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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An investigation of the kinetics and an assessment of the economics of ultrafine grinding of coal for mineral liberation

Kalligeris-Skentzos, Andreas January 1987 (has links)
No description available.
2

Modelling Mineral Liberation of Ore Breakage to Improve the Overall Efficiency of Mining Operations

Gottheil, Jeremy 18 August 2021 (has links)
As the demand for a low-carbon and environmentally friendly future increases, so does the importance of mineral and metal commodities. The production of solar panels, wind turbines, energy storage systems and other green technologies require large quantities of minerals and rare earth metals. Natural Resources Canada noted that in 2019, Canada was a global leading producer in minerals required for green technology including graphite, nickel, cobalt, and others [1]. While mineral production continues to rise year over year, the ore grade, i.e., the concentration of a desired material, of multiple common minerals continues to decline. To liberate valuable minerals from low ore grade deposits size reduction processes such as crushing and grinding are required; however, these processes account for over half of all energy consumption on the average mine. As mines are typically remote, fossil fuels are normally used as the main energy source, producing large amounts greenhouse gases, necessitating the need for more efficient size reduction processes. This could be accomplished by predicting how a particular orebody would break. With the surge in image sensing and computing technologies at mining sites many researchers are exploring ore texture and processability characteristics of the ore body. If distinct processability characteristics change based on ore textural feature from a 2D image, then general trends for optimal size reduction of orebodies of similar texture can developed. This work builds on previous work by simulating ore breakage through the superimposition of a predetermined fragmentation pattern, called a mask, onto multiple ore textures. Synthetic, periodic black and white 2D ore textures were created to find a link between simple textural features such as different mineral grain shape, size, and orientation and processability characteristics. A Monte Carlo simulation was performed to generate a large quantity of realistic product particles using the Voronoi tessellations masking technique. To assess the processability of different textures, the percentage area distribution of valuable minerals of each ore texture was compared across the complete range of particle sizes. The valuable mineral percentage area distributions were analyzed for rate and shape of the distribution as particle size decreases, with noticeable differences between textures. The distributions were also parameterized using a two-beta mixture distribution model, expanding on the traditional one beta model developed by King [2,3,4]. These distributions can eventually help the mining industry make informed decisions on how much grinding and crushing will be required to liberate desired minerals from waste rock.
3

Automated Mineral Analysis of Mine Waste

Buckwalter-Davis, Martha 26 August 2013 (has links)
Mineral Liberation Analyzer (MLA) is an automated mineralogical system originally developed to characterize ore and mill feeds for the metallurgical processing industry. Its ability to quantitatively characterize solid and particulate material, including whole rock thin sections, waste rock, tailings, soil, and sediments, has led to increasing applications in other industries. The software uses back-scatter electron imagery and energy dispersive X-ray analysis to analyze each particle’s shape, size, and mineralogical information. Energy dispersive X-ray data are compared to a user-generated Mineral Reference Library consisting of known phases and corresponding EDS spectra to classify each particle. MLA is used in this study to provide quantitative assessments of mining-related environmental samples to answer questions regarding mineralogical controls on bioaccessibility, metal leaching/acid rock drainage potential, and anthropogenic influence. Six tailings samples from the New Calumet Mine in Quebec, Canada, were analyzed using MLA. Gastric Pb bioaccessibility testing and total metal content performed on these samples indicated that Pb bioaccessibility in the <250 micron size fraction was not directly correlated with the total Pb concentration. This suggested that there were mineralogical and/or physical controls on bioaccessibility. MLA was used to quantify the relative proportions of cerussite, a highly bioaccessible Pb carbonate, and galena, a lower bioaccessibility Pb sulfide. Liberation and particle size were also analyzed as controls on bioaccessibility. Sample GD-VEG1 (highest bioaccessibility) has the highest ratio of cerussite to galena, the smallest particle size, and the most liberated Pb-bearing particles. The New Calumet tailings were also analyzed using static testing, a suite of laboratory tests used by environmental scientists and mine operators to operationally define acid rock drainage and metal leaching potential. Modal mineralogy obtained from MLA analysis was used to calculate neutralization potential (NP) and acid potential (AP), taking into account the presence of iron carbonate minerals and iron-bearing sulfides other than pyrite. Results are within several units of those obtained by static testing. Two Ni-impacted soil samples collected from the region of Kalgoorlie, Australia were characterized using MLA. Previous studies had focused on bioaccessibility and sequential extraction testing and minor mineralogical work. Preliminary XANES characterization conflicted with mineralogy predicted from sequential extraction and EMPA and MLA were used to quantitatively characterize major Ni-bearing phases and resolve previous discrepancies. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2013-08-24 08:13:18.722
4

