considered is solid composite consisting secondary polyethylene terephthalate and gravel. Theoretically and experimentally shown the possibility to use this material to borehole isolation. The technology of manufacturing and isolation of absorbing horizons by thermomechanical material has been developed. Dependence of the regime parameters of thethermomechanical process melting of material on the thermophysical properties and technical characteristics was established. Dependence of the penetrating ability of material melt on the fractures was established. The results of work can be used to recommend technology parameters providing the efficient melting rate.
The article presents the results of experimental and theoretical studies, the purpose of which was to substantiate the technology of drilling wells isolation using new thermoplastic composite material. The basis of the proposed material is gravel, and secondary polyethylene terephthalate acts as a binding material. The use of the proposed insulation material avoids a number of disadvantages specific for traditional grouting mortars. The technology of material application provides its melting in a well by thermomechanical drilling. The article deals with the issues, related to the substantiation of the optimal formulation of a thermoplastic composite material based on secondary polyethylene terephthalate, and the determination of rational operating parameters of thermomechanical drilling, which allow to melt effectively the material at the bottom of a well. The possibility of material application for the insulation of absorbing horizons in borehole conditions has been proved. Based on the analysis of the heat balance at the bottom of a well, the calculation procedure has been proposed and the dependences of the velocity and time of thermomechanical melting of the grouting thermoplastic composite material on the operating parameters of drilling, thermal properties and geometric characteristics of the drill bit, have been determined.
The purpose of the work is to increase the insulation work efficiency by using thermoplastic mixes based on polyethylene terephthalate. The tasks set were solved by a complex method of research, including the analysis and synthesis of the literary and patent sources, as well as conducting the analytical and experimental studies. The experimental data were processed on a PC using the methods of mathematical statistics. A method for insulating the absorbing horizons with thermoplastic materials has been developed and substantiated. To implement it, the following technological operations should be performed: supply of the thermoplastic materials to the borehole bottom, melting and squeezing of thermoplastic materials into absorption channels. For various geological and technical conditions of drilling, technological schemes of insulating the absorbing horizons with thermoplastic materials are proposed. The use of the household waste based on polyethylene terephthalate has been proposed as the plugging material to insulate the absorbing horizons of boreholes. For the first time, the possibility of using the household waste based on polyethylene terephthalate as the plugging thermoplastic material has been substantiated and proved. For the first time, a method for determining the efficient range of technology application for absorbing and unstable horizons insulation with thermoplastic materials through the use of bottom hole thermal sources has been substantiated analytically.
Purpose. The solution of the problem for determining a specified vertical displacement of supports in a rotating unit, taking into account the yielding in the crosscut of the supporting node, as well as the peculiarities of the structural design.Methods. When performing the work, the approaches based on the elasticity theory principles are used, taking into account the variable transverse crosscut of the unit and the different high-altitude positions of supports. To determine the general expressions describing the axis position of the studied multisupport structure, the Cauchy' function method was used. Findings.A system of solvable algebraic equations has been obtained that enables to perform calculations for a beam-type cylindrical structure on rigid and elastic supports. The expressions are presented for determining the value of vertical displacement of the supports, taking into account the operational characteristics of a unit, in particular the presence of the influence of neighboring supports and the value of existing loads. The cases have been studied of implementing the adjusting displacements, using the obtained equation system with the complete unloading of the supporting nodes, as well as with the use of the technical diagnostics data -the determined values of the total displacements of the supports. Expressions have been obtained for calculating the desired adjustment parameters. An algorithm is proposed for performing the computing operations.Originality. The method of adjustment of the specified position of supports in a rotating unit has been further developed, which is carried out through determining the elastic components, rigid displacements, complete displacement in the supporting node, as well as the results of technical diagnostics.Practical implications. The calculations have been made taking into account the yielding of the supports in the range of maximum and minimum values. It is shown that the value of certain supports displacement, which should be taken into account as a result of their yielding, can reach the extremum standard values. The presence of previous displacements of the supports predetermines a significant acting forces redistribution in the rotating furnace body and is determined by their direction. The value of adjusting displacements has been determined, which should be performed to obtain a rectilinear axis of rotation. It has been revealed that it is appropriate to implement a parallel displacement of the projected axis of rotation for reducing the adjustment parameters in the supporting nodes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.