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Papers by navid Khajehzadeh

Research paper thumbnail of Analytical Techniques for Online Mineral Identification

Research paper thumbnail of Rapid mineral detection using elemental Laser-Induced Breakdown Spectroscopy

The exploration and mining activities are strongly increasing both in Finland and internationally... more The exploration and mining activities are strongly increasing both in Finland and internationally. During the exploration, rapid and on-line scanning of rock and drillcore samples gives fast results that can be used to ease the decision-making process for geologists and to guide the future drilling activities without delays. Traditional mineral exploration activities are moderately slow. Recently, faster and more efficient ore characterization by combining various laser-based and contactless measurement techniques have drawn tremendous attention in research. This combination will enable mineralogical analysis of the drillcore and recyclable materials in a fast, cost-effective and objective manner and provides complementary and partly substitutive information for the laboratory analyses. However, complexity of different measurement setups and the difference between the sources of light make it non-economic and complicated for industry. Laser-Induced Breakdown Spectroscopy is a very s...

Research paper thumbnail of On-stream mineral identification of tailing slurries of an iron ore concentrator using data fusion of LIBS, reflectance spectroscopy and XRF measurement techniques

Minerals Engineering, 2017

Abstract This article is extension of the earlier work (Khajehzadeh et al., 2016), where quantita... more Abstract This article is extension of the earlier work (Khajehzadeh et al., 2016), where quantitative mineralogical information of slurry samples was achieved using an on-stream LIBS analyzer. Despite the great advances in the analytical methods and laser-based measurement techniques, the industrial developers are still demanding novel ideas enabling differentiation between minerals having similar elemental contents such as hematite and magnetite or silicon-bearing minerals such as quartz and other mixed silica minerals since they have different flotation properties. The available analytical techniques for LIBS spectral analysis (including the earlier work of this research) could not distinguish between such minerals with identical elemental contents. This work at first presents data fusion of LIBS and reflectance spectroscopy and then discusses the data fusion of reflectance spectroscopy and X-ray fluorescence (XRF) measurement techniques operating on the same slurry samples. The results will show that such data integrations enable on-stream and quantitative identification of slurry mineral contents specially for hematite, magnetite, quartz and ferrorichterite which are important minerals in iron ore beneficiation.

Research paper thumbnail of On-stream and quantitative mineral identification of tailing slurries using LIBS technique

Minerals Engineering, 2016

Abstract Mineral flotation processes are controlled by monitoring the grade of the present minera... more Abstract Mineral flotation processes are controlled by monitoring the grade of the present minerals. The performance of flotation can be greatly optimized by online assaying of the minerals in the slurry flows. However, online and quantitative mineral identification of the slurries is challenging. The major focus of this research is about measuring mineral contents from the elemental concentrations acquired by an on-stream slurry analyzer operating based on laser-induced breakdown spectroscopy (LIBS). A multivariate statistical method called partial least squares regression is employed to perform the elemental to mineral conversion. In this work, the samples under study come from an iron concentrator where knowledge about the grade of silicates and iron-oxides are important for controlling the flotation plant. In total, the concentrations of six out of ten minerals were successfully estimated. This accomplishment provides quantitative knowledge about mineral contents from the nearly real-time assay data without any modification on the measurement setup or further instrumentation. This can lead to many benefits such as rapid control of concentrate quality, enhanced recovery and savings in money, time, energy and manpower. The proposed technique is applicable to all types of slurry samples.

