M.W.N. Buxton
Please Note
49 records found
1
Towards Smarter Haulage Operations in an Open-Pit Limestone Mine
Quantifying the Impact of Dynamic Dispatching and a Single Autonomous Unit Using a Data-Driven DES
The results show that the implemented dynamic dispatch policy is not an effective mechanism to increase production volume in its current form. While the compliance metrics indicate that dynamic dispatch can enforce relatively tight adherence to shift-level bench targets under the thesis definition, it does so at a throughput cost. Compared to the fixed-assignment baseline, dynamic dispatch reduces total moved tonnage by about one percent and increases congestion, most notably through substantially higher loader queue time and headway-related waiting.
Single-agent autonomy produces asymmetric benefits across subsystems. Introducing a single autonomous hauler or loader yields limited gains in a mixed fleet because productive time remains bounded by shared schedules and downstream constraints. In contrast, the autonomous load-and-carry scenario produces the largest throughput increase in the core scenario set, nearly eight percent, consistent with the fact that this intervention expands the effective operating window by operating through periods that are otherwise constrained by breaks and shift transitions. This result should be interpreted in light of scope, since the load-and-carry unit is modeled as a dedicated crusher-feeding unit, whereas in practice it also performs auxiliary duties.
Overall, the findings indicate that improving a single component often yields diminishing system-level returns when the haulage cycle remains constrained by shared resources, schedules, and interaction effects. The discrete event simulation digital twin provides a validated sandbox for relative comparison of dispatch and autonomy concepts, and the results motivate future concepts that change system-level constraints more directly. ...
The results show that the implemented dynamic dispatch policy is not an effective mechanism to increase production volume in its current form. While the compliance metrics indicate that dynamic dispatch can enforce relatively tight adherence to shift-level bench targets under the thesis definition, it does so at a throughput cost. Compared to the fixed-assignment baseline, dynamic dispatch reduces total moved tonnage by about one percent and increases congestion, most notably through substantially higher loader queue time and headway-related waiting.
Single-agent autonomy produces asymmetric benefits across subsystems. Introducing a single autonomous hauler or loader yields limited gains in a mixed fleet because productive time remains bounded by shared schedules and downstream constraints. In contrast, the autonomous load-and-carry scenario produces the largest throughput increase in the core scenario set, nearly eight percent, consistent with the fact that this intervention expands the effective operating window by operating through periods that are otherwise constrained by breaks and shift transitions. This result should be interpreted in light of scope, since the load-and-carry unit is modeled as a dedicated crusher-feeding unit, whereas in practice it also performs auxiliary duties.
Overall, the findings indicate that improving a single component often yields diminishing system-level returns when the haulage cycle remains constrained by shared resources, schedules, and interaction effects. The discrete event simulation digital twin provides a validated sandbox for relative comparison of dispatch and autonomy concepts, and the results motivate future concepts that change system-level constraints more directly.
Flowsheet Development for Sustainable Processing of Kukersite Waste Rock
From Lab-Scale Mechanical to Pilot-Scale Pneumatic Flotation
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Results demonstrate a significant relationship between water depth and Fe-Mn crust composition, with a significant improvement in estimation accuracy and confidence when water depth is used as the secondary variable in Co-Kriging, with SCK and ICCK providing more accurate and confident resource estimates than OK. ICCK also performed better than IDW. For the first time, tonnage calculations for metals in Fe-Mn crusts based on a 3D block model and real geochemical data are presented, highlighting Tropic Seamount’s potential as a substantial mineral resource for Europe. The workflow developed in this study, including ILR transformation and L-ISOMAP embedding, proved effective for handling compositional data and spatial anisotropy. The study also identifies methodological limitations, such as the need for improved variography, better sampling distribution, consideration of non-metallic elements, and more advanced cross-validation techniques. The assumption that the top 1 cm of crust represents the entire deposit is noted as a simplification, and future research should address vertical stratigraphy and sampling distribution.
The findings indicate that integrating ILR transformation and Landmark-ISOMAP embedding with Co-Kriging leads to better resource estimation for Fe-Mn crusts, enabling more confident and accurate assessments. This methodology offers significant potential for mineral resource exploration and future research in both marine and terrestrial environments. ...
