Pub Date : 2022-09-30DOI: 10.33271/mining16.03.123
Bauyrzhan Tolovkhan, V. Demin, Zhursyn Amanzholov, Assemgul Smagulova, G. Tanekeyeva, S. Zairov, O. Krukovskyi, E. Cabana
Purpose. The research purpose is to develop a geomechanical model for ensuring the safety of mining operations by determining the optimal slope angles and probabilistic assessment of the stability of the open-pit walls. Methods. Three-dimensional geomechanical models for surface mining of deposits have been developed based on calculations of the stability factor (safety factor SF) of the open-pit walls in the Rocscience program to determine the rock mass stress-strain state at the end of mining using the finite element method. The geological wireframe model (GWM) has been built on the basis of the available geological sections, horizon plans and the results of the engineering-geological surveys using the Surpac geoinformation system. Findings. Strength reduction factor (SRF) has been determined taking into account the physical-mechanical properties of rocks that constitute the near-wall mass. An assessment of the stability of walls according to the selected geological sections is given, taking into account the projected contour of the Severny Katpar open-pit walls. The calculation of the projected contour stability of the open-pit walls by several different methods has revealed that the open-pit walls are generally stable. The open-pit parameters at the end of mining have been determined. Originality. For the first time, it has been determined that in the Southern and South-Western area of the Severny Katpar open-pit wall in the horizons +700…+400, there is a decrease in SF from 1.18 to 1.41 due to the predominant occurrence of siltstones and tectonic disturbances of the walls. Practical implications. The mathematical calculation results of the stability of the projected contour walls in the Severny Katpar open pit have been generalized. In addition, a geological and structural wire-frame model of the deposit has been developed, which makes it possible to ensure the safety of mining operations in the open pit.
{"title":"Substantiating the rock mass control parameters based on the geomechanical model of the Severny Katpar deposit, Kazakhstan","authors":"Bauyrzhan Tolovkhan, V. Demin, Zhursyn Amanzholov, Assemgul Smagulova, G. Tanekeyeva, S. Zairov, O. Krukovskyi, E. Cabana","doi":"10.33271/mining16.03.123","DOIUrl":"https://doi.org/10.33271/mining16.03.123","url":null,"abstract":"Purpose. The research purpose is to develop a geomechanical model for ensuring the safety of mining operations by determining the optimal slope angles and probabilistic assessment of the stability of the open-pit walls. Methods. Three-dimensional geomechanical models for surface mining of deposits have been developed based on calculations of the stability factor (safety factor SF) of the open-pit walls in the Rocscience program to determine the rock mass stress-strain state at the end of mining using the finite element method. The geological wireframe model (GWM) has been built on the basis of the available geological sections, horizon plans and the results of the engineering-geological surveys using the Surpac geoinformation system. Findings. Strength reduction factor (SRF) has been determined taking into account the physical-mechanical properties of rocks that constitute the near-wall mass. An assessment of the stability of walls according to the selected geological sections is given, taking into account the projected contour of the Severny Katpar open-pit walls. The calculation of the projected contour stability of the open-pit walls by several different methods has revealed that the open-pit walls are generally stable. The open-pit parameters at the end of mining have been determined. Originality. For the first time, it has been determined that in the Southern and South-Western area of the Severny Katpar open-pit wall in the horizons +700…+400, there is a decrease in SF from 1.18 to 1.41 due to the predominant occurrence of siltstones and tectonic disturbances of the walls. Practical implications. The mathematical calculation results of the stability of the projected contour walls in the Severny Katpar open pit have been generalized. In addition, a geological and structural wire-frame model of the deposit has been developed, which makes it possible to ensure the safety of mining operations in the open pit.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49088939","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.064
Kanay Rysbekov, M. Bitimbayev, D. Akhmetkanov, K. Yelemessov, M. Barmenshinova, A. Toktarov, D. Baskanbayeva
Purpose. The solution to one of the important problems of the underground mining method is to substantiate cost-effective, technologically feasible and safe variants for mining steeply dipping low-thickness ore bodies. Methods. Mining systems are substantiated on the basis of a detailed analysis of the developed and existing experiential variants for mining steeply dipping ore bodies, identifying production and economic disadvantages, as well as their causes. Findings.As a result of the research, the pillar raise performance in the mining system with ore shrinkage has been substantiated. The main parameters of the proposed variants for mining systems with ore shrinkage, intended for expansion-type supports and borehole breaking, have been substantiated. A design has been developed of fastening the material-running raises (MRR) and ventilating raises (VR) on the working and ventilation horizons to ensure their performance in the mining system with ore shrinkage. Originality. For the first time, dependences of dilution and labour productivity on the ore body thickness and the type of ore breaking for blast-hole stoping and borehole breaking for a single and “twinned block” have been obtained. In addition, a certain dependence of the loading and delivery performance on the average fractional composition, as well as on the delivery distance, has been obtained. Practical implications. The research is characterized by scientific innovations created for the first time, which are able to ensure the efficiency and safety of mining operations, while creating the ability to manage the loss of minerals and dilution in the block, as well as reaching their calculated optimal ratio in order to achieve the most cost-effective production rate.
