Journal of The South African Institute of Mining and Metallurgy, Aug 1, 2010
In this research, in order to predict the peak particle velocity (PPV) (as vibration indicator) c... more In this research, in order to predict the peak particle velocity (PPV) (as vibration indicator) caused by blasting projects in the excavations of the Karoun III power plant and dam, three techniques including statistical, empirical, and neural network were used and their results were interpreted and compared. First, multivariate regression analysis (MVRA) was used as statistical approach. Next, PPV was predicted using some widely used empirical models. Lastly, an artificial neural network was used. In the ANN model, maximum charge per delay, total charge per round, distance from blast site, direction of firing, blasthole length, number of blastholes, total delay in milliseconds, number of delay intervals, and average specific charge were taken into consideration as input parameters and consequently the PPV as output parameter. The results of the techniques were interpreted from two points of view. Firstly, the correlation between the observed data and predicted ones, secondly the total error between observed data and predicted ones. The MVRA had a satisfactory correlation but its error of estimation was comparatively very high. The empirical model had reliable correlation and a small error of estimation; in total the results of empirical method were more reliable than those of MVRA. Generally, the ANN approach showed very high correlation and a very small error. The results of this research indicated that the ANN model is the best predicting model for PPV in comparison with other approaches.
International journal of performability engineering, Sep 1, 2013
In this paper the Kamat-Riley (K-R) event-based Monte Carlo simulation method was used for reliab... more In this paper the Kamat-Riley (K-R) event-based Monte Carlo simulation method was used for reliability analysis of longwall shearer machine. Shearer machine consists of six subsystems; water, haulage, electrical, hydraulic, cutting arms and cable systems in a series network configuration. A shearer in the Tabas coal mine was selected as case study and its all failure data were collected and used for reliability analysis of subsystems. With negligible assumption of time to repair, a flowchart was built for programming the simulation process. The Matlab mathematical programming software was used for reliability simulation process. Finally the reliability plot of longwall shearer machine was achieved and upper and lower bound reliability were calculated. The results illustrate that the reliability of shearer machine reduces to zero in a period of 100h. There is a 50% chance that the shearer will not fail for the first 12h of operation.
In recent years, using of the resilience concept has been increased in order to evaluate the resp... more In recent years, using of the resilience concept has been increased in order to evaluate the response of systems against the failures. Resilience depicts the system ability to return to its normal operational status after failure accruing. According to the literature survey, there are various studies, which have been done in the field of engineering and non-engineering systems, and there is no study about applying resilience concept in the field of mining industry. In this paper, at first, resilience concept has been introduced and then the resilience of the mining fleet of Sungun copper mine has been estimated. Systems performance indicators include reliability; maintainability and supportability have been used in order to resilience estimation. The results showed that the resilience of the entire system for one hour of its function is equal to 83.1% and this value decreases to 37.1% after 10 hours. This means if there is a failure in the system; it will have 83.1% and 37.1% probab...
The spare parts provision is a complex process, which needs a precise model to analyze all factor... more The spare parts provision is a complex process, which needs a precise model to analyze all factors with their possible effects on the required number of spare parts. The required number of spare parts for an item can be calculated based on its reliability performance. Various factors can influence the reliability characteristics of an item, including operational environment, maintenance policy, operator skill, etc. Thus, the statistical approach of choice for reliability performance analysis should assess the effects of these factors. In this study, Reliability Regression Models (RRM) with risk factors have been used to estimate the required number of crane shovels in the Jajarm bauxite mine. For this, at the first stage, all risk factors and failure data have been collected. The required data were extracted from a database of 15 months, which were collected from different sources, such as daily reports, workshop reports, weather reports, meetings, and direct observations in the format of time to failures and risk factors. After that, the potential distribution has been nominated to model the reliability of the crane shovels bucket teeth. The Akaike information criterion and Bayesian information criterion have been used to identify the best fit distribution. The candidate distribution with the smallest AIC and BIC value is the best distribution that fits the data. After that, the required number of spare parts is calculated. The results show 18% differences between the forecasted number of required spare parts when considering and non-considering the risk factors.
