Cutting aluminium costs

Citation

(2001), "Cutting aluminium costs", Anti-Corrosion Methods and Materials, Vol. 48 No. 4. https://doi.org/10.1108/acmm.2001.12848dab.003

Cutting aluminium costs

Cutting aluminium costsKeywords: Ohio State University, Aluminium

Investigators at Ohio State University, Columbus, have developed a new anode that they believe could reduce aluminium smelting costs by one-fourth and air pollution by half.

In conventional smelting, refrigerator-sized carbon anodes are submerged in a bath of very hot fused fluoride salt solution containing alumina. The 1,000°C bath dissolves the anodes' electric current plates out pure metallic aluminium.

The new anode concept replaces the carbon with zirconia tubes carrying natural gas. An applied DC voltage draws oxygen through the tubes to oxidise the natural gas. The design is expected to eliminate fluorocarbon production, cut carbon dioxide production by half, use 40 per cent less energy, and ultimately cut aluminium smelters' total production costs by 25 per cent, predicts Robert Rapp, professor emeritus of materials science and engineering and leader of the research team.

The engineers have yet to build a model of the anode, and perfecting the technology could take many years and cost many millions of dollars, cautions Rapp. "This is a long shot with a very big potential payoff", he says. One problem that remains is how to adjust the chemistry of the salt bath so that it continues to dissolve alumina but not the zirconia tubes.