Geo-Technical Mechanics最新文献

{"title":"Hydrogen production in a combined electrochemical system: Cathode process","authors":"","doi":"10.15407/geotm2023.164.116","DOIUrl":"https://doi.org/10.15407/geotm2023.164.116","url":null,"abstract":"Today, hydrogen is recognized as a promising fuel, which is characterized by high heat generation and combustion temperature. It is also characterized by environmental safety due to the fact that no greenhouse gases are formed during the combustion of hydrogen. There are various methods of hydrogen production: traditional methods, which include electrolysis of water and conversion of hydrocarbons, and thermochemical ones. A cheap method of hydrogen obtaining from natural gas and coke is accompanied by the carbon oxides formationю Thermochemical methods are require high temperatures (up to 1000°C). The method for hydrogen production by electrolysis of aqueous solutions of alkali metal hydroxides is the most energy-intensive. However, it is considered one of the most promising in the European Union. To reduce energy consumption for hydrogen production, the authors suggest replacingthe positive electrode, which normally produces oxygen, with a dissolving anode with an equilibrium potential lower than that of oxygen, such as an iron electrode. In this case, with such a combined electrochemical method, the decomposition voltage in the system will be 0.44 V against 1.23 V with traditional water electrolysis. The overvoltage of iron dissolution in a chloride medium is several tens of millivolts. However, the potential difference between the anode and cathode ΔU becomes smaller than the equilibrium potential difference ΔE0 = 0.44 V. This research aims to substantiate the choice of the composition and concentration of electrolytes: catholyte –to ensure conditions for reducing energy consumption for hydrogen release; anolyte – to prevent passivation of the iron anode, which can lead to the oxygen release. This work results in research of the cathodic process of hydrogen release in the following solutions: 1 M (= mol/L) NaCl with the addition of 1 M hydrochloric acid in the amount of 5, 10, 15, 20 mL. Platinum is used as a cathode for the electrolysis process. The anode material is an iron, St3 grade. It has been found that in the range of changes in the composition of the electrolyte from neutral (1 M NaCl) to acidic (1 M HCl), a change in the mechanism of water discharge is observed. In a neutral medium, the discharging occurs according to the Heyrovsky mechanism, and in an acidic medium - according to the Volmer mechanism. The choice of the anolyte composition and concentration is complicated by the need to provide an acidic medium containing chlorine ions to prevent passivation of the anode. The acidity of the solution must be at least 3 for the successful extraction of dissolution products of the iron anode.","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","volume":"21 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":"134038363","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 the lifting height of dust particles after a mass explosion in an iron ore open pit","authors":"L. Novikov, K. Ishchenko, Liudmyla Lohvyna","doi":"10.15407/geotm2023.164.126","DOIUrl":"https://doi.org/10.15407/geotm2023.164.126","url":null,"abstract":"Open pit mining is accompanied by emissions of fine dust and hazardous gases into the atmosphere. This is related to the operation of open pit transport, drilling and blasting operations. The release of harmful components into the quarry space and the increase in their concentrations has a negative impact on the health of working personnel and leads to pollution of the environment. In doing so, the nature of fine dust and gases pollution depends on the mining technology and meteorological factors. The problem of reduced effectiveness of dust suppression methods after mass explosions in open pits is relate to insufficient research into the formation of dust and gas cloud. Additional theoretical and experimental research into the dust dynamics of blasting operations is therefore need. The article discusses the stages of formation of the dust and gas cloud after a mass explosion in an iron ore open pit. The results of experimental studies of the evolution of the dust and gas cloud at different points in time after the detonation of borehole charges are presented. Relations for determination of density and dynamic viscosity of gases, gas mixture and gas-dust aerosol are given. A formula for determining the time and height of ascent of spherical dust particles at the dynamic stage of dust and gas cloud formation is obtain. In this case, the assumption is madid that there is no mutual influence of the dynamic and thermal factors after detonation of the charges. The elevation of dust particles due to temperature differences during the heat stage of dust and gas cloud formation is determined. Based on the analysis of the calculation results, the duration of the dynamic stage of cloud formation is determined. It is established that, following