From waste passenger tyres to ‘green steel’, a SMaRT success story
Waste revolution a boost for 'green' steel
Rubber, plastics and palm waste are not ingredients most people associate with steel girders and beams.
New technology developed and commercialised in Australia, though, “could change the way we think about raw material resources for steelmaking”, according to inventor Veena Sahajwalla.
Salvaging our aluminium cans and newspaper may be ubiquitous but Professor Sahajwalla, director of the University of NSW’s Centre for Sustainable Materials Research and Technology, has in mind a “revolution in waste recycling”.
The crux: the use of high temperatures in steel furnaces – up to 1600 celsius – to transform waste into a useful new resource while reducing carbon dioxide emissions in one of the most energy-intensive industries.
Along with the environmental 3 Rs mantra of reduce, recycle, recycle, should be added “re-form”, Professor Sahajwalla told an international audience in the US “Steel City” of Pittsburgh this week.
Worldwide, some 1.2 billion used tyres are discarded annually. The “vast mountains” of plastics and agricultural waste also offer potential sources of raw materials for the steel industry, she said.
Read the full article by Peter Hannam in the Sydney Morning Herald.
Green Steel update, March 2016:
OneSteel, an Australian-based steel manufacturer, has been actively developing innovative process technologies to utilise waste materials such as end-of-life tyres and post-consumer plastics as an alternative carbon unit in EAF steelmaking. In close co-operation with the University of New South Wales (UNSW), OneSteel has developed and commercialized Polymer Injection Technology (PIT), which enables EAFs to inject blend of coke and rubber in place of pure coke, resulting in improved slag foaming and hence furnace efficiency. OneSteel has been using PIT as a standard practice since 2008 at its Sydney Steel Mill (SSM) and Laverton Steel Mill (LSM) in more than 84,000 heats, consuming over 2.4 million recycled tyres in the process. PIT has been granted patent protection in most major industrial countries. PIT has been commercially implemented in Thailand since May 2011, Korea since April 2014, the UK since October 2014 and in Norway since December 2015, and OneSteel is in advanced discussions with other steelmakers in Europe, the Middle East, South and North America and Asia.
Professor Sahajwalla’s landmark technology is a new method producing ‘green steel’ from scrap metal and recycling waste, avoiding unnecessary extraction of coal and using less power. Download Professor Sahajwalla’s AIST Howe Memorial Lecture here.