Darban Sina, Reynaert Camille, Ludwig Maciej, Prorok Ryszard, Jastrzębska Ilona, Szczerba Jacek
Department of Ceramics and Refractories, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland.
Laboratoire Matériaux et Durabilité des Constructions, INSA/UPS Génie Civil, Université de Toulouse, CEDEX 04, 31077 Toulouse, France.
Materials (Basel). 2022 May 10;15(10):3425. doi: 10.3390/ma15103425.
In this paper, the corrosion mechanism of commercial alumina-spinel refractory was investigated at 1350 and 1450 °C. Disc samples were coated with shells of two different slags containing 4 and 10 wt.% SiO. The after-corrosion refractory was investigated in view of changes in its microstructure and phase composition by SEM/EDS and XRD techniques, respectively. At 1350 °C slags slightly infiltrated the microstructure, whereas at 1450 °C slags infiltrated the alumina-spinel refractory causing its significant corrosion. As a result of corrosion, new phases were formed, including calcium dialuminate (CaAlO), calcium hexaluminate (CaAlO), and gehlenite (CaAlSiO). Formation of calcium aluminate layers in the microstructure of the refractory inhibited further dissolution of alumina aggregates; however, expansive behavior of CaAlO raised the microstructure porosity. The additional SiO in the slag doubled the amount of low melting gehlenite in the matrix, accelerating the corrosion process of alumina-spinel brick at high temperatures.
本文研究了工业氧化铝-尖晶石耐火材料在1350℃和1450℃下的腐蚀机理。将圆盘试样涂上含有4 wt.%和10 wt.% SiO的两种不同炉渣的壳层。分别通过扫描电子显微镜/能谱仪(SEM/EDS)和X射线衍射仪(XRD)技术,从其微观结构和相组成的变化方面对腐蚀后的耐火材料进行了研究。在1350℃时,炉渣轻微渗入微观结构,而在1450℃时,炉渣渗入氧化铝-尖晶石耐火材料,导致其显著腐蚀。腐蚀的结果是形成了新的相,包括二铝酸钙(CaAlO)、六铝酸钙(CaAlO)和钙黄长石(CaAlSiO)。耐火材料微观结构中铝酸钙层的形成抑制了氧化铝聚集体的进一步溶解;然而,CaAlO的膨胀行为增加了微观结构的孔隙率。炉渣中额外的SiO使基体中低熔点钙黄长石的量增加了一倍,加速了氧化铝-尖晶石砖在高温下的腐蚀过程。