In the development of hard rock mines, achieving maximum pull after blasting plays a crucial role. Various machines have been developed for rock cutting, but still, due to flexibility and cost-effectiveness, drilling and blasting are preferred. To enhance the effectiveness of this method, several techniques have been developed, including the use of appropriate stemming material, double-primer placement, selecting optimal initiation locations, improving blast designs, and exploring stress superposition techniques through electronic detonators. This research paper focuses on investigating the effect of the priming and explosive initiation location on pull through an experimental approach. The study specifically examines the influence of different initiation approaches on pull, with a particular focus on inverse initiation without solid decking. The findings indicate that inverse initiation without solid decking reveals the best pull for competent rock. Additionally, the inverse initiation with 1st and 2nd square cut solid decking (double detonators with different delays) and spacers in periphery holes was found to be the best choice to eliminate the post-blast sockets with reasonable pull for weathered competent rock.
{"title":"Effect of priming and explosive initiation location on pull in hard rock underground mine","authors":"K.K. Rao, B.S. Choudhary","doi":"10.46873/2300-3960.1399","DOIUrl":"https://doi.org/10.46873/2300-3960.1399","url":null,"abstract":"In the development of hard rock mines, achieving maximum pull after blasting plays a crucial role. Various machines have been developed for rock cutting, but still, due to flexibility and cost-effectiveness, drilling and blasting are preferred. To enhance the effectiveness of this method, several techniques have been developed, including the use of appropriate stemming material, double-primer placement, selecting optimal initiation locations, improving blast designs, and exploring stress superposition techniques through electronic detonators. This research paper focuses on investigating the effect of the priming and explosive initiation location on pull through an experimental approach. The study specifically examines the influence of different initiation approaches on pull, with a particular focus on inverse initiation without solid decking. The findings indicate that inverse initiation without solid decking reveals the best pull for competent rock. Additionally, the inverse initiation with 1st and 2nd square cut solid decking (double detonators with different delays) and spacers in periphery holes was found to be the best choice to eliminate the post-blast sockets with reasonable pull for weathered competent rock.","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135512409","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}
Phu Minh Vuong Nguyen, Andrzej Walentek, Petr Waclawik, Kamil Soucek, Michał Antoniuk
In the last decades, numerical modelling has been widely used to simulate rock mass behaviour in geo-engineering issues. The only disadvantage of numerical modelling is the reliability of required input data (e.g. mechanical parameters), which is not always fully provided due to the complexity of rock mass, project budget, available test methods or human errors. On the other hand, it was proven in many cases that numerical modelling is a helpful tool for solving such complex problems, especially when coupled with the results of laboratory and in-situ tests. This paper presents an attempt to determine the proper numerical constitutive model of rock and its mechanical parameters for further simulating rock mass response based on the outcomes of laboratory testing. For this purpose, the available constitutive models, including mechanical parameters, were taken into account. The simulation performance with the selected constitutive models is demonstrated by matching the numerical modelling results with the uniaxial compressive strength laboratory tests of rock samples from the Bogdanka coal mine. All numerical simulations were carried out using the finite difference method software FLAC3D
{"title":"Numerical modelling of Uniaxial Compressive Strength laboratory tests","authors":"Phu Minh Vuong Nguyen, Andrzej Walentek, Petr Waclawik, Kamil Soucek, Michał Antoniuk","doi":"10.46873/2300-3960.1393","DOIUrl":"https://doi.org/10.46873/2300-3960.1393","url":null,"abstract":"In the last decades, numerical modelling has been widely used to simulate rock mass behaviour in geo-engineering issues. The only disadvantage of numerical modelling is the reliability of required input data (e.g. mechanical parameters), which is not always fully provided due to the complexity of rock mass, project budget, available test methods or human errors. On the other hand, it was proven in many cases that numerical modelling is a helpful tool for solving such complex problems, especially when coupled with the results of laboratory and in-situ tests. This paper presents an attempt to determine the proper numerical constitutive model of rock and its mechanical parameters for further simulating rock mass response based on the outcomes of laboratory testing. For this purpose, the available constitutive models, including mechanical parameters, were taken into account. The simulation performance with the selected constitutive models is demonstrated by matching the numerical modelling results with the uniaxial compressive strength laboratory tests of rock samples from the Bogdanka coal mine. All numerical simulations were carried out using the finite difference method software FLAC3D","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136343441","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}