CHARACTERISATION OF SAMPLES OF ORE PARTICLES USING X-RAY MICRO-TOMOGRAPHY

Murat Cakici Unknown Date (has links)
The degree of mineral liberation is important for the efficiency of subsequent physical separation processes such as froth flotation. Mineral liberation studies involve determining the volumetric abundance or volumetric grade distribution of a specific mineralogical phase in a particular mineral. Currently, methodologies for assessing mineral liberation are laborious regarding sample preparation, analysis time (from weeks to months), and the need for stereological correction. These constraints can be eliminated by using X-ray CT which gives the cross-sections directly from three-dimensional data in shorter time (from ten minutes to hours) with minimal sample preparation. X-ray computed tomography (CT) is a non-destructive technique which allows three-dimensional visualisation of inner structures of an object based on the variations in density and atomic composition. Initially, it was developed as a medical tool for imaging soft tissue and bone. During the last decade, the number of X-ray CT applications in engineering and geology has steadily increased, with the improvements in performance and imaging capabilities. The aim of the present work is to apply X-ray CT technique for finely divided ore samples and to study the relationship between mineral liberation and CT results. Four different ore types were used in this study: Northparkes ore (Australia), Ernest Henry ore (Australia), Keetac ore (USA) and Cannington ore (Australia). Different settings of the desktop X-ray CT technique were applied for each particular ore sample for several ore liberation (particle size distribution) properties. Two dimensional CT images were reconstructed from the three-dimensional X-ray CT data. It was found that the settings for CT technique were a function of the ore type. Particularly in the case of Cannington (high density ore) the best setting conditions split from the rest of the ores tested. The appearance of different artifacts occurring during the analysis were studied and kept to the minimum. A functionality between mineral liberation and CT results was found. The variables affecting the most the results were the Voltage and Minimum Intensity Percentage. Contrary to the expected trends, variables having a negligible effect on the results were found to be exposure time / equivalent Al filter thickness.
5

CHARACTERISATION OF SAMPLES OF ORE PARTICLES USING X-RAY MICRO-TOMOGRAPHY

Murat Cakici Unknown Date (has links)
The degree of mineral liberation is important for the efficiency of subsequent physical separation processes such as froth flotation. Mineral liberation studies involve determining the volumetric abundance or volumetric grade distribution of a specific mineralogical phase in a particular mineral. Currently, methodologies for assessing mineral liberation are laborious regarding sample preparation, analysis time (from weeks to months), and the need for stereological correction. These constraints can be eliminated by using X-ray CT which gives the cross-sections directly from three-dimensional data in shorter time (from ten minutes to hours) with minimal sample preparation. X-ray computed tomography (CT) is a non-destructive technique which allows three-dimensional visualisation of inner structures of an object based on the variations in density and atomic composition. Initially, it was developed as a medical tool for imaging soft tissue and bone. During the last decade, the number of X-ray CT applications in engineering and geology has steadily increased, with the improvements in performance and imaging capabilities. The aim of the present work is to apply X-ray CT technique for finely divided ore samples and to study the relationship between mineral liberation and CT results. Four different ore types were used in this study: Northparkes ore (Australia), Ernest Henry ore (Australia), Keetac ore (USA) and Cannington ore (Australia). Different settings of the desktop X-ray CT technique were applied for each particular ore sample for several ore liberation (particle size distribution) properties. Two dimensional CT images were reconstructed from the three-dimensional X-ray CT data. It was found that the settings for CT technique were a function of the ore type. Particularly in the case of Cannington (high density ore) the best setting conditions split from the rest of the ores tested. The appearance of different artifacts occurring during the analysis were studied and kept to the minimum. A functionality between mineral liberation and CT results was found. The variables affecting the most the results were the Voltage and Minimum Intensity Percentage. Contrary to the expected trends, variables having a negligible effect on the results were found to be exposure time / equivalent Al filter thickness.
6

