| RESSOURCES21 Ongoing PhD projects |
In just 11 and half years of existence RESSOURCES21 has already funded 42 Phd students:
Xiaoting CHEN, 2021-2024, "Faisabilité du traitement des eaux arséniées par la souche Clostridium acidisolis CK74", supervisers: Pr Pascale BAUDA, Dr Patrick BILLARD, Dr Asfaw ZEGEYE & Dr Bénédicte SOHM
Samuel Teillaud, 2021-2024, "Évaluation comparative du potentiel de récupération de métaux stratégiques (Ni, Co) à partir de résidus miniers âgés par des approches (hydro-)métallurgiques et d'agromine et stabilisation de l'arsenic", superviser: Pr Marie-Odile SIMONNOT
Julien Leger, 2019-2022, "Reconstruction de l'orogenèse précoce et des sources des sédiments dans la zone de liaison entre les Alpes et les Pyrénées (crétacé supérieur - Paléogène)", supervisers: Dr Raphäel PIK & Dr Julien MERCADIER
Thomas Monot, 2021-2024, "AhpoG -Agromine et hyperaccumulation par des plantes de l’or en Guyane", supervisors: Pr Baptiste LAUBIE & Pr Guillaume ECHEVARRIA
Nina Fermet-Quinet, 2021-2024, "Analyse de risques multidisciplinaire de la filière minière pour la planification territoriale. Développement d’un prototype d’outil d’aide à la décision sur l’exemple de l’exploitation de l’or en Guyane", supervisors: Yann GUNZBURGER & Rasool MEHDIZADEH
Océane Rocher, 2021-2024, "Le système hydrothermal du granite de Beauvoir et son impact surla distribution des métaux" supervisors: Antonin RICHARD & Julien MERCADIER
Nicolas Esteves, 2021-2024, "BeauLiΥ: Understanding protracted differentiation and its role in Li & rare metals concentration: Petrogenetic evolution & assembly duration of the Beauvoir granite" supervisors: Pierre BOUILHOL, Lydéric FRANCE & Michel CUNEY
Naila Mezoued, 2021-2024, "Analyseportable, rapide et quantitative des éléments légers (Li, Be, F) dans les roches felsiques à métaux rares:Application au leucogranite de Beauvoir" supervisors: Cécile FABRE & Jean CAUZID
Chloé Korbel, 2021-2024, "Evaluation géométallurgique de récupération du Li par flottation à partir des granites à métaux rares : conciliation des données géochimiques et de traitement" supervisors: Pr Lev FILIPPOV
Nicolas Fierling, 2021-2024, "Analyse multi-échelle de l’impact du lithium sur les microorganismes", supervisor: Pr Pascale BAUDA
Abdoul Fattah Kiemde, 2021-2024, "Etude de l’extraction du bore contenu dans une saumure du salar de Hombre Muerto (Argentine)", supervisors: Pr Alexandre CHAGNES & Pr Victoria Flexer (CONICET, Universidad de Jujuy, Argentine)
Sergine Ly, 2021-2024, "Biomolecular and ecophysiological insights to breed the ultimate tropical nickel metal crop" Supervisor: Pr Guillaume ECHEVARRIA
Alix Hauteville, 2020-2023, "Processus minéralisateurs et traceurs géochimiques des gisements aurifères en Guyane", supervisors: Pr Anne-sylvie ANDRE-MAYER & As. Pr Aurélien EGLINGER
Guillaume Salzet, 2020-2023, "La durabilité de la forêt et de la filière bois en Guyane française : approche spatialisée des services écosystémiques", supervisor: Dr Sylvain CAURLA
Yujin Jegal, 2019-2022, "In-Situ K-Ca and Rb-Sr datings and tracing by SIMS and LA-ICP-MS", supervisors: Etienne DELOULE & Julien MERCADIER
Sylvain Favier, 2019-2022, "Facteur d’enrichissement de nickel dans les minerais saprolitiques de Nouvelle Calédonie", supervisors: Dr Fabrice GOLFIER & Dr Michel CATHELINEAU
Nicolas Dupuy, 2020-2023, "Lithium et Santé-Environnement : Etude des effets in-vitro et in-vivo du lithium en milieu aquatique", supervisors: Pr Carole COSSU-LEGUILLE & Dr. Laeticia MINGUEZ
Kristijan Rajic, 2020-2023, "Analyse isotopique du lithium et du bore dans les inclusions fluides comme traceur des circulations de fluide", supervisors: As. Pr. Antonin RICHARD
Dulce Navarrete, 2017-2020, "Plant metal hyperaccumulation in Mexico: agromining perspectives", supervisors: Pr Guillaume ECHEVARRIA
Allen Fosu, 2020-2023 "Advanced chloride route for lithium extraction from spodumene ores", supervisors : Pr Alexandre CHAGNES / UL & Dr James VAUGHAN /UQ
Bastien Jally, 2018-2021 "Agromine des terres rares" supervisors: Pr Marie-Odile SIMONNOT & Pr Batiste LAUBIE
Ottone Scammacca, 2017-2020 "Project risks in mining operations. Evaluation and commensuration of technical and societal risks, with application to open pit mines during the development and exploitation phases, especially under tropical climate" supervisors: Pr Yann GUNZBURGER & Pr RASTOOL MEHDIZADEH
