http://hdl.handle.net/2268.2/2009 Thu, 05 Mar 2026 21:29:54 GMT 2026-03-05T21:29:54Z http://hdl.handle.net/2268.2/25175 Title: Geometallurgical Characterisation of a Mixed Oxide-Silicate and Sulphide Copper Ore Abstract: This study is part of a collaborative project between University of Liège, University Mohammed VI Polytechnic (UM6P) and Ohod Mining Company (OMC), aimed at improving the processing of copper ores from the Bouizagane deposit, located in the Anti-Atlas region of Morocco. This region is recognised for its polymetallic copper–silver mineralisation and represents a promising area for future mining development. Building on previous geometallurgical investigations, this work seeks to design an optimised mineral processing flowsheet adapted to the mixed copper ore of Bouizagane. To achieve this objective, a comprehensive geometallurgical characterisation of the ore was carried out. The methodology includes rigorous sample preparation, particle size classification, and detailed chemical analyses to determine the elemental composition across size fractions. In parallel, a mineralogical study was conducted to identify the principal gangue and ore minerals, quantify their proportions, and validate the results through cross-correlation of analytical techniques. Particular emphasis was placed on determining the modal mineralogy of copper, distinguishing between oxide, silicate and sulphide phases. Furthermore, the study examines mineral liberation and mineral associations as a function of particle size, which are critical parameters for selecting appropriate processing routes. Based on these results, optimal liberation size, separation methods, and recovery strategies were evaluated. The outcomes of flotation tests were then used to propose an efficient processing flowsheet, integrating comminution, classification, and separation stages. Ultimately, this work provides a scientific basis for improving copper recovery from the Bouizagane deposit while ensuring economic and technical feasibility. Thu, 22 Jan 2026 23:00:00 GMT http://hdl.handle.net/2268.2/25175 2026-01-22T23:00:00Z http://hdl.handle.net/2268.2/20858 Title: Exploring Ultrasound-Assisted Cementation to Enhance the Recovery of Platinum Group Metals from Process Streams Abstract: Catalytic converters, essential for reducing automotive emissions, rely on platinum group metals such as platinum, palladium, and rhodium. The increasing number of end-of-life catalytic converters presents a significant opportunity for PGM recovery, critical due to the scarcity and strategic importance of these metals. Traditional extraction methods are not sufficient to meet the growing demand so in densely populated areas, recycling offers a viable solution for securing PGM supply. This study investigates the removal of PGMs from concentrated process solutions in hydrochloric medium with the cementation of palladium, platinum, and rhodium onto copper. This work focuses on optimizing parameters such as temperature, agitation, Cu/PGM molar ratio, and the use of ultrasound to enhance efficiency. Three solutions were examined: a synthetic solution to assess the feasibility of cementation, and two process solutions derived from catalytic converter leachates. The synthetic solution demonstrated complete platinum cementation at 65°C, 200 rpm, and a Cu/PGM molar ratio of 16. In the real-life solutions, optimal conditions varied, but a general trend was observed: high temperatures and agitation with a Cu/PGM molar ratio of 15 achieved high removal percentages. Ultrasound significantly improved the results, doubling efficiency in some cases and accelerating reaction kinetics. These findings contribute to developing more effective recycling methods for PGMs, supporting sustainable metal recovery practices. Wed, 04 Sep 2024 22:00:00 GMT http://hdl.handle.net/2268.2/20858 2024-09-04T22:00:00Z http://hdl.handle.net/2268.2/20568 Title: Analyse de cycle de vie et empreinte carbone d'oxyde de zinc produit à partir de matières recyclées Abstract: L’entreprise Hydrometal, spécialisée dans le recyclage de métaux non ferreux, souhaite évaluer l’impact environnemental de sa production d’oxyde de zinc (ZnO) de sa future usine basée à Dunkerque. Cette évaluation est réalisée à l’aide de données expérimentales, grâce à la méthode de l’Analyse de Cycle de Vie (ACV). Elle servira de base pour calculer l’empreinte carbone de la production de ZnO selon le guide du Together for Sustainability (TfS). Hydrometal développe actuellement un nouveau procédé de production de ZnO. Ce procédé vise à traiter des déchets métalliques à haute teneur en zinc, via l’utilisation d’acide chlorhydrique. La production d’oxyde de zinc se fait par hydrométallurgie et peut être divisée en plusieurs étapes distinctes : lixiviation, purification, cémentation cuivre et mixte, précipitation, conversion, séchage et calcination. Dans