CHARACTERISATION OF SAMPLES OF ORE PARTICLES USING X-RAY MICRO-TOMOGRAPHY

Murat Cakici Unknown Date (has links)
The degree of mineral liberation is important for the efficiency of subsequent physical separation processes such as froth flotation. Mineral liberation studies involve determining the volumetric abundance or volumetric grade distribution of a specific mineralogical phase in a particular mineral. Currently, methodologies for assessing mineral liberation are laborious regarding sample preparation, analysis time (from weeks to months), and the need for stereological correction. These constraints can be eliminated by using X-ray CT which gives the cross-sections directly from three-dimensional data in shorter time (from ten minutes to hours) with minimal sample preparation. X-ray computed tomography (CT) is a non-destructive technique which allows three-dimensional visualisation of inner structures of an object based on the variations in density and atomic composition. Initially, it was developed as a medical tool for imaging soft tissue and bone. During the last decade, the number of X-ray CT applications in engineering and geology has steadily increased, with the improvements in performance and imaging capabilities. The aim of the present work is to apply X-ray CT technique for finely divided ore samples and to study the relationship between mineral liberation and CT results. Four different ore types were used in this study: Northparkes ore (Australia), Ernest Henry ore (Australia), Keetac ore (USA) and Cannington ore (Australia). Different settings of the desktop X-ray CT technique were applied for each particular ore sample for several ore liberation (particle size distribution) properties. Two dimensional CT images were reconstructed from the three-dimensional X-ray CT data. It was found that the settings for CT technique were a function of the ore type. Particularly in the case of Cannington (high density ore) the best setting conditions split from the rest of the ores tested. The appearance of different artifacts occurring during the analysis were studied and kept to the minimum. A functionality between mineral liberation and CT results was found. The variables affecting the most the results were the Voltage and Minimum Intensity Percentage. Contrary to the expected trends, variables having a negligible effect on the results were found to be exposure time / equivalent Al filter thickness.
7

CHARACTERISATION OF SAMPLES OF ORE PARTICLES USING X-RAY MICRO-TOMOGRAPHY

Murat Cakici Unknown Date (has links)
The degree of mineral liberation is important for the efficiency of subsequent physical separation processes such as froth flotation. Mineral liberation studies involve determining the volumetric abundance or volumetric grade distribution of a specific mineralogical phase in a particular mineral. Currently, methodologies for assessing mineral liberation are laborious regarding sample preparation, analysis time (from weeks to months), and the need for stereological correction. These constraints can be eliminated by using X-ray CT which gives the cross-sections directly from three-dimensional data in shorter time (from ten minutes to hours) with minimal sample preparation. X-ray computed tomography (CT) is a non-destructive technique which allows three-dimensional visualisation of inner structures of an object based on the variations in density and atomic composition. Initially, it was developed as a medical tool for imaging soft tissue and bone. During the last decade, the number of X-ray CT applications in engineering and geology has steadily increased, with the improvements in performance and imaging capabilities. The aim of the present work is to apply X-ray CT technique for finely divided ore samples and to study the relationship between mineral liberation and CT results. Four different ore types were used in this study: Northparkes ore (Australia), Ernest Henry ore (Australia), Keetac ore (USA) and Cannington ore (Australia). Different settings of the desktop X-ray CT technique were applied for each particular ore sample for several ore liberation (particle size distribution) properties. Two dimensional CT images were reconstructed from the three-dimensional X-ray CT data. It was found that the settings for CT technique were a function of the ore type. Particularly in the case of Cannington (high density ore) the best setting conditions split from the rest of the ores tested. The appearance of different artifacts occurring during the analysis were studied and kept to the minimum. A functionality between mineral liberation and CT results was found. The variables affecting the most the results were the Voltage and Minimum Intensity Percentage. Contrary to the expected trends, variables having a negligible effect on the results were found to be exposure time / equivalent Al filter thickness.
8

CHARACTERISATION OF SAMPLES OF ORE PARTICLES USING X-RAY MICRO-TOMOGRAPHY

Murat Cakici Unknown Date (has links)
The degree of mineral liberation is important for the efficiency of subsequent physical separation processes such as froth flotation. Mineral liberation studies involve determining the volumetric abundance or volumetric grade distribution of a specific mineralogical phase in a particular mineral. Currently, methodologies for assessing mineral liberation are laborious regarding sample preparation, analysis time (from weeks to months), and the need for stereological correction. These constraints can be eliminated by using X-ray CT which gives the cross-sections directly from three-dimensional data in shorter time (from ten minutes to hours) with minimal sample preparation. X-ray computed tomography (CT) is a non-destructive technique which allows three-dimensional visualisation of inner structures of an object based on the variations in density and atomic composition. Initially, it was developed as a medical tool for imaging soft tissue and bone. During the last decade, the number of X-ray CT applications in engineering and geology has steadily increased, with the improvements in performance and imaging capabilities. The aim of the present work is to apply X-ray CT technique for finely divided ore samples and to study the relationship between mineral liberation and CT results. Four different ore types were used in this study: Northparkes ore (Australia), Ernest Henry ore (Australia), Keetac ore (USA) and Cannington ore (Australia). Different settings of the desktop X-ray CT technique were applied for each particular ore sample for several ore liberation (particle size distribution) properties. Two dimensional CT images were reconstructed from the three-dimensional X-ray CT data. It was found that the settings for CT technique were a function of the ore type. Particularly in the case of Cannington (high density ore) the best setting conditions split from the rest of the ores tested. The appearance of different artifacts occurring during the analysis were studied and kept to the minimum. A functionality between mineral liberation and CT results was found. The variables affecting the most the results were the Voltage and Minimum Intensity Percentage. Contrary to the expected trends, variables having a negligible effect on the results were found to be exposure time / equivalent Al filter thickness.
9

