Novel phenomenon of quasi‐volcanic corrosion on the alumina refractory‐slag‐air interface

Abstract

A novel phenomenon of quasi‐volcanic corrosion at refractory–slag–air interface under simulated normal smelting conditions was discovered when alumina refractory came in contact with CaO‐Al2O3‐SiO2 slags and soaked at 1600°C. Based on thermodynamic and microstructure analysis, the mechanism of quasi‐volcanic corrosion was revealed and the effect of CaO/SiO2 mass ratio (C/S ratio) on corrosion was discussed. The results indicate that a two‐stage intensified convection led to the severe upwelling corrosion of the refractory at the triple‐phase interface. Furthermore, the critical intensity of the corrosive convection at the first stage on the formation of “slag volcano” was determined. This can serve as guidance for prolonging the service life of alumina refractory.

Corrosion resistance and anti‐reaction mechanism of Al2O3‐based refractory ceramic under weak static magnetic field

“…When C/S ratio of the higher Al 2 O 3 containing slag is equal or more than 2.6, the serious quasi-volcano corrosion at the slag-refractory interface will occur. 8,9 Hence, the synthetic slags were prepared with C/S ratios less than 2.6 or higher and same Al 2 O 3 content. Table 1 lists the specific compositions of the synthetic slags.…”

“…2,7 In particular, CaO-Al 2 O 3 -SiO 2 slag with a high Al 2 O 3 content and a C/S ratio (CaO wt%/SiO 2 wt%) ≥2.6, the 'melts volcano' with a macroscale continuous peak pattern at the three-phase interface of alumina refractory-melts-air formed due to the intensified convection and the severe upwelling corrosion of the alumina crucible, which is different from formal corrosion, and drastically reduced the service life of the alumina crucible. 8,9 The slag corrosion resistance of refractories can be improved and optimized by the regulation and control of their composition and structure, [10][11][12][13] such as by whisker reinforcement and microporosization.…”

Effect of slag basicity on Turing pattern corrosion of alumina refractory ceramics in the presence of free radicals

“…High alumina content CaO–Al 2 O 3 –SiO 2 ‐based slags in aluminum containing steel smelting lead to serious corrosion damage of alumina‐based refractory materials. Recently, Zou et al 9 . selected alumina crucibles to explore a more severe quasi‐volcanic corrosion phenomenon—a novel phenomenon at the triple‐phase interface in the shape of “slag volcano” with macroscale continuous peaks at the triple‐phase interface of alumina refractory ceramics‐slag‐air, which indicated that the CaO/SiO 2 mass ratio (C/S ratio) in the slag composition is an important factor governing the growth and height of the quasi‐volcanic corrosion peaks.…”

“…8 High alumina content CaO-Al 2 O 3 -SiO 2 -based slags in aluminum containing steel smelting lead to serious corrosion damage of aluminabased refractory materials. Recently, Zou et al 9 selected Yuefang Peng, Shenghao Li, and Ao Huang contributed equally to this work.…”

Reaction Mechanism of CA6, Al2O3 and CA6-Al2O3 Refractories with Refining Slag

“…During the ladle refining process, the refractory is corroded severely due to the continuous reaction of the refining slag [ 1 , 2 , 3 ]. The slag corrosion will destroy the structure of the refractory and reduce the service life [ 4 , 5 , 6 , 7 ]. More importantly, under the continuous scouring effect of molten steel, the dislodged refractory and the corrosion products would enter the molten steel to form exogenous large size inclusions [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ], which will have a fatally harmful effect on the purity of the molten steel and the quality of the final products [ 17 , 18 , 19 , 20 ].…”