Romane Tisserand, 2017-2020 "The Ni biogeochemical cycle in a tropical agromine metal crop system", supervisors: Pr Guillaume Echevarria, Dr Antony VAN DER ENT, Pr Peter ERSKINE
Ruoyu Hu, 2017-2020 "Mobility and transfer of rare earth elements from soil to plants by arbuscular mycorrhizal fungi" supervisors: Dr Corinne LEYVAL
Meina Guo, 2016-2019 "les processus pédogénétiques qui contrôlent la formation d’une croûte sur les sols miniers et le rôle de cette croûte dans les phénomènes d’écoulement de l’eau et de l’infiltration des polluants" supervisors: Jean-Louis MOREL & Pr Geoffroy SERE
Chang Liu, 2016-2019, "les plantes accumulatrices de terres rares (Dicranopteris dichotoma), leur comportement et leur potentiel pour la végétalisation et la récupération des terres rares" supervisors: Or Jean-Louis MOREL & Pr Geoffroy SERE
Yann Foucaud , 2016-2019 "Effets synergiques des réactifs de structure moléculaire différente dans la flottation des minerais de tungstène à faible contraste de séparation", supervisor: Pr Lev FILIPPOV
Nina Bothamy, 2016-2018 "Nouveau traceurs biogéochimiques : isotopes stables des terres rares (NTB-REE)", supervisor: Pr Albert GALY
Eleonora Carocci, 2016-2019 "Magmato-hydrothermal transport and deposit of W(Sn, Nb (Ta) in magmatic-metamorphic fluids around plutons Transport and deposition of W (Sn, Nb (Ta) ores from in magmatic-metamorphic fluids around plutons", supervisors: Dr Michel CATHELINEAU & Pr Laurent TRUCHE
Nicolas Grosjean, 2015-2018 "Etude des gènes de réponse aux terres rares chez des organismes telluriques modèles (projet TeR-Genes)", supervisors: Dr Damine BLAUDEZ
François Turlin, 2015-2018 "Les gisements de REE magmatiques, traceurs des processus de croissance et de différenciation de la croûte continentale : Exemple de la Province de Grenville un orogène Protérozoïque, Québec, Canada", supervisors: Pr Anne-Sylvie ANDRE MAYER
Séverine Lopez, 2015-2018 " "Determinism of the microbial communities structure in ultramafic soils on a context of nickel agromine" supervisors: Dr Emile Benizri & Pro Jean-Louis Morel
Andrey Myagkiy, 2014-2017 "Formation des minéralisation de Ni saprolitiques en Nouvelle Calédonie: Dynamique des transferts de métaux et modélisation couplée", supervisors: Dr Michel CATHELINEAU
Guillaume Barré, 2014-2017 "Role of the sulfur speciation in geological fluids on the redox processes affecting its geochemical cycle in the lithosphere", supervisors: Pr Laurent TRUCHE
Matthieu Harlaux, 2013-2016 "Les minéralisations tardi-orogéniques varisques à tungstène et métaux associés (Sn, Nb, Ta) : source des fluides et des métaux, relations avec les évènements tectonomagmatiques fini-carbonifères sur l’exemple de gisements du massif central français", supervisors: Dr Michel CATHELINEAU
Gaelle Mollex, 2013-2016 "Génèse, évolution et altération des magmas carbonatitiques", supervisors: Pr Lydéric FRANCE
Emilie Perrat, 2013-2016 "Impacts environnementaux des agents de contraste au Gadolinium : situation locale, approches cellulaires et in vivo", supervisors: Pr Marc PARANT, Pr Carole CUSSU-LEGUILLE
Damien Parrello, 2013-2014 "Identification à l'aide de bactéires génétiquement modifiées émettant des signaux luminescents(biocenseurs) les paramètres biotiques et abiotiques induisant la mobilisation de métaux stratégiques comme le nickel", supervisors: Dr Chritian MUSTIN, Dr Asfaw ZEGEYE
Pablo Herrera, 2014 "Utilisation de la Géomodélisation 3/4D pour estimer les ressources minérales potentielles d'une province en métallogénique - applications aux Kupferschiefers", supervisors: Dr Jean-Jacques ROYER
Maxime Faivre 2012-2015 "Modélisation du comportement hydrogéomécanique d'un réseau de failles sous l'effet des variations de l'état de contrainte.", supervisors: Dr Fabrice GOLFIER, Dr Richard GIOT
Rémy Bellissont, 2012-2015 "Cycle du germanium et métaux stratégiques associés dans les concentrations métalliques : traçage élémentaire, isotopique et approche expérimentale", supervisors: Dr Marie-Christine BOIRON, Dr Béatrice LUAIS
Jennifer Andrei, 2012-2015 "Effets des nanoparticules manufacturés sur les invertébrés d'eau douce et leurs fonctions au sein des écosystèmes", supervisors: Pr François GUEROLD, Dr Sandrine PAIN-DEVIN
RESSOURCES21 PHD students defended
Allen Yushark FOSU
Defended on 01-06-2023
Under the supervision of Alexandre Chagnes and James Vaughan.
