Abstract: A high-chromium refractory material that provides improved resistance to coal slag penetration is presented. The refractory mixture comprises a blend of chromium oxide, aluminum oxide and phosphates. The refractory mixture may be blended with an aggregate and cured. In addition a phosphorous oxide may be blended with chromium oxide and aluminum oxide and additionally an aggregate. The refractory mixture reduces the rate of coal slag penetration into the surface of the cured refractory.

Abstract: Industrial applications of composites often require that the final product have a complex shape. In this invention intermetallic or ceramic phases are formed from sheets of unreacted elemental metals. The process described in this invention allows the final product shape be formed prior to the formation of the composite. This saves energy and allows formation of shaped articles of metal-intermetallic composites composed of brittle materials that cannot be deformed without breaking.

Abstract: A method for improving the high temperature properties of 42 to 70 percent by weight Al.sub.2 O.sub.3 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-Al.sub.2 O.sub.3 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 Al.sub.2 O.sub.3 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.