Research of Corrosive Destruction Mechanism of Cordierite-Mullite Refractory Materials

Abstract

Abstr act. Reasons and mechanism of cordierite-mullite refractory materials destruction in the ovens for glazing ceramic wares baking have been examined. The change of elemental and phase compositions of refractory surface layers under the influence of cyclic action of water vapour and volatile components of glazing coating has been established. The ways of increasing cordierite-mullite refractory materials longevity have been proposed.

Microstructure properties of lead silicate glasses

“…There are also absorption bands in the area of 900-850cm-1 typical for [AlO 4 ]-tetrahedron ,and the maximum at 867 cm -1 pertinent to Si-O-Al bond. The characteristic band of the cordierite phase with absorption maximum at 779 cm-1 pertinent to [Si 5 AlO 18 ] is a peculiarity of refractory IR-spectrum [20]. weak, sharp peak which also appear polarized is observed at 600 cm -1 .…”

“…3. Infrared spectrum is characterized by the presence of large absorption band between 1200 and 900cm -1 and have its maximum at 1080 cm -1 which is typical to stretching vibrations of Si-O-Si bonds [20,21] [22]. The broad bands in the range 800-1, 300 cm -1 indicate different structural orderings of the glass network due to overlapping of stretching vibrations of various silicate units.…”

Integrated Regeneration Method for Used Mineral Motor Oils

“…Taking into account the short life of cordieritemullite refractory materials, associated with destructive processes caused by aggressive factors in their surface layers [1], it is advisable to protect the surface of refractories by coating. The use of known coating compositions for the protection of cordierite-mullite refractories is unacceptable due to the significant difference between the thermal coefficients of linear expansion (TCLE) of these coatings and the substrate ((6-10)•10 -6 K -1 ) [2][3][4][5][6].…”

“…Lithium aluminosilicates have a low value of TCLE (0.5-2.0)•10 -6 K -1 , but the most acceptable crystalline phase in the composition of such coatings is magnesium aluminosilicate -cordierite. From the practice and theoretical studies of coatings for high-temperature protection it is known [7][8][9][10][11][12][13][14][15] that the maximum protective effect and minimum energy consumption can be achieved by forming the required phase component in the coating 1 Lviv Polytechnic National University, 12, Bandera St., 79013 Lviv, Ukraine * orest.m.vakhula@lpnu.ua ã Vakhula O., Pona M., Solokha I., Koziy O., Petruk M., 2021 layer during coatings pre-burning or operation. Therefore, the main attention in the studies was paid to the synthesis of cordierite α-phase directly in the coating.…”