Process for producing aluminous keatite ceramics
AssigneeCorning Glass Works
InventorDavid G. Grossman
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Abstract
In a process for producing aluminous keatite ceramics by the hydrogen-for-lithium ion-exchange treatment of non-porous glass-ceramics, the efficiency of the lithium extraction step is substantially improved if beta-spodumene glass-ceramics having an Al.sub.2 O.sub.3 :modifying oxide ratio not exceeding about 1:1 are selected as starting materials.
Claims4
In a process for the manufacture of an aluminous keatite-containing ceramic article wherein a ceramic article selected for treatment, comprising a principal crystal phase composed of beta-spodumene solid solution, is first contacted with a strong acid to replace at least some of the lithium ions therein with hydrogen, and thereafter heated to provide aluminous keatite through the removal of at least some of the water of crystallization therefrom, the improvement which comprises selecting as the ceramic article for treatment an article wherein the mole ratio of Al.sub.2 O.sub.3 to modifying oxides selected from the group consisting of Li.sub.2 O, Na.sub.2 O, K.sub.2 O, ZnO, MgO, CaO, BaO and SrO does not exceed about 1:1.
Dependencies are inferred from the claim text.