Pub Date : 2023-03-30DOI: 10.33271/mining17.01.084
Yurii Vynnykov, M. Kharchenko, S. Manhura, A. Aniskin, A. Manhura
Purpose is to analyze steel degradation of the internal well equipment during its continuous service while contacting directly the corrosive environments. Methods. A range of research concerning the damaged metal tubes of the internal equipment for oil and gas wells, in particular regarding continuous service tubing, comprised both standard and specific studies involving different variations of X-ray spectral analysis with the use of scanning electron microscope JSM-35CF (JEOL Company, Japan) and SEM-515 with microanalyzer Link by Philips Company. The studied samples have been made of tubing in the period of the unauthorized and emergency well shutdowns; life of the wells is 0 up to 15 years. To analyze both structure and chemical composition of metal inclusive of such gases as oxygen and hydrogen, chippings were produced mechanically from various parts of tube walls. Findings. X-ray structural studies have made it possible to obtain data confirming cementite decay (Fe3С) in the tube metal during continuous operation of the internal well equipment. X-ray structural analysis methods have helped identify the parameters of crystal lattice of a matrix; and a level of elastic distortions of the lattice (i.e. microstresses of the distortions) has been evaluated as well as carbon distribution within ferrite and cementite. The abovementioned offered the possibility to describe both reason and mechanism of the reduced resistance to corrosion in the context of internal well equipment. Originality. New regularities under cementite decay in tube metal have been identified in addition to changes in the parameters of a crystal a lattice; microstresses of the lattice distortions; and carbon distribution within ferrite and cementite. The aforesaid helps explain in a new way both reason and mechanism of the reduced resistance to corrosion in the context of internal well structures operating continuously in aggressive environments. The basic sources and mechanisms of tube steel degradation, resulting from the metal hydrogenation and oxidation, have been defined which becomes the foundation to develop scientifically the substantiated measures mitigating the negative impact on the condition of the internal well facilities operating continuously in the chemically aggressive environments. Practical implications. Degrading hydrogen effect on the crystal lattice of metal has been proved. The effect creates conditions under which tube structures of oil and gas wells experience their failure.
{"title":"Degradation of the internal well equipment steel under continuous service in the corrosive and aggressive environments","authors":"Yurii Vynnykov, M. Kharchenko, S. Manhura, A. Aniskin, A. Manhura","doi":"10.33271/mining17.01.084","DOIUrl":"https://doi.org/10.33271/mining17.01.084","url":null,"abstract":"Purpose is to analyze steel degradation of the internal well equipment during its continuous service while contacting directly the corrosive environments. Methods. A range of research concerning the damaged metal tubes of the internal equipment for oil and gas wells, in particular regarding continuous service tubing, comprised both standard and specific studies involving different variations of X-ray spectral analysis with the use of scanning electron microscope JSM-35CF (JEOL Company, Japan) and SEM-515 with microanalyzer Link by Philips Company. The studied samples have been made of tubing in the period of the unauthorized and emergency well shutdowns; life of the wells is 0 up to 15 years. To analyze both structure and chemical composition of metal inclusive of such gases as oxygen and hydrogen, chippings were produced mechanically from various parts of tube walls. Findings. X-ray structural studies have made it possible to obtain data confirming cementite decay (Fe3С) in the tube metal during continuous operation of the internal well equipment. X-ray structural analysis methods have helped identify the parameters of crystal lattice of a matrix; and a level of elastic distortions of the lattice (i.e. microstresses of the distortions) has been evaluated as well as carbon distribution within ferrite and cementite. The abovementioned offered the possibility to describe both reason and mechanism of the reduced resistance to corrosion in the context of internal well equipment. Originality. New regularities under cementite decay in tube metal have been identified in addition to changes in the parameters of a crystal a lattice; microstresses of the lattice distortions; and carbon distribution within ferrite and cementite. The aforesaid helps explain in a new way both reason and mechanism of the reduced resistance to corrosion in the context of internal well structures operating continuously in aggressive environments. The basic sources and mechanisms of tube steel degradation, resulting from the metal hydrogenation and oxidation, have been defined which becomes the foundation to develop scientifically the substantiated measures mitigating the negative impact on the condition of the internal well facilities operating continuously in the chemically aggressive environments. Practical implications. Degrading hydrogen effect on the crystal lattice of metal has been proved. The effect creates conditions under which tube structures of oil and gas wells experience their failure.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46912313","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 : 2023-03-30DOI: 10.33271/mining17.01.108
A. Embaby, Ashraf Ismael, Faisal A Ali, H. Farag, B. Mousa, S. Gomaa, Mohamed Elwageeh