Mahvash Naddaf Sangani, Seyed Reza Hosseinzadeh, José Francisco Martín Duque, Mahnaz Jahadi Toroghi, Kapil Kumar Malik
Land surface deformation created by mining activities can have negative impacts on the environment. Measuring them can be a tool for managing the environmental impacts of mining. Synthetic Aperture Radar Interferometry is a remote sensing method for measuring deformations. The main aim of this research is to investigate the deformation phenomenon on a region scale and extend our understanding of it to all mining deformation areas across the country. This paper used Small Baseline Subset Interferometric Synthetic Aperture Radar technology to obtain deformations information in the Sangan mine based on mining activities. We used 48 scenes of Single Look Complex(SLC) data acquired by the Sentinel-1A, C-band of the European Space Agency descending orbit paths from 2014 to 2020. The Time Series of SBAS results show that the deformation velocity rate is about –20 to –35 mm/yr, and the displacement is attributed to approximately –120 mm in the Line of Sight direction. The main deformation zone is situated in the mining area on the main alluvial fan. This study presented the relationship between deformations and mining activity's effects on the ground. Mining activities were accompanied by ground deformation in the mining area: the ground deformation is exacerbated by the increasing mining quantity, and as a result will cause erosion, flood, and other geomorphologic phenomena in the area. We compared the results of the SBAS technique with leveling data for validating the data of SBAS. Their comparison shows approximately suitable agreement with the results of SBAS.
{"title":"Open-Cast Mining Deformations Monitoring using Sentinel-1 SAR data (SBAS technique)","authors":"Mahvash Naddaf Sangani, Seyed Reza Hosseinzadeh, José Francisco Martín Duque, Mahnaz Jahadi Toroghi, Kapil Kumar Malik","doi":"10.46873/2300-3960.1394","DOIUrl":"https://doi.org/10.46873/2300-3960.1394","url":null,"abstract":"Land surface deformation created by mining activities can have negative impacts on the environment. Measuring them can be a tool for managing the environmental impacts of mining. Synthetic Aperture Radar Interferometry is a remote sensing method for measuring deformations. The main aim of this research is to investigate the deformation phenomenon on a region scale and extend our understanding of it to all mining deformation areas across the country. This paper used Small Baseline Subset Interferometric Synthetic Aperture Radar technology to obtain deformations information in the Sangan mine based on mining activities. We used 48 scenes of Single Look Complex(SLC) data acquired by the Sentinel-1A, C-band of the European Space Agency descending orbit paths from 2014 to 2020. The Time Series of SBAS results show that the deformation velocity rate is about –20 to –35 mm/yr, and the displacement is attributed to approximately –120 mm in the Line of Sight direction. The main deformation zone is situated in the mining area on the main alluvial fan. This study presented the relationship between deformations and mining activity's effects on the ground. Mining activities were accompanied by ground deformation in the mining area: the ground deformation is exacerbated by the increasing mining quantity, and as a result will cause erosion, flood, and other geomorphologic phenomena in the area. We compared the results of the SBAS technique with leveling data for validating the data of SBAS. Their comparison shows approximately suitable agreement with the results of SBAS.","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136343618","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}
Andrzej Chmiela, Małgorzata Wysocka, Adam Smoliński
Mine closure is the natural final stage of mining activity. The process of financing mine liquidation is complex and expensive. The many years of conducted hard coal extraction affect the surface height differences. Analyses of the shifts in hydrogeological conditions and water hazard states in mining plants led to legal regulation adaptations, primarily in terms of hydrogeological documentation preparation, and made it necessary to conduct work concerning new options for water hazard assessment and prevention. Current subjects of particular interest include shifts in terrain morphology and the water regime, resulting in periodic flooding and permanent flooding of the most depressed areas as well as changes in the directions and intensity of surface water flows. This publication presents a multi-criteria analysis of the possibility of reducing the liquidation costs of an inactive mine through the retrofitting of the existing system of rainwater drainage from subsidence basins. The analysis revealed the primary factors disrupting the course of the drainage process and the problems resulting from them. Technically feasible solutions is presented, together with their assessment. Applying the multi-criteria analysis made it possible to select optimal solutions from a group of proposed technical system retrofitting variants
