Iamgold’s Côté Gold: A model for modern mining and sustainability

The newest gold mine in northern Ontario has the potential to become the biggest in Canada. Iamgold’s Côté Gold open pit mine had its official ribbon-cutting ceremony at the end of May 2024. The company has declared commercial production at its 60%-owned Côté mine in northern Ontario, the company’s third producing gold mine and second in Canada. This mine will be one of Canada’s largest gold producers with an 18-year mine life. During the first six years of operation, Côté Gold’s output will be 495,000 oz., and over the life of the mine, it will average 365,000 oz. per year. Construction of Côté began in 2020 and was expected to take three years to build. The mine cost $1.9 billion to build.  

The Côté mine has proven and probable reserves of 234.6 million tonnes grading 1.01 g/t gold and containing 7.6 million oz. of gold. Reserves are included in measured and indicated resources, which are 444.8 million tonnes at 0.84 g/t and containing almost 2.3 million oz. of gold. There are also inferred resources of 60.6 million tonnes at 0.61 g/t and containing 714,000 oz. of gold. One of the most interesting advantages of the Côté Gold project is the potential upscale of the reserve base. With the recent inclusion of the Gosselin zone into the resource category, measured and indicated resources now exceed 490.4 million tonnes at 0.9 g/t, equating to 13.56 million oz. of gold. A 15,500-metre drill program slated for this year is positioned to expand the Gosselin zone, as it is still open at depth and on strike to the west.

The Côté Gold project was constructed through a partnership with Sumitomo Metal Mining. The mine, located 125 km southwest of Timmins, Ont., is owned as a 60/40 joint venture agreement entered in December 2022, which saw Iamgold retain a 60.3% ownership share in Côté and a transferred interest of 9.7% held by Sumitomo. Iamgold holds the option to return to 70% ownership, which it intends to execute before it expires in 2026. With Côté Gold commissioning, Iamgold now has three operating mines, including Essakane in Burkina Faso and Westwood in Quebec.

As expected, the mine has poured its first doré bar on March 31, 2024, with the crushing, high-pressure grinding rolls (HPGR), and processing circuits performing within expectations, including power consumption. Now that construction is complete, the construction teams have been demobilized with a successful handover to the operations team. Operations continued to ramp up in the second quarter of 2024, and commercial production is expected to be achieved during the third quarter of 2024. Commercial production means the mine has reached at least 30 consecutive days of operations at about 60% of its 37,000 t/d capacity. 

“I am delighted to announce that Côté Gold achieved the milestone of first gold pour, less than 90 days since the start of the pre-commissioning activities,” said Iamgold’s president and CEO, Renaud Adams, in a release. “This achievement represents the culmination of over 15 million hours of work over four years of construction — an incredible effort for the team on the ground as the project cost to first gold remains in line with the updated budget estimate while maintaining a near impeccable safety record,” he added.

The company expects the Côté Gold operation to end this year at approximately 90% of nameplate capacity. The goal this year is to produce between 220,000 and 290,000 oz. of gold, assuming the remaining commissioning activities go according to plan.

“Since achieving the first pour of gold, our teams have spent the last four months methodically and iteratively testing and ramping up all facets of the mine,” said Adams in a release at the end of July.

Operating at a planned capacity of 37,200 t/d, the mine will produce close to 500,000 oz. of gold yearly, with significant resource potential to grow further.

Keeping an eye on sustainability

Throughout its 30-year history, Iamgold has demonstrated its commitment to responsible and sustainable mining through consistently meeting high standards of environmental, social, and governance (ESG) practices, incorporating its Zero Harm vision in every aspect of the business.

To the company, the Zero Harm vision is a journey, rather than a goal with an end in sight, and a responsibility to continue to improve mining practices in the context of evolving sustainability opportunities and challenges.

Adhering to its Zero Harm vision, Iamgold incorporated natural channel design principles into the strategy to create self-sustaining systems that restore ecological functions. This approach reflects the company’s dedication to maintaining the highest standards in health, safety, and sustainability.

The creation of Oshki Lake: Early in July 2024, Iamgold executive and Côté Gold teams alongside their Indigenous partners from Mattagami and Flying Post First Nations and representatives from Sumitomo Metal Mining gathered at the Côté Gold mine site for a water ceremony marking the creation and official naming of Oshki Lake. This new water body was built to offset fish habitat lost during the construction of the Côté Gold mine. 

The creation of Oshki Lake was a crucial step in Iamgold’s commitment to environmental responsibility. The ore deposit for the Côté Gold mine was partially located beneath an existing lake. To proceed with the mine’s construction, the Mollie River and other nearby waterways had to be rerouted to prevent potential flooding of the open pit. This rerouting project included the creation of Oshki Lake to compensate for the loss of fish habitat. 

The rerouting project was an integral part of the environmental permitting process, conducted in close consultation with Iamgold’s Indigenous partners and other stakeholders. 

The extensive tailings management facility raise was also completed just before the spring freshet and created sufficient water storage capacity for commissioning activities. 

This year, as part of its sustainability reporting alongside the annual Sustainability Report, Iamgold published its inaugural Tailings Management Report, intended to demonstrate the company’s values of accountability and transparency by providing more details on the approach to tailings in a standalone report.

A unique feature of this mine is the implementation of an autonomous mining fleet: Côté is the first gold mining project in North America designed and built for a fully automated haulage fleet. Ten autonomous vehicles have been commissioned thus far, including Atlas Copco Pit Viper 231s (to drill 12 m benches) and a combination of Cat 6060 electric shovels and Cat 793F haul trucks. Three Cat 994s will also be on-site for loading and stockpiling. 

Grid connection to the provincial hydro grid was completed, and it provides 56 MW of power required for the processing plant. By incorporating an efficient crushing design, HPGR, and Vertimills, the project team mitigated risk by designing a plant with available grid power.

The installation of a Weir Minerals 2.4 by 2.4 metre HPGR marks the largest scale installation of an HPGR in Canada. This single HPGR will utilize 7,800 kW of power to crush up to 1,596 t/h into an 80% passing 2.4 mm product for the ball and Vertimill circuits. 

A typical SAG mill configuration, even with high ball loads, would not have been energy efficient. Pilot stage grindability test work indicated the Côté Lake deposit material is very competent and resistant to SAG milling. Test work conducted using HPGR technology confirmed its metallurgical and economic advantages over SAG milling.

The HPGR provides metallurgical benefits by inducing micro cracking in the ore which improves the cyanide leach kinetics that would not be possible if a conventional flow sheet was utilized.

Moreover, a conscious effort to maintain a safe work environment is front and centre at this mine. In early 2023, the mine surpassed 10 million project hours with a lost time injury frequency rate (LTIFR) of 0.02 (the company’s total recordable injury frequency rate (TRIFR) in 2023 was 0.69), which is clear evidence of a workforce that embraces a Zero Harm attitude.