Process and apparatus for producing cellulated vitreous refractory material in prescribed shapes and products therefrom

A process of providing a charge for a kiln, comprising in a die cavity covering the bottom thereof with a release agent, applying a mixture of solid carbonaceous aggregate and binder over said release agent, placing a charge of mineral and cellulating agent on said mixture and pressing same together.

In a process of producing vitreous cellulated silica the steps of passing through a kiln containing rollers a charge of silica and a cellulating agent, the charge being supported on an expendable carbon slab which contacts the upper periphery of said rollers.

In a process of producing a cellulated vitreous refractory material in a kiln having a linear path through said kiln, the steps of forming said refractory material and a blowing agent into a linear ribbon, continuously feeding said linear ribbon along said path through said kiln while maintaining the ribbon in its linear form and progressively heating said ribbon in its linear travels through said kiln whereby increments of said ribbon are progressively dried, sintered, then melted and cellulated.

The process of producing a cellulated vitreous fused silica product comprising crushing silica rocks selected from the group consisting of quartzite rock, and diatomaceous earth to produce agglomerates less than 1/2" in diameter, mixing the crushed silica rock with a solution in which a carbon compound, which will char upon heating, dissolved in water, whereby the solution will penetrate said agglomerates and coat the particles of which said agglomerates are composed, driving off the water from said agglomerates and charring to leave the carbon compound as a coating on said particles, thereafter melting said agglomerates at a temperatue which will cause the carbon deposited on said particles to react with available silicon and oxygen to cause cellulation of the molten silica, and thereafter cooling the cellulated silica.

The process of producing a cellulated vitreous fused silica product comprising, mixing together silica flour and colloidal silica and a solution containing a carbon compound which will char on heating dissolved in water whereby the solution coats the particles of flour and the colloidal silica, driving off the water from said solution and charring to leave a carbon coating on each particle and then melting said mixture so as to cause said carbon to react to cellulate the molten silica, and cooling the cellulated silica.

In a process of producing a vitreous cellulated clay product, the steps of admixing clay which contains iron oxide with an aqueous carbon containing solution to produce a charge, progressively passing said charge in a linear path over roller in a kiln, heating said charge in said path to first drive off the water from the mixture, then progressively sintering said mixture in said path under oxidizing conditions in said kiln so as to progressively produce a skin for said charge which melts at a temperature higher than the melting point of the interior of said charge, progressively heating said sintered charge in said path as it is moved along the rollers to a temperature at which the interior melts and cellulates but the skin does not, whereby the skin along the bottom surface of the charge prevents the molten charge from adhering to the rollers, and thereafter progressively cooling said charge.

The process of claim 28 including pressing a parting agent comprising a mixture of silica sand, fire clay and water, to the bottom surface of said charge prior to the sintering of said charge for producing a sacrificial surface which will be released to the rollers where the rollers are sticky.

The process of claim 28 including progressively pressing onto the lower surface a mixture of raw clay and calcined clay which is more refractory than the charge for producing a surface to supplement the skin in preventing adherence of the charge to the rollers and in restraining the lateral expansion of said charge.