Title: Advanced chloride route for lithium extraction from spodumene ore
Abstract
Recently, the small world of lithium has been booming, both in terms of production (exploration, mining, processing) and in modern industrial applications such as for mobile or stationary storage of electrical energy. Among the commercially suitable sources of lithium, spodumene (LiAlSi2O6) is the mineral that attracts the most interest. Consequently, various processes for recovering the lithium values from spodumene ore have been proposed. The practical applications of these processes have been largely limited to two approaches: the limestone method and the sulfuric acid process. However, these methods have intrinsic drawbacks, including high levels of sulfate and heavy metal ions in the product, the requirement for a sophisticated process for recovering sodium sulfate for the former as well as high limestone and energy requirements for the latter. It is interesting to highlight that, in spite of these drawbacks, the sulfuric acid process has become the main method for production of lithium carbonate from spodumene due to its high efficiency. The present project aims at developing an alternative process for the recovery of lithium from spodumene and to compare this new process with the conventional process relying on sulfuric roasting of spodumene concentrates, water leaching and precipitation purification. This alternative approach will implement chlorination in order to selectively produce LiCl salt, which is easily solubilized in water. The resulting aqueous solution will be purified by solvent extraction to produce LiCl salts that could be used directly for lithium metal production or to produce high-grade lithium carbonate or lithium hydroxide salts for lithium-ion battery materials. After an overview of the different processes implemented in the production of lithium and a special focus on the chemistry of lithium in chloride media, the PhD student will start to determine the best parameters to perform efficient chlorination of spodumene, which will be first thoroughly characterised. The development of the chlorination process will be performed using computational thermodynamic tools such as HSC Chemistry software. The resulting solution from chlorination containing lithium chloride and some impurities will be purified by solvent extraction and/or resin-ion exchange and/or precipitation depending on literature data and preliminary tests. Precipitation will then be performed in order to produce lithium salt. The flowsheet development will be conducted in the context of producing high-grade salt for battery application.
Kristijan RAJIC
Defended on 10-03-2023
Under the supervision of Hugues Raimbourg and Stéphane Scaillet
Title: Tectonique, métamorphisme et circulation des fluids dans les complexes d'accrétion
Abstract
Fluids are strongly involved in the majority of subduction zone processes, from influencing seismic activity via the pore fluid pressure variations, to triggering melting of the upper plate mantle through the transfer of water originated from dehydration reactions. Subducted sediments are a major carrier of fluids and volatile species into subduction. While numerous studies have focused on the deep, ductile realm, in comparison, the shallower domain at the brittle-ductile transition and above, has deserved less attention. We focused on fluid composition and fluid-rock interaction in sedimentary rocks from three accretionary complexes (the Kodiak complex, the Shimanto belt, Japan, and the Western Alps), in the temperature range 220-380℃. Field work has been conducted in Kodiak, to decipher tectonic evolution of the Kodiak complex and its thermal evolution. We were able to discriminate between deformation that occurred along the plate-boundary interface (top-to-the-trench non-coaxial shear) and as intra-wedge deformation (horizontal coaxial shortening). Thermal profile point to small variations in temperatures in the complex (220-380℃), with highest temperatures in central part. The thermal gap is recorded around the unconformity that separates the basally accreted units and the slope sediments (100-140℃), indicating vigorous vertical motion in the complex, with the amplitude of motion up to 10 km. To evaluate fluid-rock interaction, we applied a wide range of analytical techniques on whole-rock scale, minerals and fluid inclusions (FI). In metapelites from Kodiak and Shimanto, illite-to-chlorite transformation is the main mineral reaction between 250-330℃, in parallel to the salinity increase recorded in FI. Such reaction requires H2O and the simplest explanation is the consumption of pore fluids, contributing to a decrease of porosity in pelites. Textures, mineral reactions, fluid-mobile elements (FME; Li, B, Rb, Sr, Cs, Ba), and mass-balance calculations point to a local transfer of material as redistribution between minerals without external exchange in Kodiak. In contrast, samples from Shimanto show significant loss of FME from 250 to 330℃, supported by FME loss in chlorite and illite as temperature rises. Finally, δ7Li of FI was analyzed using crush-leach technique. δ7Li of FI covers a very large range, from -1.54 to +17.07. In Kodiak, the fluid is relatively heavy (+8.1 to +17.07), related to the crystallization of chlorite characterized by high lithium content. As chlorite preferentially consumes 6Li, the fluid remains isotopically heavier. Conversely, FI from Shimanto are isotopically lighter (+2.53 to +10.39) than from Kodiak, consistent with lithium loss from chlorite as temperature increases. The temperature dependent isotopic fractionation between quartz and fluid is not observed, which may be explained by disequilibrium crystallization of quartz from fluid, or as a result of dissolution-precipitation reactions postdating FI entrapment. Lithium concentrations and δ7Li of FI leachates suggest constant interaction between fluid and sediments, where δ7Li of fluids is shifted towards the signature of the protolith. While major elements and lithium isotopes do not require any external exchange both in Kodiak and Shimanto, the FME in Shimanto indicate in contrast that significant transfers occurred through the fluid phase. FME appear therefore as the most sensitive geochemical signal to track volatile and elemental transfers at depth. The difference between Kodiak (close) and Shimanto (open system with respect to FME) is interpreted as controlled by the amount of internal strain and the proximity to large-scale fault zones.