Research paper thumbnail of Data and Process Mining Applications on a Multi-Cell Factory Automation Testbed

Research paper thumbnail of Sustainability in the exploration phase of mining: a Data Envelopment Analysis approach∗∗This paper was written with the financial assistance of Alfred Korderlin fund

IFAC-PapersOnLine, 2015

Abstract Sustainability is a popular topic in many research fields, but sustainability of mining ... more Abstract Sustainability is a popular topic in many research fields, but sustainability of mining in Finland is even more so after the economic, environmental and social damage caused by case Talvivaara. Here a measure for sustainability of exploration phase of mining is introduced alongside with the mathematics of the method. The method described is called Data Envelopment Analysis (DEA), which is a versatile tool used in many instances to measure eco-efficiency. Here the main emphasis is on combining economic, ecological and social variables with DEA to produce one index for every exploration site studied. This index, between zero (0) and one (1) is called sustainability score of the given exploration site. The paper uses artificial data to introduce the idea of sustainability measurement. However, as shown in the paper, the artificial data is close to the data already collected on the exploration sites. The study at hand is able to discern a useful index called sustainability score, taking into account six variables affecting the sustainability of exploration phase of mining. It should be noted that if more explorations sites are included into evaluation, the utility is two-fold: first, the sustainability scores become more versatile, and second, there can be more variables to be included into the analysis, adding to the detail at which different factors of sustainability can be taken into account.

Research paper thumbnail of Fast mineral identification using elemental LIBS technique

IFAC-PapersOnLine, 2015

Abstract Rapid and on-line scanning of rock and drillcore samples gives fast results that can be ... more Abstract Rapid and on-line scanning of rock and drillcore samples gives fast results that can be used to ease the decision-making process during exploration and to guide the future drilling activities without delays. Recently, faster and more efficient ore characterization by combining various laser-based and contactless measurement techniques has drawn tremendous attention in research. However, complexity of different measurement setups and the difference between the sources of light make it non-economic and complicated for industry. Considering the wide range of the elements which can be detected by Laser-Induced Breakdown Spectroscopy and bearing in mind that LIBS is a very simple spectroscopic technique, the importance of applying LIBS for fast scanning purposes is certified. This study proposes a simple statistical analysis technique leading to mineral identification from the elemental results of LIBS. It is shown that LIBS can be used for calibrating and giving complementary information to other fast scanning techniques like Laser-Induced Fluorescence imaging. The application of the point-wise LIBS measurement technique for online and fast estimation of the minerals abundance from the surface of the rock and drillcore samples is discussed.

Research paper thumbnail of Fine-scale volatility-based economic dispatch for smart grid edge networks

2015 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT), 2015

The volatility of power delivery from renewable energy sources is currently limiting the scaling ... more The volatility of power delivery from renewable energy sources is currently limiting the scaling up of distributionlevel generation such as rooftop PV solar. Because volatility occurs at short time scales, its management poses challenges in coordination of the dispatch of load events. In this paper, we introduce an algorithm and supporting architecture for the control of volatility at fine time scales. The algorithm dynamically adjusts parameters of load events requested by distributed energy resources, and the architecture and processing can be implemented via integration of presently available technologies. We also introduce a unified cost measure that incorporates economic valuation of both volatility and energy as a function of time-varying pricing policies. This cost measure leads to a constrained non-linear optimization problem, and we propose a genetic algorithm to shape and dispatch load events using the cost measure as a fitness function. Numerical results demonstrate the efficacy of the approach, reveal the trade-off between volatility and energy cost under time-varying pricing policies, and show that increasing the scale of coordinated aggregation can improve performance.

Research paper thumbnail of Embedded service oriented diagnostics based on energy consumption data

2012 IEEE 6th International Conference on Information and Automation for Sustainability, 2012

Research paper thumbnail of Detection of abnormal energy patterns pointing to gradual conveyor misalignment in a factory automation testbed

2012 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2012

ABSTRACT This paper presents a method to detect gradual deterioration of behavior in discrete man... more ABSTRACT This paper presents a method to detect gradual deterioration of behavior in discrete manufacturing pieces of equipment dedicated to transportation of parts between the processing workstations. Monitored energy patterns are correlated with workload data (number of pallets occupying conveyor segments at a time). Detection of gradual conveyor misalignment relies on checking whether the output of a rule based engine mapping input workload data into classes match with the output of an Support Vector Machine classifier operating on the energy values.

