Gélinas , L-P, Belzil, G, Rocheleau, F, Dupéré , R & Cyr, V 2026, 'Lessons learned on cemented paste backfill strength prediction at the Odyssey Mine', in AB Fourie, M Horta, M Oliveira & S Wilson (eds), Paste 2026: Proceedings of the 28th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 1-12, https://doi.org/10.36487/ACG_repo/2655_09
(https://papers.acg.uwa.edu.au/p/2655_09_Gelinas/)
Abstract: Backfill is an integral component of mining studies at Agnico Eagle Mines (AEM), considered even during the earliest stages of project evaluation. From scenario evaluations to feasibility studies, best practices in backfill management are consistently applied across projects and tailored to reflect each project’s specific characteristics. These guidelines were implemented early in the Odyssey Underground Project, part of the Canadian Malartic complex. New complexities emerged from blending ore sourced from both open pit and underground orebodies, each with distinct geological characteristics, variable daily blends, and hightonnage demands.
AEM’s backfill practices had to evolve significantly to address the challenges posed by the Odyssey mining plan, including capex allocation, rising binder costs, high-volume backfill production requirements, and the need for advanced engineering solutions. Multidisciplinary collaboration, supported by cutting-edge data collection and interpretation, along with the continuous refinement of production procedures during commissioning and daily operations, enables the Odyssey project to consistently deliver high-quality engineered backfill in this Western Quebec, Canada mining operation. Strength prediction adapted to various rheological constraints, stope size, curingtime requirements, and mining strategy have been a key element from the beginning of the project to control the binder consumption ensuring paste delivered at the right time and place with sufficient strength. This paper will cover how mineralogy can dramatically affect the strength development of cemented paste backfill and how to gather relevant operational data to predict efficiently for each pour the strength of cemented paste backfill depending on given curing time. With more than 2 years’ production, comparison between project stage assumptions and everyday performance will be evaluated, as well as how these learnings can be applied for other projects and operations.

Keywords: cemented paste backfill, mineralogy, case study, binder usage optimisation, best practices