8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

**Abstract:** The content of Al2O3 in iron ore is of negative effects on sintering process, metallurgical properties of sinter and smelting of BF, which has a serious influence on the quality of molten iron. So it is very important to study the activity of Al2O3 in metallurgical slag to grasp and control the influence of content of Al2O3 on the quality of molten iron. In this paper, several measurement methods and its present status of Al2O3 activity in different slag systems are reviewed systematically. The achievements of representative studies are introduced and analyzed, both advantage and disadvantage of different methods are explained, and the rationality and accuracy of measurement methods are discussed emphatically. The theoretical analysis shows that the reference slag method can avoid the error caused by thermodynamic data, and has better scientificalness and higher precision than other methods. Therefore, the determination of activity of Al2O3 by the reference slag method has important academic value and good application prospect. **Key words: activity of Al2O3; metallurgical slag; measurement method; reference slag method; chemical equilibrium method; e.m.f method**