Shapeable insulating material for use with molten aluminum

Claim 2

A composition which consists essentially of the mixture of, in parts by weight: ______________________________________ calcium aluminate cement 30-55 parts chrysotile fiber 2-25 parts cryolite 0.5-5 parts refractory fiber 10-30 parts inorganic filler compatible with molten aluminum 10-35 parts ______________________________________ and sufficient water to render the mixture tractable yet capable of being formed by extrusion into a shape retaining insulating body suitable for use in contact with molten metal.

Claim 3

The composition of claim 1 wherein said refractory fiber comprises synthetic inorganic fibers of silicates of di-valent or tri-valent metals.

Claim 4

The composition of claim 2 wherein said refractory fibers comprise synthetic aluminosilicate fibers.

Claim 5

The composition of claim 1 consisting essentially of, in parts by weight: ______________________________________ calcium aliminate cement 40-50 parts chrysotile fiber 4-20 parts cryolite 1-3 parts refractory fiber 15-25 parts inorganic filler compartible with molten aluminum 10-35 parts water balance ______________________________________

Claim 6

The composition of claim 4 wherein said inorganic filler comprises diatomaceous earth.

Claim 7

The composition of claim 4 wherein said inorganic filler comprises the mixture of diatomaceous earth and clay.

Claim 8

A shaped insulating article compatible with and resistant to contact with molten aluminum, said article formed by extrusion from a mixture which consists essentially of, in parts by weight: ______________________________________ calcium aluminate cement 35-55 parts chrysotile fiber 2-25 parts cryolite 0.5-5 parts refractory fiber 10-30 parts inorganic filler compatible with molten aluminum 10-35 parts ______________________________________ and water in amount sufficient to render said mixture tractable yet shape retaining, said article having been cured, dried, and then treated for a period of at least 1/2 hour at a temperature of at least 480° C.

Claim 9

A shaped insulating article compatible with and resistant to contact with molten aluminum, said article formed by extrusion from a mixture which consists essentially of, in parts by weight: ______________________________________ calcium aluminate cement 35-55 parts chrysotile fiber 2-25 parts cryolite 0.5-5 parts refractory fiber 10-30 parts inorganic filler compatible with molten aluminum 10-35 parts ______________________________________ and water in amount sufficient to render said mixture tractable yet shape retaining, said article having been cured, dried, and then treated for a period of at least 1/2 hour at a temperature of at least 480° C.

Claim 10

The shaped article of claim 7 comprising an elongated trough.

Claim 11

The shaped article of claim 7 comprising a flat board.

Claim 12

A process for the formation of shaped insulating articles compatible with and resistant to contact with molten aluminum, which comprises: (a) forming a mixture consisting essentially of, in parts by weight: ______________________________________ calcium aluminate cement 35-55 parts chrysotile fiber 2-25 parts cryolite 0.5-5 parts refractory fiber 10-30 parts inorganic filler compatible with molten aluminum 10-35 parts ______________________________________ and sufficient water to render said mixture tractable yet shape retaining; (b) extruding said mixture through a die into the desired shape; (c) curing the extruded body; and (d) drying said extruded body; and (e) heat treating the extruded body at a temperature of at least 480° C. for a period of at least 1/2 hour.

Claim 13

A process for the formation of shaped insulating articles compatible with and resistant to contact with molten aluminum, which comprises: (a) forming a mixture consisting essentially of, in parts by weight: ______________________________________ calcium aluminate cement 35-55 parts chrysotile fiber 2-25 parts cryolite 0.5-5 parts refractory fiber 10-30 parts inorganic filler compatible with molten aluminum 10-35 parts ______________________________________ and sufficient water to render said mixture tractable yet shape retaining; (b) extruding said mixture through a die into the desired shape; (c) curing the extruded body; and (d) drying said extruded body; and (e) heat treating the extruded body at a temperature of at least 480° C. for a period of at least 1/2 hour.

Claim 14

The process of claim 10 wherein said heat treating is at a temperature of at least 650° C.

Claim 15

The composition of claim 4 wherein said refractory fiber comprises synthetic inorganic fibers of silicates of di-valent or tri-valent metals.

Claim 16

The composition of claim 12 wherein said refractory fiber comprises synthetic aluminosilicate fibers.