The use of elastomer additives to solve the problems in oil well cementing has been investigated ... more The use of elastomer additives to solve the problems in oil well cementing has been investigated in recent years by several research groups in the petroleum industry. This study includes the laboratory examination of the effect of elastomer additives on the physical properties of heavy‐ weight oil well cement. In the research process, a candidate well is selected and the properties of the cement slurry used in a problematic section of the well are tested in the laboratory. Then, elastomer additives are added as an elastic agent and the improvements in the cement slurry and stone properties are studied. This article discusses the problems associated with the conventional heavy‐weight oil well cement used in the candidate well and reports the detail of the improvements in cement properties obtained by adding an elastomer additive to the cement slurry formulation as an elastic agent. These properties include cement slurry rheological properties, free water, fluid loss, thickening time,...
In the context of open-pit mine planning, uncertainties including commodity price would significa... more In the context of open-pit mine planning, uncertainties including commodity price would significantly affect the technical and financial aspects of mining projects. A mine planning that takes place regardless of the uncertainty in price just develops an optimized plan at the starting time of the mining operation. Given the price change over the life of mine, which is quite certain, optimality of the proposed plan will be eliminated. This paper presents a risk-averse decision-making tool to help mine planners in mining activities under price uncertainty. The objective is to propose mine planning in a way that a target Net Present Value (NPV) is guaranteed. In order to reach this goal, Information Gap Decision Theory (IGDT) is developed to hedge the mining project against the risk imposed by the information gap between the forecasted and actual price. The proposed approach is of low sensitivity to the price change over the life of mine, and can use the estimated prices with uncertaint...
The drilling and blasting method is the first choice for rock breakage in surface or underground ... more The drilling and blasting method is the first choice for rock breakage in surface or underground mines due to its high flexibility against variations and low investment costs. However, any method has its own advantages and disadvantages. The flyrock phenomenon is one of the drilling and blasting disadvantages that the mining engineers have always been faced with in the surface mine blasting operations. Flyrock may lead to fatality and destroy mine equipment and structures, and so its risk assessment is very essential. For a flyrock risk assessment, the causing events that lead to flyrock along with their probabilities and severities should be identified. For this aim, a combination of the fuzzy fault tree analysis and multi-criteria decision-making methods are used. Based on the results obtained, the relevant causing events of flyrock in surface mines can be categorized into three major groups: design error, human error, and natural error. Finally, using the obtained probabilities a...
In mining projects, all uncertainties associated with a project must be considered to determine t... more In mining projects, all uncertainties associated with a project must be considered to determine the feasibility study. Grade uncertainty is one of the major components of technical uncertainty that affects the variability of the project. Geostatistical simulation, as a reliable approach, is the most widely used method to quantify risk analysis to overcome the drawbacks of the estimation methods used for an entire ore body. In this work, all the algorithms developed by numerous researchers for optimization of the underground stope layout are reviewed. After that, a computer program called stope layout optimizer 3D is developed based on a previously proposed heuristic algorithm in order to incorporate the influence of grade variability in the final stope layout. Utilizing the sequential gaussian conditional simulation, 50 simulations and a kriging model are constructed for an underground copper vein deposit situated in the southwest of Iran, and the final stope layout is carried out s...
An oil and gas well cementing in Gachsaran formation, where sustained annular pressure has been r... more An oil and gas well cementing in Gachsaran formation, where sustained annular pressure has been reported in many wells, presents a big challenge in Maroon field. The main challenges are preventing gas migration and achieving zonal isolation using a competent cement sealant system which is able to withstand downhole stresses and high temperatures during production cycles. Unlike conventional cement systems, properties, such as, high Poisson’s ratio and low Young’s modulus compared to that of the rock were optimized in the new system to achieve mechanical resistance and durability. The use of elastic-expandable additives to solve problems in oil well cementing has been investigated in recent years by several research groups in the petroleum industry. This study includes the laboratory examination of the effect of an elastic-expandable additive on the physical properties of a new cement sealant system. In the research process, a candidate well was selected and the properties of the use...
Optimization of the exploitation operation is one of the most important issues facing the mining ... more Optimization of the exploitation operation is one of the most important issues facing the mining engineers. Since several technical and economic parameters depend on the cut-off grade, optimization of this parameter is of particular importance. The aim of this optimization is to maximize the net present value (NPV). Since the objective function of this problem is non-linear, three methods can be used to solve it: analytical, numerical, and meta-heuristic. In this study, the Golden Section Search (GSS) method and the Imperialist Competitive Algorithm (ICA) are used to optimize the cut-off grade in mine No. 1 of the Golgohar iron mine. Then the results obtained are compared. Consecuently, the optimum cut-off grades using both methods are calculated between 40.5% to 47.5%. The NPVs obtained using the GSS method and ICA were 18487 and 18142 billion Rials, respectively. Thus the value for GSS was higher. The annual number of iterations in the GSS method was equal to 18, and that for ICA ...