Purpose. This paper aims to estimate phosphate ore grade in the Abu Tartur area, Western Desert, Egypt, using four Machine Learning Algorithms (MLA), Geostatistical Techniques (variogram and kriging models), and GIS-analysis. Methods. Four machine-learning techniques include Optimizable Decision Tree (ODT), Optimizable Support Vector Machine (OSVM), Optimizable Gaussian Process Regression (OGPR), Artificial Neural Network (ANN) are applied in this paper. The constructed variogram and kriging models, as well as GIS-analysis, provide a clear understanding of all the elements distributed in the Abu Tartur phosphate ore and are very useful at the planning and mining stages. Findings. Phosphate content has been estimated with high accuracy based on the results of four machine-learning techniques. The most efficient technique for estimating phosphate content is optimizable (OGPR), which gives correlation coefficients (R) of 0.933 and 0.927 with Mean Absolute Errors (MAE) of 0.983 and 0.933 for the training and validation data, respectively. In addition, geostatistical and GIS methods have shown that percentage of P2O5, thickness, and Fe% are suitable for phosphate mining processes, except for small pockets that require little attention at the mining stage. Originality. This research attempts to develop a quick estimation of phosphate ore grade and to provide a clear understanding about the distribution of different constituents within the ore body using different techniques. Practical implications. Grade estimation is commonly reduced to a function approximation. Artificial intelligence (AI) techniques, and in particular the chosen type of AI techniques, can provide, a valid methodology for estimating grade, and the proposed models can be applied to any other data in the range used in this research.
{"title":"An approach based on Machine Learning Algorithms, Geostatistical Technique, and GIS analysis to estimate phosphate ore grade at the Abu Tartur Mine, Western Desert, Egypt","authors":"A. Embaby, Ashraf Ismael, Faisal A Ali, H. Farag, B. Mousa, S. Gomaa, Mohamed Elwageeh","doi":"10.33271/mining17.01.108","DOIUrl":"https://doi.org/10.33271/mining17.01.108","url":null,"abstract":"Purpose. This paper aims to estimate phosphate ore grade in the Abu Tartur area, Western Desert, Egypt, using four Machine Learning Algorithms (MLA), Geostatistical Techniques (variogram and kriging models), and GIS-analysis. Methods. Four machine-learning techniques include Optimizable Decision Tree (ODT), Optimizable Support Vector Machine (OSVM), Optimizable Gaussian Process Regression (OGPR), Artificial Neural Network (ANN) are applied in this paper. The constructed variogram and kriging models, as well as GIS-analysis, provide a clear understanding of all the elements distributed in the Abu Tartur phosphate ore and are very useful at the planning and mining stages. Findings. Phosphate content has been estimated with high accuracy based on the results of four machine-learning techniques. The most efficient technique for estimating phosphate content is optimizable (OGPR), which gives correlation coefficients (R) of 0.933 and 0.927 with Mean Absolute Errors (MAE) of 0.983 and 0.933 for the training and validation data, respectively. In addition, geostatistical and GIS methods have shown that percentage of P2O5, thickness, and Fe% are suitable for phosphate mining processes, except for small pockets that require little attention at the mining stage. Originality. This research attempts to develop a quick estimation of phosphate ore grade and to provide a clear understanding about the distribution of different constituents within the ore body using different techniques. Practical implications. Grade estimation is commonly reduced to a function approximation. Artificial intelligence (AI) techniques, and in particular the chosen type of AI techniques, can provide, a valid methodology for estimating grade, and the proposed models can be applied to any other data in the range used in this research.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44128353","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 : 2023-03-30DOI: 10.33271/mining17.01.017
Khaini-Kamal Kassymkanova, S. Istekova, K. Rysbekov, B. Amralinova, G. Kyrgizbayeva, S. Soltabayeva, Gulnara Dossetova
Purpose is to improve a geophysical method of determining the boundaries of ore-bearing rocks and tectonic disturbances under complex mining and geological conditions while developing 3D geological models. Methods. 3D geological models of natural objects were developed on the basis of complex structural, geological-geophysical, and lithological facies analysis with the wide use of modern 3D seismic exploration technologies taking into consideration the parameters for prediction and selection of optimal factors for ore deposit development. Findings. The scientifically substantiated result is represented by the increased reliability and efficiency of seismic exploration for singling out the ore horizons and ore bodies as well as tectonic disturbances at different depths by specifying geological structures of the prospective areas and sites under study. Originality. Basing on the carried out studies, methods of the development of 3D geological models to study depth geological inhomogeneities of the ore-bearing complexes under complex mining and geological conditions were improved. Practical implications. The obtained results of 3D modelling of geological media basing on the applied 3D seismic exploration will help increase a confidence factor of scientifically substantiated prediction of ore deposits, provide optimal development of complex ore objects, reduce risks, and increase economic efficiency of solid deposit development under complex mining and geological conditions.
