Mr Steve Wright checking the laser flash apparatus.

Lasers lead way to efficiency gains in aluminium production

Characterising the thermal properties of new cell linings could lead to improvements in aluminium production.

• 25 June 2007 | Updated 21 August 2012

• A problem for aluminium producers
• The search for a solution

Using laser flash techniques, CSIRO researchers are working to characterise the thermal properties of promising new cell linings, which could lead to improvements in aluminium production.

A problem for aluminium producers

Cell linings, or refractories, are used to line furnaces to contain liquid metal and other melts under intense heat. For added protection, and to minimise heat loss, a layer of frozen salts often coats the refractory.

The high temperatures and harsh molten salts required to produce aluminium, however, damage refractories, limiting the cell life and creating wastes containing fluoride salt and cyanide.

The search for a solution

To improve the life of refractories and thereby reduce waste, scientists from CSIRO Minerals and CSIRO Manufacturing and Materials Technology divisions are collaborating on a Light Metals Flagship project to develop alternative refractory materials.

As the new refractory materials being explored need to withstand temperatures of up to 1 000 ˚C, characterising their thermal properties is critical.

Dr Shouyi Sun, who leads this cross-disciplinary project, says this is where laser flash is important. 'Our aim is to develop alternatives. To test their ability we use laser flash techniques, which are flexible, quick and easy to use.'

He says a laser is shone on one side of the sample, pumping energy into it. 'We then monitor the temperature on the other side and see how much and how quickly it rises. From that data we can measure thermal diffusivity and thermal conductivity – a process that takes just a few hours for a series of measurements.'

Current refractories are also tested so a comparison can be made. 'Our aim is to develop an alternative to increase the cell life and to reduce spent cell lining waste. It would mean less waste is produced per tonne of aluminium.'

'Longer-term, we want to produce a refractory suitable for new cell types being pursued by the flagship, which could lead to greater energy efficiency.'

Find out more about aluminium production by reading Aluminium production: reducing costs and energy consumption.