Binder and refractory compositions and methods

A refractory composition comprising refractory particles and a binder composition, wherein said binder composition is the result of combined ingredients comprising colloidal silica, a liquid material containing Si-OH groups, a solvent which is capable of solubilizing the liquid material and the colloidal silica, and at least one aprotic, non-ionic, non-metallic, organic compound which contains at least one element from the group consisting of phosphorus, sulfur, boron, nitrogen, and mixtures thereof and which stabilizes the binder composition against self-gelling, wherein said colloidal silica and said liquid material are present in a ratio by weight from about 1:12 to about 75:1 respectively, said liquid material contains at least about 20% by weight SiO.sub.2, and said colloidal silica contains at least 15% by weight of SiO.sub.2, and wherein said solvent and said organic compound are present in amount sufficient to solubilize the liquid material and the colloidal silica, to provide a binder composition which is stable against self-gellation, and to provide a binder composition which gels to a single phase.

A process for preparing a binder composition comprising the steps of providing a reaction mixture comprising acid, a silicate ester which is capable of being hydrolyzed to liquid materials containing Si-OH groups, and a solvent which solubilizes the silicate ester and which also will solubilize colloidal silica sol;

• and adding an aqueous based colloidal silica sol to the reaction mixture at a rate sufficient to hydrate the silicate ester without gelling the resulting binder composition, wherein the water present in the colloidal silica sol provides substantially all of the water to hydrate the silicate ester and wherein the acid is present in an amount sufficient to catalyze the hydration reaction and to provide a final pH of from about 1 to about 3 for the resulting binder composition;
• and adding to the reaction mixture at least one aprotic, non-ionic, non-metallic, organic compound which contains at least one element selected from the group consisting of phosphorus, sulfur, boron, nitrogen, and mixtures thereof and which stabilizes the resulting binder composition against self-gelling.