JOURNAL of Donetsk mining institute最新文献

{"title":"FIRE PROTECTIVE EFFICIENCY OF INTUMESCENT TYPE EPOXIDE COATING","authors":"L. Vakhitova, N. Taran, Konstantin Kalafat, V. Bessarabov, V. Shologon, S. Pridatko","doi":"10.31474/1999-981x-2021-1-143-153","DOIUrl":"https://doi.org/10.31474/1999-981x-2021-1-143-153","url":null,"abstract":"Purpose. The purpose of this work is to study the thermal degradation of epoxy polymers and nanocomposites based on them in a fire retardant intumescent coating having a composition – ammonium polyphosphate / melamine / pentaerythritol. Methods. Thermogravimetric studies have been performed on the device “Thermoscan-2”, fire tests were performed by the method of “Bunsen burner”. Results. The influence of the structure of epoxy resin as a polymer component of the intumescent system on oxidative thermal destruction and fire retardant efficiency of reactive coating has been researched. The obtained results allow us to state that the best result has been demonstrated by Araldite GY 783 – epoxy resin of bisphenols A/F with a reactive solvent. The thermal properties of various epoxy resins and nanocomposites based on them with organomodified montmorillonite have been studied. It was found that montmorillonite in the nanocomposite increases the decomposition temperature of epoxy resin. Scientific novelty. It has been shown that the variation of the polymer component of the intumescent coating has little effect on the swelling rate, but the fire retardant efficiency of the intumescent composition containing epoxy resin of bisphenols A/F is higher than the same characteristic for the composition based on epoxy resin of bisphenol A. It has been established that the exclusion of pentaerythritol from the formulation of the epoxy intumescent system causes the formation of a more regular and durable char insulation layer. It has been proved that the use of additional, including nanostructured flame retardants, namely, modified montmorillonite, can increase the fire retardant efficiency of the coating. Practical significance. The obtained results are of practical importance for the development of new scientific approaches to the design of fire-fighting materials with improved performance characteristics through the use of polymers that provide the construction of a thermostable thermal insulation char layer. Through a series of systematic tests, it has been demonstrated that the use of nanoclay and nanocomposites based on epoxy resins allows to improve the formulations of intumescent coatings with high performance with the help of budget nanotechnologies.","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123973177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MONITORING OF EXTERNAL IMPACTS ON THE ELECTROMAGNETIC SITUATION OF THE PRODUCTION ENVIRONMENT AS A COMPONENT OF THE DEVELOPMENT AND IMPLEMENTATION OF OCCUPATION SAFETY MEASURES","authors":"O. Tykhenko","doi":"10.31474/1999-981x-2019-2-100-106","DOIUrl":"https://doi.org/10.31474/1999-981x-2019-2-100-106","url":null,"abstract":"","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122396784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DEVELOPMENT DEPTH AS COMPLICATION FACTOR OF WORKING OFF CONDITIONS OF COAL SEAMS","authors":"S. Nehrii, T. Nehrii, R. Shepelenko, Mykyta Kachalov","doi":"10.31474/1999-981x-2021-2-37-50","DOIUrl":"https://doi.org/10.31474/1999-981x-2021-2-37-50","url":null,"abstract":"Purpose: development of a scientific approach to clarify the areas of technologies application for mining roadways protection on the depth of mining operations. Methodology. Analysis and generalization of the results of scientific and technical research on the impact of natural phenomena on the process of coal mining. Graphoanalytical establishment of application and areasand determination of critical depths for protection mining roadways technologies. Results. Was studied and generalized the information on the influence of natural phenomena on the process of coal mining with the transition of mining to great depths. The necessity of determining the critical depths, exceeding which complicate the conditions of coal seams development due to the negative manifestations of natural phenomena, which requires changes in the technology of mining. Critical depths for different conditions, phenomena and technologies are different. For gas-saturated seams, they are determined by the methane-bearing capacity of seams, production intensity and ventilation conditions of underground roadways, for seams prone to gas-dynamic phenomena – they are determined by the stress-strain state (SSS) and strength of surrounding rocks. The critical depth in the application of protection roadways technologies also depends on the SSS of rocks and their strength. Therefore, a scientific approach has been developed to clarify the areas of application of technologies for the protection of mining