{"title":"Improving a geophysical method to determine the boundaries of ore-bearing rocks considering certain tectonic disturbances","authors":"Khaini-Kamal Kassymkanova, S. Istekova, K. Rysbekov, B. Amralinova, G. Kyrgizbayeva, S. Soltabayeva, Gulnara Dossetova","doi":"10.33271/mining17.01.017","DOIUrl":"https://doi.org/10.33271/mining17.01.017","url":null,"abstract":"Purpose is to improve a geophysical method of determining the boundaries of ore-bearing rocks and tectonic disturbances under complex mining and geological conditions while developing 3D geological models. Methods. 3D geological models of natural objects were developed on the basis of complex structural, geological-geophysical, and lithological facies analysis with the wide use of modern 3D seismic exploration technologies taking into consideration the parameters for prediction and selection of optimal factors for ore deposit development. Findings. The scientifically substantiated result is represented by the increased reliability and efficiency of seismic exploration for singling out the ore horizons and ore bodies as well as tectonic disturbances at different depths by specifying geological structures of the prospective areas and sites under study. Originality. Basing on the carried out studies, methods of the development of 3D geological models to study depth geological inhomogeneities of the ore-bearing complexes under complex mining and geological conditions were improved. Practical implications. The obtained results of 3D modelling of geological media basing on the applied 3D seismic exploration will help increase a confidence factor of scientifically substantiated prediction of ore deposits, provide optimal development of complex ore objects, reduce risks, and increase economic efficiency of solid deposit development under complex mining and geological conditions.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49594146","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 : 2023-03-30DOI: 10.33271/mining17.01.051
Anas Driouch, L. Ouadif, A. Lahmili, Mohammed Amine Belmi, Khalid Benjmel
Purpose. The Bou Azzer Mine encounters difficulties during cobalt mining. In order to select the optimal mining sequence with the least geotechnical stability problems, one possible variant is the cut and backfill mining method used in the Bou Azzer East area at a depth of 540 m. Methods. This paper presents a methodology for selecting a sequence of the cut and backfill mining method using 2D geotechnical numerical modeling, taking into account the morphological characteristics, geomechanical properties of the ore and the surrounding rocks. Findings. The sequences of mining with rock backfill and rock-cemented backfill show that the high principal stress (Sigma 1) is in the range of 10-153 MPa, and the safety factors are in the range of 0.63-1.89. Therefore, mining sequences with cemented backfill and under cemented backfill have a principal stress (Sigma 1) in the range of 10-112 MPa and acceptable safety factors. Originality. In this study, the bottom-up mining sequence with a cemented backfill is proposed for the case of low-quality serpentine footwall. This mining sequence aims to achieve good cobalt mine production and provides a safe environment for miners. Practical implications. In the mining industry, the choice of mining method using 2D or 3D geotechnical numerical mo-deling is important to ensure the safest and most operational mining sequence in the mine lifetime.