CHARACTERISATION OF SAMPLES OF ORE PARTICLES USING X-RAY MICRO-TOMOGRAPHY

Murat Cakici Unknown Date (has links)
The degree of mineral liberation is important for the efficiency of subsequent physical separation processes such as froth flotation. Mineral liberation studies involve determining the volumetric abundance or volumetric grade distribution of a specific mineralogical phase in a particular mineral. Currently, methodologies for assessing mineral liberation are laborious regarding sample preparation, analysis time (from weeks to months), and the need for stereological correction. These constraints can be eliminated by using X-ray CT which gives the cross-sections directly from three-dimensional data in shorter time (from ten minutes to hours) with minimal sample preparation. X-ray computed tomography (CT) is a non-destructive technique which allows three-dimensional visualisation of inner structures of an object based on the variations in density and atomic composition. Initially, it was developed as a medical tool for imaging soft tissue and bone. During the last decade, the number of X-ray CT applications in engineering and geology has steadily increased, with the improvements in performance and imaging capabilities. The aim of the present work is to apply X-ray CT technique for finely divided ore samples and to study the relationship between mineral liberation and CT results. Four different ore types were used in this study: Northparkes ore (Australia), Ernest Henry ore (Australia), Keetac ore (USA) and Cannington ore (Australia). Different settings of the desktop X-ray CT technique were applied for each particular ore sample for several ore liberation (particle size distribution) properties. Two dimensional CT images were reconstructed from the three-dimensional X-ray CT data. It was found that the settings for CT technique were a function of the ore type. Particularly in the case of Cannington (high density ore) the best setting conditions split from the rest of the ores tested. The appearance of different artifacts occurring during the analysis were studied and kept to the minimum. A functionality between mineral liberation and CT results was found. The variables affecting the most the results were the Voltage and Minimum Intensity Percentage. Contrary to the expected trends, variables having a negligible effect on the results were found to be exposure time / equivalent Al filter thickness.
10

CHARACTERISATION OF SAMPLES OF ORE PARTICLES USING X-RAY MICRO-TOMOGRAPHY

Murat Cakici Unknown Date (has links)
The degree of mineral liberation is important for the efficiency of subsequent physical separation processes such as froth flotation. Mineral liberation studies involve determining the volumetric abundance or volumetric grade distribution of a specific mineralogical phase in a particular mineral. Currently, methodologies for assessing mineral liberation are laborious regarding sample preparation, analysis time (from weeks to months), and the need for stereological correction. These constraints can be eliminated by using X-ray CT which gives the cross-sections directly from three-dimensional data in shorter time (from ten minutes to hours) with minimal sample preparation. X-ray computed tomography (CT) is a non-destructive technique which allows three-dimensional visualisation of inner structures of an object based on the variations in density and atomic composition. Initially, it was developed as a medical tool for imaging soft tissue and bone. During the last decade, the number of X-ray CT applications in engineering and geology has steadily increased, with the improvements in performance and imaging capabilities. The aim of the present work is to apply X-ray CT technique for finely divided ore samples and to study the relationship between mineral liberation and CT results. Four different ore types were used in this study: Northparkes ore (Australia), Ernest Henry ore (Australia), Keetac ore (USA) and Cannington ore (Australia). Different settings of the desktop X-ray CT technique were applied for each particular ore sample for several ore liberation (particle size distribution) properties. Two dimensional CT images were reconstructed from the three-dimensional X-ray CT data. It was found that the settings for CT technique were a function of the ore type. Particularly in the case of Cannington (high density ore) the best setting conditions split from the rest of the ores tested. The appearance of different artifacts occurring during the analysis were studied and kept to the minimum. A functionality between mineral liberation and CT results was found. The variables affecting the most the results were the Voltage and Minimum Intensity Percentage. Contrary to the expected trends, variables having a negligible effect on the results were found to be exposure time / equivalent Al filter thickness.

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