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Slag corrosion mechanism of lightweight Al 2 O 3 –MgO castable in different atmospheric conditions
Author(s) -
Zou Yang,
Gu Huazhi,
Huang Ao
Publication year - 2018
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15337
Subject(s) - corrosion , ladle , partial pressure , slag (welding) , metallurgy , materials science , spinel , oxygen , oxide , iron oxide , inorganic chemistry , chemistry , organic chemistry
The slag resistance of ladle lining refractory in different atmospheric conditions is of utmost importance due to the strong variation of atmospheric environment in ladle during the process cycle. In this study, by adopting dynamic induction furnace corrosion test, the corrosion mechanism of lightweight Al 2 O 3 –MgO castable with different environmental oxygen partial pressure was investigated through macro and microanalysis, XRD , and thermodynamic simulation. The atmospheric condition was set to P (O 2 ) = 0.21 atm or P(Ar) = 1.0 atm. The attained results showed that a reduced slag corrosion but intensified slag penetration happened at low environmental oxygen partial pressure condition. With P(O 2 ) = 0.21 atm, Mn and Fe in slag were present in the form of divalent and/or trivalent cations and were incorporated into spinel to form MnFe 2 O 4 solutions and MgAl 2 O 4 solutions during the corrosion process. Since Fe, Mn ions were largely consumed, liquid with high viscosity formed and the continuing infiltration was suppressed. Under P(Ar) = 1.0 atm, Fe ions in the slag were totally reduced into elemental iron while Mn existed mainly in the state of MnO, and the amount of liquid slag was therefore reduced, leading to significantly weakened corrosion on castable aggregates. Corrosion reaction products under this condition were mainly MgAl 2 O 4 and CA 6 .