The Port Kembla Steelworks is a fully integrated steelmaking facility, which relies on most of its parts to work in sync with each other—the blast furnace needs coke and cokemaking equipment needs gas from the blast furnace to operate, etc. You get the idea!
Another key example of this chemical synergy is that the steelmaking process uses oxygen; this oxygen is made using the compressed air that is generated from other processes. For instance, working with the cryogenic plant at Coregas Pty Ltd - a Wesfarmers company, BlueScope helps to produce oxygen that is subsequently used in hospitals throughout New South Wales.
Thank you to Simon Orchard and WIN News Illawarra for the included TV-news excerpts.