An Australian smart technology that harvests blast furnace waste and converts it into a new product to make cement is being trialled for commercialisation in China. The process, known as dry slag granulation (DSG), also reduces water use and greenhouse gas emissions, and is the focus of an agreement signed by Australia’s national science agency, CSIRO and the Beijing MCC Equipment Research & Design Corporation (MCCE).
The DSG technology 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 ideal for cement manufacture, but has significantly lower associated greenhouse gas emissions than cement produced by conventional methods. Air at 500°C–600°C extracted from the DSG process can be used onsite for drying, preheating or steam generation. The technology also saves water and eliminates the underground water pollution associated with alternative wet granulation processes.
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. The agreement is the culmination of more than a decade of DSG technology development by CSIRO and industry partners including Arrium and BlueScope.
