Free flowing dry back-up insulating material

• US 20050116398A1
• Filed: 11/28/2003
• Published: 06/02/2005
• Est. Priority Date: 11/28/2003
• Status: Active Grant

• Current Assignee: Les Produits Industriels de Haute Temperature Pyrotek Inc. (Pyrotek Incorporated)
• Original Assignee: Les Produits Industriels de Haute Temperature Pyrotek Inc. (Pyrotek Incorporated)
• Inventors: Tremblay, Sylvain P.
• Granted Patent: US 7,083,758 B2
• Time in Patent Office: Days
• US Class Current: 266/280
• CPC Class Codes: C22B 1/243 inorganic
• CPC Class Codes: C22B 7/02 Working-up flue dust
• CPC Class Codes: F27D 1/0006 Linings or walls formed from bricks or layers with a particular composition or specific characteristics
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete

Abstract

Disclosed is a free flowing dry back-up material which comprises: from 67 to 96% by weight of fly-ash; from 2 to 15% by weight of a heat sensitive binder such as boric acid; from 2 to 7% by weight of a non-wetting agent such as calcium fluoride; from 0 to 10% by weight of a heat expandable material, viz. a material expandable as a function of the temperature such as vermiculite or graphite; and from 0 to 1% by weight of a dust suppressant such as kerosene. This material which is useful in particular in the aluminum industry has the advantages of being water free and free flowing, such avoiding the use of vibrator to position it into a shell. It also has a low density and a low thermal conductivity. Moreover, it is organic free as compared to the existing materials which use an organic binder to ensure a low temperature set; and it sets at a temperature lower than 400° F.

Claims

1. A free flowing dry back-up insulating material comprising

from 67 to 96% by weight of fly-ash;

from 2 to 15% by weight of a heat sensitive binder;

from 2 to 7% by weight of a non-wetting agent;

from 0 to 10% by weight of a heat expandable material; and

from 0 to 1% by weight of a dust suppressant.

2. The material for claim 1, wherein:

the fly ash consists of cenospheres;

the heat sensitive binder is selected from the group consisting of boric acid and anhydrous boron oxide;

the non-wetting agent is selected from the group consisting of calcium fluoride, magnesium fluoride and barium sulfate;

the heat expandable material is selected from the group consisting of vermiculite and graphite; and

the dust suppressant is selected from the group consisting of kerosene, mineral oils and vegetable oils.

3. The material of claim 1, wherein said material comprises:

from about 89.5% to 90% by weight of said fly ash;

about 8% by weight of said heat sensitive binder;

about 2% by weight of said non-wetting agent; and

from about 0 to 0.5% by weight of said dust suppressant.

4. The material of claim 2, wherein said material comprises:

from about 89.5% to 90% by weight of said fly ash;

about 8% by weight of said heat sensitive binder;

about 2% by weight of said non-wetting agent; and

from about 0 to 0.5% by weight of said dust suppressant.