{"title":"Substantiation of mining systems for steeply dipping low-thickness ore bodies with controlled continuous stope extraction","authors":"Kanay Rysbekov, M. Bitimbayev, D. Akhmetkanov, K. Yelemessov, M. Barmenshinova, A. Toktarov, D. Baskanbayeva","doi":"10.33271/mining16.02.064","DOIUrl":"https://doi.org/10.33271/mining16.02.064","url":null,"abstract":"Purpose. The solution to one of the important problems of the underground mining method is to substantiate cost-effective, technologically feasible and safe variants for mining steeply dipping low-thickness ore bodies. Methods. Mining systems are substantiated on the basis of a detailed analysis of the developed and existing experiential variants for mining steeply dipping ore bodies, identifying production and economic disadvantages, as well as their causes. Findings.As a result of the research, the pillar raise performance in the mining system with ore shrinkage has been substantiated. The main parameters of the proposed variants for mining systems with ore shrinkage, intended for expansion-type supports and borehole breaking, have been substantiated. A design has been developed of fastening the material-running raises (MRR) and ventilating raises (VR) on the working and ventilation horizons to ensure their performance in the mining system with ore shrinkage. Originality. For the first time, dependences of dilution and labour productivity on the ore body thickness and the type of ore breaking for blast-hole stoping and borehole breaking for a single and “twinned block” have been obtained. In addition, a certain dependence of the loading and delivery performance on the average fractional composition, as well as on the delivery distance, has been obtained. Practical implications. The research is characterized by scientific innovations created for the first time, which are able to ensure the efficiency and safety of mining operations, while creating the ability to manage the loss of minerals and dilution in the block, as well as reaching their calculated optimal ratio in order to achieve the most cost-effective production rate.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42555369","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.081
I. Zeqiri, Jahir Gashi, Frasher Brahimaj, R. Zeqiri
Purpose. Each ventilation system has its own important elements, such as the various branches of the system, which can be connected in a normal and diagonal pattern, ventilation regulators and fans. Based on a professional approach to the analysis of this aeration system, a comparison of reliability results has been conducted, which indicates the real state of the microclimate in underground mines, affecting the increase in the prospects for the development of mining activity. Methods. This paper deals with the problem of ventilation in underground mines, especially in diagonal systems, and the importance of regulating ventilation to provide the required amount of air (Q, m3/min) through the entire system, taking into account the determination of the main fan depression. Findings. To ensure the required (designed) amount of air through the system branches, various methods of effective regulation are used in mining engineering. Therefore, based on research and measurements in different mine workings, our findings provide complete safety and comfort of microclimate during mining activity. Originality. The measurements performed and the database created according to the values and results obtained from the analytical calculations present the best possible estimate, which is substantiated in the paper. Practical implications. The problem of calculating and regulating aeration for a simple diagonal system has been solved, taking into account the determination of the main mine fan depression before and after the use of aeration regulators.