{"title":"Multi-criteria analysis of the possibility of retrofitting the system of rainwater drainage from subsidence basins in a liquidated mine.","authors":"Andrzej Chmiela, Małgorzata Wysocka, Adam Smoliński","doi":"10.46873/2300-3960.1395","DOIUrl":"https://doi.org/10.46873/2300-3960.1395","url":null,"abstract":"Mine closure is the natural final stage of mining activity. The process of financing mine liquidation is complex and expensive. The many years of conducted hard coal extraction affect the surface height differences. Analyses of the shifts in hydrogeological conditions and water hazard states in mining plants led to legal regulation adaptations, primarily in terms of hydrogeological documentation preparation, and made it necessary to conduct work concerning new options for water hazard assessment and prevention. Current subjects of particular interest include shifts in terrain morphology and the water regime, resulting in periodic flooding and permanent flooding of the most depressed areas as well as changes in the directions and intensity of surface water flows. This publication presents a multi-criteria analysis of the possibility of reducing the liquidation costs of an inactive mine through the retrofitting of the existing system of rainwater drainage from subsidence basins. The analysis revealed the primary factors disrupting the course of the drainage process and the problems resulting from them. Technically feasible solutions is presented, together with their assessment. Applying the multi-criteria analysis made it possible to select optimal solutions from a group of proposed technical system retrofitting variants","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134961092","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}
Abstract The land is one of the most treasures to support life, like food, fibre, medicine, and minerals, etc. Stone quarrying is one of the key elements which supports socio-economic development and industrial expansion. RS and GIS play an important role in environmental assessment to monitor the stone quarries and related activities for time to time. The present study was carried out to evaluate the impact of stone quarrying and crushing activities (SQCA) on land resources. Therefore, matrix change analysis of 2021, 2015, 2008 and 2003 were used for change detection. High-resolution Google Earth Pro images were used for the assessment of spatial as well as temporal changes caused by stone quarries and associated activities, which result in land use/land cover changes. The results show that the temporal changes in and around the quarrying sites over 18 years have contributed to dynamic changes in land use/ land cover. According to the study, damaging mining operations have grown in the area. SQCA are mostly carried out on agricultural land as well as wasteland, which decreases about 18.44% and 59.89% during the study period. Abandoned pits left without reclamation converted to derelict ponds degrading the landscape and becoming dangerous for humans and the ecosystem.
{"title":"Remote sensing and GIS based approach to evaluate the impact of stone quarrying and crushing activities on land resources","authors":"R. Chaurasia, S. Mohapatra","doi":"10.46873/2300-3960.1392","DOIUrl":"https://doi.org/10.46873/2300-3960.1392","url":null,"abstract":"Abstract The land is one of the most treasures to support life, like food, fibre, medicine, and minerals, etc. Stone quarrying is one of the key elements which supports socio-economic development and industrial expansion. RS and GIS play an important role in environmental assessment to monitor the stone quarries and related activities for time to time. The present study was carried out to evaluate the impact of stone quarrying and crushing activities (SQCA) on land resources. Therefore, matrix change analysis of 2021, 2015, 2008 and 2003 were used for change detection. High-resolution Google Earth Pro images were used for the assessment of spatial as well as temporal changes caused by stone quarries and associated activities, which result in land use/land cover changes. The results show that the temporal changes in and around the quarrying sites over 18 years have contributed to dynamic changes in land use/ land cover. According to the study, damaging mining operations have grown in the area. SQCA are mostly carried out on agricultural land as well as wasteland, which decreases about 18.44% and 59.89% during the study period. Abandoned pits left without reclamation converted to derelict ponds degrading the landscape and becoming dangerous for humans and the ecosystem.","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74336784","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}
Krzysztof Fuławka, Lech Stolecki, P. Mertuszka, Marcin Szumny, Arkadiusz Anderko
{"title":"Predictive model of seismic vibrations’ peak value induced by multi-face blasting","authors":"Krzysztof Fuławka, Lech Stolecki, P. Mertuszka, Marcin Szumny, Arkadiusz Anderko","doi":"10.46873/2300-3960.1390","DOIUrl":"https://doi.org/10.46873/2300-3960.1390","url":null,"abstract":"","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75910357","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}