Research paper thumbnail of Laser-induced fluorescence images and Raman spectroscopy studies on rapid scanning of rock drillcore samples

International Journal of Mineral Processing, 2014

Research paper thumbnail of Analytical Techniques for Online Mineral Identification

Research paper thumbnail of Rapid mineral detection using elemental Laser-Induced Breakdown Spectroscopy

The exploration and mining activities are strongly increasing both in Finland and internationally... more The exploration and mining activities are strongly increasing both in Finland and internationally. During the exploration, rapid and on-line scanning of rock and drillcore samples gives fast results that can be used to ease the decision-making process for geologists and to guide the future drilling activities without delays. Traditional mineral exploration activities are moderately slow. Recently, faster and more efficient ore characterization by combining various laser-based and contactless measurement techniques have drawn tremendous attention in research. This combination will enable mineralogical analysis of the drillcore and recyclable materials in a fast, cost-effective and objective manner and provides complementary and partly substitutive information for the laboratory analyses. However, complexity of different measurement setups and the difference between the sources of light make it non-economic and complicated for industry. Laser-Induced Breakdown Spectroscopy is a very s...

Research paper thumbnail of On-stream mineral identification of tailing slurries of an iron ore concentrator using data fusion of LIBS, reflectance spectroscopy and XRF measurement techniques

Minerals Engineering, 2017

Abstract This article is extension of the earlier work (Khajehzadeh et al., 2016), where quantita... more Abstract This article is extension of the earlier work (Khajehzadeh et al., 2016), where quantitative mineralogical information of slurry samples was achieved using an on-stream LIBS analyzer. Despite the great advances in the analytical methods and laser-based measurement techniques, the industrial developers are still demanding novel ideas enabling differentiation between minerals having similar elemental contents such as hematite and magnetite or silicon-bearing minerals such as quartz and other mixed silica minerals since they have different flotation properties. The available analytical techniques for LIBS spectral analysis (including the earlier work of this research) could not distinguish between such minerals with identical elemental contents. This work at first presents data fusion of LIBS and reflectance spectroscopy and then discusses the data fusion of reflectance spectroscopy and X-ray fluorescence (XRF) measurement techniques operating on the same slurry samples. The results will show that such data integrations enable on-stream and quantitative identification of slurry mineral contents specially for hematite, magnetite, quartz and ferrorichterite which are important minerals in iron ore beneficiation.

Research paper thumbnail of On-stream and quantitative mineral identification of tailing slurries using LIBS technique

Minerals Engineering, 2016

Abstract Mineral flotation processes are controlled by monitoring the grade of the present minera... more Abstract Mineral flotation processes are controlled by monitoring the grade of the present minerals. The performance of flotation can be greatly optimized by online assaying of the minerals in the slurry flows. However, online and quantitative mineral identification of the slurries is challenging. The major focus of this research is about measuring mineral contents from the elemental concentrations acquired by an on-stream slurry analyzer operating based on laser-induced breakdown spectroscopy (LIBS). A multivariate statistical method called partial least squares regression is employed to perform the elemental to mineral conversion. In this work, the samples under study come from an iron concentrator where knowledge about the grade of silicates and iron-oxides are important for controlling the flotation plant. In total, the concentrations of six out of ten minerals were successfully estimated. This accomplishment provides quantitative knowledge about mineral contents from the nearly real-time assay data without any modification on the measurement setup or further instrumentation. This can lead to many benefits such as rapid control of concentrate quality, enhanced recovery and savings in money, time, energy and manpower. The proposed technique is applicable to all types of slurry samples.

Research paper thumbnail of Data and Process Mining Applications on a Multi-Cell Factory Automation Testbed

Research paper thumbnail of Sustainability in the exploration phase of mining: a Data Envelopment Analysis approach∗∗This paper was written with the financial assistance of Alfred Korderlin fund