Bastien JALLY
Defended on 22-02-2022
Under the supervision of Marie-Odile Simonnot and Yetao Tang
Title: Expanding Agromining to the rare-earth elements: Key elements of success from a chemical engineering perspective
Abstract
Agromine is a flagship theme of LabEx Resources 21. Widely studied for nickel recovery, it has been explored for other metals and elements. As part of the Joint International Laboratory Ecoland (University of Lorraine, INRA - Sun Yat-sen University of Canton), research conducted at the LRGP in collaboration with the LSE have shown that it is possible to recover rare earth extracted from the soil by phytoextraction, using the fern Dicranopteris dichotoma, from mine tailings from South China (thesis of Z. Chour, defense scheduled for late 2018). The objective of the work proposed here is to acquire more generic knowledge on the recovery of rare earths from the biomass of hyperaccumulator plants, using hydrometallurgical processes. In addition, these plants also accumulate aluminum, the recovery of which has never been studied. First of all, it will be necessary to complete the knowledge acquired with Dicranopteris dichotoma. New separation strategies will be considered to complement those already studied (precipitation, ion exchange). Optimization will be sought, with a view to achieving an efficient process in terms of yield, and with low impacts on the environment. Other plants have recently shown interest in the accumulation of rare earths and aluminum, especially Phytolacca americana, a perennial herb, also present in temperate climates (Yuang et al., 2017). This plant has very different characteristics of the fern, the latter being distinguished by a high silica content. Therefore, the strategy of recovery of rare earths will be very different. To sum up, the scientific objectives concern the hydrometallurgical separation processes that make it possible to valorize the rare earths and aluminum contained in the biomasses of the two types of accumulators, including the understanding of the solid phase and solution speciation, the mechanisms in play, the measurement of equilibrium and kinetics governing separations. Beyond scientific perspectives, this research will identify one or more innovative processes that could then be scaled up (from the laboratory to the pilot) for a possible industrial transfer (e.g. Econick). This PhD thesis will be conducted under structure of LIA Ecoland, under the direction of MO Simonnot, Pr, and B. Laubie, MC (LRGP) on the French side and Y. Tang, Pr, and RL Qiu, Pr (Professor @Lorraine) Chinese side. A committee will be set up to include experts in agromine, including JL Morel, Pr (LSE), hydrometallurgy, such as A. Chagnes, Pr (Géoressources) and mineral resources, particularly in rare earths elements. The thesis proposal responds to a strong need for research in a field in full development at the level of the various partners involved.
Yujin JEGAL
Defended on 26-01-2022
Under the supervision of Cécile Fabre and Jean Cauzid
Thesis committee President: Jan Jehlička
Thesis committee members: Cécile Fabre, Jean Cauzid, Patricia Patrier, Éric Pirard, Emmanuelle Montargès-Pelletier
Examiners: Patricia Patrier, Éric Pirard
AbstractMineral exploration focused on deeply concealed targets at depth requires effective techniques applicable in the field in order to identify ore-forming systems on a large scale and pathfinders to locate ore on a smaller scale. According to the rapid development of portable equipment in recent years, the importance of near real-time analysis in the field has been increasing by helping fast decision-making support before laboratory requests.Spectroscopic analysis using individual equipment has been widely used in the exploration of mineral resources, but it is rare to apply integrated data from several techniques to characterize “vectors”, which provide variations in lithology, geochemistry, mineralogy, and mineral chemistry. In addition, it is even rarer if the combination of spectral data is obtained from various portable instruments. Therefore, this study aims at reconciling geochemical data acquired from portable spectroscopic devices in order to determine the best geochemical information from each technique applied by combining the mineralogical and elemental information. Elemental and mineralogical data are provided in this study by six portable techniques: (i) elemental analyses such as XRF and LIBS for major, trace, and light elements, and (ii) mineralogical analyses such as Raman, VNIR-SWIR, MIR, and XRD to constrain rock-forming, ore, and alteration minerals.The final objective of this study is to identify vectors to the ore by applying the reconciled multi-spectral data obtained from the “real” sample in the Elvira volcanogenic massive sulfide (VMS) deposit. To achieve this, step-by-step procedures were carried out: (i) methodological understanding of each technique, (ii) establishment of a spectral database consisting of naturally monomineralic minerals, (iii) design of a decision tree to classify by mineral or mineral classes based on diagnostic bands, and mineral identification and quantification of (iv) carbonate and (v) phyllosilicate minerals (i.e., trioctahedral chlorites and dioctahedral micas), which are indicators of the target deposit.Several limitations of portable spectroscopy were confirmed based on the device itself and the geological environment in the Elvira deposit. Nevertheless, portable spectroscopy is effective in identifying the presence and compositional changes of various minerals from heterogeneous rock samples. Therefore, spectroscopic analysis on-site can be one of the vectoring tools to determine the implication for ore mineralization in hidden ore explorations.
