Eramet Research

Trappes, France

Eramet Research

Trappes, France
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Agency: European Commission | Branch: H2020 | Program: CSA | Phase: WASTE-4d-2015 | Award Amount: 1.50M | Year: 2015

Refractory metals (tungsten, tantalum, rhenium, molybdenum and niobium) are highly strategic metals today mainly imported from a few countries. The European primary production remains below a few percentage. However, resources exist in Europe, as primary resources but mainly as secondary resources (industrial waste, urban mines). Valorizing these resources requires coordination and networking between researchers, entrepreneurs and public authorities to harmonise technologies, processes and services, develop standards, create new potential for export of eco-innovative solutions and for seizing new markets MSP-REFRAM will address these challenges by creating of a common multi-stakeholder platform that will draw the current refractory metals value chains and identify its innovation potential in order to support the implementation of the EIP on Raw Materials. Coming from industry, research, public sectors and civil society, both Consortium Members and External Experts have joined forces with expertise covering the whole value chain including mining, processing, recycling, application. The outputs of MSP-REFRAM will help Europe improve the supply value chain of refractory metals in the coming years, optimising the use of external resources as energy and water and at the same time reducing the amount and the toxicity of waste. MSP-REFRAM will share its conclusions widely and efficiently, in a long lasting way thanks to the support of the PROMETIA association. To ensure the systemic change, the outcomes of the project will be made available to the stakeholders and to the public through different tools and reports. In the medium term, MSP-REFRAM will contribute to better-informed decision-making at EU and national level as well as industry by proposing innovative value chains that will boost the refractory metals sector. In the longer term, this should improve the availability of these refractory metals, while creating greater added value to the economy and more jobs.

METAL 2015 - 24th International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2015

Refractory linings of metallurgical furnaces have two main purposes: to control the heat flow, and to contain high temperature liquids (metal and slag). Through a proper management of heat flows, a layer of slag called freeze lining crystallizes on the internal walls of the furnace thereby protecting the bricks from the very corrosive high temperature liquid slag. The thickness, stability and properties of this frozen slag are key parameters for the performance of a safe and stable process. In situ observations of the crystallization process during furnace operations are very difficult. To overcome this difficulty, the present work proposes a combination of heat flow monitoring, numerical modeling of heat transfer and the mineralogical characterization of the residual freeze lining after the furnace operation. The combination of these tools helps with the management of the process and the understanding of how to preserve the thermal balance of the furnace and the stability of the refractory lining. Within a pilot furnace freeze lining, physical and chemical properties change depending on the operation parameters. The thickness of the free lining is one of the most important process variables to follow-up. An inverse heat transfer issue is solved using the software FLUENT in a simplified 2-D axisymmetric geometry of the furnace. After completion of the pilot, the freeze lining of the furnace is analyzed and characterized. All the significant evolutions in the operating parameters (temperature variations, slag chemistry changes) are recorded within the oxide layers of the skull. Additionally to characterization, the crystallization paths that occurred during the process can be calculated using thermodynamic equilibrium computations. This work provides a multi-disciplinary approach to understand usually unobservable phenomena within the furnace, allowing an estimation of the thickness, and physical and chemical properties of the freeze lining inside furnace.

Morgan R.,University Paris - Sud | Orberger B.,University Paris - Sud | Orberger B.,Eramet Research | Rosiere C.A.,Federal University of Minas Gerais | And 3 more authors.
Precambrian Research | Year: 2013

This is the first petrographic and chemical study on the origin of co-existing calcite, dolomite, ankerite and sideroplesite in the 2.4. Ga Itabira Group, Brazil. The Itabira Group hosts silicic and dolomitic BIFs, known as quartz itabirites and carbonate itabirites, which are composed of micritic quartz and dolomite with inclusions of nano- and micro-hematite. Nanometric Si-bearing ferrihydrite clusters are observed in the micritic dolomite. Mineralogical and textural features indicate a primary oxidising depositional environment for the Itabira Group at 2.4. Ga. Limestones of the Itabira Group include early diagenetic hematite nodules intergrown with dolomite. Silica in the ferrihydrite structure increases its stability up to 500. °C, and the nano- and micro-hematite included in dolomite and quartz were partially protected from later transformation by being enclosed within the dolomite and quartz crystals.Positive Eu and Y anomalies and heavy rare earth element enrichments of all lithofacies, along with their low terrestrial element abundance (excluding the shales), indicate their primary precipitation from a mixed hydrothermal-marine environment. In the case of the carbonate itabirites, fluids were CO2 rich. Dolomite precipitated abiotically due to higher temperatures (~100°C) and high Mg/Ca ratios. The facies changes from carbonate-rich to quartz-rich are attributed to transgression and regression episodes and/or a change in the upwelling hydrothermal fluid composition.Post depositional reductive dissolution affected the quartz itabirites facilitating the precipitation of ankerite, sideroplesite and magnetite/sulphides from a reducing diagenetic solution, rich in Mn, Mg and Fe, either as lenses or disseminated, in the quartz itabirites and shales. The sideroplesite-richest samples have the most negative δ13C values (quartz itabirite: -9.49‰; shale: -5.76‰), indicating that at least part of the C is of organic origin, either through the oxidation of organic matter or introduced via the diagenetic fluids. Specularite is replacive and likely related to a post-depositional hydrothermal event.This study shows that careful mineralogical investigations combined with REE. +. Y and trace element geochemistry is necessary in order to decipher the depositional environments, which are oxidising, mixed marine-hydrothermal. Post-depositional reductive diagenesis masks in part these primary conditions. © 2012 Elsevier B.V.

