U.S. Pat. 4,568,652, 1986 Feb; :1-13
A method for improving the high temperature properties of 42 to 70 percent by weight Al2O3 containing alumina refractories by adding thereto a soluble metal compound and firing to at least 1450.degree. C. for a time sufficient to convert the soluble metal compound to a refractory oxide or phase and for the refractory oxide or phase to react with the non-Al2O3 constituents of the refractory for preventing or reducing the presence or effect of detrimental compounds or phases on the high temperature properties of the refractory. The resulting relatively low Al2O3 content, porous, alumina refractory includes within its pores from 1 to 10% by weight of a refractory oxide or phase and is characterized by high temperature property values substantially greater than the corresponding values for the same refractory body without said refractory oxide or phase in its pores.