Romane TISSERAND
Defended on 12-02-2021
Under the supervision of Guillaume Echevarria and Antony van der Ent
Title: The Ni biogeochemical cycle in a tropical agromine metal crop system
Thesis committee President: Marie-Odile Simonnot.
Thesis committee members: Guillaume Echevarria, Antony van der Ent, Aïda Bani, Markus Puschenreiter, Joseph A. Pollard.
Examiners: Aïda Bani, Markus Puschenreiter
Abstract
Hyperaccumulation is a phenomenon that was only discovered 45 years ago, it has been the focused of very intensive research because of the unusual behaviour of metals in the ecosystem and also because it offers a vast potential for nature-based solutions. Describing the Ni biogeochemical cycle within the soil-hyperaccumulator plants ecosystem is necessary to elucidate the ecological role of hyperaccumulator plants in their natural environment, but also to understand their potential behaviour under tropical agromining systems. Agromining and exporting Ni rich-biomass will interrupt the cycle. It is therefore important to understand the mechanisms which govern the Ni biogeochemical cycle in both natural and agromining systems: What are the Ni cycles (internal and external) and their impact on the ecological functioning of tropical hyperaccumulator forest? How rapid are the Ni fluxes across the soil-plant compartments, and what is the turnover of Ni in a hyperaccumulator tropical system? How fast can a tropical Agromining crop deplete Ni in soil? How can we manage soil fertilisation for a sustainable tropical Ni agromining crop? Therefore, the objectives were: (i) to study the biogeochemical cycling of a natural forest of Phyllanthus rufuschaneyi in order to assess and evaluate the natural fluxes of Ni in the ecosystem; (ii) to manipulate such an ecosystem in order to perform a sensitivity test of the ecosystem for the following flux: litter return to the soil; (iii) to optimize the cropping system of P. rufuschaneyi for Ni agromining. Two parallel stands of P. rufuschaneyi were instrumented, monitored and compared over two years (2018 and 2019), (i) a natural secondary 100-m2 forest and (ii) a densely planted field in which litter returns to the soil were calibrated; from no return (export) to a doubling of the return.This study did not prove allelopathy of tropical hyperaccumulator plants, despite the extreme influence of Ni hyperaccumulators in building up available Ni stocks in topsoils. Nickel cycle was mainly driven by internal fluxes, i.e. degradation and recycling of the hyperaccumulator biomass. The percentage of Ni recycled by litterfall tended to decrease with increasing litter addition to the soil and was not influenced by coppicing, at least in the short term. Major nutrient (NPK) fertilisation did not affect Ni yield (i.e. 75kg Ni ha-1 yr-1) in the short term either, even if N fertilisation reduced Ni concentrations in leaves and plant biomass production. Nickel turnover should be taken into account when designing tropical agromining crops and natural secondary forests are a good surrogate to evaluate the long term impacts of agromining. Further study of the weathering processes would help to precise the contribution of bedrock and soil mineral horizons in the Ni and nutrient budgets of the system.
Ruoyu HU
Defended on 10-03-2021
Under the supervision of Corinne Leyval
Title: Mobility and transfer of rare earth elements from soil to plants by arbuscular mycorrhizal fungi
Thesis committee President: Laure Giamberini
Thesis committee members: Corinne Leyval, Thierry Lebeau, Erik Joner, Ye-Tao Tang, Nathalie Séjalon-Delmas, Alexis De Junet.
Examiners: Thierry Lebeau, Erik Joner.
Abstract
Rare earth elements (REE) are a group of strategic metals that have been widely used in modern technologies in the recent decades. However, due to the corresponding REE emission from industries and the over-exploitation, large amounts of anthropogenic rare earth can accumulate in the environment, and be phytotoxic. Arbuscular mycorrhizae (AM) benefit to plants in metal-contaminated soils by improving their survival and growth and alleviating metal toxicity, but little information is available about soil contaminated by rare earth elements. The objective of this PhD project is to understand the transfer of REEs from soil to plants and especially the role of AM fungi on plant growth and REE transfer to plants in REE contaminated soils. Experiments were launched using a model legume plant alfalfa (Medicago sativa), a model REE samarium (Sm), and a metal-tolerant Funneliformis mosseae fungus in a growth chamber. We first studied the bioavailability and transfer of an REE to Medicago sativa grown on two contaminated soils differing in their chemical characteristics. The results showed that DTPA extractable Sm was well correlated with Sm uptake in alfalfa shoots. Although the soil to plant transfer factor was low, alfalfa biomass was reduced when the soils were spiked with 100 to 200 mg kg-1 of Sm. Then the hypothesis was drawn that arbuscular mycorrhizal fungi might protect the plant against REE toxicity. Therefore, a pot experiment was launched to study the role of AM fungi on alfalfa growth and a compartment experiment was performed to study the transfer of Sm to alfalfa via AM fungal hyphae. The biomass of alfalfa grown on Sm-spiked soil was significantly higher following arbuscular mycorrhiza inoculation. P content was also higher in mycorrhizal than nonmycorrhizal plants, but there was no significant Sm transfer to the plant by F.mosseae. Since there are often multiple REEs in contaminated soils, including light (LREE) and heavy (HREE) REEs, a compartment experiment was launched using 4 REEs, alfalfa and ryegrass, which confirmed that there was no transfer of the 4 REEs to alfalfa plants by F.mosseae. Finally, an REE mining soil collected from China was used to analyze the toxicity of REEs to AM fungal spores and to leek plants inoculated or not with the AM fungus, using spore germination assays and a plant growth experiment. The high concentration of REEs significantly inhibited plant growth and spore germination rate, and the fungus tolerated relatively high REE concentrations, but there was no significant difference in REE tolerance between two isolates of F.mosseae. Other fungi and plants should be tested, and field experiments performed, but our results suggest that arbuscular mycorrhizal plants might be considered in phytorestoration of REE-contaminated soils.
