Grant: CCI Applied Research and Development Grants

Metals circularity is becoming a growing necessity in an industrial framework focused on electrification of transport and processes. At the same time, soil remediation must be emphasized in a context where pressure on land use is an issue for communities, industries and individuals as well. Thus, at its Sainte-Catherine (Quebec) site, Secure Energy, headquartered in Calgary and represented by Quebec’s engineering firm Tetra Tech, is actively seeking a recycling option for 130 000 tons of landfilled lead rich slags. In line with a circular economy perspective, Tetra Tech mandated the Centre de transfert technologique en écologie industrielle (CTTEI) to develop an innovative and ecologically viable solution to recover lead from slags and make it usable for a nearby lead-battery recycling plant. CTTEI, thanks to its expertise in inorganic materials recycling, waste valorization and minerals chemistry, proposes to explore both hydrometallurgical and solvometallurgy processes for lead recovery from lead slags. First, exploratory tests will be carried out on finely crushed slags, followed by optimized tests on slags in their raw state. Emphasis will be given to: (i) solvents recovery in order to minimize their use in the hydrometallurgical process, and (ii) on understanding the kinetics of solvometallurgy, which is an innovative way of extracting metals without using aqueous solvent, and thus reducing the need for wastewater management. A third stage will explore the possibilities of reusing treated slags, according to residual metal content and toxicity after treatment. Based on the recommendations arising from this research, Tetra Tech and Secure Energy will be able to move ahead with pilot tests, taking into account the geographical and industrial context of the processed slags. The results of this project will provide practical and valuable knowledge for other remediation activities involving lead or other slags. Environmental concerns have led the project’s research and engineering teams to focus on reducing the impact of conventional hydrometallurgical processes. In addition, the research and applicability of solvometallurgy for lead recovery will enable the exploration of this new type of metallurgical processes, which could be promising for future critical and strategic minerals projects, widely needed to achieve energy transition.