Mechanism on behaviors of iron ore dissolution and sintering melt flow
ZHAI Xiao-bo1, ZHENG Jun1, WANG Gang1, ZOU Zhong-ping1, ZHOU Heng2
1. Low-carbon Technology Research Institute, CISDI Engineering Co., Ltd., Chongqing 401122, China; 2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Abstract：During iron ore sintering, iron ores dissolve partially into sintering melt, which has a direct effect on the properties of melt, and hence the bonding of sinter. In order to clarify the interaction between iron ore and sintering melt, adhering fines of calcium ferrites existing in forms of Ca3.6Fe14.4O25.2 and CaFe2O4 were prepared by calcination of chemical pure reagents. The behaviors of iron ore dissolution and sintering melt flow were studied through laboratory sintering method on the sintering couple composed of seven kinds of nuclei ore and adhering fines of calcium ferrites (w(CaO)=15%). Based on this, chemical compositions of nuclei ore were simulated using chemical pure reagents, and therefore the influence law of SiO2 contents and Al2O3 contents in nuclei ore on horizontal flow area of melt and dissolution index of nuclei ore as well as its mechanism were explored. The results show that when nuclei ore dissolves into CaO-Fe2O3 system liquid phase, the interaction region is formed. After the minerals in iron ore, especially quartz, dissolves into the melt, complex CaO-Fe2O3 system liquid phase is formed at the area near the melt. At the same time, simple CaO-Fe2O3 system liquid phase is transformed into CaO-Fe2O3-SiO2 system liquid phase at the area near nuclei ore. As the main minerals, calcium ferrites and hematite precipitate at the area near the melt, while silicates and hematite precipitate at the area near nuclei ore. With increasing of SiO2 content in nuclei ore, on the one hand, the amount of SiO2 dissolved into the melt increases, resulting in raising of dissolution index of nuclei ore. On the other hand, the viscosity of simple CaO-Fe2O3 system liquid phase is increased, resulting in reducing of horizontal flow area of melt. With increasing of Al2O3 content in nuclei ore, amount of Al2O3 dissolved into the melt increases, which decreases horizontal flow area of melt, but increases dissolution index of nuclei ore. Al2O3 in nuclei ore has stronger influence than SiO2 on the behaviors of iron ore dissolution and sintering melt flow.
翟晓波, 郑军, 王刚, 邹忠平, 周恒. 铁矿石溶解与烧结熔体流动行为机理[J]. 钢铁, 2022, 57(8): 60-68.
ZHAI Xiao-bo, ZHENG Jun, WANG Gang, ZOU Zhong-ping, ZHOU Heng. Mechanism on behaviors of iron ore dissolution and sintering melt flow[J]. Iron and Steel, 2022, 57(8): 60-68.
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2022, Vol. 57 
