An agreement aiming to trial CSIRO’s Dry Slag Granulation (DSG) technology on an industrial scale has been signed between CSIRO, Australia’s national science agency, and the Beijing Research Institute of Metallurgical Equipment, MCC Group (MCCE).
The agreement marks the culmination of more than a decade of DSG technology development by CSIRO and industry partners, including worldsteel member companies, Arrium and BlueScope. The work covered initial design and proof of concept stages through to the construction and operation of prototype DSG pilot plants on small, intermediate and large scales.
The technology, which is to be trialed in China, has a threefold advantage: not only does it convert by-product to base products for cement, but it also reduces greenhouse gas emissions from power generation by using waste heat from hot slag and, lastly, it saves water.
The DSG technology that is fitted to the blast furnace 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 pea-size ‘glassy’ product that is ideal for cement manufacture but has significantly lower associated greenhouse gas emissions than cement produced by conventional methods.
Air at 500-600°C extracted from the DSG process can be used on-site for drying, preheating or steam generation for power. The technology also saves evaporating water for granulation.
In entering the collaboration with MCCE, CSIRO has recognised the R&D reputation of the Beijing-based company and its ability to scale up the technology and introduce it into China - where 50 percent of the world’s 300 million tonnes of iron blast furnace slag is produced each year.
Under the agreement, MCCE is to scale up and demonstrate the technology at industrial scale and, upon success, commercialise it in China and then potentially worldwide.
Commenting on the new technology, CSIRO Director of the Mineral Resources Flagship, Jonathan Law said: “The benefits each year from full commercialisation and adoption of DSG technology are in the order of 60 million m3 of water, 800 petajoules of heat energy and 60 million tonnes of greenhouse gas emissions. Those savings are equivalent to 14 percent of Australia’s energy use and about 10 per cent of its greenhouse gas emissions each year.”