Deblonde G.J.-P.,Chimie Paristech | Deblonde G.J.-P.,Eramet Research | Chagnes A.,Chimie Paristech | Belair S.,Eramet Research | Cote G.,Chimie Paristech
Hydrometallurgy | Year: 2015

Abstract The solubility of both Nb(V) and Ta(V) has been investigated as a function of pH at 25 °C in alkaline media. Solid phase analysis revealed that a phase transition between Nb2O5·nH2O(s) and Na7HNb6O19·15H2O(s) occurs even under mild conditions (8 ≤ pH ≤ 12). Similar phase transition is also expected to take place between Ta2O5·nH2O(s) and Na8Ta6O19·mH2O(s), but at pH higher than 12. The observations, supported by Raman spectroscopy and XRD analysis of the solid phases and UV spectrophotometry of the solutions, show that hexaniobate ions HxNb6O19x - 8 (0 ≤ x ≤ 3) play a major role in the solubility of Nb(V) in alkaline media. The solubility of Na7HNb6O19·15H2O(s) was investigated at 25 °C and strongly depends on the interactions with the background electrolyte. Modeling of the solubility data suggests that ion-pairs are not formed between Na+(aq) and HNb6O197 -(aq). The solubility product measured for Na7HNb6O19·15H2O(s) is Ks = 2.275 ∗ - 10- 12 at 25 °C. Oppositely, ion-paring effect occurs in K+-containing media leading to an enhancement of the solubility of Na7HNb6O19·15H2O(s). This effect could be of interest for the development of Nb recovery processes. © 2015 Elsevier B.V.

Damian A.,Ecole Polytechnique - Palaiseau | Damian A.,Eramet Research | Maroun F.,Ecole Polytechnique - Palaiseau | Allongue P.,Ecole Polytechnique - Palaiseau
Nanoscale | Year: 2016

We investigate by in situ scanning tunnelling microscopy (STM) the potential dependence of the electrochemical dealloying of NiPd monoatomic layers electrodeposited on Au(111). The dealloying process is achieved by Ni selective dissolution and was studied as a function of NiPd composition: for an alloy with a Ni content ≥70%, quasi-complete Ni dissolution is achieved at a potential of -0.9 VMSE whereas for a Ni content <70%, Ni dissolution at the same potential drastically slows down after the removal of small amounts of Ni. The alloy morphology at this "passivation state" is characterized by the presence of holes in the alloy monolayer with evidence for the Pd enrichment at the hole edges. These findings are confirmed by Monte Carlo simulations. Further Ni dissolution at passivation was achieved by applying more positive potentials which depend on the alloy composition. These results allowed us to determine the correlation between the Ni dissolution onset potential and the local Pd content. © 2016 The Royal Society of Chemistry.

Deblonde G.J.-P.,Chimie Paristech | Deblonde G.J.-P.,Eramet Research | Moncomble A.,Lille University of Science and Technology | Cote G.,Chimie Paristech | And 2 more authors.
RSC Advances | Year: 2015

The UV-visible properties of hexaniobate (HxNb6O19x-8) and hexatantalate (HxTa6O19x-8) ions were investigated experimentally and by DFT calculations. Due to the huge discrepancies among the reported values found in prior studies, the extinction coefficients of hexaniobate ions were determined from multiple samples in various media. A simple and low-cost method was then developed for the determination of the niobium content of both synthetic and industrial samples. Taking advantage of the UV spectra of the hexaniobate ions, the first protonation constant of Nb6O198- could be determined experimentally (pKa = 13.4 ± 0.1 at 25 °C, ΔrH = -95 kJ mol-1 in 3 M KOH/KCl) and is in accordance with the reported values previously extrapolated from potentiometric measurements (pKa = 13.3 ± 0.6). UV batch titrations performed at different ionic strengths suggest that the equilibrium between the monoprotonated and the deprotonated forms of the Lindqvist ion is accompanied by an exchange of potassium ions and that the cluster is easier to deprotonate in Na+ media. This study highlights the importance of the ion-pairing on the chemistry of these polyoxometalates. The tremendous difference between the UV spectrum of Nb6O198- and Ta6O198- was investigated by DFT computations. The UV spectra were reproduced and show a good agreement with the experimental data. Moreover this study revealed some insights into the evolution of the spectra together with the pH of the medium by studying the nature of the transitions involved in this spectral domain. © 2015 The Royal Society of Chemistry.

