Silica Refractories for Glassworks-Use

JSGT 1918 V02 T253 -T259  (7 pages)

The most important difference in the behaviour on continued heating of clay firebricks and silica firebricks is that the former contract whilst the latter expand. Consequently, silica bricks are mainly used in such positions as the upper parts and crowns of furnaces where good refractory properties, combined with an absence of shrinkage at high temperatures, is desirable. Semi-silica bricks in which the proportions of clay and silica are so adjusted that the contraction of the clay is neutralised by the expansion of the silica whilst rather less refractory than silica bricks, also find their uses for positions in which constancy of volume is of importance.

W. J. Rees