Otonne SCAMMACCA
Defended on 03-12-2020
Mining risk assessment at the territory scale : development of a tool tested on the example of gold mining in French Guiana
Under the supervision of Yann Gunzburger and Rasool Mehdizadeh
Thesis committee President: Jean-Louis Morel
Thesis committee members: Yann Gunzburger, Rasool Mehdizadeh, Franck Marle, Claire Côte, Nicolas Rollo, Magali Rossi, Anne-Sylvie André-Mayer.
Examiners: Franck Marle, Claire Côte
Abstract
Mining can be the source and target of opportunities and threats of different natures exceeding the mine-site perimeter, affecting the socio-ecological system where mining is performed and leading to social tensions and entrepreneurial risks for mining companies. Hence, a mining project is a matter of land-planning rather than a simple industrial object. Nevertheless, current mandatory risk and impact assessment methods are often performed on one project at a time, sometimes neglecting the cumulative dimension of risks, the great variability of coexistent mining activities, and the socio-ecological vulnerability in which mining is performed. This thesis proposes an approach to develop and compare, based on the assessment of their risk, different potential scenarios for land-planning strategies in mining territories. This approach is operationalized through the development of a framework via its application on French Guiana gold mining sector. Here, gold mining involves a great variety of forms and techniques in a very sensitive socio-ecological context. Five territorial mining scenarios (TMS) involving different mine-types (e.g. legal artisanal, medium, large scale mining, illegal mining) are developed for the same amount of gold production. For each TMS, two types of risk scenarios are distinguished whether they concern the normal or accidental (e.g. dam failure) functioning of the mining project(s). Risks are assessed through a GIS-based approach that consider the socio-ecological vulnerability of the territory where the mines are located. The TMS are finally weighted, discussed and compared based on a global risk score. Despite the reliability of its results, this thesis provides an original and adaptable approach for the rapid comparison of mining strategies at the territory level, based on risk assessment. Further developments need to be achieved in order to optimize and improve the proposed approach and its application to the selected case-study (e.g. integration of the uncertainty analysis, better probabilistic models, data availability, GIS-automated tools).
Dulce MONTSERRAT NAVARRETE GUTIERREZ
Defended on 30-11-2020
Under the supervision of Guillaume Echevarria, Jesús A. Cuevas Sánchez and Marie-Noëlle Pons.
Title: Plant Metal Hyperaccumulation in Mexico : Agromining Perspectives
Thesis committee President: Clístenes W. Araújo do Nascimento.
Thesis committee members: Guillaume Echevarria, Jesús A. Cuevas Sánchez, Marie-Noëlle Pons, Christina Siebe, Teodoro Gómez Hernández.
Examiners: Clístenes W. Araújo do Nascimento, Christina Siebe.
Abstract
Agromining technology involves the recovery of strategic metals from metalliferous soils through the cultivation of metal(loid) hyperaccumulator plants. The impetus of this research was to evaluate the potential of Mexican plant resources for the future development of agromining. The main objectives were then to identify and to study some metal hyperaccumulator plant species in Mexico, and to assess the agronomy of one promising “metal crop” for agromining. We first undertook field explorations in three nickel-rich ultramafic regions of central and southern Mexico. Despite the availability of soil and climatic conditions, no nickel (Ni) hyperaccumulation was found in any of these regions. A second strategy based on plant phylogeny as a prediction tool for metal hyperaccumulation was followed. In total, ten plant metal hyperaccumulator species were identified during this research (Rubiaceae and Violaceae) in Ni-enriched soils influenced by volcanic activity in Southeastern Mexico; most of them were priorly unknown. Our studies revealed two of the strongest hypernickelophores reported so far (>4%wt Ni) and two new Ni hyperaccumulator genera (Orthion and Mayanaea). Special focus was given to the hypernickelophore tree Blepharidium guatemalense. The phloem on leaves, roots, stems and petioles of this plant are the richest in Ni suggesting an unusual re-distribution mechanism via the phloem. Different agronomic practices were tested for this plant. Synthetic fertilization strongly increased nickel uptake without any change in plant growth or biomass, whereas organic fertilization enhanced plant shoot biomass with a negligible effect on foliar Ni concentrations. A 5-year-old stand which was subsequently harvested twice per year produced the maximum Ni yield tree⁻¹ yr⁻¹, with an estimated total nickel yield of 142 kg ha⁻¹ yr⁻¹. Blepharidium guatemalense is a prime candidate for Ni agromining on the account of its valuable traits: extremely efficient Ni uptake, high biomass production, fast growth rate, and easy to reproduce.
