Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

The current mining paradigm forces mining companies to exploit more and more refractory ores with complex mineralogy. As a general rule, the distribution of gold in a deposit is defined by geologists (exploration phase) while metallurgists focus on physical and chemical characteristics of the rocks to optimize gold recovery (pre-feasibility phase). However, an early understanding of gold recovery parameters and of potential environmental impacts could provide a competitive advantage to a mining company. This can be achieved by early-stage geometallurgy investigations, which integrate several disciplines of the geosciences to relate mineral recovery and environmental impacts to the mineralogical constraints. Ore processing can be optimized by the use of geometallurgical domains, which are zones with homogeneous mineralogical assemblages associated with specific metallurgical and/or environmental characteristics. This master project aims at developing a methodto help create geometallurgical domains using data from the exploration phase of the project, using Agnico Eagle Mines Whale Tail deposit in Nunavut as a case study. The Whale Tail deposit is in the Kivalliq region of Nunavut and belongs to the neo-Archean rocks of the Woodburn Lake group within the Rae Domain in the Churchill province. At Amaruq, mineralized zones are hosted in a volcano-sedimentary sequence made of mafic to ultramafic volcanics, greywackes, cherts and iron formations. Gold is predominantly associated with iron and arsenic sulphides. The ore mineral assemblages and contrasted host rocks are responsible for some metallurgical and environmental challenges. The main objectives of the project are to: 1) complete a petrographic and metallographic characterization of the Whale Tail deposit; and 2) to correlate exploration data with metallurgical and environmental data. The results demonstrate the potential of geometallurgy to improve the feasibility of a mining project and to limit its environmental impact.