Australia and China to collaborate on green steelmaking

Thursday, 19 March, 2015

CSIRO’s Dry Slag Granulation (DSG) technology, which harvests blast furnace waste and converts it into a new product to make cement, is the focus of an agreement signed between the organisation and the Beijing MCC Equipment Research & Design Corporation (MCCE).

The DSG technology that is fitted to blast furnaces includes a spinning disc and granulation chamber that separates molten slag into droplets under centrifugal forces, uses air to quench and solidify the droplets, and extracts a granulated slag product as well as heated air. The process produces a ‘glassy’ product that is suitable for cement manufacture, but has lower associated greenhouse gas emissions than cement produced by conventional methods.

Molten slag is spun out into droplets and cooled to be used in cement manufacture.

Air at 500-600°C extracted from the DSG process can be used on-site for drying, preheating or steam generation. The technology also saves water and eliminates the underground water pollution that can be associated with alternative wet granulation processes.

The technology is currently being trialled for commercialisation in China, where 60% of the world’s iron blast furnace slag is produced each year. MCCE plans to scale-up and demonstrate the technology at industrial scale and, on success, commercialise it in China and then potentially worldwide.

The DSG rig is fitted to blast furnaces to produce granulated slag and heated air.

“Our collaboration is an exciting step towards the uptake of an innovation with real prospects of transforming the productivity and environmental performance of global iron smelting,” said CSIRO Director of the Mineral Resources Flagship Jonathan Law.

“The benefits each year from full commercialisation and adoption of DSG technology are in the order of 60 billion litres of water, 800 PJ of heat energy and 60 million tonnes of greenhouse gas emissions,” said Law - equivalent to 14% of Australia’s energy use and about 10% of its greenhouse gas emissions each year.