Results demonstrate a significant relationship between water depth and Fe-Mn crust composition, with a significant improvement in estimation accuracy and confidence when water depth is used as the secondary variable in Co-Kriging, with SCK and ICCK providing more accurate and confident resource estimates than OK. ICCK also performed better than IDW. For the first time, tonnage calculations for metals in Fe-Mn crusts based on a 3D block model and real geochemical data are presented, highlighting Tropic Seamount’s potential as a substantial mineral resource for Europe. The workflow developed in this study, including ILR transformation and L-ISOMAP embedding, proved effective for handling compositional data and spatial anisotropy. The study also identifies methodological limitations, such as the need for improved variography, better sampling distribution, consideration of non-metallic elements, and more advanced cross-validation techniques. The assumption that the top 1 cm of crust represents the entire deposit is noted as a simplification, and future research should address vertical stratigraphy and sampling distribution.
The findings indicate that integrating ILR transformation and Landmark-ISOMAP embedding with Co-Kriging leads to better resource estimation for Fe-Mn crusts, enabling more confident and accurate assessments. This methodology offers significant potential for mineral resource exploration and future research in both marine and terrestrial environments.
Pre-Feasibility Study On Secondary Recovery Potential from Ferro-Nickel Furnace Slags
Case Studies of Cerro Matoso (Colombia) and Loma de Níquel (Venezuela)
Ni, Co, Fe) and exhibit favorable characteristics for multiple re-use pathways. However, feasibility is largely influenced by mineralogical entrapment, as well as economical and regulatory constraints. This study explores the untapped value of FNS and emphasizes the importance of further investigating secondary recovery strategies. It contributes to the broader discourse on sustainable resource management by demonstrating how industrial waste can transition from liability to asset when viewed through a circular economy lens.
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Ni, Co, Fe) and exhibit favorable characteristics for multiple re-use pathways. However, feasibility is largely influenced by mineralogical entrapment, as well as economical and regulatory constraints. This study explores the untapped value of FNS and emphasizes the importance of further investigating secondary recovery strategies. It contributes to the broader discourse on sustainable resource management by demonstrating how industrial waste can transition from liability to asset when viewed through a circular economy lens.
A Multidisciplinary Approach to Mine Waste Rehabilitation
A Case Study Integrating Environmental and Social Impacts in the Iberian Pyrite Belt
The heat stress assessment applied Wet Bulb Globe Temperature (WBGT) measurements using both natural wet-bulb and globe temperature sensors, to quantify thermal comfort under varying metabolic rates. Receiver Operating Characteristic (ROC) analysis revealed that the WBGT index exhibited the strongest discrimination between acceptable and unacceptable temperatures under low metabolic rates, while high metabolic rate conditions achieved optimal balance, detecting well acceptable conditions and avoiding marking unacceptable conditions as acceptable. The operational WBGT thresholds were rounded to zero decimal places.
The temperature forecasting component employed regression modeling using surface conditions and production plans, across multiple mine regions, validated through holdout, k-fold, and leave-one-out cross-validation methods. Model performance varied regionally, with stability closely linked to dataset size and composition. Larger combined datasets produced more reliable predictions, while smaller or imbalanced datasets led to higher variance and lower R² values.
Overall, the results emphasize the necessity of mine-specific thermal comfort thresholds and rigorous model validation procedures. By combining physiological heat stress evaluation with predictive temperature modeling, this research provides Luossavaara-Kiirunavaara Aktiebolag with a practical approach for safer, energy-efficient ventilation management in deep mining operations. ...
The heat stress assessment applied Wet Bulb Globe Temperature (WBGT) measurements using both natural wet-bulb and globe temperature sensors, to quantify thermal comfort under varying metabolic rates. Receiver Operating Characteristic (ROC) analysis revealed that the WBGT index exhibited the strongest discrimination between acceptable and unacceptable temperatures under low metabolic rates, while high metabolic rate conditions achieved optimal balance, detecting well acceptable conditions and avoiding marking unacceptable conditions as acceptable. The operational WBGT thresholds were rounded to zero decimal places.
The temperature forecasting component employed regression modeling using surface conditions and production plans, across multiple mine regions, validated through holdout, k-fold, and leave-one-out cross-validation methods. Model performance varied regionally, with stability closely linked to dataset size and composition. Larger combined datasets produced more reliable predictions, while smaller or imbalanced datasets led to higher variance and lower R² values.
