Abstract
Steelmaking based on natural gas rather than coal is proposed as a logical solution to concerns about climate change and global warming. Highly preheated iron ore fines are fed onto the surface of the molten iron carrier medium in a single loop melt circulation reactor. A thin layer of liquid iron ore is formed and reduction occurs as the molten iron oxide containing melt is transported along the length of the reduction arm countercurrent to natural gas in situ generated reducing gases flowing at high velocity. Issues relating to Kelvin–Helmholtz instability are addressed and detailed consideration is given to soot formation and its subsequent gasification in the bulk gas phase. Key parameters for 1 Mtpa liquid steel are evaluated based on thermal decomposition of methane by convective heat transfer and reduction of ferrous oxide controlled by gaseous diffusion. A breakdown of capital and operating costs indicates the relative importance of key elements.