Abstract: Optical waveguide preforms and other glass articles produced by gas-drying and consolidating porous glass soot preforms are provided utilizing a consolidation method wherein consolidation proceeds from the drying gas inlet to the drying gas outlet end of the preform, this method resulting in more uniform water attenuation characteristics in the articles.

Abstract: Fired refractory articles are made of a shaped refractory composition predominantly comprising grain of fusion-cast AZS refractory having: (i) a three-phase microstructure of interlocking crystals of corundum (alpha alumina) phase and baddeleyite (zirconia) phase with intercrystalline glassy phase therebetween, the glassy phase being about 15-30 vol.% of the AZS refractory, and (ii) an oxide analysis consisting of 35-60 wt.% Al.sub.2 O.sub.3 plus Cr.sub.2 O.sub.3 with Cr.sub.2 O.sub.3 .ltoreq. 60 wt.% of Al.sub.2 O.sub.3 plus Cr.sub.2 O.sub.3, 25-50 wt.% ZrO.sub.2, 10-18 wt.% SiO.sub.2, 0.8-1.8 wt.% Na.sub.2 O plus K.sub.2 O, and up to 0.7 wt.% other ingredients (e.g. impurities). Refractory composition consists of: (A) 25-60 wt.% fusion-cast AZS refractory coarse grain being at least 89 wt.% -6+20 Tyler mesh, (B) 0-38 wt.% fusion-cast AZS refractory medium grain being at least 73 wt.% -10+35 Tyler mesh, and (C) 30-50 wt.% at least one component selected from the group consisting of: (1) 0-50 wt.