{"title":"Geotechnical modeling of the method for mining cobalt deposits at the Bou Azzer Mine, Morocco","authors":"Anas Driouch, L. Ouadif, A. Lahmili, Mohammed Amine Belmi, Khalid Benjmel","doi":"10.33271/mining17.01.051","DOIUrl":"https://doi.org/10.33271/mining17.01.051","url":null,"abstract":"Purpose. The Bou Azzer Mine encounters difficulties during cobalt mining. In order to select the optimal mining sequence with the least geotechnical stability problems, one possible variant is the cut and backfill mining method used in the Bou Azzer East area at a depth of 540 m. Methods. This paper presents a methodology for selecting a sequence of the cut and backfill mining method using 2D geotechnical numerical modeling, taking into account the morphological characteristics, geomechanical properties of the ore and the surrounding rocks. Findings. The sequences of mining with rock backfill and rock-cemented backfill show that the high principal stress (Sigma 1) is in the range of 10-153 MPa, and the safety factors are in the range of 0.63-1.89. Therefore, mining sequences with cemented backfill and under cemented backfill have a principal stress (Sigma 1) in the range of 10-112 MPa and acceptable safety factors. Originality. In this study, the bottom-up mining sequence with a cemented backfill is proposed for the case of low-quality serpentine footwall. This mining sequence aims to achieve good cobalt mine production and provides a safe environment for miners. Practical implications. In the mining industry, the choice of mining method using 2D or 3D geotechnical numerical mo-deling is important to ensure the safest and most operational mining sequence in the mine lifetime.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49252376","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 : 2023-03-30DOI: 10.33271/mining17.01.059
Tien Trung Vu, Son Anh Do
Purpose. It is important to conduct a study to identify the displacement zone caused by mining operations. By numerical modeling the process of mining the longwall 31104 in Seam 11 at the Nui Beo Coal Mine, Vietnam, the authors have deter-mined the total height of the rock mass displacement zone and the boundary of the affected area on the topographic surface. Methods. In this study, the authors use a numerical modeling method. The models are developed based on the UDEC (Universal Distinct Element Code) software. In addition, field survey methods and statistical analysis methods are used. Findings. Based on the analysis of the numerical modeling results, it has been determined that the total height of the displacement zone, when exploiting the longwall 31104 in Seam 11, is about 63 m. The analysis of the numerical modeling results also shows that the roof collapse angle is 52°, which determines the area of influence on the topographic surface in the range of 160 m. Originality. Based on the UDEC software, the authors have developed a simulation model for the mining process of the longwall 31104 in Seam 11. Analysis of the model results has shown the state of the displacement zone of the surrounding rock mass. In this study, the numerical modeling method is applied to simulate the longwall displacement zone, which is consistent with the actual production of the underground mine. Practical implications. Based on the analysis of the surrounding rock mass displacements zone, when exploiting the longwall 31104 in Seam 11 at the Nui Beo Coal Mine, the affected boundary on the topographic surface has been determined. At the same time, the height of the rock mass displacement zone has also been calculated. Thus, the research results can be used as a basis for implementation in actual production at the Nui Beo Coal Mine.
{"title":"Determination of the rock mass displacement zone by numerical modeling method when exploiting the longwall at the Nui Beo Coal Mine, Vietnam","authors":"Tien Trung Vu, Son Anh Do","doi":"10.33271/mining17.01.059","DOIUrl":"https://doi.org/10.33271/mining17.01.059","url":null,"abstract":"Purpose. It is important to conduct a study to identify the displacement zone caused by mining operations. By numerical modeling the process of mining the longwall 31104 in Seam 11 at the Nui Beo Coal Mine, Vietnam, the authors have deter-mined the total height of the rock mass displacement zone and the boundary of the affected area on the topographic surface. Methods. In this study, the authors use a numerical modeling method. The models are developed based on the UDEC (Universal Distinct Element Code) software. In addition, field survey methods and statistical analysis methods are used. Findings. Based on the analysis of the numerical modeling results, it has been determined that the total height of the displacement zone, when exploiting the longwall 31104 in Seam 11, is about 63 m. The analysis of the numerical modeling results also shows that the roof collapse angle is 52°, which determines the area of influence on the topographic surface in the range of 160 m. Originality. Based on the UDEC software, the authors have developed a simulation model for the mining process of the longwall 31104 in Seam 11. Analysis of the model results has shown the state of the displacement zone of the surrounding rock mass. In this study, the numerical modeling method is applied to simulate the longwall displacement zone, which is consistent with the actual production of the underground mine. Practical implications. Based on the analysis of the surrounding rock mass displacements zone, when exploiting the longwall 31104 in Seam 11 at the Nui Beo Coal Mine, the affected boundary on the topographic surface has been determined. At the same time, the height of the rock mass displacement zone has also been calculated. Thus, the research results can be used as a basis for implementation in actual production at the Nui Beo Coal Mine.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45517396","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 : 2023-03-30DOI: 10.33271/mining17.01.138
