Foamed clay process

Claim 2

A process as in claim 1 wherein the bloatable ceramic composition has a maximum bloating capacity of less than 25 p.c.f. and wherein the temperature in the dropping zone is regulated so that the ratio of the bulk density of bloated particles immediately before collection thereof, to the bulk density of particles before dropping is from aBout 0.20 to about 0.75.

Claim 3

The process of claim 3 wherein the bulk density ratio is from about 0.30 to about 0.50.

Claim 4

A process as in claim 3 wherein the temperature of the dropping zone is from about 175* C. to about 400* C. above the initial melting temperature of the composition, and wherein the temperature of the collection zone is from about 50* C. to about 250* C. above the initial melting temperature of the bloatable ceramic composition.

Claim 5

A process as in claim 5 wherein the temperature of the dropping zone is from about 200* C. to about 305* C. above the initial melting temperature of the composition, and wherein the temperature of the collection zone is from about 125* C. to about 225* C. above the initial melting temperature of the bloatable ceramic composition with the time of residence of the collected particles and foamed ceramic slab in the collection zone being about 0.5 to 5.0 minutes.

Claim 6

A process as in claim 6 wherein the initial melting temperature of the bloatable ceramic composition is about 1,020* C., the dropping zone temperature is about 1,260* C., with the falling time for particles being about 0.80 second, and wherein the collection zone temperature is about 1,165* C.

Claim 7

A process for preparing an agglomerated foamed ceramic material having a uniform density of about 12 pounds per cubic foot or less comprising: a. dropping particles of a bloatable ceramic composition containing from about 0.50 to about 2.0 percent by weight of organic carbon and having a maximum bloating capacity of less than about 25 p.c.f. downwardly through a heated dropping zone wherein the temperature is sufficiently in excess of the initial melting temperature of the composition to bloat the particles sufficiently to provide a ratio of the bulk density of the bloated particles immediately before collection thereof to the bulk density of the particles before dropping from about 0.20 to about 0.75, b. agglomerating the bloated particles below the dropping zone in a heated collection zone to form an initial agglomerate of a partially foamed ceramic material, c. heating said initial agglomerate at a temperature above the initial melting temperature and below the temperature of the dropping zone for a time sufficient to further bloat and coalesce the particles to form a foamed ceramic agglomerate, and d. cooling the foamed ceramic agglomerate.

Claim 8

A process for preparing an agglomerated foamed ceramic material having a uniform density of about 10 pounds per cubic foot or less comprising: a. dropping particles of a bloatable ceramic composition containing from about 0.50 to about 2.0 per cent by weight of organic carbon and having a maximum bloating capacity of less than about 20 p.c.f. downwardly through a heated dropping zone wherein the temperature is sufficiently in excess of the initial melting temperature of the composition to bloat the particles sufficiently to provide a ratio of the bulk density of the bloated particles immediately before collection thereof to the bulk density of the particles before dropping from about 0.30 to about 0.50, b. agglomerating the bloated particles below the dropping zone in a heated collection zone to form an initial agglomerate of a partially foamed ceramic material, c. heating said initial agglomerate at a temperature above the initial melting temperature of said composition and below the temperature of the dropping zone for a time sufficient to further bloat and coalesce the particles to form a foamed ceramic agglomerate, and d. cooling the foamed ceramic agglomerate.