Horne Smelter shelves study and opts for ‘optimized’ environmental approach

Canada’s only copper smelter in Rouyn-Noranda, Quebec is proposing a new approach to meet environmental targets. The Horne Smelter, part of Glencore Canada, processes 210,000 tonnes of copper and precious metals annually.

A 2022 study by Quebec’s public health body revealed the smelter exposed Rouyn-Noranda to harmful arsenic and cadmium levels for decades. The Quebec government required the company to reduce emissions substantially, though without a defined timeline. Glencore and provincial authorities have been negotiating over the years on emissions controls, although the company has reported steady progress.

Glencore’s Horne Smelter decided against its own Aeris project, citing difficulties in meeting emission targets through this route. The company studied the feasibility of Aeris in 2024, aiming to achieve an annual arsenic concentration of 15 nanograms per cubic meter (ng/m³) in ambient air. The study evaluated technical, environmental, safety, and financial aspects.

The study concluded that fully implementing Aeris would compromise the plant’s operational stability, long-term viability, and timeline for achieving emission goals. The study also highlighted three major challenges: construction complexity due to existing infrastructure and ground conditions, extensive changes required in the production process, and technical limitations affecting copper production and the entire production chain.

Given these findings, Glencore proposed an optimized approach to meet the arsenic target of 15 ng/m³ annually, measured at the legal monitoring station. This strategy includes encapsulating the smelting zone—covering equipment like the reactor, Noranda converter, and anodes—to control emissions at the source. High-performance purification systems, compatible with existing operations, will complement this setup. This approach aims to improve air quality while ensuring the smelter’s safety, stability, and sustainability. The proposal awaits government approval.

Vincent Plante, executive general manager for North America copper value chain, commented: “I’m extremely proud of the rigorous work carried out by our teams. Thanks to their commitment, we’ve found a solution that will allow us to deliver results with more predictability than Aeris. This is excellent news for the Rouyn-Noranda community and our teams. Moreover, our 2024 results clearly demonstrate the effectiveness of this new direction: the average arsenic concentration in ambient air, measured at the legal monitoring station, has dropped by 46.5% since 2022, reaching 39.1 ng/m³ in 2024—below the regulatory ceiling of 45 ng/m³. 99% of the urban area of Rouyn-Noranda has an average arsenic concentration equal to or below 15 ng/m³. The team and I look forward to engaging with our stakeholders regarding this optimized approach.”

The facility employs more than 650 people in its Rouyn-Noranda plant in Quebec and works with many contractors. All its copper anode production is shipped to CCR Refinery in Montréal, where another 500 workers contribute to the North American copper and critical minerals value chain.

More information is posted on  www.Glencore.ca/en/horne.