{"title":"Effectiveness of ventilation regulation in a simple diagonal system of underground mines","authors":"I. Zeqiri, Jahir Gashi, Frasher Brahimaj, R. Zeqiri","doi":"10.33271/mining16.02.081","DOIUrl":"https://doi.org/10.33271/mining16.02.081","url":null,"abstract":"Purpose. Each ventilation system has its own important elements, such as the various branches of the system, which can be connected in a normal and diagonal pattern, ventilation regulators and fans. Based on a professional approach to the analysis of this aeration system, a comparison of reliability results has been conducted, which indicates the real state of the microclimate in underground mines, affecting the increase in the prospects for the development of mining activity. Methods. This paper deals with the problem of ventilation in underground mines, especially in diagonal systems, and the importance of regulating ventilation to provide the required amount of air (Q, m3/min) through the entire system, taking into account the determination of the main fan depression. Findings. To ensure the required (designed) amount of air through the system branches, various methods of effective regulation are used in mining engineering. Therefore, based on research and measurements in different mine workings, our findings provide complete safety and comfort of microclimate during mining activity. Originality. The measurements performed and the database created according to the values and results obtained from the analytical calculations present the best possible estimate, which is substantiated in the paper. Practical implications. The problem of calculating and regulating aeration for a simple diagonal system has been solved, taking into account the determination of the main mine fan depression before and after the use of aeration regulators.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48239221","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.022
Alfonso Alogo Nguema, Isnel Rodríguez González, Maday Cartaya Pire
Purpose. The purpose of this research is to determine the index of the rock mass stress-strain state in the Imex quarry, Bioko Island, Equatorial Guinea. Methods. To determine the number of required samples by the method of stratified random sampling, the t-Student principle is used. The physical-mechanical properties of rocks have been determined by tests and methods of saturation, pycnometry, hydrostatic weighing, axial loads and clock-type indicators. The classification of the degree of weathering has been carried out to assess its impact on the physical-mechanical properties of rocks and rock mass on the basis of direct observation in different areas of the studied rock mass. To determine the rock mass stress-strain state, the Hoek-Brown failure criterion is used, including laboratory tests to determine the models, dimensions and shapes of ruptures. Findings. Significant changes in rocks, high values of stress and weathering, which generate distributions of new forces in the rock mass and originate instability and large deformations, as well as a high porosity index, average values of compressive strength and a high value of elasticity modulus, have been revealed. Significant differences in the degree of weathering in the prevailing zones, from insignificant values of weathering in the northern areas to moderate values of weathering in the south, have been confirmed. Originality. Information is presented on the physical-mechanical properties, the degree of weathering and the stress-strain state index of the rock mass in the Imex quarry, Bioko Island, Equatorial Guinea. Practical implications. Knowledge about the rock quality, management and implementation of technological processes during operation can be used as a useful material for the construction industry.
