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- Guldris Leon, Lorena, 1983
(författare)
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Analysis and Modelling of Mineral and Element Composition in Compression Breakage
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The outstanding properties of tungsten and tantalum make them valuable metals and, in some cases, irreplaceable in applications. The growing interest due to the high economic importance and the limited supply places these metals in the critical metals risk list. As a consequence of the increasing global demand for these metals, there is also a need to develop more efficient extraction processes. Coarse comminution processes are commonly assessed by the size reduction of particles, however, liberation and mineralogy are not taken into consideration. The main hypothesis of this research is that critical metals are not evenly distributed in the different size fractions during coarse comminution processes since the breakage of particles will be affected by the mineralogy and texture. Further, to demonstrate the significant impact that mineralogy understanding has during breakage and develop a test procedure to include the concentration of the critical metals which will increase the resolution of coarse comminution models. This thesis focuses on finding an experimental methodology to analyse the rock properties and its general characteristics, followed by defining a multicomponent model that combines size reduction and concentration for critical metals. In this research, the work is divided into 3 stages. The first main stage is the rock materials characterisation which consists of two parts: mechanical and mineralogical analyses. The second stage is the modelling and the third stage is theoretic implementation. The mechanical characterisation includes compressive breakage through the use of interparticle breakage. Mineralogical characterisation was evaluated through the assessment of size fractions with a scanning electron microscopy (SEM) and geochemical analysis. Results from these tests give information about breakage, mineral composition and element concentration. The second main stage corresponds to modelling. The first modelling part was the methodology of fitting measured data into a size reduction model. The second part corresponds developing a model capable of predicting the rare metal concentration as a function of the particle size distribution after a cycle of the compression crushing process. The model was developed by selecting a bimodal Weibull distribution for calibration which is shown to be capable of simulating critical metal concentration as a function of the compression ratio. The third stage is a simulation. The aim of this section is to demonstrate a theoretical case where the concentration model allows to make well based estimations of how a plant should be designed. Evaluations have shown that by considering the information of the ore and its behaviour in terms of concentration and performance of the crushing, the process could be improved by changing machine parameters, i.e. closed side setting and adding a pre-screening before the milling process. The work shows that considering the effect of mineralogy and element concentration in the coarse comminution models, it is possible to achieve better performance in terms of cone crusher and plant design.
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| 2. |
- Guldris Leon, Lorena, 1983, et al.
(författare)
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Analysis of the concentration in rare metal ores during compression crushing
- 2018
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Ingår i: Minerals Engineering. - : Elsevier BV. - 0892-6875 .- 1872-9444. ; 120, s. 7-18
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Tidskriftsartikel (refereegranskat)abstract
- Given the increasing global demand for rare metals, there is a need for the development of fundamental predictive models to improve extraction processes. Comminution models commonly predict particle size reduction based on the compressive breakage behaviour; however, few of them include mineral concentration or mineral liberation at a coarse scale. This paper focuses on developing a model to predict the mineral concentration of rare metals as a function of the particle size distribution after a cycle of the compression crushing process. In this study, compressive breakage and geochemical analysis experiments were conducted on four different rare metal ores of tantalum and tungsten. The work is divided into two stages: the methodology of modelling particle size and modelling concentration by selecting a bimodal Weibull distribution for calibration. A novel model for simulating the concentration of rare metals as a function of the compression ratio is presented.
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| 3. |
- Guldris Leon, Lorena, 1983, et al.
(författare)
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Evaluation of Refractory Metal Concentrations in Nano-Particulate Pressed-Powder Pellets Using LA-ICP-MS
- 2022
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Ingår i: Minerals. - : MDPI AG. - 2075-163X. ; 12:7
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Tidskriftsartikel (refereegranskat)abstract
- Whole-rock geochemical analysis is a standard method to measure the chemical composition of ores. Analysis of refractory ore metals such as Ta and W typically requires fused bead and acid digestion followed by inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively coupled mass spectrometry (ICP-MS). Since these techniques are time-consuming and expensive, there is a demand for methods that can quantitatively measure low elemental concentration of refractory ore metals using a less expensive and simple approach. This paper evaluates preparation and analytical procedures developed to obtain whole-rock element concentrations of ore samples and mineral concentrates. It shows that the production of nano-particulate pressed-powder pellets followed by LA-ICP-MS analysis of W and Ta ores can be used to determine, within the error margin, the concentrations of the refractory metals W, Ta, Nb, and Sn compared to a reference values obtained by solution analysis. The results have implications for developing a commercially viable method for analysis of refractory elements to benefit mineral processing given the simplicity and resource-efficiency of the combined pressed pellet production and laser ablation analytical methodology.
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| 4. |
- Guldris Leon, Lorena, 1983, et al.
(författare)
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Selective Comminution Applied to Mineral Processing of a Tantalum Ore: A Technical, Economic Analysis
- 2022
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Ingår i: Minerals. - Basel : MDPI AG. - 2075-163X. ; 12:8
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Tidskriftsartikel (refereegranskat)abstract
- There is an increasing demand to simulate and optimize the performance and profit of comminution circuits, especially in low-grade ore processing, as is the case with critical metals minerals. Recent research has shown that the optimization result is greatly influenced by quality aspects of the products, such as cost, profit, and capacity. This paper presents a novel approach to performing a multi-objective technical and economic analysis of tantalum ore processing to increase the production of critical metals minerals. The article starts with mineral composition analysis to highlight the potential of strategies for balancing the process layout for maximized production. The introduction of a combined technical and economic analysis presents the possibility of improving the profit by rearranging the mass flow given the rock's mineral composition. Results show that selective comminution can improve process capacity by 23% and decrease production cost by 10% for the presented case.
