As society strives to transition for sustainable energy generation is it a major challenge to optimize and develop the renewable energy generation that currently exists, both in terms of individual components and their interactions in the entire energy system. The generation from renewable sources is often irregular and not always when the demand arises. By being able to store the excess energy generated and then deliver it when the demand occur results in a more sustainable energy system. Flow batteries are a possible technology for energy storage. An important component of flow batteries are vanadium and to find methods for extracting vanadium in an economical way is an important step in the development of this technology. The idea behind the thesis was therefore to investigate different extraction methods for vanadium where the most promising methods, from an economic and energy perspective, are examined in more detail. The vanadium should then be used to electrolyte in flow batteries. It has also been examined how the cost is affected by moving a planned facility for extraction from the ashes to a developing country with lower personnel costs. In the thesis was also included to explore similar projects on a larger scale conducted in Sweden, how the view of vanadium is from an EU perspective and how flow batteries can be a part of an energy system. The methods considered most promising is extraction from mineral mining and extraction from ashes. A planned production plant has been dimensioned for both processes of production and energy demand is calculated. The study showed that both processes are expected to produce vanadium below current purchase price, which would then contribute to a cheaper production cost of flow batteries. It turned out that the production of vanadium from ash extraction would be significantly reduced by moving the business to a developing country. The operation stage in the mining operation which accounts for the highest energy demand is the size reduction of the ore. In the extraction process of vanadium from ash, it is primarily the fusion furnace and the fly ash filter required which has the highest energy demand. The similar extraction projects investigated was, from ashes, the so-called SOTEX process in Stenungsund and the mineral mining process had the Ranstad project as reference. The EU approach to vanadium is currently that the metal is not classified as a critical raw material but if economic instability would occur in any of the major manufacturing countries it would be considered as a more critical raw material. Flow batteries functioning as energy storage in a PV hybrid system was investigated and it was concluded that flow batteries are technically well suited for energy storage in this type of system. / Då samhället strävar efter att övergå till en hållbar energiproduktion är det en stor utmaning att effektivisera och utveckla den förnyelsebara energiproduktion som idag finns, både när det gäller enskilda komponenter och deras samspel i hela energisystem. Produktion från förnyelsebara energikällor sker ofta ojämnt och inte alltid när behovet uppstår. Genom att kunna lagra den överskottsenergi som produceras och sedan leverera den då behovet uppstår medför det till ett mer hållbart energisystem. Flödesbatterier är en möjlig teknik för lagring av energi. En viktig komponent i flödesbatterierna är vanadin och att hitta metoder för att utvinna vanadin på ett ekonomiskt sätt är ett viktigt steg i utvecklingen av denna teknik. Idén bakom examensarbetet var därför att kartlägga olika utvinningsmetoder för vanadin där de mest lovande metoderna, från ett ekonomiskt och energi perspektiv, undersöks mer utförligt. Vanadinet i sin tur ska sedan användas till elektrolyt i flödesbatterier. Det har även undersökts hur kostnaden påverkas av att flytta en tänkt anläggning för utvinning ur aska till ett utvecklingsland med lägre personalkostnader. I examensarbetet ingick även att undersöka liknande projekt i större skala som bedrivits i Sverige, hur synen på vanadin är ur ett EU perspektiv samt hur flödesbatterier kan vara en del av ett energisystem. De metoder som ansetts mest lovande är utvinning från mineralbrytning samt utvinning ur aska. En tänkt produktionsanläggning har dimensionerats för båda processer där produktionskostnad och energiförbrukning beräknats. Studien visade att båda processerna förväntas kunna producera vanadin under dagens inköpspris vilket då skulle bidra till en billigare produktionskostnad för flödesbatterier. Det visade sig att produktionen av vanadin ur askutvinning skulle minskas avsevärt genom att flytta verksamheten till ett utvecklingsland. Det moment i gruvdriften som står för största energiförbrukningen är storleksreduceringen av den malm som bryts. Vid processen för utvinning av vanadin ur aska är det främst den smältningsugn samt det filter för flygaska som krävs. De liknande projekt som verkat inom utvinning ur aska var den s.k. SOTEX processen i Stenungsund och för mineralbrytning har Ranstad projektet undersökts. EU:s syn på vanadin är i nuläget att metallen inte klassas som en kritisk råvara men om ekonomisk instabilitet skulle uppstå i något av de större tillverkande länderna skulle råvaran klassas som mer kritisk. Flödesbatteri fungerande som energilagring i ett förnyelsebart energisystem undersöktes där slutsatsen var att flödesbatterier tekniskt sett är mycket väl lämpade som energilagring i denna typ av system.

Abstract Screen modelling has traditionally been based on rudimentary empirical ‘factor’ methods, or semi-empirical data-fitting techniques. Both of these methods have significant limitations in practice, and industrial screen optimization remains somewhat of a ‘black art’. This thesis introduces the concept of dimensional analysis and scale model similitude to the problem of modelling vibrating screens. This leads to a new method of modelling industrial screens. A small-scale screen can be built at a more convenient scale in the laboratory, and used to predict the performance of a large industrial scale machine. Verification of the scaling theory is based on three separate methods: 1. Firstly, the scaling theory is developed by analysing particle-level forces acting in a dry granular system. It is shown that scale-up of granular systems can be achieved using Froude scaling: that is, if the geometry and operating variables in an experiment are scaled in a pre-defined manner, the behaviour of the particles in the full-scale can be predicted from the behaviour of the particles at the smaller scale. 2. Secondly, the scaling rules are applied to a number of idealized granular systems using numerical simulations via the discrete element method (DEM). The granular systems modelled include inclined vibrating feeders and inclined vibrating screens. It is found that simulations performed at different scales yield almost identical dimensionless responses when the geometry and operating conditions are scaled according to Froude scaling rules. 3. Thirdly, the scaling rules are applied to modelling physical screening data. A dataset obtained from a larger pilot-scale screen in a thesis by R. De Pretto (1992) is reproduced at a smaller scale in this thesis using a purpose-built laboratory-scale screen. The throughput, efficiency curves and cut size are shown to be predictable at all feed rates, despite the former dataset being based on a screen with a feed sample size of around 5000 kg per test and the latter dataset obtained using a feed sample size of less than 30 kg per test. The thesis also touches on modelling the screening efficiency curves. A fully dimensionless version of the proven and familiar Whiten screen model is proposed. Scale-up and modelling of industrial screens M. M. Hilden viii Finally, some of the further possibilities of this theory are discussed briefly in a section on further work; these include further applications of the Screening Physical Model and the application of Froude scaling to the modelling of other granular systems.

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.

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.

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.

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.

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.

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.

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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