Abstract: A composition for forming a high temperature, acid and alkali resistant refractory fiber. The compositional formulation, by weight, is 56-76% silica, 12-33% alumina, and 3-22% zirconia. These fibers are chemically resistant in both acidic and alkaline environments even when heat treated to temperatures exceeding 500.degree. F. (260.degree. C.) in such environments.

Abstract: A composition for forming a high temperature, alkali resistant refractory fiber. The compositional formulation, by weight, is 46-52% silica, 32-38% alumina, 13-18% zirconia with a silica to zirconia ratio in the range from 2.6 to 3.8. These fibers have a maximum service temperature in the range of 2550.degree. F. (1400.degree. C.) to 2650.degree. F. (1455.degree. C.) and exhibit better shrinkage resistance than similarly rated commercially available refractory fiber.

Abstract: An improved process for the formation of alumina-containing fiber is described. The process utilizes alumina having an alpha crystalline phase content in the range of from 5% to 60%, preferably 5% to 35%, as compared to the alpha alumina contents of 75% to 90% of the prior art materials. Use of the low alpha crystalline phase content alumina permits substantial increase in the melt rate of the alumina-containing composition and thus increases production of fiber without any significant deterioration of other processing parameters or properties of the finished fiber.