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

稀土元素(REE)在全球经济中的重要性随着几个现代元素的出现而蓬勃发展 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)。因为在10亿美元的市场中，有95% 代表稀土的生产掌握在中国手中，全球利益在于发现新的 以确保这一战略市场的安全。稀土的一个非常有趣的来源是铝土矿残渣(BR)。铝土矿渣是拜耳法产生的最重要的废弃物，是铝生产中的关键一步。BR的年产量为90万吨(仅限于加拿大)，是一个环境问题，铝生产商正在寻找减少和评估这一重要副产品的方法。然而，众所周知，每吨溴可能含有多达1公斤的稀土，根据目前的市场价格，这代表着一个接近10亿美元的市场。通过与力拓-加拿大铝业公司和魁北克水电公司的合作，该项目的PI旨在开发能够选择性地从几种基质中提取稀土的新型材料，包括溴、核废料和电子废料以及稀土矿物和采矿残渣。目标包括：a)开发能够显示稀土结合亲和力的选择性的新型有机分子，b)将这些有机分子嫁接到二氧化硅和碳载体上，以及c)将这些新型材料用于液-固萃取溴以分离和提纯稀土。除了这种技术的经济优势外，它还将最大限度地减少BRS对环境的影响，并使目前的稀土提取过程更加环保，因为所使用的技术对能源和化学要求非常高，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.