Geometallurgical Modelling of the Dumont Deposit
By M. Sciortino*, J. Muinonen, J. Korczak and A. St-Jean,
Royal Nickel Corp.
* Presenting author
The Dumont deposit is a large (1179 Mt reserve), disseminated (0.27 per cent nickel) nickel sulfide project located in the Abitibi region 25 km west of Amos, Quebec. Royal Nickel Corporation (RNC) acquired the project in 2007 and has since taken the deposit through to feasibility. The disseminated nickel sulfide and alloy mineralization is hosted within the serpentinized dunite subzone of the Dumont Sill; a differentiated, pervasively serpentinized, ultramafic sill of komatiitic affinity. Pentlandite ((Ni,Fe)9S8), heazlewoodite (Ni3S2) and awaruite (Ni3Fe) are the dominant nickel-bearing metallic phases and can be recovered by conventional methods (flotation, magnetic separation). Non-recoverable nickel is also present within serpentine and olivine of the silicate matrix.
A detailed mineralogical program including 1420 QEMSCAN® samples and 4400 electron microprobe points was undertaken to increase the understanding of the nickel deportment in the various recoverable and non-recoverable phases in a spatial context across the deposit. A total of 105 metallurgical tests have been performed under a standard procedure which have linked the mineralogy to metallurgical performance. This has allowed the creation and modelling of geometallurgical domains on a block-by-block basis to understand the recovery variation and metallurgical performance throughout the deposit. Understanding the spatial variability of Ni deportment in recoverable and non-recoverable phases through mineralogy is the key to understanding metallurgical performance, thus unlocking the value of the Dumont deposit and other large tonnage low-grade ultramafic nickel deposits.
Michelle Sciortino – (P.Geo, M.A.Sc) is a Project Geologist for Royal Nickel Corp. She joined the Royal Nickel team in Amos, Quebec in 2008 as a Junior Geologist where she spent 3 years working onsite in various roles to support the early stages of project development. She has been involved in data collection, acquisition and analysis for various Dumont development projects from Scoping through Feasibility. Since moving to Royal Nickel’s Toronto head office 3 years ago as a Project Geologist, she has been intimately involved in the mineralogical and geometallurgical characterization of the Dumont project. Ms. Sciortino is a Professional Geologist registered with the Association of Professional Geologists of Ontario. She holds a Masters of Applied Science in Geology from the University of Toronto.