Deblonde G.J.-P.,Chimie Paristech | Deblonde G.J.-P.,Eramet Research | Chagnes A.,Chimie Paristech | Weigel V.,Eramet Research | Cote G.,Chimie Paristech
Hydrometallurgy | Year: 2015

The recovery of Nb(V) and Ta(V) from alkaline solutions was investigated using calcium-bearing reagents (CaCl2(aq), Ca(CH3COO)+ (aq), Ca(NTA)- (aq), Ca(EDTA)2- (aq), CaCO3(s) and Ca(OH)2(s)) at 25°C. It was found that hexaniobate and hexatantalate ions (HxNb6O19 x-8 and HxTa6O19 x-8; 0≤x≤3) can be quantitatively precipitated with calcium chloride, calcium acetate or calcium hydroxide when the ratio (Ca/M)initial is at least 0.4mol/mol (M=Nb, Ta). Precipitation yields higher than 95% are obtained for solutions that contain, as low as, 3*10-4 mol/L of Nb and 1*10-4 mol/L of Ta. Moreover, the proposed precipitation method can be operated in a wide pH range and consumes two times less reactant than the classical way for recovering Nb and Ta which consists of neutralizing their alkaline solutions with a mineral acid. The amorphous calcium niobate concentrate was characterized by elemental analysis (ICP-OES), thermogravimetric analysis (TGA-MS) and Raman spectroscopy and the solid phase K3Ca2.2(H0.6Nb6O19)·nH2O was identified under specific conditions. © 2015 Elsevier B.V.

Damian A.,Ecole Polytechnique - Palaiseau | Damian A.,Eramet Research | Maroun F.,Ecole Polytechnique - Palaiseau | Allongue P.,Ecole Polytechnique - Palaiseau
Electrochimica Acta | Year: 2010

In this work we study the electrochemical growth and dissolution of a Ni on Pd-Au(1 1 1) bimetallic surfaces using in situ scanning tunnelling microscopy. We also compare Ni deposition on monometallic electrodes, i.e. Au(1 1 1) and Pd(1ML)/Au(1 1 1), using electrochemical characterizations. Results evidence that the first Ni monolayer grows preferentially on Au(1 1 1) in a wide potential range, and that a full Ni monolayer covering the entire Pd-Au surface can be selectively dissolved from Pd islands. No such selectivity is observed upon growth of subsequent Ni atomic planes. We demonstrate that the Ni-substrate interactions play a key role in the above mentioned selectivity. The binding energy of Ni to Pd is found to be 80 meV smaller than of Ni to Au. The sign and the amplitude of this difference are discussed in light of the d band filling of the Pd-Au(1 1 1) bimetallic surface and the presence of adsorbed H on Pd before deposition. © 2010 Elsevier Ltd. All rights reserved.

Beltrami D.,ERAMET Research | Deblonde G.J.-P.,ERAMET Research | Belair S.,ERAMET Research | Weigel V.,ERAMET Research
Hydrometallurgy | Year: 2015

To overcome the low recovery, generally obtained for the heavy and middle rare earth elements (HREE and MREE) by sodium double sulfate precipitation, the recovery of the MREE and HREE as phosphate salts was investigated. High recovery yields (≥95%) were obtained even for sulfate solutions containing low concentrations of REE and a high concentration of iron(II). The influence of many industry-relevant parameters (temperature, pH, stoichiometric excess of phosphate, aluminum contamination, residence time) is discussed in order to optimize the REE recovery and to minimize the precipitation of iron. The developed process was also validated in continuous operation at a pilot scale. Finally, the REE phosphate concentrate could be converted into REE hydroxides which allows its dissolution into diluted HCl. Taking into account the phosphate precipitation, the conversion into hydroxides and the dissolution in HCl(aq), high recovery yields were obtained for Y, Gd and La (68%, 77% and 86% respectively). The results show that it is possible to economically obtain purified REE solutions starting from industrial solutions which are usually discarded. © 2015 Elsevier B.V.

PubMed | Chimie Paristech and Eramet Research
Type: Journal Article | Journal: Dalton transactions (Cambridge, England : 2003) | Year: 2016

Solvent extraction of Nb(v) from alkaline aqueous media using quaternary ammonium solutions, especially Aliquat 336 diluted in an aliphatic diluent, was investigated. The hexaniobate ions (H

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