International. Journal of Mining & Geo-Engineering, 2016
Tires represent a critical spare part in mines. There is a shortage of medium and large tires. In... more Tires represent a critical spare part in mines. There is a shortage of medium and large tires. In addition, with increased mining activities and the creation of new mines, the demand for tires has increased significantly. Thus, it is particularly important for mining engineers to identify tire characteristics and correctly manage the spare part inventory. Spare parts management is critical from an operational perspective, especially in asset intensive industries, such as mining, as well as in organizations owning and operating costly assets. A knowledge of the tires’ behavior (historical data) must be considered together with the operating environment conditions (covariates). This study uses multiple regression analysis based on Cox’s regression model to incorporate machine operating environment information into systems reliability analysis to estimate spare parts. It considers a proportional hazard model and a stratified Cox regression model for time independent and dependent covar...
Due to uncertain nature of grade in ore deposits, considering uncertainty is inevitable in geolog... more Due to uncertain nature of grade in ore deposits, considering uncertainty is inevitable in geological modelling of resources and mine planning. In other words, uncertainty in grade of mineralized materials, is one of the most significant parameters need attention in mine planning. In this paper, a comparative procedure utilizing Sequential Gaussian Simulation (SGS) and traditional Ordinary Kriging (OK) was applied in an iron ore mine, and the influence of ore grade uncertainty in mine planning was investigated. It was observed that grade distribution, resulted from the SGS is almost identical to that of the real exploration data as compared to the OK method. Also it is emphasized that uncertainties including ore grade of deposit would significantly affect the technical and financial aspects of plans. Comparison shows that the simulation-based ultimate pits exhibits less risk in deviating from quantity and quality targets than traditional approach based on a single orebody model obta...
Determining the limit of underground mining and stope layout is one of the most important points ... more Determining the limit of underground mining and stope layout is one of the most important points in underground mining and production planning. Numerous algorithms have been offered to address the stope layout optimization problem both in two-dimensional and three-dimensional space based on economic value. In this paper, a new heuristic algorithm with different strategies was developed to generate optimal and sub-optimal underground stope layouts. In this algorithm, all possible stopes were created based on an entirely economic block model considering stope dimensions in the three-dimensional space. Afterward, the algorithm generated a family of non-overlapping stopes over all possible stopes and selected the highest economic value as the final solution. Also, a user-friendly computer program named Stope Layout Optimizer (SLO3D) was designed in C# object-oriented program, and two separate examples were set for a better understanding of the algorithm. The application of the proposed...
Mining can become more sustainable by developing and integrating economic, environmental, and soc... more Mining can become more sustainable by developing and integrating economic, environmental, and social components. Among the mining industries, coal mining requires paying a serious attention to the aspects of sustainable development. Therefore, in this work, we investigate the impacting factors involved in the sustainable development of underground coal mining from the structural viewpoint. For this purpose, the decision-making trial and evaluation laboratory (DEMATEL) technique, which is a graph-based method, is utilized. To do so, at first, twenty effective factors are determined for three components. Then the hierarchical structure and the systematic approach are used to determine the total exerted influence or total received influence of the components. The results obtained show that the environmental and social components are the most important, and the economic components are the least important among them.
International Journal of System Assurance Engineering and Management, 2021
Resilience is about the ability of the system to resist, adapt to, and expeditiously recover from... more Resilience is about the ability of the system to resist, adapt to, and expeditiously recover from a disruptive event. The first and maybe the crucial step of resilience management is known as resilience analysis. However, there are many obstacles in front of the analyzers to analyze the resilience of systems. One of these obstacles is precise resilience data accessibility. Conventional resilience analysis methods frequently only consider historical data (e.g., time to repair and time to failure). However, to analyze the system resilience more precisely, the effect of the risk factors, which are known as observed and unobserved covariates, should be considered in the collected resilience database. These covariates will lead to the observed and unobserved heterogeneities among the collected database. Ignoring the effect of covariate may lead to erroneous conclusion about the resilience level of the system. Since it is hard to find a homogeneous operating condition, in this study, a formulation is proposed to model the effect of these covariates on complex system resilience. Finally, it is applied to a transportation system of a surface mine.