Abdel-ali Kharis, S. Ilmen, M. Aissa, L. Baidder, Azizi Moussaid, Hafid Mezougane, Bouchra Baidada, Nouamane El Ouad, Y. Atif, Hicham Houane, L. Maacha
Purpose. The purpose of the present research is to provide a new lithological, structural and magmatic features of the Oumjrane-Boukerzia Mining District. The results obtained are used to guide exploration works for identifying the new Cu, Ni, Pb, Zn depositions and Ba-bearing mineralization within the whole Oumjrane-Boukerzia domain. Methods. This research is based on detailed mapping, structural surveys and geochemical studies performed on the magmatic rocks in the studied area. Findings. Structural and microstructural analyses of the studied area have revealed three complex polyphase tectonic events related to the Variscan orogeny: (i) an extensive phase during the Devonian period; (ii) a NW-SE compressional phase of Namuro-Westphalian age; (iii) a NE-SW compressional phase of Stephanian-Autunian age, and (iv) an extensive late phase probably related to the opening of the Central Atlantic ocean during the Late Trias-Jurassic periods. The sedimentary rocks of the district are locally intruded by small undated gabbroic intrusions. Geochemically, these gabbroic bodies are described as olivine-rich gabbros with a continental tholeiitic affinity and suggested to be related to the Central Atlantic magmatic province (CAMP) during the Pangea break-up. Originality. The present study describes the host-rocks and structural events responsible for Cu, Ni, Zn, Pb deposition and Ba-bearing mineralization in the Oumjrane-Boukerzia Mining District (Eastern Anti-Atlas, Morocco). Practical implications. The geological studies, especially lithostratigraphic, tectonic and magmatism are essential in the mineral exploration. They help exploration geologists identify and define metallotects to discover new minerals.
{"title":"The Oumjrane-Boukerzia Mining District (Eastern Anti-Atlas, Morocco): Constraints of its geological and tectono-magmatic setting","authors":"Abdel-ali Kharis, S. Ilmen, M. Aissa, L. Baidder, Azizi Moussaid, Hafid Mezougane, Bouchra Baidada, Nouamane El Ouad, Y. Atif, Hicham Houane, L. Maacha","doi":"10.33271/mining17.01.138","DOIUrl":"https://doi.org/10.33271/mining17.01.138","url":null,"abstract":"Purpose. The purpose of the present research is to provide a new lithological, structural and magmatic features of the Oumjrane-Boukerzia Mining District. The results obtained are used to guide exploration works for identifying the new Cu, Ni, Pb, Zn depositions and Ba-bearing mineralization within the whole Oumjrane-Boukerzia domain. Methods. This research is based on detailed mapping, structural surveys and geochemical studies performed on the magmatic rocks in the studied area. Findings. Structural and microstructural analyses of the studied area have revealed three complex polyphase tectonic events related to the Variscan orogeny: (i) an extensive phase during the Devonian period; (ii) a NW-SE compressional phase of Namuro-Westphalian age; (iii) a NE-SW compressional phase of Stephanian-Autunian age, and (iv) an extensive late phase probably related to the opening of the Central Atlantic ocean during the Late Trias-Jurassic periods. The sedimentary rocks of the district are locally intruded by small undated gabbroic intrusions. Geochemically, these gabbroic bodies are described as olivine-rich gabbros with a continental tholeiitic affinity and suggested to be related to the Central Atlantic magmatic province (CAMP) during the Pangea break-up. Originality. The present study describes the host-rocks and structural events responsible for Cu, Ni, Zn, Pb deposition and Ba-bearing mineralization in the Oumjrane-Boukerzia Mining District (Eastern Anti-Atlas, Morocco). Practical implications. The geological studies, especially lithostratigraphic, tectonic and magmatism are essential in the mineral exploration. They help exploration geologists identify and define metallotects to discover new minerals.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44818204","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 : 2023-03-30DOI: 10.33271/mining17.01.120
Shaib Abdulazeez Shehu, Kudirat Oziohu Yusuf, H. Zabidi, O. A. Jimoh, M. Hashim
Purpose. Mine and quarry operators determine blasting efficiency by the sizes of fragments, while regulatory agencies evaluate the same from the level of environmental discomfort. Thus, a conflict of interest exists. This research distinguishes fragmentation efficiency from blasting efficiency. It proposes a new approach for evaluating blasting efficiency to break the conflict of interests between the quarry operators and the regulatory agencies. Methods. Five blasting events in the FYS granite aggregate quarry have been studied, and design parameters have been obtained. As an indicator of blast-induced environmental discomfort, vibrations and air blasts are measured using a seismograph. The WipFrag desktop and Kuz-Ram model are used to assess the resulting fragmentations. Blasting efficiency is evaluated as a function of fragmentation and environmental constraints. Findings. The powder factor affects the fragment size distribution and the environmental hazards of blasting but in a conflicting manner. Increased powder factor enhances good fragmentation but results in further environmental discomfort. Blast event 4 has the highest fragmentation efficiency of 46.53%, while 3 has the highest environmental control efficiency of 69.47%. Cumulatively, blast event 4 has the highest overall blasting efficiency of 45.43%. Future research is expected to standardise this novel approach and incorporate more blasting effects. Originality. This work is the first attempt to quantify the efficiency of blasting operations in the aggregate quarry by combining the fragmentation produced and the resulting environmental hazards in a single model. Practical implications. The model proposed in this research can be adopted by quarry operators and regulatory agencies for sustainable quarrying and mining to address identified conflicts of interest between them.
