doiSerbia

Dissolution mechanism of Al2O3 in refining slags containing Ce2O3

Wang L.J. (University of Science and Technology, State Key lab of Advanced Metallurgy, Beijing, China + University of Science and Technology, School of Metallurgical and Ecological Engineering, Dept. of Physical chemistry, Beijing, China)
Wang Q. (University of Science and Technology, State Key lab of Advanced Metallurgy, Beijing, China + University of Science and Technology, School of Metallurgical and Ecological Engineering, Dept. of Physical chemistry, Beijing, China)
Li J.M. (Taiyuan Iron & Steel Group Co., Ltd., Shanxi, China)
Chou K.C. (University of Science and Technology, State Key lab of Advanced Metallurgy, Beijing, China + University of Science and Technology, School of Metallurgical and Ecological Engineering, Dept. of Physical chemistry, Beijing, China)

In the present work, the rate of dissolution of Al2O3 rod in CaO-SiO2-Al2O3 and CaO-SiO2-Al2O3-Ce2O3 slags were carried out in the temperature range of 1793 K (1520ºC) - 1853 K (1580ºC) under static conditions. The cross section of the rod and the boundary layers were identified and analyzed by SEM-EDS. The dissolution of Al2O3 was favored with the increasing CaO/Al2O3 ratio, elevating temperatures as well as the addition of Ce2O3. An intermediate product 3CaO5Al2O3Ce2O3 was detected. The mechanism of dissolution of Al2O3 in the Ce2O3 containing slag were also proposed as three steps involved: 1) the formation of calcium aluminates CaO•Al2O3 at the interface 2) the formation of 3CaO5Al2O3Ce2O3 as the reaction progresses; and 3) the dissolution of 3CaO5Al2O3Ce2O3 into the slag.

Keywords: clean steel, dissolution rate, inclusions, alumina, refining slag, Ce2O3