{"title":"Stress-strain state index of the Imex quarry rock mass, Bioko Island, Equatorial Guinea","authors":"Alfonso Alogo Nguema, Isnel Rodríguez González, Maday Cartaya Pire","doi":"10.33271/mining16.02.022","DOIUrl":"https://doi.org/10.33271/mining16.02.022","url":null,"abstract":"Purpose. The purpose of this research is to determine the index of the rock mass stress-strain state in the Imex quarry, Bioko Island, Equatorial Guinea. Methods. To determine the number of required samples by the method of stratified random sampling, the t-Student principle is used. The physical-mechanical properties of rocks have been determined by tests and methods of saturation, pycnometry, hydrostatic weighing, axial loads and clock-type indicators. The classification of the degree of weathering has been carried out to assess its impact on the physical-mechanical properties of rocks and rock mass on the basis of direct observation in different areas of the studied rock mass. To determine the rock mass stress-strain state, the Hoek-Brown failure criterion is used, including laboratory tests to determine the models, dimensions and shapes of ruptures. Findings. Significant changes in rocks, high values of stress and weathering, which generate distributions of new forces in the rock mass and originate instability and large deformations, as well as a high porosity index, average values of compressive strength and a high value of elasticity modulus, have been revealed. Significant differences in the degree of weathering in the prevailing zones, from insignificant values of weathering in the northern areas to moderate values of weathering in the south, have been confirmed. Originality. Information is presented on the physical-mechanical properties, the degree of weathering and the stress-strain state index of the rock mass in the Imex quarry, Bioko Island, Equatorial Guinea. Practical implications. Knowledge about the rock quality, management and implementation of technological processes during operation can be used as a useful material for the construction industry.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45374611","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.049
Anas Driouch, L. Ouadif, Khalid Benjmel, Mohamed Bhilisse, S. Ilmen
Purpose. This paper deals with the determination of the regional stress field direction of the Bou Azzer inlier using the remote sensing tool. Methods. CIn this study, we use an approach to digital mapping by remote sensing, including the steps of pre-processing and processing of Landsat-8 OLI images. Then, an automatic extraction of lineaments based on directional filtering has been performed. To determine the main directions of major mean fractures, these results have been supplemented and confirmed by an integrated model, including a synthesis of bibliographic works and field studies. Findings. The directional rosette analysis results show four systems of major directions namely, N0°, N45°, N90° and N135°. The regional stress field in the study area, according to tectonic history, is characterized by a horizontal compression tectonic regime, as indicated by several systems of strike-slip faults with a high tendency to deformation. Thus, the abundance of brittle and ductile microtectonic indicators confirms the direction of the main compressive stress N°30. The direction of the three-dimensional stress field: σ1: N°30, σ2: N°120, σ3: Vertical component. Originality. The present study allows to determine the regional stress field direction of the Bou Azzer inlier, in particular, in areas affected by complex tectonics of various scales, as well as in hard-to-reach areas. Practical implications. In mining practice, the study of stability using 2D and 3D geotechnical numerical modeling of underground mine workings is essential. The stress field direction is an important input parameter to develop more realistic decision support models, as well as to ensure the safety of people and materials at the Bou Azzer mine.
{"title":"Determining the regional tectonic stress field by remote sensing in the Bou Azzer inlier, Central Anti-Atlas, Morocco","authors":"Anas Driouch, L. Ouadif, Khalid Benjmel, Mohamed Bhilisse, S. Ilmen","doi":"10.33271/mining16.02.049","DOIUrl":"https://doi.org/10.33271/mining16.02.049","url":null,"abstract":"Purpose. This paper deals with the determination of the regional stress field direction of the Bou Azzer inlier using the remote sensing tool. Methods. CIn this study, we use an approach to digital mapping by remote sensing, including the steps of pre-processing and processing of Landsat-8 OLI images. Then, an automatic extraction of lineaments based on directional filtering has been performed. To determine the main directions of major mean fractures, these results have been supplemented and confirmed by an integrated model, including a synthesis of bibliographic works and field studies. Findings. The directional rosette analysis results show four systems of major directions namely, N0°, N45°, N90° and N135°. The regional stress field in the study area, according to tectonic history, is characterized by a horizontal compression tectonic regime, as indicated by several systems of strike-slip faults with a high tendency to deformation. Thus, the abundance of brittle and ductile microtectonic indicators confirms the direction of the main compressive stress N°30. The direction of the three-dimensional stress field: σ1: N°30, σ2: N°120, σ3: Vertical component. Originality. The present study allows to determine the regional stress field direction of the Bou Azzer inlier, in particular, in areas affected by complex tectonics of various scales, as well as in hard-to-reach areas. Practical implications. In mining practice, the study of stability using 2D and 3D geotechnical numerical modeling of underground mine workings is essential. The stress field direction is an important input parameter to develop more realistic decision support models, as well as to ensure the safety of people and materials at the Bou Azzer mine.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47835051","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.087