the release of solid and gaseous detonation products into the atmosphere, a height distribution of dust particles is observed as a function of their diameter. That said during, the dynamic stage of dust and gas cloud formation, the height of dust particle lift is directly proportional to their diameter, while during the heat stage the inverse relationship is observe. That at the beginning of the thermal stage the deposition of coarse dust particles takes place are established. In this process, fine dust particles rise to a maximum height and are then carried outside the open pit by the airflow.","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","volume":"21 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":"127572552","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":"Research and substantiation of rational parameters of drilling and blasting operations when using emulsional explosives in underground mining","authors":"","doi":"10.15407/geotm2021.158.033","DOIUrl":"https://doi.org/10.15407/geotm2021.158.033","url":null,"abstract":"Purpose. To determine and substantiate the rational parameters of drilling and blasting operations using emulsion explosives such as Ukrainit PP-2B and to develop a methodology for their determination for the effective development of mineral deposits underground mining method. Methodology. To achieve this goal, a set of modern research methods was used, including an analysis of literature sources, design documentation and the practice of mining iron ore deposits at great depths, theoretical generalization of laboratory and industrial experiments, methods and techniques of technical and economic, graphic-analytical, correlation analysis. Results. The regularities of the change in the value of least resistance line from the ultimate strength of the ore to uniaxial compression and the diameter of blast holes were established. The obtained regularities made it possible to develop a methodology for calculating the rational parameters of drilling and blasting operations using an emulsion explosive of the Ukrainit PP–2B type in the deep horizons of the Kryvbas mines. Dependences of the technical and economic indicators of the use of the emulsion explosive of the Ukrainit PP–2B type in ore breaking on mining-geological and mining-technical factors were established. On the basis of the established rational parameters of drilling and blasting operations, a variant of the technological scheme for breaking iron ores by using an emulsion explosive of the Ukrainit PP–2B type with loading of ascending fans of deep wells using a self-propelled charging module RTCh–23 was proposed and economically justified. Originality. Power-law dependences of the least resistance line on the ultimate strength of the ore for uniaxial compression and the diameter of blast holes were established when using an emulsion explosive of the Ukrainit PP-2B type. Practical value. The method is developed for calculating the parameters of drilling and blasting operations with using an emulsion explosive of the Ukrainit PP-2B type in the deep horizons of the Kryvbas mines. The economically justified version of the technological scheme for breaking off iron ores with using an emulsion explosive of the Ukrainit PP-2B type, which will make it possible to achieve an annual economic effect in the amount of UAH 11.9 million. Conclusions. It is established that the use of an emulsion explosive of the Ukrainit PP-2B type is a non-alternative direction in the further development of minerals at great depths, which will make it possible to reduce the cost of the technological process of breaking by 21% and reduce the harmful environmental impact on the world by 2,6–3,9 times.","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","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":"132985913","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":"Features of material movement in a vertical chamber of a vibratory jaw crusher when producing a fine-grained product","authors":"","doi":"10.15407/geotm2023.164.071","DOIUrl":"https://doi.org/10.15407/geotm2023.164.071","url":null,"abstract":"Currently, vibrating jaw crushers show a fairly high efficiency of the technological process. An extensive amount of research carried out at the Dnipro University of Technology made it possible for the first time to substantiate the possibility of using a vibratory jaw crusher with a vertically located chamber and a pendulum suspension of the jaws as an independent grinding unit for the production of powder materials. The high-frequency impact nature of the load on the material implemented in vibrating jaw crushers made it possible to reduce the energy consumption and metal consumption of the plant, to increase the degree of crushing, which can reach the value i > 100. However, the specifics of the process of interaction of the material with the surface of the jaws in the vertical working chamber and the features of its unloading remain unknown. The refinement of this process was carried out by an experimental method on a