Spare-part management has a significant effect on the productivity of mining equipment. The requi... more Spare-part management has a significant effect on the productivity of mining equipment. The required number of spare parts can be estimated using failure and repair data collected under the name of reliability data. In the mining industry, failure and repair times are decided by the operational environment, rock properties, and the technical and functional behavior of the system. These conditions are heterogeneous and may change significantly from time to time. Such heterogeneity can change equipment’s reliability performance and, consequently, the required number of spare parts. Hence, it is necessary for effective spare-part planning to check the heterogeneity among the reliability data. After that, if needed, such heterogeneity should be modeled using an adequate statistical model. Heterogeneity can be categorized into observed and unobserved caused by risk factors. Most spare-part estimation studies ignore the effect of heterogeneity, which can lead to unrealistic estimations. I...
Risk management is a fundamental approach to improving critical infrastructure systems’ safety ag... more Risk management is a fundamental approach to improving critical infrastructure systems’ safety against disruptive events. This approach focuses on designing robust critical infrastructure systems (CISs) that could resist disruptive events by minimizing the possible events’ probability and consequences using preventive and protective programs. However, recent disasters like COVID-19 have shown that most CISs cannot stand against all potential disruptions. Recently there is a transition from robust design to resilience design of CISs, increasing the focus on preparedness, response, and recovery. Resilient CISs withstand most of the internal and external shocks, and if they fail, they can bounce back to the operational phase as soon as possible using minimum resources. Moreover, in resilient CISs, early warning enables managers to get timely information about the proximity and development of distributions. An understanding of the concept of resilience, its influential factors, and avai...
It is an essential task to estimate the remaining useful life (RUL) of machinery in the mining se... more It is an essential task to estimate the remaining useful life (RUL) of machinery in the mining sector aimed at ensuring the production and the customer's satisfaction. In this study, a conceptual framework was used to determine the RUL under the reliability analysis in a frailty model. The proposed framework was implemented on a Komatsu PC-1250 excavator from the Sungun copper mine. Also, the Weibull-frailty model was selected to describe the failure behavior and compare it with the classical-exponential model. The frailty model was also used to evaluate the impact of unobserved environmental conditions on the RUL values. Both applied models were fitted to the obtained data from 80 operational hours of the Komatsu PC-1250 excavator. Plotting the results from the reliability analysis of two models demonstrated that the mine system with the frailty model performs better than the classical model before reaching the reliability of 80%. Besides, the frailty model shows a coherent with the operational time of the excavator, while the classical model demonstrates a sinusoid variation. The obtained results may be used for the development of maintenance, preventive repairs planning, and the spare parts replacement intervals.
Proceedings of the First International Conference on Underground Mining Technology, 2017
Stope layout optimisation improves the economic potential of any underground mining operation and... more Stope layout optimisation improves the economic potential of any underground mining operation and maximises profitability over mine life. A limited number of algorithms are available for underground stope layout optimisation. However, the available algorithms do not guarantee an optimal solution in three-dimensional space. In this paper, existing algorithms for underground stope layout optimisation were reviewed and a computer program called Stope Layout Optimizer 3D (SLO3D) was developed as a C# user interface to implement a heuristic algorithm for optimisation of underground stope boundaries. SLO3D provides an interactive environment to define and edit important parameters related to the stope layout optimisation, including block model parameters, stope geometry, and economic factors. Finally, an example is presented to demonstrate the implementation of algorithm with different stope limits and selection type strategies.
According to underground construction development and its high cost process, an accurate assessme... more According to underground construction development and its high cost process, an accurate assessment and prevention tions. In this paper, the aim is to develop a new soft computing model to evaluate tunnel support systems. Firstly, a nu-2D software to excavate a sequence model and support system installation. The design loads including the axial force, moment, and shear force were calculated for some important points of the support system including the crown, the middle of the bottom and the side walls. bee colony as a meta-heuristic algorithm and a k-means algorithm using Matlab software. The results of clustering were compared by the safety factor of the support system. The results indicated that the section points that are in cluster 1 have the initial assessment of tunnel support systems based on the axial force, moment, and shear force.
