Greenstone mine nears finish line

Construction 85% of way to 2024 gold pour

There is a new gold mine coming to Ontario. The Greenstone mine, located 275 km northeast of Thunder Bay near Geraldton, is being developed in partnership by Equinox Gold Corp. (60%) and Orion Mine Finance Group (40%). Construction is on track to pour gold in the first half of 2024.

Greenstone is going to be among the largest open pit gold mines in Canada, with production averaging 400,000 oz. of gold per year for the first five years and more than 360,000 oz. per year over the initial 14-year mine life.

First a short history: Gold was discovered on the property about 1916-18. Between 1938 and 1970, the Hardrock mine produced more than 2.0 million oz. as an underground mine. Premier Gold Mines acquired the project in 2008 and two years later, after completing additional exploration drilling, produced a resource estimate. Premier Gold continued to advance the project, completing a preliminary economic assessment in 2014, a 50:50 joint venture with Centerra Gold in 2015 and a feasibility study in 2016. Premier Gold also advanced permitting and engineering, and by 2019 the project was fully permitted and shovel ready.

In December 2020, Orion bought Centerra’s 50% interest and Equinox Gold announced plans to acquire Premier Gold. The acquisition was finalized in April 2021, Equinox Gold bought an additional 10% from Orion to hold a 60% controlling interest, and the new partners kicked the newly named Greenstone project into high gear.

The construction groundbreaking ceremony in October 2021 was commemorated with speeches by the local mayor, the Ontario Minister of Mines and the project’s Indigenous partners. Long-term benefit agreements are in place with five local Indigenous communities. The project is located on the traditional territories of four First Nations – Animbiigoo Zaagi’igan Anishinaabek, Aroland First Nation, Ginoogaming First Nation, and Long Lake #58 First Nation. It is also home to the citizens of the Métis Nation of Ontario.

On the fast track to mining

With 5.5 million oz. of gold reserves at the project, anyone would be encouraged to develop a new gold mine. This time around, the Greenstone mine is to be a conventional truck and hydraulic shovel open pit operation.

At the end of July, construction at Greenstone was about 85% complete and the project remains on budget, with US$937 million of the US$1.23 billion construction budget spent at June 30. The build has been accomplished with an integrated team of both owner’s personnel and contractors seconded from G Mining Services.

At the helm is general manager Eric Lamontagne with 25 years of experience. He was manager of project development for Premier Gold, and before that worked for Agnico Eagle Mines at the Meadowbank mine and as project manager for the Meliadine gold mine.

“The majority of the Greenstone team have been working on the project since the beginning, which I think has been integral to the success of this build,” said Lamontagne. “We have strong relationships within the team, within the community and with the project’s Indigenous partners, and we are all committed to the success of this project. We have also had very strong support from Equinox Gold and Orion. This mine is going to transform the region, bringing meaningful employment, new business opportunities and benefits to all stakeholders, and we’re all looking forward to pouring first gold next year.”

Mining will begin in a starter pit and proceed in five main phases. The final dimensions of the open pit will be 1.8 km long, 1.0 km wide, and 600 metres deep. Blasthole drilling will proceed in 10-metre benches, and the holes loaded with bulk emulsion. The average life of mine strip ratio will be 5.1:1, and five waste dumps will be established.

The deposit will be mined for 13 years, following pre-production. When the ore is depleted, the mill will process low-grade stockpiled material for nine months. In addition, an underground extension and the near-mine Brookbank, Kailey, and Key Lake open pit deposits host nearly 5.0 million oz. of gold resources and could provide ore to extend the mine life beyond the initial 14 years contemplated today.

The processing plant has the capacity for daily throughput of 27,000 tonnes. It will include a crushing circuit (gyratory and cone), a grinding circuit (high-pressure grinding rolls and ball mills), pre-leach thickening and cyanide leaching, a carbon-in-pulp (CIP) circuit, carbon elution and regeneration, electrowinning and gold refining, cyanide destruction and a tailings management facility.

Other infrastructure includes water management facilities, a power plant powered by natural gas, site access and haul roads, explosives and reagent storage facilities, fuel storage and distribution, a recycling facility, and site security.

The golden future

When in production, Greenstone will be Equinox Gold’s largest mine, and its only mine in Canada. Equinox Gold expects to produce around 590,000 oz. in 2023 from seven other mines in the U.S., Mexico and Brazil. With another approximately 240,000 oz. per year from Greenstone (Equinox Gold’s 60% share), plus production growth from expansion plans at three other mines, it’s easy to see a company with huge growth potential.