Overall, the results emphasize the necessity of mine-specific thermal comfort thresholds and rigorous model validation procedures. By combining physiological heat stress evaluation with predictive temperature modeling, this research provides Luossavaara-Kiirunavaara Aktiebolag with a practical approach for safer, energy-efficient ventilation management in deep mining operations.
WEF Nexus Phalaborwa
Multidisciplinary Project (MDP)
...
This research aims to get a better understanding of the cavern convergence and permeation processes after abandonment. For this, a cavern convergence- and brine permeation model is made. Next to this the potential surface subsidence due to the migration of brine to more permeable layers is investigated. In the convergence model, the cavern is modelled as a stack of cylinders and a Norton-Hoff power law squeeze model is applied to the cavern. The squeeze model consists of 2 parts, a linear and a nonlinear part. The nonlinear part is most significant during the production phase and in these high-pressure deficits the squeeze model is fitted on the available production data. Recent creep tests on salt samples under lower pressure deficits (Bérest et al., 2019) have confirmed that the linear part becomes the most significant in the low-pressure deficit region and have shown that the linear creep is smaller than the linear component of existing squeeze model used for production.
Next to this a sensitivity analysis was done on the convergence model by varying the input variables of the model. The parameters that have a large uncertainty and have a large impact on the model were the linear part of the squeeze model and the width of a slice. To give a range of outputs of the convergence model a P10, P50 and P90 scenario is created where these are percentiles from the input range of the sensitivity analysis. The outcome of the convergence model at a cavern size of 1Mm3 suggests a yearly cavern convergence of around of 5, 103 and 2313 m3/year for the P10, P50 and P90 cases respectively.
Since there is an equilibrium between the cavern convergence and the brine permeation, the output of the convergence model (convergence rate) can be used as an input for the permeation model (permeation rate). For the permeation model, different paraboloid shapes are fitted on each layer and are filled with brine from the converging cavern. Once all the salt layers are filled in, the brine reaches more permeable layers and can freely flow over a larger area. The permeation model is run with the P10, P50 and P90 convergence model scenarios as an input and predicts that the system fills after 26, 588 and 12,363 years respectively. At this point there could be some subsidence because the brine can freely flow over a larger area in the more permeable layers above the Zechstein. This subsidence is 0.016 mm/year for the P50 case after 588 years. A negligible amount compared to unrelated subsidence processes.
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To conclude the cavern convergence rates (even the P10 at 5m3/year) are high compared to the permeability of salt according to the Darcy flow law (around 17 l/year). This could have multiple explanations. From the cavern perspective, the cavern convergence rates could be lower. This could be because of a threshold pressure for salt creep to occur (van Oosterhout et al., 2022) or because of some inaccuracies in the linear component of the squeeze model. Future research could focus on determining the creep rates of salt under low-pressure deficits. From the permeation perspective, other permeation paths next to permeability could be at play as well. In the cavern there could be permeation via anhydrite alterations or via micro fractures created during the production phase of the cavern. It would be good to look at these permeation processes in the future. Next to this the secondary porosity of the salt remains a question as well. A good understanding of this porosity is needed to assess the storage capacity of the overlying salt layers before the brine enters more permeable zones. ...
This research aims to get a better understanding of the cavern convergence and permeation processes after abandonment. For this, a cavern convergence- and brine permeation model is made. Next to this the potential surface subsidence due to the migration of brine to more permeable layers is investigated. In the convergence model, the cavern is modelled as a stack of cylinders and a Norton-Hoff power law squeeze model is applied to the cavern. The squeeze model consists of 2 parts, a linear and a nonlinear part. The nonlinear part is most significant during the production phase and in these high-pressure deficits the squeeze model is fitted on the available production data. Recent creep tests on salt samples under lower pressure deficits (Bérest et al., 2019) have confirmed that the linear part becomes the most significant in the low-pressure deficit region and have shown that the linear creep is smaller than the linear component of existing squeeze model used for production.
