POZZOLANIC COMPOSITIONS CONTAINING FLY ASH AND REMEDIATION AGENTS FOR USE IN CEMENTITIOUS MATERIALS

• US 20150376061A1
• Filed: 06/24/2015
• Published: 12/31/2015
• Est. Priority Date: 06/25/2014
• Status: Active Grant

• Current Assignee: Cr Minerals Company Llc
• Original Assignee: Cr Minerals Company Llc
• Inventors: Carter, Richard Douglas, Thomas, Joseph Earl, Whidden, Jeffrey Alexander
• Granted Patent: US 9,561,983 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C04B 14/04 Silica-rich materials; Silicates
• CPC Class Codes: C04B 14/08 Diatomaceous earth
• CPC Class Codes: C04B 14/106 Kaolin
• CPC Class Codes: C04B 14/12 Expanded clay
• CPC Class Codes: C04B 14/14 Minerals of vulcanic origin granite C04B14/048
• CPC Class Codes: C04B 14/16 porous, e.g. pumice
• CPC Class Codes: C04B 14/18 Perlite
• CPC Class Codes: C04B 14/22 Glass ; Devitrified glass
• CPC Class Codes: C04B 18/023 Fired or melted materials
• CPC Class Codes: C04B 18/08 Flue dust , i.e. fly ash
• CPC Class Codes: C04B 18/088 in high volume fly ash compositions
• CPC Class Codes: C04B 18/141 Slags
• CPC Class Codes: C04B 18/146 Silica fume
• CPC Class Codes: C04B 2103/0088 Compounds chosen for their latent hydraulic characteristics, e.g. pozzuolanes
• CPC Class Codes: C04B 2111/2015 Sulfate resistance
• CPC Class Codes: C04B 2111/2023 Resistance against alkali-aggregate reaction
• CPC Class Codes: C04B 2111/21 Efflorescence resistance
• CPC Class Codes: C04B 2111/26 Corrosion of reinforcement resistance
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 28/021 Ash cements, e.g. fly ash cements fly ash as filler C04B18/08; Cements based on incineration residues, e.g. alkali-activated slags from waste incineration alkali-activated combustion residues as such C04B7/243; mixtures of the lime-pozzuolane type C04B28/18; Kiln dust cements
• CPC Class Codes: C04B 28/18 : containing mixtures of the silica-lime type
• CPC Class Codes: C04B 40/0039 : Premixtures of ingredients
• CPC Class Codes: C04B 7/02 : Portland cement
• CPC Class Codes: C04B 7/12 : Natural pozzuolanas; Natural pozzuolana cements; Artificial pozzuolanas or artificial pozzuolana cements other than those obtained from waste or combustion residues, e.g. burned clay; Treating inorganic materials to improve their pozzuolanic characteristics cements containing slag C04B7/14
• CPC Class Codes: C04B 7/26 : from raw materials containing flue dust , i.e. fly ash C04B7/243 takes precedence
• CPC Class Codes: Y02P 40/10 : Production of cement, e.g. improving or optimising the production methods; Cement grinding
• CPC Class Codes: Y02W 30/91 : Use of waste materials as fillers for mortars or concrete

Abstract

It has been unexpectedly discovered that the addition of a natural or other pozzolan to non-spec fly ash significantly improves the properties of the non-spec fly ash to the extent it can be certified under ASTM C618 and AASHTO 295, as either a Class F or Class C fly ash. The natural pozzolan may be a volcanic ejecta, such as pumice or perlite. Other pozzolans may also be used for this beneficiation process. Many pozzolans are experimentally tested and may be used to beneficiate non-spec fly ash into certifiable Class F fly ash. Additionally, this disclosure provides a method of converting a Class C fly ash to a more valuable Class F fly ash. This discovery will extend diminishing Class F fly ash supplies and turn non-spec fly ash waste streams into valuable, certified fly ash pozzolan which will protect and enhance concrete, mortars and grouts.