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| 5. |
- Guldris Leon, Lorena, 1983
(författare)
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Selective Comminution Applied to Mineral Processing of Critical Metals
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The outstanding properties of tungsten and tantalum make them valuable metals and, in some cases, irreplaceable in applications. Due to the vital economic importance and limited supply, growing interest places these metals on the critical metals risk list. Due to increasing global demand for these metals, there is also a need to develop more efficient extraction processes. The size reduction of particles commonly assesses coarse comminution processes. Nevertheless, does not include mineralogy and element content. The primary hypothesis of this research is that the utilization of selective comminution could enhance the efficiency of critical metal extraction, rendering it a valuable and cost-effective method in comparison to conventional approaches. As critical metals do not uniformly distribute across distinct size fractions during coarse comminution processes, owing to the influence of mineralogical composition and texture on particle breakage. To underscore the significant role of mineralogy in breakage, a novel testing procedure is proposed, which involves the concentration of critical metals following compressive breakage, aiming to augment the resolution of coarse comminution models. This study is dedicated to formulating an analytical methodology and test protocols aimed at analysing and characterizing selective comminution possibilities during compression breakage. The research progresses across three key phases. The primary phase involves the comprehensive characterization of rock materials, encompassing mechanical, chemical, and mineralogical analyses. The subsequent phase involves modelling, followed by the third phase, which entails the technical and economic evaluation of material in a theoretical plant distribution case study. Mechanical characterization includes laboratory-based compressive crushing, encompassing interparticle breakage, while chemical and mineralogical characterization is conducted by evaluating size-fractioned samples post-compression breakage, employing techniques such as scanning electron microscopy (SEM) and geochemical analysis. These tests yield valuable insights into breakage behaviour, mineral composition, and elemental concentration, with implications for early material rejection strategies. Geochemical analysis is carried out using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Additionally, the production of particles in nano sizes, pressed powder pellets, followed by analysis via Laser Ablation Inductively Coupled Plasma Mass Spectrometry (PPP LA-ICP-MS), offers a cost-effective and suitable means to measure elemental content, circumventing the laborious and costly steps associated with standard techniques such as fused bead and acid digestion. The data generated through the developed analytical methodology undergoes rigorous analysis and is fitted into a model, which employs a bimodal Weibull distribution for calibration. This concentration model excels in simulating critical metal concentrations based on compression ratios, and it can forecast rare metal concentrations in relation to particle size distributions following compression crushing. Following comprehensive study, analysis, and modelling of mineral composition, a tool is devised that combines technical and economic models, enabling the optimization of production by enhancing product quality, cost-efficiency, profitability, and capacity. The results demonstrate that the proposed model facilitates the determination and enhancement of process capacity and profitability. Utilizing the technical and economic model offers the prospect of elevating profitability by reconfiguring mass flows based on the mineral composition of the rock, aligning with plant distribution objectives. In conclusion, the implementation of the developed analytical method enhances the assessment of coarse mineral liberation characteristics, offering fundamental insights into how various ore materials tend to break post-compressive crushing, concerning mineral and elemental distributions. Armed with this information, it becomes possible to propose, refine, and assess the cost of process adjustments, such as machine parameters, plant design, and early material rejection strategies, tailored to the specific properties of each ore.
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| 6. |
- Guldris Leon, Lorena, 1983, et al.
(författare)
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Understanding Mineral Liberation during Crushing Using Grade-by-Size Analysis - A Case Study of the Penuota Sn-Ta Mineralization, Spain
- 2020
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Ingår i: Minerals. - : MDPI AG. - 2075-163X. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Coarse comminution test-work and modeling are powerful tools in the design and optimization of mineral processing plants and provide information on energy consumption. Additional information on mineral liberation characteristics can be used for assessing the potential of pre-concentration stages or screens in the plant design. In ores of high-value metals (e.g., Ta, W), standard techniques-such as the mineralogical quantification of grain mounts by quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) or chemical analysis by X-ray fluorescence (XRF) can be challenging, due to the low relative abundance of such valuable minerals. The cost of QEMSCAN is also a limiting factor, especially considering the large number of samples required for the optimization of coarse comminution. In this study, we present an extended analytical protocol to a well-established mechanical test of interparticle breakage to improve the assessment of coarse mineral liberation characteristics. The liberation of ore minerals is a function of the rock texture and the difference in size and mechanical properties of the valuable minerals relative to gangue minerals and they may fraction in certain grain sizes if they behave differently during comminution. By analyzing the bulk-chemistry of the different grain size fractions produced after compressional testing, and by generating element by size diagrams, it is possible to understand the liberation characteristics of an ore. We show, based on a case study performed on a tantalum ore deposit, that element distribution can be used to study the influence of mechanical parameters on mineral liberation. This information can direct further mineralogical investigation and test work.
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