Next to this a sensitivity analysis was done on the convergence model by varying the input variables of the model. The parameters that have a large uncertainty and have a large impact on the model were the linear part of the squeeze model and the width of a slice. To give a range of outputs of the convergence model a P10, P50 and P90 scenario is created where these are percentiles from the input range of the sensitivity analysis. The outcome of the convergence model at a cavern size of 1Mm3 suggests a yearly cavern convergence of around of 5, 103 and 2313 m3/year for the P10, P50 and P90 cases respectively.
Since there is an equilibrium between the cavern convergence and the brine permeation, the output of the convergence model (convergence rate) can be used as an input for the permeation model (permeation rate). For the permeation model, different paraboloid shapes are fitted on each layer and are filled with brine from the converging cavern. Once all the salt layers are filled in, the brine reaches more permeable layers and can freely flow over a larger area. The permeation model is run with the P10, P50 and P90 convergence model scenarios as an input and predicts that the system fills after 26, 588 and 12,363 years respectively. At this point there could be some subsidence because the brine can freely flow over a larger area in the more permeable layers above the Zechstein. This subsidence is 0.016 mm/year for the P50 case after 588 years. A negligible amount compared to unrelated subsidence processes.
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To conclude the cavern convergence rates (even the P10 at 5m3/year) are high compared to the permeability of salt according to the Darcy flow law (around 17 l/year). This could have multiple explanations. From the cavern perspective, the cavern convergence rates could be lower. This could be because of a threshold pressure for salt creep to occur (van Oosterhout et al., 2022) or because of some inaccuracies in the linear component of the squeeze model. Future research could focus on determining the creep rates of salt under low-pressure deficits. From the permeation perspective, other permeation paths next to permeability could be at play as well. In the cavern there could be permeation via anhydrite alterations or via micro fractures created during the production phase of the cavern. It would be good to look at these permeation processes in the future. Next to this the secondary porosity of the salt remains a question as well. A good understanding of this porosity is needed to assess the storage capacity of the overlying salt layers before the brine enters more permeable zones.
An Advanced Tool for Evaluating the Probability of Failure of Existing Tailings Dams
A Scientific Approach Supporting the Prioritisation of Mitigating Measures and Minimise Risk within the 'As Low As Reasonably Practicable' Principle
The tool utilises a semi-quantitative approach, combining observation frequency and expert judgment. A baseline PoF for each dam construction method and failure category is established using a database of 450 tailings dam incidents and accidents developed in this study. This baseline PoF is subsequently modified based on site-specific factors influencing failure prevalence. A total of 255 key contributing factors are identified based on a fault tree analysis, the Global Industry Standard on Tailings Management (GISTM), and experts in the field. The factors encompass site conditions, design elements, and the level of practise, which address all major credible failure modes and mechanisms. The factors are linked to the failure categories they influence and assigned relative weights through the analytical hierarchy processing method for each dam construction method and failure category. Subsequently, the weights are multiplied by modifiers to account for the effects of site-specific conditions (favourable: 0.2, neutral: 1, adverse: 5, and unknown: 2). Within the tool, users can choose fulfilment conditions for each factor from drop-down menus and the selected inputs are connected to the modifiers. The adjusted weights are multiplied by the baseline PoF of each failure category, given the dam construction method. The summation of these products yields the total PoF of the investigated dam.
The results provide preliminary insight into factors significantly affecting the total PoF for the dam under investigation, aiding in evaluating whether the PoF reduction justifies costs. It facilitates preliminary, rational prioritisation of mitigation measures in accordance with the ALARP principle, contributing to ongoing efforts to improve tailings dam safety.
To validate the tool’s capabilities, two case studies with available data are analysed: the Aznalcóllar failure to examine the ability to identify high-risk factors and a recently improved dam to evaluate if the mitigation efforts are adequately reflected. The studies demonstrate the tool’s potential but also reveal uncertainties, inaccuracies, and limitations. These stem from discrepancies in the baseline PoF, weightings, modifiers, and unaccounted factors. Therefore, caution is warranted in the tool’s utilisation. Recommendations include various improvements and further verification and validation across a broader range of case studies. Value can be added by incorporating additional components and adapting the tool for new dams. ...