roadways on the depth of mining. The critical depths are determined by the strength conditions of the rocks according to the relevant criteria. It based on the Ncr/Rc criterion, graphoanalytical method for determining the areas of application and determining the critical depths for different technologies of protection mining roadways was proposed. Scientific novelty: was developed a scientific approach to clarify the areas of application of protection mining roadways technologies on the depth of mining. Practical significance: the proposed approach to clarify the areas of application for the protection of mining roadways technologies at different depths simplifies the search for effective engineering solutions during planning mining operations.","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126133529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DETERMINATION OF CONDITIONS OF STABILITY OF ROOF ROOF STEEP COAL COAST","authors":"A. Kipko, V. Gogo, I. Iordanov, Y. Simonova, Yevgen Podkopayev, H. Boichenko, Llc Mine Svyato-Pokrovskaya No. Mine","doi":"10.31474/1999-981x-2019-2-28-38","DOIUrl":"https://doi.org/10.31474/1999-981x-2019-2-28-38","url":null,"abstract":"","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128797230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DEVELOPMENT OF THE SOCKET MODULE OF THE ELECTRICAL NETWORK","authors":"O. Zemlianskyi, O. Miroshnyk, T. Kostenko","doi":"10.31474/1999-981x-2021-1-102-109","DOIUrl":"https://doi.org/10.31474/1999-981x-2021-1-102-109","url":null,"abstract":"Purpose of the work is to determine the method of emergency de-energization of the object by cutting stranded live wires without the manifestation of emergency modes of electrical networks. Methods. As research methods, a comprehensive approach is used, which includes the analysis of research on emergency de-energization, laboratory research to determine a safe way to cut stranded wires under voltage. Results. De-energizing various objects during rescue operations and firefighting is one of the important tasks that must be performed in order to create safe working conditions for rescuers themselves. It is established that one of the ways by which it is possible to cut live multicore wires without short circuits is the use of abrasive cutting discs made of rotating electrocorundum. The design of a device for trouble-free cutting of live wires, which has a rod, a cutting element, a transmission mechanism and a device for fixing the wire. In the middle of the rod is a transmission mechanism, which is used as a shaft, one end of which is connected to the motor, and the other end through a gearbox, which is fixed to the device for fixing the wire, with a cutting element. In the laboratory conducted experimental studies that showed that the cutting of wires occurs without the manifestation of dangerous factors of electric current – short circuits, sparks, electric arcs. Scientific novelty. Approaches to cutting live multicore wires with corundum disks are substantiated, which excludes the occurrence of emergency modes of electrical networks, in particular short circuits. Practical significance. The obtained results can be used to create tools for safe emergency de-energization, which creates the preconditions for improving the safety of this type of work.","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126296550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE INFLUENCE OF EXTRACTION ON GAS EMISSION FROM THE PRODUCTION SPACE OF STOPPED LAVA","authors":"A. Oleinichenko, E. Filatieva, M. Filatiev, Y. Rudniev, Y. Merzlikina","doi":"10.31474/1999-981x-2022-1-100-107","DOIUrl":"https://doi.org/10.31474/1999-981x-2022-1-100-107","url":null,"abstract":"Purpose: to establish the quantitative dependences of gas emissions from the forged coal seam outside the operated areas on the degree of development of treatment works in the mine field. Methodology: the method provides for a comparative analysis of experimental data obtained during the development of several benches in the wing of the minefield. Results: the theoretical model of formation of zones of possible gas evolution from the forged coal seam outside the operated excavation sections at discrete increase of the produced space of the mine field wing by the length of the spent lava is considered. The maximum gas emission both on the excavation site and outside it is associated with the subsidence of the main roof as the development of treatment works and the removal of the treatment face from the split work. Activation of the shift of the counterfeit coal seam outside the excavation section causes an intensive increase in gas evolution, which can significantly exceed its release within the operated excavation section. Such circumstances, to a large extent, affect the safety of mining operations and indicate the need to improve the regulatory framework for the forecast