Journal of The South African Institute of Mining and Metallurgy, Aug 1, 2010
In this research, in order to predict the peak particle velocity (PPV) (as vibration indicator) c... more In this research, in order to predict the peak particle velocity (PPV) (as vibration indicator) caused by blasting projects in the excavations of the Karoun III power plant and dam, three techniques including statistical, empirical, and neural network were used and their results were interpreted and compared. First, multivariate regression analysis (MVRA) was used as statistical approach. Next, PPV was predicted using some widely used empirical models. Lastly, an artificial neural network was used. In the ANN model, maximum charge per delay, total charge per round, distance from blast site, direction of firing, blasthole length, number of blastholes, total delay in milliseconds, number of delay intervals, and average specific charge were taken into consideration as input parameters and consequently the PPV as output parameter. The results of the techniques were interpreted from two points of view. Firstly, the correlation between the observed data and predicted ones, secondly the total error between observed data and predicted ones. The MVRA had a satisfactory correlation but its error of estimation was comparatively very high. The empirical model had reliable correlation and a small error of estimation; in total the results of empirical method were more reliable than those of MVRA. Generally, the ANN approach showed very high correlation and a very small error. The results of this research indicated that the ANN model is the best predicting model for PPV in comparison with other approaches.
International journal of performability engineering, Sep 1, 2013
In this paper the Kamat-Riley (K-R) event-based Monte Carlo simulation method was used for reliab... more In this paper the Kamat-Riley (K-R) event-based Monte Carlo simulation method was used for reliability analysis of longwall shearer machine. Shearer machine consists of six subsystems; water, haulage, electrical, hydraulic, cutting arms and cable systems in a series network configuration. A shearer in the Tabas coal mine was selected as case study and its all failure data were collected and used for reliability analysis of subsystems. With negligible assumption of time to repair, a flowchart was built for programming the simulation process. The Matlab mathematical programming software was used for reliability simulation process. Finally the reliability plot of longwall shearer machine was achieved and upper and lower bound reliability were calculated. The results illustrate that the reliability of shearer machine reduces to zero in a period of 100h. There is a 50% chance that the shearer will not fail for the first 12h of operation.
In recent years, using of the resilience concept has been increased in order to evaluate the resp... more In recent years, using of the resilience concept has been increased in order to evaluate the response of systems against the failures. Resilience depicts the system ability to return to its normal operational status after failure accruing. According to the literature survey, there are various studies, which have been done in the field of engineering and non-engineering systems, and there is no study about applying resilience concept in the field of mining industry. In this paper, at first, resilience concept has been introduced and then the resilience of the mining fleet of Sungun copper mine has been estimated. Systems performance indicators include reliability; maintainability and supportability have been used in order to resilience estimation. The results showed that the resilience of the entire system for one hour of its function is equal to 83.1% and this value decreases to 37.1% after 10 hours. This means if there is a failure in the system; it will have 83.1% and 37.1% probab...
The spare parts provision is a complex process, which needs a precise model to analyze all factor... more The spare parts provision is a complex process, which needs a precise model to analyze all factors with their possible effects on the required number of spare parts. The required number of spare parts for an item can be calculated based on its reliability performance. Various factors can influence the reliability characteristics of an item, including operational environment, maintenance policy, operator skill, etc. Thus, the statistical approach of choice for reliability performance analysis should assess the effects of these factors. In this study, Reliability Regression Models (RRM) with risk factors have been used to estimate the required number of crane shovels in the Jajarm bauxite mine. For this, at the first stage, all risk factors and failure data have been collected. The required data were extracted from a database of 15 months, which were collected from different sources, such as daily reports, workshop reports, weather reports, meetings, and direct observations in the format of time to failures and risk factors. After that, the potential distribution has been nominated to model the reliability of the crane shovels bucket teeth. The Akaike information criterion and Bayesian information criterion have been used to identify the best fit distribution. The candidate distribution with the smallest AIC and BIC value is the best distribution that fits the data. After that, the required number of spare parts is calculated. The results show 18% differences between the forecasted number of required spare parts when considering and non-considering the risk factors.