The tool utilises a semi-quantitative approach, combining observation frequency and expert judgment. A baseline PoF for each dam construction method and failure category is established using a database of 450 tailings dam incidents and accidents developed in this study. This baseline PoF is subsequently modified based on site-specific factors influencing failure prevalence. A total of 255 key contributing factors are identified based on a fault tree analysis, the Global Industry Standard on Tailings Management (GISTM), and experts in the field. The factors encompass site conditions, design elements, and the level of practise, which address all major credible failure modes and mechanisms. The factors are linked to the failure categories they influence and assigned relative weights through the analytical hierarchy processing method for each dam construction method and failure category. Subsequently, the weights are multiplied by modifiers to account for the effects of site-specific conditions (favourable: 0.2, neutral: 1, adverse: 5, and unknown: 2). Within the tool, users can choose fulfilment conditions for each factor from drop-down menus and the selected inputs are connected to the modifiers. The adjusted weights are multiplied by the baseline PoF of each failure category, given the dam construction method. The summation of these products yields the total PoF of the investigated dam.
The results provide preliminary insight into factors significantly affecting the total PoF for the dam under investigation, aiding in evaluating whether the PoF reduction justifies costs. It facilitates preliminary, rational prioritisation of mitigation measures in accordance with the ALARP principle, contributing to ongoing efforts to improve tailings dam safety.
To validate the tool’s capabilities, two case studies with available data are analysed: the Aznalcóllar failure to examine the ability to identify high-risk factors and a recently improved dam to evaluate if the mitigation efforts are adequately reflected. The studies demonstrate the tool’s potential but also reveal uncertainties, inaccuracies, and limitations. These stem from discrepancies in the baseline PoF, weightings, modifiers, and unaccounted factors. Therefore, caution is warranted in the tool’s utilisation. Recommendations include various improvements and further verification and validation across a broader range of case studies. Value can be added by incorporating additional components and adapting the tool for new dams.
The following research questions will be answered in this study: What factors contribute to deviations from the predicted performance? What factors are the most significant? What is the effect of automated trucks on shovel productivity? Can a data-driven model be developed to predict the actual productivity of the shovel in the real world?
The underlying causes of reduced shovel production are assessed through a literature review and five case studies. The case studies consisted of three data analytical desk studies, interviews with industry professionals, and a mine visit to north Africa.
The literature review shows that the mining industry uses formulas to determine the theoretical production rates. The factors in the shovel production formula should be predicted with frequency distributions. Also, truck automation will increase trucking hours, impacting shovel productivity through truck exchange time. The first case study shows a sensitivity analysis of the shovel formula. This sensitivity analysis shows that the swell factor, density, bucket fill, efficiency, and cycle time have a more significant impact than truck exchange time, dumping of the first bucket, and the number of cycles. The second case study shows the underperformance of different electric rope shovel models in different mining operations. The third case study compares the theoretical shovel capacity with the total material moved for 16 years. This shovel capacity and total material ratio should be between 1-2.5 for a mining operation to be classified as above-average-in-class. The fourth case study shows the different factors influencing shovel productivity based on the interviewees' responses. The last case study shows the effects of operational decisions on a mining operation. The literature review and case studies are used to develop a flowchart regarding the factors influencing shovel productivity.
This flowchart was used to synthesise the results. The difference between theoretical and real-world production rates can be decreased when the frequency distributions are known for all the shovel production formula factors. This shovel production formula for annual production rate can be divided into three main pillars. These three pillars are the hourly production rate, use of availability, and mechanical availability. The pillars allow OEMs or mining companies to implement the correct improvement measures to improve shovel productivity. However, one solution for every mining operation will be impossible due to the uncertainty in the data and variability of each mining operation.
To conclude, the factors that contribute to deviations from the predicted performance are categorised as uncontrollable (weather and geographical location), direct (density and cycle time), and indirect (fragmentation and face dimensions), which all impact shovel productivity. The most significant factors are not found during the study, but solving underperformance in the direct factors will solve most of the problems. The effect of automated trucks on shovel productivity will result in additional trucking capacity, which will need to be absorbed by the shovel. Lastly, a data-driven model can be developed with access to all the data from a mining operation. However, this data is often not available to an OEM. Therefore, it is not advisable to develop such a model. ...
The following research questions will be answered in this study: What factors contribute to deviations from the predicted performance? What factors are the most significant? What is the effect of automated trucks on shovel productivity? Can a data-driven model be developed to predict the actual productivity of the shovel in the real world?
