Recyclage sélectif de terres rares à partir de composés intermétalliques venant de batteries NiMH

par Matthieu Gras

Projet de thèse en 2MGE : Matériaux, Mécanique, Génie civil, Electrochimie

Sous la direction de Eric Chainet et de Farouk Tedjar.

Thèses en préparation à Grenoble Alpes , dans le cadre de I-MEP2 - Ingénierie - Matériaux, Mécanique, Environnement, Energétique, Procédés, Production , en partenariat avec Laboratoire d'Electrochimie et de Physico-Chimie des Matériaux et des Interfaces. (laboratoire) depuis le 15-10-2015 .

  • Résumé

    Ce projet se focalise sur l'extraction sélective de terres rares (La,Ce,Nd,Pr) et de métaux de transitions (Ni,Co,Mn,Al) par les liquides ioniques à partir de véritables batteries NiMH. Cette thèse s'inscrit dans un partenariat entre l'équipe LEPMI de Grenoble-INP et l'entreprise de recyclage Recupyl. Le doctorat est financé par le labex CEMAM.

  • Titre traduit

    Selective rare earth recycling from intermetallic compounds of NiMH batteries

  • Résumé

    The recycling rate of NiMH batteries is currently low. In addition, the existing processes are not sustainable because they use hazardous materials and are energy consuming. NiMH batteries contain various valuable metals such as Co, Ni, Mn and mixtures of lanthanides (Ln) including La, Ce, Pr, Nd. Lanthanides are part of the rare earth elements, that are among the 20 critical metals established by the European Commission. The present project proposes to develop new methods for separating these different elements, including the rare earth metals using ionic liquids. Extraction of lanthanides and separation from base metals using ionic liquids have gained significant interest in the recent years and promising results were reported in several works in the literature. The main objective is to elaborate a full process for the recycling of NiMH batteries. The first step of crushing of batteries will use essentially already-known techniques and equipments already available in the industrial partner of the project, Recupyl. Research will be focusing on the separation of elements subsequent to the crushing of batteries. A first objective will be to recover all light metals (transition metals: Co, Ni, Mn, Fe) in a stream which will be further treated using separation processes available at Recupyl for Li batteries. Then, the second key step of the PhD will consist in recovering Ln metals using ionic liquids. Several strategies will be studied, such as selective precipitation, selective liquid-liquid extraction or any other mean that would be promising. Subsequently, recovery of pure metals will be investigated using electrochemical reduction or back extraction processes. This work will be carried out in collaboration between a recycling company called Recupyl and the LEPMI lab. and will be financially supported with a PhD grant provided by the CEMAM labex.