A la carte dissolution of rare earth elements from lateritic and karstic bauxite residues at mild pH: Toward sustainable extraction processes

International audienceRecovery of rare earth elements from bauxite residues of lateritic versus karstic origin was explored at a pH ranging between 2.7 and 4.5 using a mixture of citric acid and citrate in water. Dissolution yields of up to 82 % for lanthanum and 62 % for yttrium were achieved with excellent selectivity toward iron (a selectivity factor of up to 4200), the main element of bauxite residues. An experimental Box-Behnken statistical design identified the concentration of citric acid/citrate and temperature as key factors controlling the dissolution yield and selectivity of rare earth elements. Observed differences in dissolution yields and selectivity as a function of origin were attributed to differences in the speciation of rare earth elements in the two bauxite residues. It is therefore possible to draw an "à la carte" graph that identified the optimum citric acid/citrate concentrations and dissolution temperatures for dissolution yields and selectivity for the two BRs. This work provides fundamental knowledge for the future development of sustainable processes for the recovery of rare earth elements from bauxite residues derived from bauxites of different origin

Coopérer pour le bien-être ou collaborer pour la croissance ?: Compte-rendu de la conférence introductive d’Eloi Laurent

Numéro coordonné par Lucie Bruis-Gervasone et Anne-Gaëlle BeurierInternational audienc

Few-layered-graphene - Si3N4 composite powders prepared by decomposition of methane onto a Si3N4 powder bed: Control of the average number of layers in the graphene stack

International audienc

The difficult conversion of an industrial town nostalgic for its past into a creative city

International audienc

Subordinates' perceptions of the need- supportive, need-thwarting, and need- indifferent behaviors used by their supervisors: A person-centered investigation

International audienceAdopting a recent tripartite operationalization of subordinates’ perceptions of their supervisors’ behaviors, anchored in Self-Determination Theory (SDT), this person-centered study considers the co-existence of subordinates’ perceptions of their supervisors’ need-supportive, -thwarting, and -indifferent behaviors. Moreover, we also consider how these various combinations (or profiles) of perceived supervisor behaviors relate to subordinates’ levels of work motivation, well-being, attitudes, behaviors, and work-home functioning. A sample of 596 French employees (Mage = 31.22; 73.5% women) participated in this study. Our results revealed six profiles of subordinates characterized by distinct configurations of perceived need-related behaviors from supervisors (Globally Unfavorable; Globally Favorable and Supportive; Moderate-Indifferent; Moderately Favorable and Involved; Moderately Unfavorable; Moderately Favorable). These profiles displayed well-differentiated patterns of associations, consistent with our expectations, with all of the outcomes considered in this study. These findings underscored the key role of subordinates’ specific perceptions of need-supportive, -thwarting, and -indifferent behaviors, over and above their global perceptions of their supervisors’ behaviors, in determining how beneficial or harmful supervisory profiles are. In particular, our results also highlighted the critical role played by need-indifferent behaviors, which prove to be a very important, and yet typically neglected, component of subordinates’ perceptions of their supervisors’ behaviors

Digital Transformation for DIY Business Sustainability and Growth in Emerging Markets

International audienc

Lexical aspect: the case of prefixes in Old French

International audienc

Réussir à innover en matière de prévention des risques : de la recherche-action collaborative à la mise en retrait des chercheurs

National audienc

Benefits of a group-based running session on feelings of energy and fatigue: No augmenting effect of green exercise during the defoliation season

International audienc