Analysis of the Formed Protective Layer Inhibiting Alkali Corrosion in Aluminosilicate Refractory Castables
Valentin Antonovič,
Rimvydas Stonys,
Povilas Zdanevičius,
Romualdas Mačiulaitis,
Renata Boris,
Jurgita Malaiškienė
Affiliations
Valentin Antonovič
Laboratory of Composite Materials, Institute of Building Materials, Faculty of Civil Engineering, Vilnius Gediminas Technical University, Linkmenu St. 28, 08217 Vilnius, Lithuania
Rimvydas Stonys
Laboratory of Composite Materials, Institute of Building Materials, Faculty of Civil Engineering, Vilnius Gediminas Technical University, Linkmenu St. 28, 08217 Vilnius, Lithuania
Povilas Zdanevičius
Laboratory of Composite Materials, Institute of Building Materials, Faculty of Civil Engineering, Vilnius Gediminas Technical University, Linkmenu St. 28, 08217 Vilnius, Lithuania
Romualdas Mačiulaitis
Laboratory of Composite Materials, Institute of Building Materials, Faculty of Civil Engineering, Vilnius Gediminas Technical University, Linkmenu St. 28, 08217 Vilnius, Lithuania
Renata Boris
Laboratory of Composite Materials, Institute of Building Materials, Faculty of Civil Engineering, Vilnius Gediminas Technical University, Linkmenu St. 28, 08217 Vilnius, Lithuania
Jurgita Malaiškienė
Laboratory of Composite Materials, Institute of Building Materials, Faculty of Civil Engineering, Vilnius Gediminas Technical University, Linkmenu St. 28, 08217 Vilnius, Lithuania
This article analyzes the mechanism of the protective layer formation under the action of alkali in a refractory castable when ground quartz sand (GQS) is used as an admixture to produce refractory conventional castables (CC) and medium cement castables (MCC). It was found that, independently of the castable composition, the addition of GQS (2.5%) reduces the degree of K2CO3 dissolution at high temperature, and the released potassium reacts with the silica and forms a viscous potassium silicate glass, which reduces the mobility of alkali. The liquid phase formed filled some of the open pores and hindered the penetration of potassium into the deeper layers of the refractory castable. The thickness of the formed protective layer, after three cycles of the alkaline corrosion test, varies from 700 µm up to 1300 µm, depending on the castable composition.
