Waste plastic makes steel

Veena Sahajwalla, the Director of Sustainable Materials Processing Research at the University of New South Wales, has shown the steel industry that they can use waste plastic bottles to make steel. The plastic replaces coal as a source of carbon in the steel-making process.

It's been a hard sell in a conservative industry, but now steel-makers around the world are picking up on the idea and the technology could be in use in Australia and the US within two years.

Forty per cent of the world's steel is produced in electric arc furnaces operating at 1600°C. "Up to 30% of the coal in these furnaces can be replaced with recycled plastic and we are aiming for more," says Sahajwalla.

"Not only does the plastic replace coal as a carbon source, it also acts as a fuel, reducing the power requirements for the furnace, and the extreme temperatures of steelmaking eliminate pollutants like dioxins."

"In Australia, we consume more than one million tonnes of plastic each year. Eighty per cent is incinerated or becomes landfill. So plastic waste remains a major environmental concern," she says.

Sahajwalla is collaborating with leading steel producers in Australia and the US. She says they are excited about the potential of the process.

"We are currently testing mixtures of waste plastics, and we hope to implement our technology in the steel industry in Australia and the US within the next two years."