Fly ash-based foam geopolymer, preparation method therefor, and use thereof

Patent metadata

Field	Value
Publication number	US-12151973-B2
Application number	US-202218570315-A
Country	US
Kind code	B2
Filing date	Mar 3, 2022
Priority date	Jun 15, 2021
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

Disclosed herein are a fly ash-based foam geopolymer, a preparation method therefor, and the use thereof. The fly ash-based foam geopolymer is prepared from raw materials comprising the following components in parts by weight: 900-1000 parts of a fly ash-based material; 600-700 parts of a composite alkali solution; 0-10 parts of a thickening agent; 2-6 parts of a foam stabilizer A; 5-10 parts of a water reducer; and 20-40 parts of a foaming agent. The preparation method of the present application is simple, and processes such as ball milling, water washing and calcining do not need to be carried out on the raw materials, such that the investment in a grinding equipment, a water washing equipment, a sewage treatment equipment, and a calcining equipment is reduced, and the energy consumption and carbon emissions are reduced. The fly ash-based foam geopolymer prepared by using the fly ash-based material as the main raw material in the present application has a low apparent density and a high early strength, and can be used in the field of fabricated buildings.

First claim

What is claimed is:

1. A fly ash-based foamed geopolymer, wherein raw materials for preparing the fly ash-based foamed geopolymer comprise the following components in parts by weight:
900-1000 parts of a fly ash-based material;
600-700 parts of a composite alkali solution;
0-10 parts of a thickener;
2-6 parts of a foam stabilizer A;
5-10 parts of a water reducer; and
20-40 parts of a foaming agent;
wherein when a calcareous material is present, the fly ash-based material is prepared by the following preparation method:
mixing fly ash with the calcareous material to obtain the fly ash-based material;
wherein based on a mass of the fly ash-based material being 100%, the fly ash has a content of 90%-100%, and the calcareous material has a content of 0%-10%;
wherein the calcareous material comprises any one or a combination of at least two of cement, ore slags, gypsum or metakaolin;
wherein the composite alkali solution is prepared by the following preparation method:
mixing a composite alkali activator, a metal complexing agent and a foam stabilizer B to obtain the composite alkali solution;
based on a mass of the composite alkali solution being 100%, the composite alkali activator has a content of 95%-98%, the metal complexing agent has a content of 0.05%-0.5%, and the foam stabilizer B has a content of 1.95%-4.5%;
wherein the foam stabilizer A comprises trisodium phosphate and/or calcium stearate powders;
the foam stabilizer B comprises any one or a combination of at least two of sodium dodecylbenzenesulfonate powders, sodium dodecyl sulfate powders, trisodium phosphate powders or calcium dodecyl sulfate powders.

2. The fly ash-based foamed geopolymer according to claim 1 , wherein the composite alkali activator has a modulus of 1.0-1.5.

3. The fly ash-based foamed geopolymer according to claim 1 , wherein the metal complexing agent comprises any one or a combination of at least two of triethanolamine, methyldiethanolamine, diisopropanolamine, diethanolisopropanolamine, triethanolamine or triisopropanolamine.

4. The fly ash-based foamed geopolymer according to claim 3 , wherein the metal complexing agent has a solid content of not less than 78%.

5. The fly ash-based foamed geopolymer according to claim 1 , wherein the foam stabilizer B has a purity of not less than 88%.

6. The fly ash-based foamed geopolymer according to claim 1 , wherein the composite alkali activator is prepared by the following preparation method:
adding sodium hydroxide powders and water into water glass, and stirring to obtain the composite alkali activator.

7. The fly ash-based foamed geopolymer according to claim 6 , wherein based on a mass of the composite alkali activator being 100%, the sodium hydroxide powders have a content of 8.5%-9%, the water has a content of 4.5%-7%, and the water glass has a content of 84%-87%.

8. The fly ash-based foamed geopolymer according to claim 6 , wherein the sodium hydroxide powders have a purity of not less than 96%.