P. Saik, M. Berdnyk
Purpose. A mathematical model development for heat transfer during underground coal gasification based on the transcendental equation solution by the Newton-Raphson method. Methods. The heat-transfer model development is based on the research into a temperature field with a variable size of the gasification zone when passing through the phase transformation boundary, which changes abruptly. The research on the coal seam T(x, t) temperature field and the displacement length of the phase transition boundary S(t) is based on the integration of the differential heat-transfer equation with the fulfillment of one-phase Stefan problem conditions. The proportionality factor (β), characterizing the ratio of the displacement length of the “generator gas – coal” phase transition boundary to the time of coal seam gasification, is determined by substituting the Boltzmann equation and using the Newton-Raphson method based on solving the obtained transcendental equation. Findings. The main problems related to laboratory research on the coal gasification process have been identified. A mathematical model of heat transfer during underground coal gasification for a closed georeactor system has been developed, taking into account the effective change in its active zones. Originality. A mathematical model of heat transfer during underground coal gasification at the phase transition boundary has been developed, under which the one-phase Stefan problem conditions are fulfilled. Dependences of the change in the underground gas generator temperature, taking into account the change in the active zones of chemical reactions along the length of the combustion face and the gasification column, have been revealed. In addition, the dependences of the change in the phase transition boundary of a “generator gas – coal” heterogeneous system have been determined, which characterize the displacement length of the phase transition boundary on time and reveal the relationship between the thermal conductivity coefficient, specific heat capacity, as well as bulk density of coal and its calorific value. Practical implications. A method has been developed to determine the displacement length of the phase transition boundary of a “generator gas – coal” heterogeneous system and its relationship between the time and temperature of gasification process. This makes it possible to predict in the future the change in the active zones of the underground gas generator along the length of the gasification column.
{"title":"Mathematical model and methods for solving heat-transfer problem during underground coal gasification","authors":"P. Saik, M. Berdnyk","doi":"10.33271/mining16.02.087","DOIUrl":"https://doi.org/10.33271/mining16.02.087","url":null,"abstract":"Purpose. A mathematical model development for heat transfer during underground coal gasification based on the transcendental equation solution by the Newton-Raphson method. Methods. The heat-transfer model development is based on the research into a temperature field with a variable size of the gasification zone when passing through the phase transformation boundary, which changes abruptly. The research on the coal seam T(x, t) temperature field and the displacement length of the phase transition boundary S(t) is based on the integration of the differential heat-transfer equation with the fulfillment of one-phase Stefan problem conditions. The proportionality factor (β), characterizing the ratio of the displacement length of the “generator gas – coal” phase transition boundary to the time of coal seam gasification, is determined by substituting the Boltzmann equation and using the Newton-Raphson method based on solving the obtained transcendental equation. Findings. The main problems related to laboratory research on the coal gasification process have been identified. A mathematical model of heat transfer during underground coal gasification for a closed georeactor system has been developed, taking into account the effective change in its active zones. Originality. A mathematical model of heat transfer during underground coal gasification at the phase transition boundary has been developed, under which the one-phase Stefan problem conditions are fulfilled. Dependences of the change in the underground gas generator temperature, taking into account the change in the active zones of chemical reactions along the length of the combustion face and the gasification column, have been revealed. In addition, the dependences of the change in the phase transition boundary of a “generator gas – coal” heterogeneous system have been determined, which characterize the displacement length of the phase transition boundary on time and reveal the relationship between the thermal conductivity coefficient, specific heat capacity, as well as bulk density of coal and its calorific value. Practical implications. A method has been developed to determine the displacement length of the phase transition boundary of a “generator gas – coal” heterogeneous system and its relationship between the time and temperature of gasification process. This makes it possible to predict in the future the change in the active zones of the underground gas generator along the length of the gasification column.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49468734","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.055
L. Kieush, A. Koveria, M. Boyko, Maksym Yaholnyk, A. Hrubiak, L. Molchanov, V. Moklyak