of gas emissions in coal mines. Scientific novelty: statistical processing of experimental data allowed establishing the dependence of the level of gas emissions in mine workings and degassing wells simultaneously from three main factors – coal production and the degree of development of treatment works at the excavation site and within the minefield wing. Practical value: the analysis of long-term experimental results of observations of gas evolution from the forged coal-bearing stratum within the exploited sites and outside them is carried out. With sufficient development of treatment works in the wing of the mine field, the gas emissions outside the operated excavation site can significantly exceed the gas emissions in the site workings and degassing wells.","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131863667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ROCKS – SEGNETOELASTICS","authors":"Nikolay Ryazantsev, Alexander Nosach, Anton Ryazantsev","doi":"10.31474/1999-981x-2020-2-72-82","DOIUrl":"https://doi.org/10.31474/1999-981x-2020-2-72-82","url":null,"abstract":"Purpose. Identification of the features and the properties of segnetoelastics in rocks. Research Methods. Laboratory experiments on the deformation of rocks in a volume field of compressive stresses, macro- and microscopic studies of the deformations and the orientations of an optical indicatrix, analysis of the data obtained. Research results. As a result of microscopic and optical studies of rocks in thin sections on a polarizing microscope, tests of rocks under the conditions of unequal triaxial compression, analysis of the results obtained, it was found that the rock-forming minerals of the sedimentary sequence at a normal temperature and in the absence of an external load have a domain structure. Under the conditions of a triaxial unequal component compression, the volumetric deformations at the micro and macro levels do not exceed hundredths, while the relative micro deformations fully correspond to the dilatancy volume at the macro level. Shear rotational deformations reach 15–20%, their resonant increment increases several times over three periods before the destruction. During the loading, the direction of the rotation is changed 3-4 or more times, an optical indicatrix changes the direction. All deformations are alternating in sign and, until resonance, the amplitude of their increment does not exceed 0.5%. During the loading, the deformation, elastic, optical, electromagnetic, and other parameters are changed abruptly (structural-phase transitions of the second, and upon the destruction, of the first and third kind). The interconnection between the load and the deformations is nonlinear, a number of characteristic deformations are distinguished at which these jumps occur. All said indicate that rocks are classical distortion segnetoelastics. The following parameters can be taken as parameters of a segnoelastic transition: the value or increase in the value of relative deformation; an elastic modules varying within ± ∞; the sign and the magnitude of the increment of the Lode angle for the deformations; the angle of rotation of the optical indicatrix, the presence of structural-phase transitions in the minerals. Scientific novelty. It has been shown for the first time that all five signs and traits of segnetoelastics are present in sedimentary rocks. Practical significance. The possibility for isolating of segnetoelastics without laborious microscopic and electromagnetic studies.","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"26 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129856161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ASSESSMENT OF FIRE RESISTANCE OF FIREPROOF STEEL BEAMS","authors":"A. Kovalov, Roman Purdenko, Y. Otrosh, Vitalii Tomenko, Evhen Kachkar, R. Maiboroda","doi":"10.31474/1999-981x-2022-2-43-53","DOIUrl":"https://doi.org/10.31474/1999-981x-2022-2-43-53","url":null,"abstract":"Purpose. Development of a computer model for the study of fire resistance of steel structures protected by fire-resistant coatings, using the example of a fire-resistant steel beam created in the LIRA-SAPR software complex (Ukraine). Methods. Finite element method, application of computational methods of numerical modelling of the LIRA-SAPR software complex, mathematical modelling of thermal processes of non-stationary thermal conductivity. Results. A computer model was developed in the LIRA- SAPR software complex, with the help of which thermal engineering calculation of the beam was carried out. The model makes it possible to evaluate the fire resistance of both unprotected and fire-protected steel beams, to take into account the properties of the beam material and the material of the fire-resistant coating. The peculiarity of modelling the non-stationary heating of a fire-resistant steel beam is to specify the thermophysical characteristics