Calcium aluminate clinker as a refractory aggregate with and without barium addition and use thereof

• US 8,123,853 B2
• Filed: 09/27/2010
• Issued: 02/28/2012
• Est. Priority Date: 08/25/2003
• Status: Active Grant

• Current Assignee: Allied Mineral Products, LLC
• Original Assignee: Westmoreland Advanced Materials Inc.
• Inventors: McGowan, Kenneth A.
• Primary Examiner(s): Marcantoni, Paul
• Application Number:
  US12/891,262
• Publication Number:
  US 20110011213A1
• Time in Patent Office: 519 Days
• Field of Search: 106/692
• US Class Current: 106/692
• CPC Class Codes: C04B 14/30 Oxides other than silica ferrites C04B14/363
• CPC Class Codes: C04B 14/303 Alumina
• CPC Class Codes: C04B 16/06 fibrous
• CPC Class Codes: C04B 18/023 Fired or melted materials
• CPC Class Codes: C04B 20/002 Hollow or porous granular materials
• CPC Class Codes: C04B 20/0048 Fibrous materials
• CPC Class Codes: C04B 2103/0011 Ba
• CPC Class Codes: C04B 2103/40 Surface-active agents, dispersants
• CPC Class Codes: C04B 2103/408 Dispersants
• CPC Class Codes: C04B 2111/00146 Sprayable or pumpable mixtures
• CPC Class Codes: C04B 2111/00215 Mortar or concrete mixtures defined by their oxide composition
• CPC Class Codes: C04B 2111/00431 Refractory materials
• CPC Class Codes: C04B 22/142 Sulfates
• CPC Class Codes: C04B 22/16 containing phosphorus in the anion, e.g. phosphates
• CPC Class Codes: C04B 2235/3205 Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3213 Strontium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3215 Barium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
• CPC Class Codes: C04B 2235/72 : Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 2235/727 : Phosphorus or phosphorus compound content
• CPC Class Codes: C04B 2235/77 : Density
• CPC Class Codes: C04B 2235/80 : Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 28/06 : Aluminous cements monolithic refractories or refractory mortars C04B35/66
• CPC Class Codes: C04B 35/44 : based on aluminates
• CPC Class Codes: C04B 35/62695 : Granulation or pelletising devices for shaping artificial aggregates from ceramic mixtures B28B1/004
• CPC Class Codes: C04B 35/66 : Monolithic refractories or refractory mortars, including those whether or not containing clay making or repairing of linings F27D1/16
• CPC Class Codes: C04B 38/08 : by adding porous substances
• CPC Class Codes: C04B 40/0028 : Aspects relating to the mixing step of the mortar preparation
• CPC Class Codes: C04B 7/32 : Aluminous cements
• CPC Class Codes: C04B 7/42 : Active ingredients added before, or during, the burning process after the burning process C04B22/00, C04B24/00

Abstract

The present invention provides for a refractory aggregate composition comprising an improved calcium aluminate clinker having the formula C_nA_x wherein C is calcium oxide and A is aluminum oxide, wherein n is an integer from about 1 to about 12, wherein x is an integer from about 1 to about 24, and wherein said clinker has from zero to less than about fifty weight percent C₁₂A₇. Analogs, derivatives and hydrates of the improved calcium aluminate clinker are provided. A refractory composition and a sprayable refractory composition are disclosed comprising the improved calcium aluminate clinker. A method for improving the insulating character and/or penetration resistance of a liner in contact with molten aluminum in an aluminum manufacturing process or during aluminum transport is provided.

Claims

1. A method for improving the insulating character and/or penetration resistance of a liner in contact with material in a manufacturing process or during material transport, comprising:

lining a rotary kiln and/or processing equipment with a refractory composition comprising a refractory aggregate consisting essentially of a calcium aluminate clinker having the formula C_nA_x, wherein C is equal to calcium oxide, wherein A is equal to aluminum oxide, wherein n is an integer from about 1 to about 12, wherein x is an integer from about 1 to about 24, and wherein said calcium aluminate clinker has from zero to less than about fifty weight percent C₁₂A₇, and wherein greater than 98 weight percent of said calcium aluminate clinker having a particle size ranging from 325 mesh to +10 mesh, for forming a liner prior to contacting said equipment with the material and for improving the insulating character and/or penetration resistance of said liner.

2. The method of claim 1 including wherein the refractory aggregate is porous.

3. The method of claim 1 including wherein the refractory aggregate is formed by sintering.

4. The method of claim 1 including wherein the refractory aggregate has little to no porosity.

5. The method of claim 1 including wherein the refractory aggregate is formed by a fusion process.

6. The method of claim 1 including treating said refractory composition with heat to a temperature not exceeding about 1820 degrees Centigrade.

7. The method of claim 1 including wherein the refractory composition includes analogs or derivatives of said C_nA_x, and optionally includes wherein barium is substituted for calcium in said calcium aluminate clinker.

8. The method of claim 1 including wherein the refractory composition comprises a source of barium, wherein said barium source is present in one or more phases as BaO, BA₆, and C₂BA₄, and combinations thereof.

9. The method of claim 6 including wherein the refractory composition comprises a source of barium, wherein said barium source is present in one or more phases as BaO, BA₆, and C₂BA₄, and combinations thereof.

10. The method of claim 1 including wherein the refractory composition comprises one or more of a reactive alumina, a calcined alumina, a tabular alumina, and a bubble alumina, and combinations thereof.

11. The method of claim 1 including wherein said refractory composition comprises one or more lightweight aggregates.

12. The method of claim 11 including wherein said lightweight aggregate is one or more of a bubble alumina, an expanded clay, a perlite, and a pyrophilite, and combinations thereof.

13. The method of claim 1 including wherein the refractory composition comprises at least one of a surfactant, and a fibrous material, and combinations thereof.

14. The method of claim 1 including wherein said refractory composition comprises a calcium aluminate cement.

15. The method of claim 1 including wherein said refractory composition comprises one or more of a set retarder, and a set accelerator, and combinations thereof.

16. The method of claim 14 including wherein said refractory composition comprises one or more of a reactive alumina, a surfactant, a fibrous material, a set retarder, and a set accelerator, and combinations thereof.

17. The method of claim 1 including adding an effective amount of water to achieve a pressable, castable, pumpable, or sprayable consistency of said refractory composition and for creating a hydrate phase of said C_nA_x.

18. The method of claim 17 including wherein said refractory composition comprises a calcium aluminate cement.

19. The method of claim 18 including wherein said sprayable refractory composition comprises a pumpable first component comprising said refractory composition and an effective amount of a dispersant, and said water, and optionally a second component comprising an effective amount of a flocculating agent, wherein said optional second component is added to said pumpable first component for achieving installation of the sprayable refractory composition.

20. The method of claim 19 including employing in combination with said dispersants one or more rheology affecting additives.

21. The method of claim 20 including wherein said rheology affecting additives are one or more of a boric acid retarder, a citric acid retarder, and a lithium carbonate, and combinations thereof.

22. The method of claim 17 including pressing said refractory composition into shape.

23. The method of claim 1 including pressing said refractory composition into shape.

24. The method of claim 1 including employing said refractory composition in a filtration process.