Purpose. The research purpose is to substantiate the use of biocoke as a fuel in the iron ore sintering, as well as its influence on the performance and properties of the resulting sinter. To completely replace conventional coke breeze, biocoke is produced using 5 wt.% biomass wood pellets at different carbonization temperatures of 950 or 1100°C. Further, the influence of biocoke on the sintering process and the sinter quality is studied at a high proportion of biomass pellets of 10, 15, 30, 45 wt.% and a carbonization temperature of 950°C. Methods. Carbonization is performed in shaft-type electric furnaces to produce laboratory coke or biocoke. Afterward, the sintering of iron ores is conducted on a sinter plant. To assess the sintering process and the quality of the resulting sinter, the filtration rate is determined on a laboratory sinter plant using a vane anemometer designed to measure the directional flow average velocity under industrial conditions. The sinter reducibility is studied using a vertical heating furnace to assess the effect of coke and biocoke on the sinter’s physical-chemical properties. Findings. It has been determined that biocoke, carbonized at a temperature of 950°C, has good prospects and potential for a shift to a sustainable process of iron ore sintering. Originality. It has been proven that biocoke with a biomass pellet ratio of up to 15 wt.%, obtained at a temperature of 950°C, does not affect the parameters characterizing the sintering process. The sinter strength indicators correspond to the use of 100 wt.% conventional coke breeze. Biocoke used with a high proportion of biomass pellets of 30 and 45 wt.% causes a deterioration in the sinter quality. Practical implications. The results of using biocoke with the addition of 5-15 wt.% biomass pellets and at a temperature of 950°C are within the standard deviation, which makes it possible to use biocoke with 15 wt.% biomass pellets instead of industrial coke breeze.
{"title":"Influence of biocoke on iron ore sintering performance and strength properties of sinter","authors":"L. Kieush, A. Koveria, M. Boyko, Maksym Yaholnyk, A. Hrubiak, L. Molchanov, V. Moklyak","doi":"10.33271/mining16.02.055","DOIUrl":"https://doi.org/10.33271/mining16.02.055","url":null,"abstract":"Purpose. The research purpose is to substantiate the use of biocoke as a fuel in the iron ore sintering, as well as its influence on the performance and properties of the resulting sinter. To completely replace conventional coke breeze, biocoke is produced using 5 wt.% biomass wood pellets at different carbonization temperatures of 950 or 1100°C. Further, the influence of biocoke on the sintering process and the sinter quality is studied at a high proportion of biomass pellets of 10, 15, 30, 45 wt.% and a carbonization temperature of 950°C. Methods. Carbonization is performed in shaft-type electric furnaces to produce laboratory coke or biocoke. Afterward, the sintering of iron ores is conducted on a sinter plant. To assess the sintering process and the quality of the resulting sinter, the filtration rate is determined on a laboratory sinter plant using a vane anemometer designed to measure the directional flow average velocity under industrial conditions. The sinter reducibility is studied using a vertical heating furnace to assess the effect of coke and biocoke on the sinter’s physical-chemical properties. Findings. It has been determined that biocoke, carbonized at a temperature of 950°C, has good prospects and potential for a shift to a sustainable process of iron ore sintering. Originality. It has been proven that biocoke with a biomass pellet ratio of up to 15 wt.%, obtained at a temperature of 950°C, does not affect the parameters characterizing the sintering process. The sinter strength indicators correspond to the use of 100 wt.% conventional coke breeze. Biocoke used with a high proportion of biomass pellets of 30 and 45 wt.% causes a deterioration in the sinter quality. Practical implications. The results of using biocoke with the addition of 5-15 wt.% biomass pellets and at a temperature of 950°C are within the standard deviation, which makes it possible to use biocoke with 15 wt.% biomass pellets instead of industrial coke breeze.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45600294","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.073
L. X. Thanh, H. Bun
Purpose. The research purpose is to study the relationship between the number of electric excavators and their impact on reducing the voltage losses. As a result of the research, it becomes possible to obtain factors that can help the manager to correctly understand the effect of power compensation caused by the over-excitation mode of electric excavators. Methods. The paper uses the Jacobian matrix transformation to simulate the power flows of electric excavators, the driving mechanisms of which are mainly synchronous motors. The input data for the simulation is the in-situ measurement data representing the inverse power flow. A diagram and a software to determine the factors corresponding to the number of electric excavators are also provided. Findings. A cross-reference table has been compiled showing the ratio of factors corresponding to the number of electric excavators in a 6kV grid. An appropriate software has also been developed, including a table for correcting typical equations for calculating voltage losses. Originality. The proposed factor is conditioned by over-excitation mode of excavators operating as compensation machines in a 6kV grid. Practical implications. When calculating the voltage loss in a 6kV grid of surface mines, if the design feeder contains electric excavators, a modified factor should be added to give a correct idea of the voltage quality.