cette étude, deux méthodes de séchage et de calcination (appelées vis et flash) envisagées pour ce procédé sont étudiées. Les résultats obtenus sont comparés à ceux de l’oxyde de zinc de l’entreprise Silox. La production d’un kilogramme de ZnO d’une pureté minimale de 98% est étudiée grâce à la méthode EF 3.1. Le système étudié va du berceau à la porte de l’usine et l’approche « cut-off » est utilisée. L’étude étant basée sur des données expérimentales, il est probable que la valeur réelle de la production de ZnO se situe dans une marge d’erreur de ±10%. Différentes analyses de sensibilités ont permis de tester la robustesse du modèle, ainsi que les hypothèses qui ont été faites. La pondération a permis de mettre en évidence trois catégories d’impact ayant le plus d’importance : le changement climatique, l’utilisation des ressources fossiles et l’utilisation des ressources métalliques. Le changement climatique a la production de la chaux éteinte comme principal contributeur, à plus de 50%. L’utilisation des ressources fossiles a la consommation électrique comme principal contributeur. L’utilisation des ressources minérales et métalliques a la production de poudre de zinc comme principal contributeur. Plusieurs pistes d’améliorations sont possibles pour ces trois catégories d’impact. L’empreinte carbone de la production du ZnO pour le nouveau procédé développé par Hydrometal est de 1,23 kg équivalent CO₂/kg ZnO pour le procédé flash, contre 1,05 kg équivalent CO₂/kg ZnO pour le procédé vis. Trois quarts des émissions sont assimilées au scope 3. La quasi-totalité de ces émissions est d’origine fossile. Les résultats montrent que le procédé vis, dans lequel seules les étapes de séchage et calcination diffèrent du procédé flash, présente un impact significativement plus faible au niveau du changement climatique. Les autres catégories d’impact ne présentent pas de différences significatives entre les deux procédés. Cependant, étant donné le manque de fiabilité des données expérimentales, il serait nécessaire de confirmer de ce résultat avant de pouvoir affirmer que la méthode de calcination vis est réellement plus avantageuse. Enfin, la comparaison entre le procédé vis d’Hydrometal et la production d’oxyde de zinc de Silox avec l’allocation élémentaire montre que le procédé d’Hydrometal présente des résultats significativement meilleurs dans neuf catégories d’impact, incluant les catégories de changement climatique et d’utilisation des ressources fossiles, minérales et métalliques. Sun, 23 Jun 2024 22:00:00 GMT http://hdl.handle.net/2268.2/20568 2024-06-23T22:00:00Z http://hdl.handle.net/2268.2/18153 Title: Development of a methodology for the characterisation of native graphite in a gold ore by an automated mineralogy system Abstract: When a gold deposit contains carbonaceous material such as graphite, the processing plant may face a loss in the gold recovery because of the preg-robbing generated. The preg-robbing capacity of the carbonaceous material, and therefore the associated gold loss, depends on several parameters such as the surface and the crystallinity/maturity of the carbonaceous material, but also on the organic matter content, as well as the presence of different functional groups on the surface of the carbon material. Thus, it is necessary to be able to characterise it. This thesis focuses on a technique of characterisation of graphite (carbonaceous material) by an automated mineralogy system based on a scanning electron microscope that allows to evaluate the liberation and associations of minerals and to quantify them. To do this, samples must be mounted in polished blocks, however, the usual preparation, which consists of a homogeneous mixture of epoxy resin, hardener and an aliquot of material, poses several problems such as differential sedimentation of the particles, touching particles and systematic orientation of the particles. In addition, the backscattered electron image of the scanning electron microscope shows a low contrast between graphite and epoxy resin due to their similar average atomic number. Tests had been done in the past at the University of Liège to solve this issue but were inconclusive. The main objective of this thesis was to develop a polished block preparation that allowed the native graphite of a gold deposit to be analysed via a scanning electron microscope. A series of tests based on the preparation usually used at the University of Liège and on the information found in the literature review was conducted. The results of the various tests carried out made it possible to establish a polished block preparation allowing the characterisation of the native graphite by an automated mineralogy system based on a scanning electron microscope although additional work on the method of polishing is necessary. Sun, 03 Sep 2023 22:00:00 GMT http://hdl.handle.net/2268.2/18153 2023-09-03T22:00:00Z