The use of elastomer additives to solve the problems in oil well cementing has been investigated ... more The use of elastomer additives to solve the problems in oil well cementing has been investigated in recent years by several research groups in the petroleum industry. This study includes the laboratory examination of the effect of elastomer additives on the physical properties of heavy‐ weight oil well cement. In the research process, a candidate well is selected and the properties of the cement slurry used in a problematic section of the well are tested in the laboratory. Then, elastomer additives are added as an elastic agent and the improvements in the cement slurry and stone properties are studied. This article discusses the problems associated with the conventional heavy‐weight oil well cement used in the candidate well and reports the detail of the improvements in cement properties obtained by adding an elastomer additive to the cement slurry formulation as an elastic agent. These properties include cement slurry rheological properties, free water, fluid loss, thickening time,...
In the context of open-pit mine planning, uncertainties including commodity price would significa... more In the context of open-pit mine planning, uncertainties including commodity price would significantly affect the technical and financial aspects of mining projects. A mine planning that takes place regardless of the uncertainty in price just develops an optimized plan at the starting time of the mining operation. Given the price change over the life of mine, which is quite certain, optimality of the proposed plan will be eliminated. This paper presents a risk-averse decision-making tool to help mine planners in mining activities under price uncertainty. The objective is to propose mine planning in a way that a target Net Present Value (NPV) is guaranteed. In order to reach this goal, Information Gap Decision Theory (IGDT) is developed to hedge the mining project against the risk imposed by the information gap between the forecasted and actual price. The proposed approach is of low sensitivity to the price change over the life of mine, and can use the estimated prices with uncertaint...
The drilling and blasting method is the first choice for rock breakage in surface or underground ... more The drilling and blasting method is the first choice for rock breakage in surface or underground mines due to its high flexibility against variations and low investment costs. However, any method has its own advantages and disadvantages. The flyrock phenomenon is one of the drilling and blasting disadvantages that the mining engineers have always been faced with in the surface mine blasting operations. Flyrock may lead to fatality and destroy mine equipment and structures, and so its risk assessment is very essential. For a flyrock risk assessment, the causing events that lead to flyrock along with their probabilities and severities should be identified. For this aim, a combination of the fuzzy fault tree analysis and multi-criteria decision-making methods are used. Based on the results obtained, the relevant causing events of flyrock in surface mines can be categorized into three major groups: design error, human error, and natural error. Finally, using the obtained probabilities a...
In mining projects, all uncertainties associated with a project must be considered to determine t... more In mining projects, all uncertainties associated with a project must be considered to determine the feasibility study. Grade uncertainty is one of the major components of technical uncertainty that affects the variability of the project. Geostatistical simulation, as a reliable approach, is the most widely used method to quantify risk analysis to overcome the drawbacks of the estimation methods used for an entire ore body. In this work, all the algorithms developed by numerous researchers for optimization of the underground stope layout are reviewed. After that, a computer program called stope layout optimizer 3D is developed based on a previously proposed heuristic algorithm in order to incorporate the influence of grade variability in the final stope layout. Utilizing the sequential gaussian conditional simulation, 50 simulations and a kriging model are constructed for an underground copper vein deposit situated in the southwest of Iran, and the final stope layout is carried out s...
An oil and gas well cementing in Gachsaran formation, where sustained annular pressure has been r... more An oil and gas well cementing in Gachsaran formation, where sustained annular pressure has been reported in many wells, presents a big challenge in Maroon field. The main challenges are preventing gas migration and achieving zonal isolation using a competent cement sealant system which is able to withstand downhole stresses and high temperatures during production cycles. Unlike conventional cement systems, properties, such as, high Poisson’s ratio and low Young’s modulus compared to that of the rock were optimized in the new system to achieve mechanical resistance and durability. The use of elastic-expandable additives to solve problems in oil well cementing has been investigated in recent years by several research groups in the petroleum industry. This study includes the laboratory examination of the effect of an elastic-expandable additive on the physical properties of a new cement sealant system. In the research process, a candidate well was selected and the properties of the use...
Optimization of the exploitation operation is one of the most important issues facing the mining ... more Optimization of the exploitation operation is one of the most important issues facing the mining engineers. Since several technical and economic parameters depend on the cut-off grade, optimization of this parameter is of particular importance. The aim of this optimization is to maximize the net present value (NPV). Since the objective function of this problem is non-linear, three methods can be used to solve it: analytical, numerical, and meta-heuristic. In this study, the Golden Section Search (GSS) method and the Imperialist Competitive Algorithm (ICA) are used to optimize the cut-off grade in mine No. 1 of the Golgohar iron mine. Then the results obtained are compared. Consecuently, the optimum cut-off grades using both methods are calculated between 40.5% to 47.5%. The NPVs obtained using the GSS method and ICA were 18487 and 18142 billion Rials, respectively. Thus the value for GSS was higher. The annual number of iterations in the GSS method was equal to 18, and that for ICA ...
