Functionalized mesoporous materials for lanthnides (rare earths) extraction from industrial and mining wastes

稀土元素在全球经济中的重要性正在随着几个现代 使用这些元素的应用（电子产品、手机、平板电视、绿色技术、医疗 设备、军事技术、磁铁、太阳能电池板等）。因为95%的十亿美元的市场， 代表着稀土的生产掌握在中国手中，全球的兴趣在于发现新的 生产商必须确保这一战略市场。一个非常有趣的稀土来源是铝土矿残渣（BR）。铝土矿残渣是拜耳法产生的最重要的废物，拜耳法是铝生产的关键步骤。BR的年产量为90万吨（仅加拿大），是一个环境问题，铝生产商正在寻找减少和稳定这一重要副产品的方法。然而，据了解，每吨BR可能含有高达1公斤的稀土元素，根据目前的市场价格，这代表了近10亿美元的市场。与力拓铝业公司和魁北克水电公司合作，该提案的PI旨在开发新材料，可以从几种基质中选择性地提取稀土元素，包括BR，核和电子废物以及稀土矿物和采矿残留物。这些目标包括：a）开发新型有机分子，其将显示对RE的结合亲和力的选择性，B）将这些有机分子接枝在二氧化硅和碳载体上，和c）将这些新型材料用于BR的液-固萃取以分离和纯化RE。除了这种技术的经济优势外，它还将最大限度地减少生物再生物质对环境的影响，并将使目前的稀土元素提取过程更加绿色，因为所使用的技术对能源和化学要求很高，而且是污染最严重的采矿过程之一。

The importance of rare-earth elements (REEs) in the global economy is booming with several modern applications using these elements (electronics, cell phones, flat screen TVs, green technologies, medical devices, military technologies, magnets, solar panels, etc.). Since 95% of the billion dollars market that represents the production of REEs is in the hands of China, a global interest lies in the discovery of new producers to secure this strategic market. A very interesting source of REEs is bauxite residues (BR). The bauxite residues are the most important waste generated by the Bayer process, which is a crucial step in the production of aluminium. Produced at the scale of 900 000 tons annually (for Canada only), the BR are an environmental concern and the aluminum producers are looking for ways to reduce and valorize this important by-product. It is known however that each ton of BR could contains up to one kg of REEs, which according to the current market price represents a market close to one billion dollars. In partnership with Rio-Tinto Alcan and Hydro-Québec, the PIs of this proposal aim at the development of novel materials that can selectively extract REEs from several matrices, including BR, nuclear and electronic wastes and REE mineral and mining residues. The objectives include: a) the development of novel organic molecules that would show selectivity in the binding affinities of REEs, b) the grafting of these organic molecules on silica and carbon supports, and c) the use of these novel materials in the liquid-solid extraction of BR for the separation and purification of REEs. In addition to the economic advantage of such technology, it would also minimize the environmental impact of BRs, and would make the current extraction process of REEs greener, since the technology used is energy and chemically very demanding and is in one of the most polluting mining process.