Abstract: One-dimensional unstable reduction model based on porous medium model was developed aiming at the complex problems in acquaintance of single ferric oxide particle during magnetization roasting of limonite.By numerical calculation，the conversion degree of limonite was studied at different temperature，various CO concentration and different initial porosity.The research results showed that random pore model can be applied to reduction model well，and transmission characteristics of gas within the porous media channels have some degree of impacts on reaction.It takes only about 18 s for particles of 100 μm in diameter to complete reduction course at 800 ℃.

Key words: Single limonite particle, Random pore model, Reduction model, Numerical simulation