9. The fly ash-based foamed geopolymer according to claim 6 , wherein the water is tap water.

10. The fly ash-based foamed geopolymer according to claim 6 , wherein the water glass has a modulus of 1.0-3.8 and a Baume degree of 34.0-42.0.

11. The fly ash-based foamed geopolymer according to claim 1 , wherein the thickener comprises methyl cellulose ether and/or carboxymethyl cellulose ether.

12. The fly ash-based foamed geopolymer according to claim 11 , wherein the thickener comprises methyl cellulose ether and carboxymethyl cellulose ether.

13. The fly ash-based foamed geopolymer according to claim 11 , wherein the thickener has a purity of not less than 96%.

14. The fly ash-based foamed geopolymer according to claim 11 , wherein the thickener has a viscosity of not less than 30000 cp.

15. The fly ash-based foamed geopolymer according to claim 1 , wherein the trisodium phosphate has a purity of not less than 98%.

16. The fly ash-based foamed geopolymer according to claim 1 , the calcium stearate powders have a purity of not less than 99%.

17. The fly ash-based foamed geopolymer according to claim 1 , wherein the water reducer comprises any one or a combination of at least two of a polycarboxylic acid water reducer, a naphthalene sulfonate water reducer, an aliphatic water reducer, a lignosulfonate water reducer or an amino-sulfonate water reducer.

18. The fly ash-based foamed geopolymer according to claim 1 , wherein the foaming agent comprises a hydrogen peroxide solution.

19. The fly ash-based foamed geopolymer according to claim 18 , wherein the hydrogen peroxide solution has a concentration of not less than 30%.

20. A preparation method for the fly ash-based foamed geopolymer according to claim 1 , comprising the following steps:
(1) stirring the fly ash-based material, the composite alkali solution, the thickener, the foam stabilizer A and the water reducer according to formula amounts to obtain a slurry;
(2) adding the foaming agent into the slurry obtained in step (1), stirring to obtain a mixture, and then injecting the mixture into a mold; and
(3) placing the mixture and the mold in step (2) in a curing chamber for curing, demoulding, and then placing the demoulded sample in a curing environment for curing, so as to obtain the fly ash-based foamed geopolymer.

21. The preparation method according to claim 20 , wherein the stirring in step (1) is carried out in a mixing kettle.

22. The preparation method according to claim 20 , wherein a stirring blade for the stirring in step (1) has a revolution speed of 115-135 r/min and a rotation speed of 275-295 r/min.

23. The preparation method according to claim 20 , wherein the stirring in step (1) is performed for a period of 4-6 min.

24. The preparation method according to claim 20 , wherein a stirring blade for the stirring in step (2) has a revolution speed of 57-67 r/min and a rotation speed of 135-145 r/min.

25. The preparation method according to claim 20 , wherein the stirring in step (2) is performed for a period of 20-40 s.

26. The preparation method according to claim 20 , wherein the process of injecting the mixture into the mold in step (2) is to inject the mixture into a depth of ½ of the mold.

27. The preparation method according to claim 20 , wherein the curing chamber in step (3) has a temperature of 65-75° C.

28. The preparation method according to claim 20 , wherein the process of curing in the curing chamber in step (3) is performed for a period of 12-24 h.

29. The preparation method according to claim 20 , wherein the curing environment in step (3) has a temperature of 18-22° C. and a humidity of at least 95%.

30. The preparation method according to claim 20 , wherein a process of curing in the curing environment in step (3) is performed for a period of 7 days.

Assignees

• Univ Shenzhen

Inventors

• Cui Hongzhi
• Feng Weipeng
• Zheng Dapeng
• Jin Yu
• Dong Zhijun

Classifications

• C04B2111/40

  Porous or lightweight materials · CPC title

• C04B2103/48

  Foam stabilisers · CPC title

• C04B2103/44

  Thickening, gelling or viscosity increasing agents · CPC title

• C04B2103/302

  Water reducers · CPC title

• C04B2103/10

  Accelerators; Activators · CPC title