Nina BOTHAMY
Defended on 01-10-2020
Under the supervision of Raphaël Pik
Title: Anthropogenic and natural fractionation of stable neodymium (Nd) isotopes in the environment
Thesis committee President: Laure Giamberini
Thesis committee members: Raphaël Pik, Jean-Alix Barrat, Aline Dia, Sylvain Pichat.
Examiners: Jean-Alix Barrat, Aline Dia
Abstract
With the worldwide growing demand for various applications (new technologies, green energies, etc.), rare earth elements (REEs) are now considered as emerging pollutants. These pollutions are/will be of industrial origin (e.g. industrial wastes), of mining origin, or caused by the inappropriate storage of industrial products (e.g. neodymium (Nd) magnets fragile against corrosion). In this context, this PhD project aims to develop a new tool: the study of the mass-dependent isotopic fractionation of Nd (δNd in ‰). The goals of this work were to i) bring the maximum of information in order to help to identify and trace anthropogenic Nd in the environment, and ii) help the understanding of how plants accumulate REEs, especially the hyperaccumulator Dicranopteris linearis ferns, in order to support the studies about the phytoremediation of polluted areas. The δNd of anthropogenic materials (pure Nd synthetic solutions, Nd2Fe14B industrial magnets; δ148Nd range of 1.45 ‰, literature included) was compared to the signature of natural terrestrial rocks of the literature (δ148Nd range of 0.66 ‰). Our results show that the use together of i) the 143Nd radiogenic isotope (ε143Nd, tracer of sources), ii) the stable Nd isotopic composition of Nd (δNd, tracer of sources and processes) and, iii) the kind of stable Nd isotopic fractionation (kinetic or thermodynamic equilibrium), could allow the distinction of the natural from the anthropogenic Nd, and to trace the anthropogenic Nd in the environment. The measurement of the δNd of 5 D. linearis fern specimens, and of 3 biological standards (lichen, apple leaves and duck weed) allowed discovering that biology can fractionate the stable Nd isotopes. Extreme δ148Nd values are -0.415 ± 0.060 ‰ and -0.011 ± 0.022 ‰ (2σmean), respectively for one of the fern petiole and the duck weed. Three principal results were obtained: i) the δNd fractionation is correlated to the fractionation of the light REEs than the heavy REEs for all the studied samples (ferns, lichen, apple leaves, duck weed and all soil materials); ii) the distribution and transport of Nd (and REEs) in the different parts of ferns are correlated to those of manganese (Mn), suggesting similar transport mechanisms for REEs and Mn, for ferns but also for other plants as apple trees; iii) the degradation of clay minerals, on which REEs are mostly adsorbed in the studied soils, can induce the fractionation of stable Nd isotopes, from natural processes (e.g. biological) or anthropogenic processes (REEs mining acidic extraction).
Eleonora CAROCCI
Defended on 13-12-2019
Title: Tungsten transport and deposition in magmatic-hydrothermal environments : the example of Panasqueira (Portugal
Under the supervision of Michel Cathelineau and Laurent Truche
Thesis committee President: Mercedes Fuertes-Fuente.
Thesis committee members: Michel Cathelineau, Laurent Truche, Johann Raith, Jean-Louis Hazemann, Cécile Fabre.
Examiners: Johann Raith, Jean-Louis Hazemann
Abstract
Panasqueira W-Cu-Sn deposit (Portugal) consists of sub-horizontal mineralized veins of Qtz-Wfm-Cst-Ms-Toz-sulfurs. Qtz dissolution-recrystallization is the rule, complicating the setting up of the paragenetic sequence and the study of earliest stages over later superimposition. A considerable part of this thesis is devoted to the mineralogical study of the first wolframite (Wfm) depositional stage, which is the most valuable in terms of ore (W)-quantity. It is preceded by a tourmalinization coeval with W-rich rutile (305.25.7Ma). Studies on rutile have shown that oscillatory zoning is the result of the successive mixing between a W-rich, Nb + Ta poor fluid, with a Nb+Ta-rich and W-poor fluid. Also, Tur crystal composition (good recorder of the ore-fluid chemistry) has confirmed a multi-sources origin for W-transport and Wfm deposition. However, the hydrothermal transport and deposition of W are not well constrained. Here we use Raman spectroscopy coupled to the fused silica glass capillary technic to define the stability of the tungsten-polymers at different temperatures (up to 400°C) and pH. As a result, tungsten has a strong tendency to form complexes characterized by Kegging structures in acidic conditions which precipitate at high T, while its solubility increase with the pH increment. Fluid inclusion studies have been taken in consideration in this work, to evaluate the evolution of Panasqueira hydrothermal system. FI on quartz belonging to latest depositional stages have been examined and results have shown that trapping conditions are characterized by lower pressure and elevated temperatures. This allows to conclude that high geothermal gradient affected the studied zones at several stages and are related to heat advection produced by concealed granites from 305 to 295 Ma.
