Abstract:Effects of roasting temperature, roasting time and ratio of carbon to oxygen on roasting process of coal-based magnetization were investigated, and the transformation process of iron-containing oxides was characterized by chemical analysis, XRD, SEM and thermogravimetric analysis. With the increase of roasting temperature, the transformation process of physical phase of iron-containing oxides is Fe2O3→Fe3O4→FeO. With the extension of roasting time of magnetization roasting, Fe2O3 in the tailings is first reduced to Fe3O4 by carbon, and the reduced Fe3O4 can be re-oxidized to Fe2O3 by oxygen in air. Under low ratio of carbon to oxygen conditions, the magnetization rate is close to 2.33. When the ratio of carbon to oxygen exceeds 3, the excess coal is mixed with the tailings, and resulting the incomplete reduction of Fe2O3. The magnetization rate of roasted ore is 2.34 under the optimum roasting conditions including roasting temperature of 645 ℃, roasting time of 45 min, and ratio of carbon to oxygen of 3.