The underlying causes of reduced shovel production are assessed through a literature review and five case studies. The case studies consisted of three data analytical desk studies, interviews with industry professionals, and a mine visit to north Africa.
The literature review shows that the mining industry uses formulas to determine the theoretical production rates. The factors in the shovel production formula should be predicted with frequency distributions. Also, truck automation will increase trucking hours, impacting shovel productivity through truck exchange time. The first case study shows a sensitivity analysis of the shovel formula. This sensitivity analysis shows that the swell factor, density, bucket fill, efficiency, and cycle time have a more significant impact than truck exchange time, dumping of the first bucket, and the number of cycles. The second case study shows the underperformance of different electric rope shovel models in different mining operations. The third case study compares the theoretical shovel capacity with the total material moved for 16 years. This shovel capacity and total material ratio should be between 1-2.5 for a mining operation to be classified as above-average-in-class. The fourth case study shows the different factors influencing shovel productivity based on the interviewees' responses. The last case study shows the effects of operational decisions on a mining operation. The literature review and case studies are used to develop a flowchart regarding the factors influencing shovel productivity.
This flowchart was used to synthesise the results. The difference between theoretical and real-world production rates can be decreased when the frequency distributions are known for all the shovel production formula factors. This shovel production formula for annual production rate can be divided into three main pillars. These three pillars are the hourly production rate, use of availability, and mechanical availability. The pillars allow OEMs or mining companies to implement the correct improvement measures to improve shovel productivity. However, one solution for every mining operation will be impossible due to the uncertainty in the data and variability of each mining operation.
To conclude, the factors that contribute to deviations from the predicted performance are categorised as uncontrollable (weather and geographical location), direct (density and cycle time), and indirect (fragmentation and face dimensions), which all impact shovel productivity. The most significant factors are not found during the study, but solving underperformance in the direct factors will solve most of the problems. The effect of automated trucks on shovel productivity will result in additional trucking capacity, which will need to be absorbed by the shovel. Lastly, a data-driven model can be developed with access to all the data from a mining operation. However, this data is often not available to an OEM. Therefore, it is not advisable to develop such a model.
The accuracy presented by GroundProbe of _3 mm for periodic measurements is difficult to achieve in an underground environment with mining activity. Especially the deformation of measurement points that are at a more oblique angle to the scanner prove to be difficult to assess. The geological LiDAR data can be used to distinguish different rock types and geological features with limited subjectivity. The transition zones from one rock type to the other become clearly visible from the geological LiDAR data. Additionally, geological features such as joints can be identified when combining LiDAR data with RGB image analysis. The primary promotor of tunnel wall convergence is the hanging wall that pushes down on the foot wall in combination with non-uniform waste rock areas, that are for example split into two sections by a joint. In a tunneling environment where mining activities are conducted, such as the application of shotcrete, scaling, blasting and leveling of the floor, periodic measurements with a LiDAR set-up on a tripod are difficult. One of the main limitations is the absence of stable reference points that the LiDAR scanner uses to determine its XYZ-position. The oblique angle can also be a limiting factor, measurement points closer to the LiDAR scanner provide more reliable results. For continuous measurements however, this proves to be less relevant because the repositioning error can be omitted. The LiDAR scanning technology has the potential to be used as geological mapping tool based on the varying reflectivities of different rock types. By combining LiDAR technology with RGB image analysis, a more thorough understanding of the geological setting can be obtained. By relating this understanding to the quantification of the tunnel wall convergence, this technique can be used to correlate the geology to the movement of the rock mass.
...
The accuracy presented by GroundProbe of _3 mm for periodic measurements is difficult to achieve in an underground environment with mining activity. Especially the deformation of measurement points that are at a more oblique angle to the scanner prove to be difficult to assess. The geological LiDAR data can be used to distinguish different rock types and geological features with limited subjectivity. The transition zones from one rock type to the other become clearly visible from the geological LiDAR data. Additionally, geological features such as joints can be identified when combining LiDAR data with RGB image analysis. The primary promotor of tunnel wall convergence is the hanging wall that pushes down on the foot wall in combination with non-uniform waste rock areas, that are for example split into two sections by a joint. In a tunneling environment where mining activities are conducted, such as the application of shotcrete, scaling, blasting and leveling of the floor, periodic measurements with a LiDAR set-up on a tripod are difficult. One of the main limitations is the absence of stable reference points that the LiDAR scanner uses to determine its XYZ-position. The oblique angle can also be a limiting factor, measurement points closer to the LiDAR scanner provide more reliable results. For continuous measurements however, this proves to be less relevant because the repositioning error can be omitted. The LiDAR scanning technology has the potential to be used as geological mapping tool based on the varying reflectivities of different rock types. By combining LiDAR technology with RGB image analysis, a more thorough understanding of the geological setting can be obtained. By relating this understanding to the quantification of the tunnel wall convergence, this technique can be used to correlate the geology to the movement of the rock mass.
