Fire brick for bottom portion of float bath and method for production thereof

摘要

It is to provide a process for producing a float bath bottom refractory brick which can suppress a reaction with Na 2 O from glass at the surface of the refractory brick and thereby prevents flaking phenomena, as a refractory brick to be used for a float bath bottom for production of plate glass by float process. A process for producing a float bath bottom refractory brick using a clayey material comprising from 30 to 45 mass% of Al 2 O 3 and from 50 to 65 mass% of SiO 2 and having a Na 2 O content of at most 1 mass%, wherein a potassium compound is added so that the K 2 O content in the float bath bottom refractory brick to be produced would be from 2 to 4 mass%.