of the fire-resistant coating when solving the problem of non-stationary thermal conductivity. The results of the calculated determination of the fire resistance of the fire-resistant steel beam were compared with experimental data. As a result, a satisfactory convergence of the results of the calculation and experimental study of fire resistance was established (the error is no more than 12%). The results of the experimental determination of the fire resistance of unloaded beams under fire conditions of the standard fire temperature regime were analysed. The accuracy of the developed computer model was evaluated with the results of the experiment. Scientific novelty. A finite-element model of a fire-resistant steel beam has been developed in the LIRA- SAPR software complex, which allows calculating the fire resistance limits of beams protected by fire-resistant coatings with scientifically justified parameters with sufficient accuracy for engineering calculations. Practical significance. It consists in creating the basis for the calculated assessment of fire resistance of building structures protected by fire-resistant coatings by creating computer models capable of performing fire resistance calculations. Due to this, there should be a significant reduction in the cost of work on fire resistance assessment and, as a result, an increase in the effectiveness of measures to increase the fire resistance of building structures.","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132563249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SUBSTANTIATION OF THE FEASIBILITY OF CHOOSING A SUSPENSION BASED ON THE SODIUM GROUP IN THE TREATMENT OF COAL MINING WASTE DUMPS","authors":"I. Chobotko","doi":"10.31474/1999-981x-2023-1-118-125","DOIUrl":"https://doi.org/10.31474/1999-981x-2023-1-118-125","url":null,"abstract":"Purpose. To study the effectiveness of sodium group based suspensions: sodium hydroxide, sodium hydrocarbonate and sodium carbonate for neutralisation of spontaneous combustion processes of waste rock during the operation and formation of coal mining waste. To establish the dependence of the influence of suspensions on the chemical elements of the waste stockpile, taking into account external environmental factors.\u0000\u0000Methods. For solving the set tasks, methods of comparative analysis of theoretical and laboratory studies of the impact of suspensions on the processes of the mechanism of redox reactions of spontaneous combustion of waste heaps obtained in the process of processing minerals of coal mines were used. The application of rational method of processing the results of the experimental study of the interaction of waste mass with sodium solutions using the correlation analysis of Student’s t-criterion is described.\u0000\u0000Results. The spontaneous ignition mechanisms of the stockpile have been investigated, based on the interaction of the active chemical elements in the stockpile: pyrite, sulphur and iron oxide with the environment. The selection and optimization of the parameters of a sodium group based slurry when treating the stockpile will solve the problem of spontaneous combustion in the treatment of the stockpile by crystallizing the active chemical elements and filling in its porous structure.\u0000\u0000Scientific novelty. The dependence of the influence of the environment on the processes of thermal oxidation of waste rock mass is established. The expediency of application of methods and techniques for elimination of self-ignition foci, as the main factors of environmental pollution, is substantiated. A new expedient method and method has been proposed, which will allow estimating not only the economic effect but also the ecological one, which will contribute to improving the ecological and economic situation of the mining regions where mining wastes are located.\u0000\u0000Practical implication. It consists in the development of recommendations for methods and techniques to eliminate spontaneous combustion of mining wastes. The methodology for determining the required quantitative and qualitative composition of inert substances (suspensions) containing sodium group to eliminate sulphurous zones of exogenous combustion processes of waste mass is proposed. Recommendations on the use of these means and methods have been developed.","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129673299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DETERMINATION OF STELL TRUSS TECHNICAL CONDITION WITH THE INDICATOR OF RELIABILITY INDEX β","authors":"S. Kolesnichenko, Buildings, I. Chernykh","doi":"10.31474/1999-981x-2019-1-107-115","DOIUrl":"https://doi.org/10.31474/1999-981x-2019-1-107-115","url":null,"abstract":"","PeriodicalId":344647,"journal":{"name":"JOURNAL of Donetsk mining institute","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125539553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}