M. Kononenko, O. Khomenko, I. Sadovenko, V. Sobolev, Yuliya Pazynich, A. Smoliński
Abstract Using the theory of elasticity and the main provisions of the quasi-static-wave hypothesis of the mechanism of the destruction of a solid medium under the action of an explosion, analytical modelling of the parameters of the formation of crumpling zones and crushing of the rock mass around the charging cavity during its explosive loading was carried out. Analytical models of the radii of the crumpling, intensive fragmentation and fracturing zones formed around the charging cavity in the rock mass during its explosive loading, taking into account the pressure of the explosion products, the limit of tensile-compressive strength of the rocks, their structural composition, fracturing and compaction under the action of rock pressure, were developed. Based on the change in the stress-strain state of the rock mass under the action of the explosion, numerical modelling of the radii of the zones of crumpling, intensive fragmentation and fracturing was performed using the finite element method. According to the simulation results, the power dependence of the change in the radii of the crumpling and fragmentation zones of the rock mass was determined depending on the diameter of the charging cavity, the pressure of the explosion products, and the limit of rock compressive strength. By comparing the results of analytical and numerical modelling for rigid boundary conditions of a homogeneous non-cracked rock mass, the difference in the values of the radii of the defined zones was established as being 4, 8 and 6%, respectively. The resulting analytical models of the radii of crushing zones, intensive fragmentation and fracturing increase the accuracy of estimating the parameters of rock mass destruction by explosion by up to 50% and improve the parameters of drilling and blasting operations when carrying out mining operations, special purpose cavities and rocking of the rock mass.
{"title":"Managing the rock mass destruction under the explosion","authors":"M. Kononenko, O. Khomenko, I. Sadovenko, V. Sobolev, Yuliya Pazynich, A. Smoliński","doi":"10.46873/2300-3960.1391","DOIUrl":"https://doi.org/10.46873/2300-3960.1391","url":null,"abstract":"Abstract Using the theory of elasticity and the main provisions of the quasi-static-wave hypothesis of the mechanism of the destruction of a solid medium under the action of an explosion, analytical modelling of the parameters of the formation of crumpling zones and crushing of the rock mass around the charging cavity during its explosive loading was carried out. Analytical models of the radii of the crumpling, intensive fragmentation and fracturing zones formed around the charging cavity in the rock mass during its explosive loading, taking into account the pressure of the explosion products, the limit of tensile-compressive strength of the rocks, their structural composition, fracturing and compaction under the action of rock pressure, were developed. Based on the change in the stress-strain state of the rock mass under the action of the explosion, numerical modelling of the radii of the zones of crumpling, intensive fragmentation and fracturing was performed using the finite element method. According to the simulation results, the power dependence of the change in the radii of the crumpling and fragmentation zones of the rock mass was determined depending on the diameter of the charging cavity, the pressure of the explosion products, and the limit of rock compressive strength. By comparing the results of analytical and numerical modelling for rigid boundary conditions of a homogeneous non-cracked rock mass, the difference in the values of the radii of the defined zones was established as being 4, 8 and 6%, respectively. The resulting analytical models of the radii of crushing zones, intensive fragmentation and fracturing increase the accuracy of estimating the parameters of rock mass destruction by explosion by up to 50% and improve the parameters of drilling and blasting operations when carrying out mining operations, special purpose cavities and rocking of the rock mass.","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73664073","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}
Abstract Determining GSI as a representation of the presence of rock mass in slope analysis continues to develop. The development of the quantitative GSI method was carried out because the basic (qualitative) GSI values were deemed too subjective so the results from the use of the quantitative GSIwere expected to be more objective and accurate. The method used is to combine 3 GSI quantitative methods to find GSI based on surface conditions and joint structure. The results showed that the Quantitative GSI value was smaller than the GSI predictive value (qualitative). The GSI approach with RQD and UCS parameters is also presented to describe rock mass conditions due to changes in GSI values, and the third result shows a directly proportional relationship, the greater the GSI value, the greater the RQD and UCS values. The combined application of these three quantification methods is suitable for slopes that have not been properly exposed so that surface and structural conditions can only be seen from visual observations of outcrops and some initial construction slopes.
