The Voisey’s Bay mine expansion project involves the development of an underground operation and related infrastructure at the existing Voisey’s Bay open-pit mine in Canada.
Owned and operated by Vale, the project is the largest underground mine construction in the country.
The underground expansion was announced in July 2015 and construction began in 2016 while commissioning is scheduled for 2022. It will produce 40,000t of nickel-in-concentrate and 20,000t of copper-in-concentrate each year at peak production.
The expansion project will prolong the mine life of Voisey’s Bay by 15 years until at least 2032. The overall capital expenditure on the construction and commissioning of the project is estimated at $1.7bn.
The project is expected to create approximately 650 jobs during the peak construction period and 400 additional full-time, permanent jobs to support operations.
Voisey’s Bay location, geology, and mineralisation
The Voisey’s Bay mine is located on the Canadian Province of Labrador approximately 1,500km north-east of Montreal.
The nickel deposits are hosted by a troctolite layer belonging to the Nain Plutonic Suite. A total of four principal types of sulphide mineralisation occur at Voisey’s Bay including massive, leopard-textured, breccias, and disseminated sulphides.
The nickel mineralisation at Voisey’s Bay is hosted within three east plunging intrusions including the Ovoid, lower Reid Brook and the upper Eastern Deeps.
The existing open-pit mining operation is primarily based on the Ovoid deposit. The new underground operation will be focused on the north Labrador deposits of Reid Brook and Eastern Deeps next to the current open-pit mine.
Voisey’s Bay mine mineral reserves
The Ovoid deposit at Voisey’s Bay open-pit mine contains estimated proven and probable resources of 32 million tonnes (Mt).
The Voisey’s Bay project also contains 40Mt of indicated resources and 6Mt of inferred resources.
Voisey’s Bay mine expansion project details
The underground operations of the Voisey’s Bay mine will include the construction of declines and ramps from the surface to reach the ore bodies. The first blast at the Reid Brook deposit marking the start of underground construction occurred in October 2018.
Supporting infrastructure such as a paste backfill plant, and material handling systems, including crushing and conveying equipment, will be developed. In addition, an underground ventilation system comprising fresh and return air fans, pumping systems, a garage, and refuge stations will be developed.
Surface infrastructure for the expansion will include additional power and heat generation facilities, and accommodation facilities. The existing offices, warehousing, and maintenance shops and water and sewage treatment facilities will also be expanded.
The nickel-in-concentrate produced at Voisey’s Bay is currently being processed at a hydrometallurgical processing facility in Long Harbour, Newfoundland, which began operations in 2014. The concentrate produced by the underground operations will also be processed at the Long Harbour facility.
Vale entered two separate agreements with Wheaton Precious Metals (WPM) and Cobalt 27 in June 2018 for the acquisition of 75% of Voisey’s Bay cobalt production from both the open-pit and underground operations effective 1 January 2021.
WPM will pay $390m for 42.4% of the cobalt stream while Cobalt 27 will provide $300m to purchase of 32.6% of the cobalt stream.
The cobalt stream from the mine will deliver approximately 1.9 million pounds (Mlb) of cobalt a year to Cobalt 27 and 31Mlb of cobalt to WPM.
Hatch is constructing the two new underground mines and associated facilities under an engineering and project management services contract. It is implementing a fit-for-purpose operations management system for the construction phase of the underground project.