Our operations produce various types of air emissions such as sulphur dioxide (SO₂), nitrogen oxide (NOx) and dust, which we manage in accordance with our environmental regulatory approvals and permit discharge limits.
All of our operations are required to obtain and comply with regulatory approved air quality limits and approvals, supported by routine monitoring and trends analysis, wherever we operate. By working to manage these emissions, we can minimise their impact on local communities and the environment.
We monitor all material air emissions from our activities, and look for ways to reduce emissions. These include ‘stack’ emissions, and fugitive emissions.
Wherever we operate, we comply with relevant regulatory limits for air emissions. Where these are less stringent than our own standards, we apply our higher standards.
Types of air emissions we manage
Our metallurgical smelters emit sulphur dioxide (SO2), dust and nitrogen oxide (NOx) as both stack and fugitive emissions, under permit conditions developed through the regulatory approvals process.
Stack emissions emanate consistently from a fixed source, such as a smelter furnace, and are measurable.
There are many control options for stack emissions, including mitigation during production processes, and capturing and treating off-gases prior to emission through technologies such as electrostatic precipitators, scrubbers or sulphuric acid plants.
Fugitive emissions emanate irregularly from many diffuse sources.
Controlling and managing fugitive dust emissions (also referred to as ‘particulate matter’ or ‘PM’) are a main environmental management focus area for our mining assets. These can occur during the blasting, excavating, moving and crushing of ore rock, or the removal of topsoil, overburden or waste rock, especially in environments that are more arid.
Stationary filter equipment technologies are not effective for fugitive emissions, so other controls are utilised, such as dust suppression, construction of berms to prevent dust travelling to communities, optimising our blasting activities, watering our haul roads and using protective coatings on product and waste storage facilities.
Our assets also undertake progressive rehabilitation once active operations have completed to reduce or eliminate dust-related impacts on our local communities.
Reducing emissions and cutting power costs
In 2019, we signed an agreement to build a power-generation facility that will reduce emissions and energy requirements and associated cut power costs at our ferrochrome smelter at Lydenburg, South Africa. This partnership is another example of our ongoing commitment to supporting a transition to a low-carbon economy through incorporating technological innovations to change how we operate for the better.