International. Journal of Mining & Geo-Engineering, 2016
Tires represent a critical spare part in mines. There is a shortage of medium and large tires. In... more Tires represent a critical spare part in mines. There is a shortage of medium and large tires. In addition, with increased mining activities and the creation of new mines, the demand for tires has increased significantly. Thus, it is particularly important for mining engineers to identify tire characteristics and correctly manage the spare part inventory. Spare parts management is critical from an operational perspective, especially in asset intensive industries, such as mining, as well as in organizations owning and operating costly assets. A knowledge of the tires’ behavior (historical data) must be considered together with the operating environment conditions (covariates). This study uses multiple regression analysis based on Cox’s regression model to incorporate machine operating environment information into systems reliability analysis to estimate spare parts. It considers a proportional hazard model and a stratified Cox regression model for time independent and dependent covar...
Due to uncertain nature of grade in ore deposits, considering uncertainty is inevitable in geolog... more Due to uncertain nature of grade in ore deposits, considering uncertainty is inevitable in geological modelling of resources and mine planning. In other words, uncertainty in grade of mineralized materials, is one of the most significant parameters need attention in mine planning. In this paper, a comparative procedure utilizing Sequential Gaussian Simulation (SGS) and traditional Ordinary Kriging (OK) was applied in an iron ore mine, and the influence of ore grade uncertainty in mine planning was investigated. It was observed that grade distribution, resulted from the SGS is almost identical to that of the real exploration data as compared to the OK method. Also it is emphasized that uncertainties including ore grade of deposit would significantly affect the technical and financial aspects of plans. Comparison shows that the simulation-based ultimate pits exhibits less risk in deviating from quantity and quality targets than traditional approach based on a single orebody model obta...
Determining the limit of underground mining and stope layout is one of the most important points ... more Determining the limit of underground mining and stope layout is one of the most important points in underground mining and production planning. Numerous algorithms have been offered to address the stope layout optimization problem both in two-dimensional and three-dimensional space based on economic value. In this paper, a new heuristic algorithm with different strategies was developed to generate optimal and sub-optimal underground stope layouts. In this algorithm, all possible stopes were created based on an entirely economic block model considering stope dimensions in the three-dimensional space. Afterward, the algorithm generated a family of non-overlapping stopes over all possible stopes and selected the highest economic value as the final solution. Also, a user-friendly computer program named Stope Layout Optimizer (SLO3D) was designed in C# object-oriented program, and two separate examples were set for a better understanding of the algorithm. The application of the proposed...
Mining can become more sustainable by developing and integrating economic, environmental, and soc... more Mining can become more sustainable by developing and integrating economic, environmental, and social components. Among the mining industries, coal mining requires paying a serious attention to the aspects of sustainable development. Therefore, in this work, we investigate the impacting factors involved in the sustainable development of underground coal mining from the structural viewpoint. For this purpose, the decision-making trial and evaluation laboratory (DEMATEL) technique, which is a graph-based method, is utilized. To do so, at first, twenty effective factors are determined for three components. Then the hierarchical structure and the systematic approach are used to determine the total exerted influence or total received influence of the components. The results obtained show that the environmental and social components are the most important, and the economic components are the least important among them.
International Journal of System Assurance Engineering and Management, 2021
Resilience is about the ability of the system to resist, adapt to, and expeditiously recover from... more Resilience is about the ability of the system to resist, adapt to, and expeditiously recover from a disruptive event. The first and maybe the crucial step of resilience management is known as resilience analysis. However, there are many obstacles in front of the analyzers to analyze the resilience of systems. One of these obstacles is precise resilience data accessibility. Conventional resilience analysis methods frequently only consider historical data (e.g., time to repair and time to failure). However, to analyze the system resilience more precisely, the effect of the risk factors, which are known as observed and unobserved covariates, should be considered in the collected resilience database. These covariates will lead to the observed and unobserved heterogeneities among the collected database. Ignoring the effect of covariate may lead to erroneous conclusion about the resilience level of the system. Since it is hard to find a homogeneous operating condition, in this study, a formulation is proposed to model the effect of these covariates on complex system resilience. Finally, it is applied to a transportation system of a surface mine.
