Foamed colloidal silica binder for lightweight refractory casting compositions and method of making it
AssigneeMagneco/Metrel, Inc.
InventorDominic Pautler
Life of this patent
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Abstract
A foamed colloidal silica binder having a total porosity of about 50% to about 95% by volume includes a synthetic, non-protein foaming agent mixed with colloidal silica and water. The foamed colloidal silica binder has sufficient durability and integrity to withstand the mixing with dry refractory ingredients to form a porous refractory composition, casting the refractory composition into a refractory shape, and drying the shape to form a porous refractory article having a porosity of about 25% to about 75% by volume. The resulting refractory articles have excellent high-temperature durability and insulating properties. A method of making the foamed colloidal silica binder is also provided.
Claims25
A foamed colloidal silica binder for a refractory composition, comprising:
- about 20% to about 70% by weight colloidal silica particles;
- about 30% to about 80% by weight water;
- and
- a synthetic non-protein foaming agent present in a weight ratio to the water of about 1:25 to about 1:1500;
- wherein the foamed colloidal silica binder has a total porosity of about 50% to about 95% by volume, a total pore volume of about 0.75 to about 15.0 cm3/gram, and a half-life of at least about 1 hour.
A method of making a foamed colloidal silica binder, comprising the steps of:
- adding a synthetic non-protein foaming agent to water in a weight ratio of foaming agent to water of about 1:25 to about 1:1500;
- adding colloidal silica particles to the water in an amount of about 20% to about 70% colloidal silica particles and about 30% to about 80% by weight water;
- and
- mixing the synthetic non-protein foaming agent, colloidal silica particles and water together to form the foamed colloidal silica binder;
- wherein the foamed colloidal silica binder has a total porosity of about 50% to about 95% by volume and a total pore volume of about 0.75 to about 15.0 grams/cm3 and a half-life of at least about 1 hour.
A three-part system for making a refractory composition, comprising:
- an aqueous colloidal silica binder, a synthetic, non-protein containing foaming agent, and a solid component composed of dry refractory ingredients, provided in separate containers or in discrete parts of the same container.
Dependencies are inferred from the claim text.