Claims

1. A pozzolanic composition for use in concrete, said composition comprising fly ash combined with a natural or other pozzolan.

2. The pozzolanic composition of claim 1, wherein said natural or other pozzolan is present in a concentration of about 1 wt % to about 99 wt %.

3. The pozzolanic composition of claim 2, wherein said natural or other pozzolan is present in a concentration of about 10 wt % to about 90 wt %.

4. The pozzolanic composition of claim 1, wherein a weight ratio of said natural or other pozzolan to said fly ash is from about 0.01 to about 100.

5. The pozzolanic composition of claim 4, wherein a weight ratio of said natural or other pozzolan to said fly ash is from about 0.1 to about 10.

6. The pozzolanic composition of claim 1, wherein said natural or other pozzolan is a pozzolanic ash.

7. The pozzolanic composition of claim 1, wherein said natural or other pozzolan is derived from pumice, perlite, ignimbrites, or any other volcanic material.

8. The pozzolanic composition of claim 1, wherein said natural or other pozzolan is selected from the group consisting of pumice, pumicite, perlite, volcanic ash, metakaolin, diatomaceous earth, silica fume, ignimbrites, ground granulated blast-furnace slag, vitrified calcium alumino-silicates, ground waste glass, calcined shale, calcined clay, and combinations thereof.

9. The pozzolanic composition of claim 1, wherein said natural or other pozzolan is calcined.

10. The pozzolanic composition of claim 1, wherein said composition is certified under ASTM C618-12 and/or AASHTO M295 as a Class F pozzolan.

11. The pozzolanic composition of claim 1, said composition further comprising an additive to adjust viscosity of said composition.

12. The pozzolanic composition of claim 1, said composition further comprising an additive to adjust water demand of said composition in concrete.

13. A cementitious mixture comprising a pozzolanic composition for use in concrete, said composition comprising fly ash combined with a natural or other pozzolan.

14. The cementitious mixture of claim 13, wherein a weight ratio of said natural or other pozzolan to said fly ash is from about 0.01 to about 100.

15. The cementitious mixture of claim 14, wherein a weight ratio of said natural or other pozzolan to said fly ash is from about 0.1 to about 10.

16. The cementitious mixture of claim 13, wherein said natural or other pozzolan is selected from the group consisting of pumice, pumicite, perlite, volcanic ash, ignimbrites, metakaolin, diatomaceous earth, silica fume, ground granulated blast-furnace slag, vitrified calcium alumino-silicates, ground waste glass, calcined shale, calcined clay, and combinations thereof.

17. The cementitious mixture of claim 13, wherein said pozzolanic composition is certified under ASTM C618-12 and/or AASHTO M295 as a Class F pozzolan.

18. A concrete product or structure comprising aggregate and said cementitious mixture of claim 13, or a reaction product thereof.

19. A method of producing a pozzolanic composition for use in concrete, said method comprising:

providing a source of fly ash;

providing a natural or other pozzolan; and

combining said fly ash with said natural or other pozzolan, to produce a pozzolanic composition.

20. The method of claim 19, wherein said fly ash is upgraded, by the presence of said natural or other pozzolan, to enhance its pozzolanic properties.

21. The method of claim 19, wherein a Class C fly ash is upgraded to a Class F fly ash.

22. The method of claim 19, wherein a non-spec, waste fly ash is upgraded to a Class F fly ash.

23. The method of claim 19, wherein said natural or other pozzolan is present in a concentration of about 1 wt % to about 99 wt % in said pozzolanic composition.

24. The method of claim 23, wherein said natural or other pozzolan is present in a concentration of about 10 wt % to about 90 wt % in said pozzolanic composition.

25. The method of claim 19, wherein said natural or other pozzolan is selected from the group consisting of pumice, pumicite, perlite, volcanic ash, ignimbrites, metakaolin, diatomaceous earth, silica fume, ground granulated blast-furnace slag, vitrified calcium alumino-silicates, ground waste glass, calcined shale, calcined clay, and combinations thereof.