Abstract: In order to provide theoretical guidance for further research of coal-based direct reduction of siderite ore, a siderite ore from Jiayuguan was chosen for sample to study the conversion behavior of various minerals in the coal-based direct reduction process of the siderite ore, by the technologies of XRD, SEM, energy spectrum analysis and thermodynamics calculation. The results show that: with low consumption of coal, iron(magnesium) olivine is the first product in the process of solid reaction, then the excess iron minerals exist in the wutite form and forming iron core in some fu's body; iron particles are growing up with the coal consumption increasing, through the reduction of the wutite around the iron core to iron. In addition, along with the increasing of coal consumption, the main gangue iron magnesium olivine also convert into part of metallic iron through the procedure: iron magnesium olivine-iron peridot-wutite-iron.

Key words: Siderite ore, Coal-based direct reduction, Minerals conversion behavior, Metallic iron, Coal consumption