{"title":"Blasting efficiency in granite aggregate quarry based on the combined effects of fragmentation and weighted environmental hazards","authors":"Shaib Abdulazeez Shehu, Kudirat Oziohu Yusuf, H. Zabidi, O. A. Jimoh, M. Hashim","doi":"10.33271/mining17.01.120","DOIUrl":"https://doi.org/10.33271/mining17.01.120","url":null,"abstract":"Purpose. Mine and quarry operators determine blasting efficiency by the sizes of fragments, while regulatory agencies evaluate the same from the level of environmental discomfort. Thus, a conflict of interest exists. This research distinguishes fragmentation efficiency from blasting efficiency. It proposes a new approach for evaluating blasting efficiency to break the conflict of interests between the quarry operators and the regulatory agencies. Methods. Five blasting events in the FYS granite aggregate quarry have been studied, and design parameters have been obtained. As an indicator of blast-induced environmental discomfort, vibrations and air blasts are measured using a seismograph. The WipFrag desktop and Kuz-Ram model are used to assess the resulting fragmentations. Blasting efficiency is evaluated as a function of fragmentation and environmental constraints. Findings. The powder factor affects the fragment size distribution and the environmental hazards of blasting but in a conflicting manner. Increased powder factor enhances good fragmentation but results in further environmental discomfort. Blast event 4 has the highest fragmentation efficiency of 46.53%, while 3 has the highest environmental control efficiency of 69.47%. Cumulatively, blast event 4 has the highest overall blasting efficiency of 45.43%. Future research is expected to standardise this novel approach and incorporate more blasting effects. Originality. This work is the first attempt to quantify the efficiency of blasting operations in the aggregate quarry by combining the fragmentation produced and the resulting environmental hazards in a single model. Practical implications. The model proposed in this research can be adopted by quarry operators and regulatory agencies for sustainable quarrying and mining to address identified conflicts of interest between them.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47399499","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 : 2022-12-30DOI: 10.33271/mining16.04.029
K. Sundari, Subari, B. D. Erlangga
Purpose. The research focuses on the improvement of local clay-based ceramic pottery bodies from Alas Angker in Buleleng Regency in Bali. The main purpose is to utilize the clay which meets the standards of ceramics such as smooth and hard earthenware, especially to reduce its water absorption property. Methods. Firstly, the clay is analyzed for its physical and chemical composition. Two ceramic body formulations are made using the clay with the BWNAA1 and BWNAA2 codes. The specimens are measured in terms of clay ceramics properties including plasticity, dry shrinkage, firing shrinkage and water absorption. The cracked ceramic products are also analyzed for a comparison. Findings. The ceramic properties show similar results, except for the water absorption percentage. The BWNAA2 code formulation has lower water absorption rate by 10.8% and meets the requirements for the type of smooth and hard earthenware body in compliance with the national standard SNI:7275-2018. The water absorption rate is about half of the existing products, which is effective in avoiding the problem of cracks. Originality. Comparison of the existing ceramic products and specimens made in this study shows a significant difference in water absorption and crack growth. Adding a certain amount of kaolin, feldspar, ball clay and quartz sand has significantly reduced the water absorption rate of ceramic bodies. Practical implications. This research can be a potential solution to increase the quality of ceramic pottery products in the vicinity of Buleleng Regency which use the clay of this kind.