laboratory sample of a vibratory jaw crusher ВЩД-130 using high-speed photography. The crusher includes the main elements: a body mounted on elastic elements, crushing jaws, articulated with the body by means of axes. The side surfaces of the crushing chamber are limited by transparent glass walls rigidly connected to the crusher body. The vertical movement of the jaws was determined by the readings of the vernier. The starting material was pieces larger than 40 mm and large bulk material with a grain size of 10…15 mm. An analysis of the nature of the movement of material throughout the crushing chamber showed the need to consider the chamber of a vibratory jaw crusher as two interconnected zones: crushing and grinding. Further studies were carried out for each zone.The productivity of the crushing zone is determined by a known method. It is necessary to create a rational profile of the working surface of the jaws on the basis of additional studies. Studies of the grinding zone made it possible to obtain a physical picture of the interaction of the material with the jaws over the period. In the lowest position, at the initial moment of unloading, the speed of the finished product is practically zero. When determining the productivity of the grinding zone, it is advisable not to take into account the unloading of the material at the initial speed.","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","volume":"5 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":"133228464","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":"Oscillatory liquid motion in capillaries, the geometry of which changes weakly","authors":"","doi":"10.15407/geotm2022.163.174","DOIUrl":"https://doi.org/10.15407/geotm2022.163.174","url":null,"abstract":"","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","volume":"66 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":"114891833","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 methane filtration parameters in coal seams","authors":"А.N. Molchanov, I. Vengerov, I. Diedich, T. Pichka, G. A. Troitskiy, А.А. Кamchatniy, S. Works","doi":"10.15407/geotm2019.149.038","DOIUrl":"https://doi.org/10.15407/geotm2019.149.038","url":null,"abstract":"","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","volume":"21 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":"123220176","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":"Regularities of variability of methane content in the coal layers of the Western Donbass","authors":"Natalia Khomenko, V. Prykhodchenko, S. Prykhodchenko","doi":"10.15407/geotm2021.156.046","DOIUrl":"https://doi.org/10.15407/geotm2021.156.046","url":null,"abstract":"The article considers the factors that contribute to the accumulation and preservation of methane in the coal seams of the Western Donbass. Mines of the district develop lower and middle carbon bituminous coal. It is characterized by a low degree of catagenetic transformations, increased collector properties. Regional regularities of change of methane bearing capacity of coal seams and content of free methane in them are established. In tectonic terms, the area is a monoclinal with domed and brachyform local structures associated with rupture. Methane-bearing anomalies, in turn, are associated with the vaults of such structures, both anticlinal and synclinal types. When bending into the anticlinal fold, the fracture of the rocks increases in the upper part of the formation, which increases their filtration rates. Roof rocks are characterized by high permeability and this leads to degassing of the anticline fold. During the formation of synclines, fractured zones are formed in the bottom of the coal seams and the screen for methane migration becomes directly the coal seam, which contributes to the preservation of methane in such structures. As a result, local synclines mostly have positive methane and free methane content and local anticline bends are mostly negative. It is established that the methane reservoirs in the study area are coal seams, argillites and siltstones with high reservoir properties, which are located in the vaults of plicative structures. The established patterns will improve reliability of the forecast of methane accumulations within coal deposits Keywords: methane bearing capacity, local folding, syncline structures, free methane, reservoir properties.","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","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":"126157677","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":"Distribution of the bulk material in the sieve with horizontal rotation axis","authors":"A. Kobets, Dnipro State Agrarian, V. I. Dyrda, M. M. Naumenko, S. Sokol, D. V. Filipenko, V. O. Huridova","doi":"10.15407/geotm2019.144.111","DOIUrl":"https://doi.org/10.15407/geotm2019.144.111","url":null,"abstract":"","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","volume":"40 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":"127407019","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":"Reducing the negative impact