{"title":"Identifying the factors influencing the voltage quality of 6kV grids when using electric excavators in surface mining","authors":"L. X. Thanh, H. Bun","doi":"10.33271/mining16.02.073","DOIUrl":"https://doi.org/10.33271/mining16.02.073","url":null,"abstract":"Purpose. The research purpose is to study the relationship between the number of electric excavators and their impact on reducing the voltage losses. As a result of the research, it becomes possible to obtain factors that can help the manager to correctly understand the effect of power compensation caused by the over-excitation mode of electric excavators. Methods. The paper uses the Jacobian matrix transformation to simulate the power flows of electric excavators, the driving mechanisms of which are mainly synchronous motors. The input data for the simulation is the in-situ measurement data representing the inverse power flow. A diagram and a software to determine the factors corresponding to the number of electric excavators are also provided. Findings. A cross-reference table has been compiled showing the ratio of factors corresponding to the number of electric excavators in a 6kV grid. An appropriate software has also been developed, including a table for correcting typical equations for calculating voltage losses. Originality. The proposed factor is conditioned by over-excitation mode of excavators operating as compensation machines in a 6kV grid. Practical implications. When calculating the voltage loss in a 6kV grid of surface mines, if the design feeder contains electric excavators, a modified factor should be added to give a correct idea of the voltage quality.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47900406","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.001
R.Ya. Kondrat, L. Matiishyn
Purpose is to improve the efficiency of extraction of remaining hydrocarbons within the oil and gas fields at the final stage of their development while optimizing operational conditions of the production wells. Methods. Software package PipeSim by Schlumberger has been applied to improve the efficiency of the current well stock under the conditions complicated by liquid accumulation within a bottomhole. A hypothetic well has been used. Findings. The basic operational parameters of a production well have been calculated for different values of water coefficient (i.e. 50; 100; 150; 200; 250; 300; 350; 400 and 450 l/th.m3). The research has helped identify that increase in the water coefficient results in the increased rate of liquid as well as decreased gas rate. A nodal analysis method has been applied to identify the following: at the level of 450 l/th.m3, a production well stops flowing. The results of the studies support the idea that to activate a well efficiency at the level of 18 th.m3/day, it is required either to replace 62.0 tubing string with 50.3 mm one or reduce wellhead pressure from 10.16 down to 9.88 MPa or develop gas lift injection at the level of 1.9 th.m3/day. In addition, the results give the evidence of engineering efficiency as for the method implementation. However, expediency of the application depends upon the processing limits of industrial facilities as well as upon the ratio between the water-free and wet deposit areas. Originality. The correlation dependencies have been determined to forecast operational indices of highly watered wells. The research results help substantiate promptly the methods intensifying hydrocarbon output depending upon different types of geological and engineering limitations. Practical implications. Implementation of the results will help optimize operation of production wells under active edge and bottom water inflow into the productive pools and increase their hydrocarbon extraction respectively.
