Corrosion mechanism of Cr2O3-Al2O3-ZrO2 refractories in a coal-water slurry gasifier: A post-mortem analysis

•Corroded microstructure of a Cr2O3-Al2O3-ZrO2 refractory brick used in a gasifier was fully characterized, revealing four separate layers.•Behaviors of the main corrosive constituents (Fe, Si) involved in the corrosion process were examined.•An isolation layer comprising (Mg, Fe2+)(Cr, Fe)2O4 compl...

Full description

Saved in:
Bibliographic Details
Published in:Corrosion science 2020-02, Vol.163, p.108250, Article 108250
Main Authors: Chen, Junfeng, Xiao, Junli, Zhang, Yu, Wei, Yaowu, Han, Biangqiang, Li, Youqi, Zhang, Shaowei, Li, Nan
Format: Article
Language:English
Subjects:
Aluminum oxide
Chromium oxides
Coal-water slurry gasifier
Corrosion
Corrosion mechanisms
Cr2O3-Al2O3 refractories
Crystallization
Gasification
Mapping
Phase separation
Post-mortem analysis
Refractories
Repair & maintenance
Slurries
Zirconium dioxide
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Corroded microstructure of a Cr2O3-Al2O3-ZrO2 refractory brick used in a gasifier was fully characterized, revealing four separate layers.•Behaviors of the main corrosive constituents (Fe, Si) involved in the corrosion process were examined.•An isolation layer comprising (Mg, Fe2+)(Cr, Fe)2O4 complex spinel was formed on the refractory’s surface.•A corrosion model was introduced to discuss corrosion behaviors of Cr2O3-Al2O3 aggregates under different slag concentration gradients. Corroded microstructure of a Cr2O3-Al2O3-ZrO2 refractory brick after 4200 h service in a gasifier was investigated. An isolation layer comprising mainly (Mg, Fe2+)(Cr, Fe)2O4 complex spinel was formed on the refractory’s surface, which effectively suppressed the infiltration of main corrosive constituents in the slag (FeXO, MgO). Furthermore, a quantitative analysis of main corrosive elements in the corroded/uncorroded interface was carried out based on EDS mapping. The results indicated that the overall corrosion depth was dependent on the penetration distance of FeXO. Finally, the corrosion behavior of Cr2O3-Al2O3 aggregates in the refractory was investigated, and a dissolution-phase separation-crystallization mechanism proposed.
ISSN:0010-938X
1879-0496
DOI:10.1016/j.corsci.2019.108250