Spare-part management has a significant effect on the productivity of mining equipment. The requi... more Spare-part management has a significant effect on the productivity of mining equipment. The required number of spare parts can be estimated using failure and repair data collected under the name of reliability data. In the mining industry, failure and repair times are decided by the operational environment, rock properties, and the technical and functional behavior of the system. These conditions are heterogeneous and may change significantly from time to time. Such heterogeneity can change equipment’s reliability performance and, consequently, the required number of spare parts. Hence, it is necessary for effective spare-part planning to check the heterogeneity among the reliability data. After that, if needed, such heterogeneity should be modeled using an adequate statistical model. Heterogeneity can be categorized into observed and unobserved caused by risk factors. Most spare-part estimation studies ignore the effect of heterogeneity, which can lead to unrealistic estimations. I...
Risk management is a fundamental approach to improving critical infrastructure systems’ safety ag... more Risk management is a fundamental approach to improving critical infrastructure systems’ safety against disruptive events. This approach focuses on designing robust critical infrastructure systems (CISs) that could resist disruptive events by minimizing the possible events’ probability and consequences using preventive and protective programs. However, recent disasters like COVID-19 have shown that most CISs cannot stand against all potential disruptions. Recently there is a transition from robust design to resilience design of CISs, increasing the focus on preparedness, response, and recovery. Resilient CISs withstand most of the internal and external shocks, and if they fail, they can bounce back to the operational phase as soon as possible using minimum resources. Moreover, in resilient CISs, early warning enables managers to get timely information about the proximity and development of distributions. An understanding of the concept of resilience, its influential factors, and avai...
It is an essential task to estimate the remaining useful life (RUL) of machinery in the mining se... more It is an essential task to estimate the remaining useful life (RUL) of machinery in the mining sector aimed at ensuring the production and the customer's satisfaction. In this study, a conceptual framework was used to determine the RUL under the reliability analysis in a frailty model. The proposed framework was implemented on a Komatsu PC-1250 excavator from the Sungun copper mine. Also, the Weibull-frailty model was selected to describe the failure behavior and compare it with the classical-exponential model. The frailty model was also used to evaluate the impact of unobserved environmental conditions on the RUL values. Both applied models were fitted to the obtained data from 80 operational hours of the Komatsu PC-1250 excavator. Plotting the results from the reliability analysis of two models demonstrated that the mine system with the frailty model performs better than the classical model before reaching the reliability of 80%. Besides, the frailty model shows a coherent with the operational time of the excavator, while the classical model demonstrates a sinusoid variation. The obtained results may be used for the development of maintenance, preventive repairs planning, and the spare parts replacement intervals.
Proceedings of the First International Conference on Underground Mining Technology, 2017
Stope layout optimisation improves the economic potential of any underground mining operation and... more Stope layout optimisation improves the economic potential of any underground mining operation and maximises profitability over mine life. A limited number of algorithms are available for underground stope layout optimisation. However, the available algorithms do not guarantee an optimal solution in three-dimensional space. In this paper, existing algorithms for underground stope layout optimisation were reviewed and a computer program called Stope Layout Optimizer 3D (SLO3D) was developed as a C# user interface to implement a heuristic algorithm for optimisation of underground stope boundaries. SLO3D provides an interactive environment to define and edit important parameters related to the stope layout optimisation, including block model parameters, stope geometry, and economic factors. Finally, an example is presented to demonstrate the implementation of algorithm with different stope limits and selection type strategies.
According to underground construction development and its high cost process, an accurate assessme... more According to underground construction development and its high cost process, an accurate assessment and prevention tions. In this paper, the aim is to develop a new soft computing model to evaluate tunnel support systems. Firstly, a nu-2D software to excavate a sequence model and support system installation. The design loads including the axial force, moment, and shear force were calculated for some important points of the support system including the crown, the middle of the bottom and the side walls. bee colony as a meta-heuristic algorithm and a k-means algorithm using Matlab software. The results of clustering were compared by the safety factor of the support system. The results indicated that the section points that are in cluster 1 have the initial assessment of tunnel support systems based on the axial force, moment, and shear force.
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Papers by mohammad ataei