{"title":"Characterization of Buleleng clay and improvement of its ceramic properties","authors":"K. Sundari, Subari, B. D. Erlangga","doi":"10.33271/mining16.04.029","DOIUrl":"https://doi.org/10.33271/mining16.04.029","url":null,"abstract":"Purpose. The research focuses on the improvement of local clay-based ceramic pottery bodies from Alas Angker in Buleleng Regency in Bali. The main purpose is to utilize the clay which meets the standards of ceramics such as smooth and hard earthenware, especially to reduce its water absorption property. Methods. Firstly, the clay is analyzed for its physical and chemical composition. Two ceramic body formulations are made using the clay with the BWNAA1 and BWNAA2 codes. The specimens are measured in terms of clay ceramics properties including plasticity, dry shrinkage, firing shrinkage and water absorption. The cracked ceramic products are also analyzed for a comparison. Findings. The ceramic properties show similar results, except for the water absorption percentage. The BWNAA2 code formulation has lower water absorption rate by 10.8% and meets the requirements for the type of smooth and hard earthenware body in compliance with the national standard SNI:7275-2018. The water absorption rate is about half of the existing products, which is effective in avoiding the problem of cracks. Originality. Comparison of the existing ceramic products and specimens made in this study shows a significant difference in water absorption and crack growth. Adding a certain amount of kaolin, feldspar, ball clay and quartz sand has significantly reduced the water absorption rate of ceramic bodies. Practical implications. This research can be a potential solution to increase the quality of ceramic pottery products in the vicinity of Buleleng Regency which use the clay of this kind.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42719569","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 : 2022-12-30DOI: 10.33271/mining16.04.011
O. Sdvyzhkova, S. Moldabayev, A. Bascetin, D. Babets, E. Kuldeyev, Zh Sultanbekova, Maksat Amankulov, Bakhytzhan Issakov
Purpose. A methodology development for predicting the geomechanical situation when mining an ore deposit with steep-dipping layers, taking into account the uncertainty in determining the rock properties, which is a consequence of the rock mass heterogeneity. Methods. The assessment of the open-pit wall stability is based on a combination of numerical simulation of the rock stress-strain state (SSS) and probabilistic analysis. The finite element method is used to determine the changes in the SSS that occur at various stages of mining operations due to design changes in the overall open-pit slope angle. The elastic-plastic model of the medium and the Mohr-Coulomb failure criterion are implemented in the codes of the 3D finite element analysis program RS3 (Rocscience). Stochastic simulation is used to assess random risks associated with natural object state variations. Findings. The distribution of maximum shear strains, which localizes the real or potential sliding surfaces in the open-pit wall at various stages of ore mining, has been identified. Based on the Shear Strength Reduction procedure, the open-pit wall Strength Reduction Factor (SRF) has been determined. The probabilities of open-pit wall stability loss, as well as the decrease in the strength reduction factor below the standard level at all stages of the ore body mining, have been revealed. Originality. For the first time, for real mining-geological conditions of a deep ore open pit, the dependence of the strength reduction factor on the overall wall slope angle, which changes during mining of each steep layer, has been determined. For each stage of mining operations, for the first time, the probability of a decrease in the open-pit wall stability below the standard level has been determined based on stochastic simulation. Practical implications. The ratio between the open-pit contour characteristic (overall slope angle) and the probabilistic safety factor is the basis for practical solutions to ensure the efficiency and safety of mining at various stages of friable and hard overburden excavation, ore extraction, as well as for the subsequent optimization of the open-pit design contours.
{"title":"Probabilistic assessment of slope stability at ore mining with steep layers in deep open pits","authors":"O. Sdvyzhkova, S. Moldabayev, A. Bascetin, D. Babets, E. Kuldeyev, Zh Sultanbekova, Maksat Amankulov, Bakhytzhan Issakov","doi":"10.33271/mining16.04.011","DOIUrl":"https://doi.org/10.33271/mining16.04.011","url":null,"abstract":"Purpose. A methodology development for predicting the geomechanical situation when mining an ore deposit with steep-dipping layers, taking into account the uncertainty in determining the rock properties, which is a consequence of the rock mass heterogeneity. Methods. The assessment of the open-pit wall stability is based on a combination of numerical simulation of the rock stress-strain state (SSS) and probabilistic analysis. The finite element method is used to determine the changes in the SSS that occur at various stages of mining operations due to design changes in the overall open-pit slope angle. The elastic-plastic model of the medium and the Mohr-Coulomb failure criterion are implemented in the codes of the 3D finite element analysis program RS3 (Rocscience). Stochastic simulation is used to assess random risks associated with natural object state variations. Findings. The distribution of maximum shear strains, which localizes the real or potential sliding surfaces in the open-pit wall at various stages of ore mining, has been identified. Based on the Shear Strength Reduction procedure, the open-pit