Scientific Research Network for CSM Research Results, Global CSM Issues, Printed Circuits, Defence and Rare Earth Separation

Quebec produces 90% of Canada’s aluminum, approximately 2.8 Mt annually. However, this production generates waste that must be managed responsibly. Among these are spent potlining (SPL), which is produced at the end of the life cycle of electrolysis cells and consists of graphitized carbon blocks (cathodes) and refractory bricks contaminated by electrolyte bath materials.

Rio Tinto’s SPL treatment plant, located in Jonquière, can process up to 80,000 tonnes of SPL annually to generate inert and recoverable by-products. Previous pilot tests have shown that the carbon-based by-product can reach graphite concentrations close to 90% by adding a flotation step to the current industrial process.

The goal of the current project is to use this floated material and develop new purification processes—either hydrometallurgical or pyrometallurgical—that could upgrade the by-product to a battery-grade graphite. To carry out this project, and with financial support from CRITM, Rio Tinto has partnered with Canadian research groups that possess the technical and scientific expertise in graphite purification and battery performance testing. A mandate has also been given to the Université du Québec à Chicoutimi to analyze graphite purification scenarios from a life cycle perspective and compare them to existing supply chains.

Recycling end-of-life Li-ion batteries, as well as production scrap, is a strategic step for building a strong circular economy. Until now, efforts to develop recycling processes have mainly focused on recovering metals contained in the black mass produced by recyclers. However, the recovery of used graphite represents both a major technological challenge and a strategic opportunity for the industry. We have demonstrated that our purification process, GraphRenew^TM, can effectively remove impurities present in used graphite from several black mass sources, and achieve purity levels compatible with Li-ion batteries requirements. We will present the physicochemical properties of used and purified graphite, as well as their electrochemical performance evaluated in coin cells. Finally, we will discuss our main conclusions and the future directions for graphite regeneration.

Disinformation about mineral resources is a major strategic issue in the global competition for control of SAMs. This type of behaviour is part of the economic war waged by states to attract foreign investment, reinforce their strategic weight and national discourse, protect their security and sovereignty, or conceal corrupt practices. The weakness of management bodies within states often contributes to this, leaving room for exclusively political approaches. This may involve over-estimation, under-estimation or deliberate opacity regarding mineral resources and/or associated investments. The power of self-intoxication through social networks, the scarcity of objective sources, and the collusion between private and public interests thus lead to toxic behaviour on the part of governments, both environmentally and socially. On the other hand, transparency can sometimes lead to naivety. Numerous examples illustrate this phenomenon, particularly in areas of recent conflict: Afghanistan, Ukraine, West and Central Africa… Geological information is therefore a strategic weapon and should be accompanied by ethical rules.