Fluoride
Particulate and gaseous fluoride emissions are generated in aluminium smelters when converting alumina to aluminium, and to a lesser extent, from coke and coal consuming activities.
Fluoride has been associated with impacts on human health. It can be taken up by plants and enter the food chain and can have an effect the strength of teeth and bones.
How we minimise the health risks
We identify and try to minimise air pollutant emissions and their potential impacts by applying our Air Quality Control Standard which calls for assessment and prioritisation of emission sources and requires installation of emission controls to ensure protection of ambient air quality.
Our results
96 per cent of our emissions were from aluminium smelters in 2007, we emitted 1.2 thousand tonnes of fluoride, which is similar to our 2006 emissions which were 10 per cent higher than 2005 levels. This net increase was influenced by:
- A gradual build-up of production at Rio Tinto Aluminium's new Yarwun facility.
- An upgrade of the fluoride emissions measurement system at Rio Tinto Aluminium Bell Bay that improved data accuracy.
- Emissions control equipment at Boyne Smelters reaching the end of its lifecycle (due for replacement in early 2007).
- Process and practice improvements at Anglesey Aluminium that resulted in a decrease in fluoride emissions, which partially offset the increases reported by other operations.