A visual assessment tool for mine development
The development of an evaluation tool to compare the visual impact of opencast mining operations in the pre-feasibility phase
which scenario will be developed further in the feasibility phase. In this context, the visual impact is defined as the perceived change in the landscape as a result of mine development on local communities around the surface mine development. The scenarios are defined as the option of pitshells designed during the pre-feasibility phase of mine development.
The tool makes a distinction between the physical changes in the landscape caused by the surface mining operation and how this physical change is perceived by anyone viewing the operation.
The tool is GIS based and utilizes the free open-source software QGIS to calculate the physical change in the landscape. The tool calculates the vertical and horizontal visibility angle. The visibility angle describes the extent that the change in the landscape takes up in the view of an observer. In addition
to that, the tool calculates the contrast between the changed colour in the landscape and its surroundings, which describes how much the change stands out. It requires two sets of data to work: a digital elevation model of the prospected surface mine pitshell and the surrounding landscape and a
RGB satellite image of the surrounding area. The DEM provides elevation data for every square metre of the landscape to the GIS, while the satellite image provides RGB colour data. All other data can be generated from the previously mentioned data features.
The tool is tested using a case study, in which several distinct pitshell scenarios are compared against one another on their visual impact. The case study is based on the extension of a limestone quarry in
Belgium, which aims to secure reserve for future operations. The area of interest is surrounded by several small to medium size villages, which would be affected visually by the extension. Therefore, a comparison should be made regarding the visual impact of the several pitshell scenarios. The results showed it is possible to determine the visual impact of surface mining operations before the
development has started. On this basis, it is possible to compare different pitshell scenarios and determine which scenario would be least impactful in terms of visual impact on the local community and surrounding landscape. The reliability of the tool can only be assessed theoretically, however a high level of accuracy is achieved by adhering to guiding principles which are set out in this thesis. ...
which scenario will be developed further in the feasibility phase. In this context, the visual impact is defined as the perceived change in the landscape as a result of mine development on local communities around the surface mine development. The scenarios are defined as the option of pitshells designed during the pre-feasibility phase of mine development.
The tool makes a distinction between the physical changes in the landscape caused by the surface mining operation and how this physical change is perceived by anyone viewing the operation.
The tool is GIS based and utilizes the free open-source software QGIS to calculate the physical change in the landscape. The tool calculates the vertical and horizontal visibility angle. The visibility angle describes the extent that the change in the landscape takes up in the view of an observer. In addition
to that, the tool calculates the contrast between the changed colour in the landscape and its surroundings, which describes how much the change stands out. It requires two sets of data to work: a digital elevation model of the prospected surface mine pitshell and the surrounding landscape and a
RGB satellite image of the surrounding area. The DEM provides elevation data for every square metre of the landscape to the GIS, while the satellite image provides RGB colour data. All other data can be generated from the previously mentioned data features.
The tool is tested using a case study, in which several distinct pitshell scenarios are compared against one another on their visual impact. The case study is based on the extension of a limestone quarry in
Belgium, which aims to secure reserve for future operations. The area of interest is surrounded by several small to medium size villages, which would be affected visually by the extension. Therefore, a comparison should be made regarding the visual impact of the several pitshell scenarios. The results showed it is possible to determine the visual impact of surface mining operations before the
development has started. On this basis, it is possible to compare different pitshell scenarios and determine which scenario would be least impactful in terms of visual impact on the local community and surrounding landscape. The reliability of the tool can only be assessed theoretically, however a high level of accuracy is achieved by adhering to guiding principles which are set out in this thesis.