of potassium ore waste of the tyubegatan potassire deposit on the environment","authors":"","doi":"10.15407/geotm2021.156.153","DOIUrl":"https://doi.org/10.15407/geotm2021.156.153","url":null,"abstract":"In the article, solutions are presented for the placement of rock salt from the excavation of mine workings during the construction of a mine in a salt dump and salt waste of the processing plant of the Dekhkanabad potash fertilizer plant in the tailing dump. The technology of anti-seepage protection of the salt dump and the brine collector was recommended, which allows to reduce the negative impact on the environment and groundwater. The recommended anti-filtration protection of the base of the salt plate includes a device 1) of a Bentomat screen, a protective layer of loams, an attachment layer, and 2) above the screen drain of geocomposite material TenCatePolyfelt DC 602E. To ensure rational use of land and safe exploitation of salt wells, landslide formation issues were considered. Mathematical descriptions of the trajectory of movement of the center of mass of a landslide, its parameters and speed of movement are described. In order to prevent landslides, experiments were carried out on salt traps to secure their surface with sodium silicate solutions. Based on the results of laboratory experiments and experimental-industrial tests, it was established that density and calcium module of the fixing solution, as well as porosity and filtration coefficient of the fixed salt waste affect the gelling time, the penetration rate of the solution and the fastening strength of the salt waste. Based on the results of the theoretical, laboratory and pilot-industrial studies of the process of fixing salt waste, a method, recipe, project and plan of measures for checking the quality of work and safety measures for the implementation of the chemical method for fixing salt waste from the Tyubegatan potash deposit were developed. The fixing solution is proposed to be applied by spraying. The flow rate of the fixing solution for fixing 1 m3 of sand is justified and the speed is established, its injection scheme is: four point-pair, diagonal-sequential. Keywords: salt dump, tailings storage, anti-filtration protection technology, reduce the negative impact on the environment and groundwater, the process of fixing salt waste, formulation, chemical method.","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","volume":"65 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":"127341413","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":"Technique for reducing methane concentration in the stope of the extraction site of a coal mine","authors":"","doi":"10.15407/geotm2021.158.141","DOIUrl":"https://doi.org/10.15407/geotm2021.158.141","url":null,"abstract":"The article presents the results of research on means and techniques for increasing load on mining face of a coal mine which is constrained by a considerable methane emission from gas-bearing coal seams being developed, by the specified value of methane concentration in the outgoing longwall jet and air speed at mine working. Based on the analysis of the distribution of air flow masses in the longwall, it is established that there is a reserve for using air masses which move to the working face. It has been substantiated that, apart from preliminary degassing of the developed seam and improvement of ventilation schemes for mining areas, it is possible to increase the load on the longwall through using special pipelines. One of the pipelines (pressure line) is attached to the elements of the powered support directly at the bottom and cleans the atmospheric air in the longwall through the system of nozzles, whereas the other one (suction line), which is fixed on the side of the mined-out space, removes the polluted air with the help of the nozzles. Both pipelines are equipped with an individual air draft source. The technique has been developed to reduce the methane concentration in the extraction space by changing the turbulent characteristics of the ventilation flow by means of a pressure air pipe with dispersed fresh air supply and a suction air pipe with dispersed suction of outlet air, which are mounted along the longwall. This allows one to optimally distribute the air masses fed into the extraction space in cross section, and thereby increase the amount of air in the longwall, which, in turn, will significantly increase the load on the working face The efficiency of the proposed technique is confirmed by the results of studies on 3D models in CAD systems in the CDF software package. The developed technique for ventilation of the working face of the excavation area of a coal mine will allow maintaining the methane concentration and air velocity in the longwall within sanitary norms using the most powerful mechanized systems currently used in coal mining internationally.","PeriodicalId":222378,"journal":{"name":"Geo-Technical Mechanics","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":"128884817","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}