Abstract: Effect of basicity on the liquid phase formation properties was simulated and calculated by using the thermodynamic software Factsage 7.1, and the sintering pot tests with different basicity were carried out. The results show that with the increase of basicity, the theoretical liquid phase production of sinter increases, the liquid phase viscosity decreases, the mass ratio of (Fe2O3/CaO) in the liquid phase composition increases, which is beneficial to improve the formation conditions of calcium ferrite. When the basicity is 1.95, the calcium ferrite binder phase content is the highest, the combination of CaO and Fe2O3 to form a stable calcium ferrite binder phase, which is beneficial to reduce the reduction degradation of Fe2O3. When the basicity increases to 2.05, the coarser limonite and hematite will further contact and mineralize with CaO, which results in the increase of hematite content, the decrease of calcium ferrite and magnetite content, the decrease of liquid viscosity and the increase of porosity. Thus the uniformity of sinter structure becomes worse, which leads to the deterioration of ability of the sinter matrix structure to resist the lattice distortion generated in the reduction process, as a result, the sinter degradation becomes serious. Comprehensively considering the influence of basicity on the drum strength and lowtemperature reduction degradation performance of sinter, the appropriate basicity should be controlled to 1.95 under the sintering raw material condition used in the experiment.
ZHANG Guocheng,LUO Guoping,CHAI Yifan,WANG Yici,SONG Wei.
Effect of basicity on liquid phase formation properties and microstructure of sinter[J]. Journal of Iron and Steel Research, 2021, 33(7): 584-592 https://doi.org/10.13228/j.boyuan.issn1001-0963.20200242