The tank spouts and parts of the tank superstructure of a soda-lime-flint glass melts for the production of flat and container glass aren mostly lined with fused-cast blocks today. Besides baddeleyite and corundum, these materials contain (depending on the brick grade in different concentrations) a corresponding amount of a hgih silicic acid (silicon dioxide) glassy phase. It is know than, on account of the production process,s the texture is non-homogeneous. It turned out time and again in industrial operation that especially in high-stress tank areas, such as throat, corner blocks and dam, those blocks are subject to substantial werar. The corrosion follows chemical and mechanical courses and leads to faults in the glass caused by crystalline inclusions that are surrounded by alumina cords.
