Emissions reduction project

An Optimized Approach to Reach 15 ng/m³

Considering the work conducted during the feasibility study, and building on the results of transitional measures to improve air emissions already implemented, the Horne Smelter has developed an optimized approach to aim to reach the arsenic target: an annual average of 15 ng/m³ in ambient air, measured at the sampling station closest to the Smelter (legal station).

This new strategy includes encapsulating the smelting zone—encompassing all key equipment such as the reactor, Noranda converter, converters, and anodes—to better control emissions at the source. This will be combined with high-performance purification systems, already proven and compatible with the current process. This approach offers the potential to deliver of tangible, material improvements in air quality, while safeguarding the safety, operational stability, and long-term sustainability of the smelter. The new optimized approach we wish to propose, as well as its implantation timeline, will require governmental approvals

History

In 2022, the Horne Smelter announced the Aeris project. Initially, the aim of this project was to build a brand new, state-of-the-art section of the plant.

To continue reducing atmospheric emissions, the teams in place have been working on optimization projects since 2023.

Work has been carried out in the concentrate unloading area.
A new dome was erected to store an additional 6,000 tonnes of copper concentrate.
Roads have also been paved to reduce the amount of dust generated by routing activities in this sector.

In 2024, the Horne Smelter announced that the Aeris project was moving to the feasibility stage, carried out with top internal and external expertise. This rigorous process, carried out with top internal and external expertise, aimed to objectively evaluate the project from multiple perspectives: technical, environmental, occupational health and safety, as well as financial.

In 2025, the conclusions of the feasability study were announced.

The study’s conclusions appear clear to us: given the complexity of the Aeris project, implementing it fully would compromise the operational stability, as well as long-term viability of the plant, and would have extended the timeframe to achieve our emissions targets. However, this work allowed us to identify an optimized approach that, we hope, will achieve the desired environmental performance.

Three key findings emerge from the study:

The project involves complex construction. Building on existing infrastructure, combined with challenging ground conditions and a large number of unavoidable interferences, would make construction extremely challenging.
Integrating Aeris would require significantly more equipment and infrastructure than originally anticipated. It would mean a complete overhaul of the production process, which would also take much more time.
Successfully introducing new technologies at the plant depends on essential technical conditions that are not currently met. Their integration could impact the entire production chain—even the ability to produce copper itself.