wall Strength Reduction Factor (SRF) has been determined. The probabilities of open-pit wall stability loss, as well as the decrease in the strength reduction factor below the standard level at all stages of the ore body mining, have been revealed. Originality. For the first time, for real mining-geological conditions of a deep ore open pit, the dependence of the strength reduction factor on the overall wall slope angle, which changes during mining of each steep layer, has been determined. For each stage of mining operations, for the first time, the probability of a decrease in the open-pit wall stability below the standard level has been determined based on stochastic simulation. Practical implications. The ratio between the open-pit contour characteristic (overall slope angle) and the probabilistic safety factor is the basis for practical solutions to ensure the efficiency and safety of mining at various stages of friable and hard overburden excavation, ore extraction, as well as for the subsequent optimization of the open-pit design contours.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41672534","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 : 2022-12-30DOI: 10.33271/mining16.04.080
Yanpeng Xu, Xiao Chen, J. Yu
Purpose. The purpose of this paper is to solve the scientific problem that the classical diffusion model in columnar coal cores cannot accurately describe the whole process of gas diffusion. Methods. The diffusion-percolation experiments were carried out using the laboratory’s homemade experimental equipment with standard ϕ 50mm×100 mm columnar raw coal cores under different air pressures. Findings. The classical diffusion model was used to fit the experimental data. The experiment has found that the classical diffusion model of the columnar coal core can only partially describe the gas diffusion process. The longer the experimental time, the larger the error between the model and the experiment, and the analysis has found that the apparent diffusion coefficient shows decay changes with time. The dynamic diffusion coefficient concept is then proposed in order to con-struct a radial multi-scale dynamic prominent diffusion-percolation model for columnar coal cores. The theoretical curve of the new model nearly coincides with the experimental curve, and the new model can describe the gas diffusion-percolation process of columnar coal cores more accurately. The multi-scale dynamic diffusion-percolation model covers the classical diffusion model. It explains the mechanism of gas diffusion-percolation in multi-scale pores, i.e., at the beginning of the flow, gas flows out from the large external pores first, from the surface inwards. Over time, the pore size through which gas flows gradually becomes smaller, the diffusion resistance gradually increases, and the apparent diffusion coefficient slowly decreases. Originality. This paper proposes a new multi-scale dynamic diffusion-percolation model to compare the old and new model analysis, as well as carefully studying the mechanism of gas flow in coal. Practical implications. This research has important engineering significance for the accuracy of measuring the gas content of coal seams, as well as predicting coal and gas content.
{"title":"Experimental study of the radial multi-scale dynamic diffusion model for gas-bearing coal","authors":"Yanpeng Xu, Xiao Chen, J. Yu","doi":"10.33271/mining16.04.080","DOIUrl":"https://doi.org/10.33271/mining16.04.080","url":null,"abstract":"Purpose. The purpose of this paper is to solve the scientific problem that the classical diffusion model in columnar coal cores cannot accurately describe the whole process of gas diffusion. Methods. The diffusion-percolation experiments were carried out using the laboratory’s homemade experimental equipment with standard ϕ 50mm×100 mm columnar raw coal cores under different air pressures. Findings. The classical diffusion model was used to fit the experimental data. The experiment has found that the classical diffusion model of the columnar coal core can only partially describe the gas diffusion process. The longer the experimental time, the larger the error between the model and the experiment, and the analysis has found that the apparent diffusion coefficient shows decay changes with time. The dynamic diffusion coefficient concept is then proposed in order to con-struct a radial multi-scale dynamic prominent diffusion-percolation model for columnar coal cores. The theoretical curve of the new model nearly coincides with the experimental curve, and the new model can describe the gas diffusion-percolation process of columnar coal cores more accurately. The multi-scale dynamic diffusion-percolation model covers the classical diffusion model. It explains the mechanism of gas diffusion-percolation in multi-scale pores, i.e., at the beginning of the flow, gas flows out from the large external pores first, from the surface inwards. Over time, the pore size through which gas flows gradually becomes smaller, the diffusion resistance gradually increases, and the apparent diffusion coefficient slowly decreases. Originality. This paper proposes a new multi-scale dynamic diffusion-percolation model to compare the old and new model analysis, as well as carefully studying the mechanism of gas flow in coal. Practical implications. This research has important engineering significance for the accuracy of measuring the gas content of coal seams, as well as predicting coal and gas content.","PeriodicalId":43896,"journal":{"name":"Mining of Mineral Deposits","volume":" ","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46248686","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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