Air
We understand that our operations release gases and particulates into the atmosphere that may have an effect on people and the environment. These emissions are the result of burning fossil fuels, moving ores and wastes, and smelting metals.
In line with our air quality strategy and our air quality control standard, we constantly review our emissions, look for ways to improve our performance and apply controls to minimise related health or environmental impacts. We also monitor particulate gas and vapour exposure in the workplace, in line with our occupational health standards.
- Approach
- Emission sources
- Results
SOx
Our sulphur dioxide (SO2) and sulphur trioxide (SO3) emissions are expressed as sulphur dioxide equivalents (SOx).
In 2010, our operations emitted 194 thousand tonnes of SOx gases to the atmosphere, a decrease of 10 thousand tonnes compared to 2009. Emissions from stationary sources such as smelters, refineries, roasters and concentrators (SRRC sources) continue to account for the majority of our emissions (84 per cent in 2010).
Our capture of SOx gases before they were emitted to the atmosphere remained at 81 per cent , the same as in 2009.
NOx
Our oxides of nitrogen (NO and NO2) emissions are expressed as equivalent nitrogen dioxide emissions (NOx).
During 2010, total NOx emissions were 68 thousand tonnes, an increase of nearly four thousand tonnes from 2009. This was the result of increased fuel use, partly offset by reduced emissions from power stations in Western Australia. Emissions from stationary sources accounted for 31 thousand tonnes with 38 thousand tonnes being emitted from mobile sources.
Fluorides
In 2010, our aluminium smelters contributed 96 per cent of our 4.0 thousand tonnes of fluoride emissions. This was a decrease of 0.4 thousand tonnes from 2009.
Particulate emissions
Particulates less than 10 micrometers in diameter (PM10) are released from our mining activities, our metal manufacturing processes, and our power stations.
In 2010, we released 109 thousand tonnes of PM10, a decrease of 2 thousand tonnes from 2009. Emissions in 2010 were:
- 94 thousand tonnes from fugitive sources such as wind blowing on stockpiles, loading and unloading stockpiles, vehicles operating on unsealed roads and our blasting activities.
- 13 thousand tonnes from our smelting, roasting, refining and concentrating stationary point sources.
- 2 thousand tonnes from other point sources such as power stations.