{"title":"Application Geological Strength Index (GSI) quantification method on the characterization of carbonate rock mass","authors":"S. Saptono, Danu Mirza Rezky","doi":"10.46873/2300-3960.1387","DOIUrl":"https://doi.org/10.46873/2300-3960.1387","url":null,"abstract":"Abstract Determining GSI as a representation of the presence of rock mass in slope analysis continues to develop. The development of the quantitative GSI method was carried out because the basic (qualitative) GSI values were deemed too subjective so the results from the use of the quantitative GSIwere expected to be more objective and accurate. The method used is to combine 3 GSI quantitative methods to find GSI based on surface conditions and joint structure. The results showed that the Quantitative GSI value was smaller than the GSI predictive value (qualitative). The GSI approach with RQD and UCS parameters is also presented to describe rock mass conditions due to changes in GSI values, and the third result shows a directly proportional relationship, the greater the GSI value, the greater the RQD and UCS values. The combined application of these three quantification methods is suitable for slopes that have not been properly exposed so that surface and structural conditions can only be seen from visual observations of outcrops and some initial construction slopes.","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84134902","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}
I. Contrucci, D. Namjesnik, P. Niemz, Paloma Primo, A. Kotyrba, G. Mutke, P. Konicek, P. Dominique, T. Rudolph, S. Möllerherm, J. Kinscher, E. Klein, S. Cesca
Abstract Following the Paris Agreement adopted in 2015, Europe has committed to reducing its greenhouse gas emissions. In this context, the abandonment of coal as an energy source, both in terms of consumption and production, will lead to the closure of many mines in the years to come. Mine closure guidelines to manage residual mining risks already exist in European countries. However, they do not include post-mining seismic risk management due to a lack of sufficient studies and knowledge on this subject. After mining closure, the flooding of the mining works leads to hydromechanical loading of the underground and, in the longer term, to diffusion and an increase in the pore pressure. These conditions can lead, in certain situations, to the reactivation of tectonic faults, which may cause seismic events strong enough to be felt on the surface or even produce damage. Events of lower magnitudes, usually attributed to the remobilization of old mining works, are referred to as post-mining seismic hazards. The European RFCS PostMinQuake project, which started in 2020, aims to study this hazard at five mining basins located in France, Germany, Poland and the Czech Republic, known to have experienced significant seismicity during their operation. This analysis, based on the feedback of the partners of the project, aims to frame an inventory of the five studied mining basins, which all encounter post-mining seismicity problem today. Three basins out of five show events with local magnitudes of the order of 3 to 3.5, which took place between nine and thirteen years after the closure of the mines. Even though the magnitudes of these earthquakes are small to moderate, they are felt on the surface as they occur at shallow depths. In all of the considered countries, a national seismological network exists, however, none of them is fully dedicated to post-mining seismic monitoring. These networks generally consist of a sparse mesh of stations, which does not allow the detection of events of magnitude less than 1 and the location of events have high spatial uncertainties. France is not an exception, but it relies on microseismic monitoring to detect early signs of instability at the level of mining structures and to anticipate the possible appearance of surface disorders. Out of the five basins that are studied, the Gardanne basin, which has been monitored since 2008, is the most documented case study of post-mining seismicity. This article also shows the difficulty in identifying the key conditions and factors that can lead to the remobilization of faults.