IFAC-PapersOnLine, 2015

Abstract Sustainability is a popular topic in many research fields, but sustainability of mining ... more Abstract Sustainability is a popular topic in many research fields, but sustainability of mining in Finland is even more so after the economic, environmental and social damage caused by case Talvivaara. Here a measure for sustainability of exploration phase of mining is introduced alongside with the mathematics of the method. The method described is called Data Envelopment Analysis (DEA), which is a versatile tool used in many instances to measure eco-efficiency. Here the main emphasis is on combining economic, ecological and social variables with DEA to produce one index for every exploration site studied. This index, between zero (0) and one (1) is called sustainability score of the given exploration site. The paper uses artificial data to introduce the idea of sustainability measurement. However, as shown in the paper, the artificial data is close to the data already collected on the exploration sites. The study at hand is able to discern a useful index called sustainability score, taking into account six variables affecting the sustainability of exploration phase of mining. It should be noted that if more explorations sites are included into evaluation, the utility is two-fold: first, the sustainability scores become more versatile, and second, there can be more variables to be included into the analysis, adding to the detail at which different factors of sustainability can be taken into account.

Research paper thumbnail of Fast mineral identification using elemental LIBS technique

IFAC-PapersOnLine, 2015

Abstract Rapid and on-line scanning of rock and drillcore samples gives fast results that can be ... more Abstract Rapid and on-line scanning of rock and drillcore samples gives fast results that can be used to ease the decision-making process during exploration and to guide the future drilling activities without delays. Recently, faster and more efficient ore characterization by combining various laser-based and contactless measurement techniques has drawn tremendous attention in research. However, complexity of different measurement setups and the difference between the sources of light make it non-economic and complicated for industry. Considering the wide range of the elements which can be detected by Laser-Induced Breakdown Spectroscopy and bearing in mind that LIBS is a very simple spectroscopic technique, the importance of applying LIBS for fast scanning purposes is certified. This study proposes a simple statistical analysis technique leading to mineral identification from the elemental results of LIBS. It is shown that LIBS can be used for calibrating and giving complementary information to other fast scanning techniques like Laser-Induced Fluorescence imaging. The application of the point-wise LIBS measurement technique for online and fast estimation of the minerals abundance from the surface of the rock and drillcore samples is discussed.

Research paper thumbnail of Fine-scale volatility-based economic dispatch for smart grid edge networks

2015 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference (ISGT), 2015

The volatility of power delivery from renewable energy sources is currently limiting the scaling ... more The volatility of power delivery from renewable energy sources is currently limiting the scaling up of distributionlevel generation such as rooftop PV solar. Because volatility occurs at short time scales, its management poses challenges in coordination of the dispatch of load events. In this paper, we introduce an algorithm and supporting architecture for the control of volatility at fine time scales. The algorithm dynamically adjusts parameters of load events requested by distributed energy resources, and the architecture and processing can be implemented via integration of presently available technologies. We also introduce a unified cost measure that incorporates economic valuation of both volatility and energy as a function of time-varying pricing policies. This cost measure leads to a constrained non-linear optimization problem, and we propose a genetic algorithm to shape and dispatch load events using the cost measure as a fitness function. Numerical results demonstrate the efficacy of the approach, reveal the trade-off between volatility and energy cost under time-varying pricing policies, and show that increasing the scale of coordinated aggregation can improve performance.

Research paper thumbnail of Embedded service oriented diagnostics based on energy consumption data

2012 IEEE 6th International Conference on Information and Automation for Sustainability, 2012

Research paper thumbnail of Detection of abnormal energy patterns pointing to gradual conveyor misalignment in a factory automation testbed

2012 IEEE International Conference on Systems, Man, and Cybernetics (SMC), 2012

ABSTRACT This paper presents a method to detect gradual deterioration of behavior in discrete man... more ABSTRACT This paper presents a method to detect gradual deterioration of behavior in discrete manufacturing pieces of equipment dedicated to transportation of parts between the processing workstations. Monitored energy patterns are correlated with workload data (number of pallets occupying conveyor segments at a time). Detection of gradual conveyor misalignment relies on checking whether the output of a rule based engine mapping input workload data into classes match with the output of an Support Vector Machine classifier operating on the energy values.

Research paper thumbnail of Laser-induced fluorescence images and Raman spectroscopy studies on rapid scanning of rock drillcore samples

International Journal of Mineral Processing, 2014