Rio Tinto Alcan collaboration to reduce smelter energy use

CSIRO is helping Rio Tinto Alcan develop a new generation of aluminium production cells that will cut energy use by ten per cent, reducing operating costs and greenhouse gas emissions.

• 1 October 2007 | Updated 14 October 2011

• Composite success
• Broader collaboration
• Recent achievements and activities
• Long term benefits
• Additional projects

CSIRO has been working with Comalco (now Rio Tinto Alcan) to improve the energy efficiency of its aluminium production cells, in which alumina is reduced to aluminium through electrolysis.

The cost and environmental impact of high energy use is one of the most significant challenges facing the aluminium sector worldwide

Composite success

CSIRO’s collaboration with Rio Tinto Alcan began in the late 1980s, when Rio Tinto Alcan had already begun developing a new type of aluminium reduction cell – a drained cathode cell (DCC) – that requires less energy than traditional cells.

However, the viability of such a cell relies on the performance of a composite containing titanium diboride, which can be ‘wetted’ by molten aluminium.

The composite can withstand high temperatures, is resistant to the molten aluminium and electrolyte, and is electrically conductive.

CSIRO worked with Rio Tinto Alcan to successfully develop a low-cost process for manufacturing high-quality titanium diboride tailored to the aluminium reduction application.

Broader collaboration

In 2003, when CSIRO announced the establishment of the Light Metals Flagship, Rio Tinto Alcan was considering accelerating its DCC research.

The timing was fortuitous.

Both parties signed a formal agreement in February 2004 and, since then, the research has broadened to include:

• computational fluid dynamics (CFD) 
• physical modelling of the prototype cells
• further materials development.

Because it is a new generation technology that will require significant capital investment, the development of a commercial DCC will require a considerable development effort.

Recent achievements and activities

The Flagship's partnership with Rio Tinto Alcan has already seen many achievements including:

• development of a CFD model of a Rio Tinto Alcan drained cathode cell that is used to predict the effect of design and process changes. The model is continuing to be refined for higher levels of accuracy and wider ranges of applicability
• development of an advanced coating technology with greater potential to protect the titanium diboride composite during cell startup
• use of advanced analytical techniques to gain an understanding of composite performance in the cell
• establishment and ongoing evaluation of a full-sized DCC operating at Rio Tinto Alcan’s Bell Bay smelter on the Tamar River near George Town in Northern Tasmania.

Long term benefits

Rio Tinto Alcan expects to achieve electrical energy savings of at least ten per cent with its drained cathode cell.

Given current levels of energy consumption, this will translate into substantial cost savings and reduced greenhouse gas emissions.

Through the partnership, CSIRO has been developing expertise in modelling aluminium reduction cells, which can be applied to conventional cells to identify opportunities for smaller, more immediate energy savings and process operating efficiencies.

Additional projects

CSIRO has also been working with Rio Tinto Alcan on a project to reduce contamination of tapped molten aluminium by electrolyte (or ‘bath’), and there is the prospect of further collaboration in other areas of smelter operation.

Find out more about Partnering with CSIRO.