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Horne Smelter

Air quality

Reducing our impact on the environment and the community has long been a key priority for Horne Smelter. We aim to comply with all applicable environmental standards, and are taking steps to achieve our annual targets.

Ambient air quality

Emissions data for the Horne Smelter is now available via an interactive map.

  • View data

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  • FAQ

    Questions concerning the data

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Currently, around 99% of Rouyn-Noranda's urban perimeter is at 15 ng/m3 of arsenic or less.

Quarterly averages

Each quarter, we publish the average concentrations of arsenic, lead and cadmium. As of the second quarter of 2025 (March 16 to September 15), the average concentrations recorded at the Horne legal station, located at the boundary of our property, are as follows:

  • Arsenic : 45,2 ng/m³
  • Cadmium : 6 ng/m³
  • Lead : 178 ng/m³

 

The results are in line with our projections, and we remain confident that we will meet the established target of an ambient air arsenic concentration of 45 ng/m³ at the Horne station for the year 2025 (March 16, 2025 to March 15, 2026). It is important to note that arsenic concentrations decrease rapidly as distance from the smelter increases. For example, at the Glencore Arena (approximately 400 metres from the smelter), the concentration is 13.7 ng/m³, based on second-quarter 2025 results.

Quarterly results for parameters regulated under the ministerial authorization

We have five stations that measure metal concentrations in ambient air. Below are the results for the second quarter of 2025 (March 16 to September 15, 2025).

*All data presented are in ng/m³.

Since 2005, the average annual concentration of arsenic in ambient air at the legal station has decreased by over 70% thanks to the implementation of numerous projects.

  • Construction of concentrate storage domes

  • Acquisition of vacuum and water trucks

  • Installation of a truck wheel cleaning station

  • Construction of a windbreak fence

  • Installation of two domes and a shelter for receiving concentrates

  • Optimization of the fugitive gas capture network in the anode sector

Annual arsenic averages at the Horne legal station from 2005 to 2023 (in ng/m3)

Le soufre est un élément naturellement contenu dans les concentrés de cuivre que l’on reçoit des mines. Combiné à l’oxygène injecté dans nos fours pour le procédé de purification du cuivre, il se transforme sous l’état gazeux, en dioxyde de soufre. 

  • Sulphuric acid plant

    Our sulphuric acid plant enables us to capture over 96% of the sulphur contained in the concentrates we receive from the mines.

Intermittent control system

We have existing procedures for controlling SO2 emissions in order to limit our impact on the community, such as the intermittent control system mode.

This system, which consists of slowing down our operations at the Noranda Converter, comes into operation when there are winds affecting the town. This reduces SO2 emissions at the stack, thereby limiting plume downwash.

In 2024, we activated the ICS mode more than 350 times to minimize SO2 emissions.

(available in french only)