{"title":"Improving the efficiency of production wells at the final stage of gas field development","authors":"R.Ya. Kondrat, L. Matiishyn","doi":"10.33271/mining16.02.001","DOIUrl":"https://doi.org/10.33271/mining16.02.001","url":null,"abstract":"Purpose is to improve the efficiency of extraction of remaining hydrocarbons within the oil and gas fields at the final stage of their development while optimizing operational conditions of the production wells. Methods. Software package PipeSim by Schlumberger has been applied to improve the efficiency of the current well stock under the conditions complicated by liquid accumulation within a bottomhole. A hypothetic well has been used. Findings. The basic operational parameters of a production well have been calculated for different values of water coefficient (i.e. 50; 100; 150; 200; 250; 300; 350; 400 and 450 l/th.m3). The research has helped identify that increase in the water coefficient results in the increased rate of liquid as well as decreased gas rate. A nodal analysis method has been applied to identify the following: at the level of 450 l/th.m3, a production well stops flowing. The results of the studies support the idea that to activate a well efficiency at the level of 18 th.m3/day, it is required either to replace 62.0 tubing string with 50.3 mm one or reduce wellhead pressure from 10.16 down to 9.88 MPa or develop gas lift injection at the level of 1.9 th.m3/day. In addition, the results give the evidence of engineering efficiency as for the method implementation. However, expediency of the application depends upon the processing limits of industrial facilities as well as upon the ratio between the water-free and wet deposit areas. Originality. The correlation dependencies have been determined to forecast operational indices of highly watered wells. The research results help substantiate promptly the methods intensifying hydrocarbon output depending upon different types of geological and engineering limitations. Practical implications. Implementation of the results will help optimize operation of production wells under active edge and bottom water inflow into the productive pools and increase their hydrocarbon extraction respectively.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43517613","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}
Pub Date : 2022-06-30DOI: 10.33271/mining16.02.027
Yukun Ma, Yanpeng Xu
Purpose. In order to solve the serious problem of borehole deflection in coal mine gas drainage, the precision directional drilling tool has been developed and improved, as well as the general borehole deflection laws have been studied. Methods. By using ordinary drilling pipes, one set of precision directional drilling tool and two sets of precision directional drilling tools, gas-drainage boreholes have been drilled in the mine and, subsequently, the borehole trajectory parameters have been measured using an inclinometer. Findings. The borehole inclination angle first tends to decrease and then to increase, while the azimuth angle generally increases. The precision directional drilling tool is effective, especially when using two sets of drilling tools. In this case, the average 100-meter final borehole deflection is reduced by 66.0%, the average inclination angle is reduced by 52.3%, and the average azimuth angle is reduced by 46.5%. Originality. A tool for precision directional drilling has been developed and improved, and its effectiveness has been confirmed; the general laws of borehole deflection have been summarized from the overall for subsection intervals. Practical implications. The research results are of great guiding significance for preventing the gas-drainage borehole deflections and further research on the tool for precision directional drilling.
{"title":"Research into technology for precision directional drilling of gas-drainage boreholes","authors":"Yukun Ma, Yanpeng Xu","doi":"10.33271/mining16.02.027","DOIUrl":"https://doi.org/10.33271/mining16.02.027","url":null,"abstract":"Purpose. In order to solve the serious problem of borehole deflection in coal mine gas drainage, the precision directional drilling tool has been developed and improved, as well as the general borehole deflection laws have been studied. Methods. By using ordinary drilling pipes, one set of precision directional drilling tool and two sets of precision directional drilling tools, gas-drainage boreholes have been drilled in the mine and, subsequently, the borehole trajectory parameters have been measured using an inclinometer. Findings. The borehole inclination angle first tends to decrease and then to increase, while the azimuth angle generally increases. The precision directional drilling tool is effective, especially when using two sets of drilling tools. In this case, the average 100-meter final borehole deflection is reduced by 66.0%, the average inclination angle is reduced by 52.3%, and the average azimuth angle is reduced by 46.5%. Originality. A tool for precision directional drilling has been developed and improved, and its effectiveness has been confirmed; the general laws of borehole deflection have been summarized from the overall for subsection intervals. Practical implications. The research results are of great guiding significance for preventing the gas-drainage borehole deflections and further research on the tool for precision directional drilling.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48761421","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}
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