Yann FOUCAUD
Defended on 25-10-2019
Title: Tungsten recovery from a skarn with a low separation contrast : Contribution of molecular modelling in the flotation of calcium minerals
Under the supervision of Lev Filippov and Inna Vladimirovna Filippova
Thesis committee President: Vanessa Fierro
Thesis committee members: Lev Filippov, Inna Vladimirovna Filippova, Jean-François Paul, Martin Rudolph.
Examiners: Jean-François Paul, Jan D. Miller
Abstract
Nowadays, skarns represent more than 40% of the global resources in tungsten, which has been classified as a critical raw material in the European Union. In particular, the Tabuaço deposit constitutes an archetype of tungsten skarns and contains high amounts of calcium minerals, including fluorite, apatite, and vesuvianite, in close association with scheelite (CaWO4). According to their similar surface properties, the separation of these minerals by flotation with fatty acids is significantly difficult and, therefore, remains a scientific challenge. In this study, which has been conducted within the framework of the FAME H2020 European project, an economic, environment friendly, and transferable process has been developed for the Tabuaço ore to demonstrate the feasibility of the tungsten skarns processing. In the froth flotation process, the Na2CO3/Na2SiO3 system has exhibited the best efficiency in terms of gangue minerals depression due to considerable synergistic effects that have been subsequently described by statistical, spectroscopic, and atomistic methods. Meanwhile, the influence of the ratios between different carboxylic acids in the collector formulations (Tall Oil Fatty Acids) has been assessed to improve the flotation selectivity. In addition, the enhanced gravity separation (Falcon centrifuge concentrator) has been investigated, optimised, and combined with the flotation to produce a marketable scheelite concentrate assaying 63% WO3 with 59% recovery. Besides, to gain understanding in the molecular mechanisms involved in the flotation process, the fluorite and scheelite interfaces have been modelled using the density functional theory. This study has allowed to characterise the hydration state of these minerals, which display different affinities for water molecules. Furthermore, the adsorption of fatty acids on fluorite has been studied to unravel the adsorption mechanisms of these molecules on calcium minerals, confirmed by experimental investigations.
Nicolas GROSJEAN
Title: Study of rare earth element responsive genes in model organisms
Under the supervision of Elisabeth M. Gross and Marie Le Jean
Thesis committee President: Sébastien Thomine
Thesis committee members: Markus J. Tamás, Catherine Curie, Adam Schikora, Damien Blaudez, Michel Chalot
Examiners: Markus J. Tamás, Catherine Curie
Abstract
Rare earth elements (REEs) are strategic metals whose demand in the 21st century is increasing as a result of their essential properties useful to the fields of renewable energies, medicine, and high-technologies. They are classified as heavy REEs (HREEs), light REEs (LREEs) and non-lanthanides. Their dissemination in the environment, together with poor recyclability, leads REEs to be considered emerging contaminants, for which toxicity studies are currently very fragmented. To build a strong general foundation on the cellular and molecular response to REEs, we first adopted high-throughput and complementary strategies to study the REE stress response and their uptake in the unicellular eukaryotic model Saccharomyces cerevisiae. The deletome, transcriptome, proteome and ionome of yeast were analysed together with in-depth physiological experiments. Although common responses between REEs and other metals were highlighted, REE-specific responses were predominant. Cell wall composition, sphingolipid biosynthesis, the ESCRT pathway and endocytosis were emphasized as key elements in the cellular response to REEs. Second, we explored how REEs affect the transcriptome and ionome of the plant model Arabidopsis thaliana. REE exposure negatively affected the root architecture, as revealed by the modulation of auxin-related genes. REEs impaired the ionome, and Fe deficiency-related genes were largely represented among the most differentially expressed genes in both roots and leaves. Additionally, to identify new REE-accumulating plant models, collections of ferns and Phytolacca species were screened. Despite a conserved REE accumulation trait for Phytolacca and a few fern genera, HREE enrichment was observed in Phytolacca, while LREEs were preferentially transferred into the fronds of all fern species. However, several Dryopteris species harboured contrasting REE contents in the fronds. The latter species will be of great importance in deciphering the mechanisms of REE accumulation and tolerance. Overall, the response towards REEs differed according to their ionic radius. The cell wall composition, vacuolar detoxification, and the accumulation and fractionation of REEs notably accounted for these differences. Our findings support LREE-mediated entry through calcium channels, while new evidence was provided for the role of Fe transporters in the accumulation of HREEs. In conclusion, we have provided new insights into REE toxicity and specificities, together with the molecular elucidation of REE effects that have not previously been mechanistically explained. This work is a first multi-approach comprehensive groundwork that will be used for future studies to deepen the understanding and assessment of REE toxicity in organisms.