{"title":"European feedback on post-mining seismicity","authors":"I. Contrucci, D. Namjesnik, P. Niemz, Paloma Primo, A. Kotyrba, G. Mutke, P. Konicek, P. Dominique, T. Rudolph, S. Möllerherm, J. Kinscher, E. Klein, S. Cesca","doi":"10.46873/2300-3960.1385","DOIUrl":"https://doi.org/10.46873/2300-3960.1385","url":null,"abstract":"Abstract Following the Paris Agreement adopted in 2015, Europe has committed to reducing its greenhouse gas emissions. In this context, the abandonment of coal as an energy source, both in terms of consumption and production, will lead to the closure of many mines in the years to come. Mine closure guidelines to manage residual mining risks already exist in European countries. However, they do not include post-mining seismic risk management due to a lack of sufficient studies and knowledge on this subject. After mining closure, the flooding of the mining works leads to hydromechanical loading of the underground and, in the longer term, to diffusion and an increase in the pore pressure. These conditions can lead, in certain situations, to the reactivation of tectonic faults, which may cause seismic events strong enough to be felt on the surface or even produce damage. Events of lower magnitudes, usually attributed to the remobilization of old mining works, are referred to as post-mining seismic hazards. The European RFCS PostMinQuake project, which started in 2020, aims to study this hazard at five mining basins located in France, Germany, Poland and the Czech Republic, known to have experienced significant seismicity during their operation. This analysis, based on the feedback of the partners of the project, aims to frame an inventory of the five studied mining basins, which all encounter post-mining seismicity problem today. Three basins out of five show events with local magnitudes of the order of 3 to 3.5, which took place between nine and thirteen years after the closure of the mines. Even though the magnitudes of these earthquakes are small to moderate, they are felt on the surface as they occur at shallow depths. In all of the considered countries, a national seismological network exists, however, none of them is fully dedicated to post-mining seismic monitoring. These networks generally consist of a sparse mesh of stations, which does not allow the detection of events of magnitude less than 1 and the location of events have high spatial uncertainties. France is not an exception, but it relies on microseismic monitoring to detect early signs of instability at the level of mining structures and to anticipate the possible appearance of surface disorders. Out of the five basins that are studied, the Gardanne basin, which has been monitored since 2008, is the most documented case study of post-mining seismicity. This article also shows the difficulty in identifying the key conditions and factors that can lead to the remobilization of faults.","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84658331","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}
Abstract The processing of lower-grade laterites to obtain nickel has increased due to the gradual depletion of higher-grade sulphide ore reserves. However, the extraction from laterites has been limited because conventional technologies imply a considerable expense of energy or reagents. In this document, the effect of thermal pre-treatments on a laterite sample is demonstrated to improve nickel leaching under moderate conditions. The influence of agents such as coke, coal and NaCl in the heat treatment was also studied. With the results it is presumed that part of the nickel occluded in the goethite migrates to the iron oxides surface during the heat treatment; this is why the dissolution of nickel is linked to that of iron. The highest extractions (64.7% nickel) were achieved by combining heat treatment and leaching with 1M H2SO4 at ambient conditions. Compared to direct leaching of unpretreated laterite, leaching rates for this metal are increased by 26.5%. The chlorinating calcination and the optimization of the studied variables will be favourable to reach higher metallic extractions.
{"title":"Nickel recovery from low-grade laterites: study of thermal pre-treatments to improve the efficiency of the hydrometallurgical process","authors":"J. Borda, R. Torres","doi":"10.46873/2300-3960.1389","DOIUrl":"https://doi.org/10.46873/2300-3960.1389","url":null,"abstract":"Abstract The processing of lower-grade laterites to obtain nickel has increased due to the gradual depletion of higher-grade sulphide ore reserves. However, the extraction from laterites has been limited because conventional technologies imply a considerable expense of energy or reagents. In this document, the effect of thermal pre-treatments on a laterite sample is demonstrated to improve nickel leaching under moderate conditions. The influence of agents such as coke, coal and NaCl in the heat treatment was also studied. With the results it is presumed that part of the nickel occluded in the goethite migrates to the iron oxides surface during the heat treatment; this is why the dissolution of nickel is linked to that of iron. The highest extractions (64.7% nickel) were achieved by combining heat treatment and leaching with 1M H2SO4 at ambient conditions. Compared to direct leaching of unpretreated laterite, leaching rates for this metal are increased by 26.5%. The chlorinating calcination and the optimization of the studied variables will be favourable to reach higher metallic extractions.","PeriodicalId":37284,"journal":{"name":"Journal of Sustainable Mining","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74487333","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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