Aerated composite materials, methods of production and uses thereof

Patent metadata

Field	Value
Publication number	US-10787390-B2
Application number	US-201815972760-A
Country	US
Kind code	B2
Filing date	May 7, 2018
Priority date	Aug 21, 2013
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

The invention provides novel aerated composite materials that possess excellent physical and performance characteristics of aerated concretes, and methods of production and uses thereof. These composite materials can be readily produced from widely available, low cost raw materials by a process suitable for large-scale production with improved energy consumption, desirable carbon footprint and minimal environmental impact.

First claim

The invention claimed is:

1. A process for producing an article of an aerated composite material, comprising:
forming a wet mixture, wherein the wet mixture comprises:
water,
a ground calcium silicate, comprising one or more of synthetic wollastonite, pseudo-wollastonite, rankinite, gehlenite, belite, and alite, having a specific particle size, d 10 in the range from about 0.25 μm to about 5 μm, d 50 in the range from about 5 μm to about 20 μm, and d 90 in the range of about 25 μm to about 100 μm,
filler particles comprising calcium oxide or silica having a particle size (d 50 ) in the range from about 0.25 μm to about 200 μm, and
an aerating agent,

casting the wet mixture in a mold;
providing conditions for generation of a gaseous product from the aerating agent thereby causing volume expansion of the wet mixture;
pre-curing the expanded mixture at a temperature in the range from about 20° C. to about 100° C. under an atmosphere of water and CO 2 for a time sufficient to result in a pre-cured object;
de-molding and/or cutting the pre-cured object to desired dimensions; and
further curing the de-molded and/or cut pre-cured object at a temperature in the range from about 20° C. to about 100° C. for about 6 hour to about 60 hours under an atmosphere of water vapor and CO 2 .

2. The process of claim 1 , wherein the wet mixture further comprises: a set-controlling agent; a bubble stabilizing agent, an activating-agent, and a dispersing/viscosity-modifying agent.

3. The process of claim 2 , wherein forming a wet mixture comprises mixing the following ingredients in the specified order of addition:
adding a the calculated portion of water;
adding and mixing the set-controlling agent;
adding and mixing the dispersing/viscosity-modifying agent;
adding and mixing ground calcium silicate;
adding and mixing the filler particles to form a uniform slurry; and
adding and mixing the aerating agent.

4. The process of claim 2 , wherein the wet mixture comprises mixing the following ingredients in the specified percentages:
the ground calcium silicate in about 40 wt % to about 95 wt % of the wet mixture;
the filler particles in about 0 wt % to about 30 wt % of the wet mixture;
the set-controlling admixture in about 0 wt % to about 0.05 wt % of the wet mixture;
the dispersing/viscosity-modifying agent in about 0.05 wt % to about 0.25 wt % of the wet mixture; and
the aerating agent in about 0.05 wt % to about 0.30 wt % of the wet mixture.

5. The process of claim 2 , wherein the wet mixture further comprises an additive selected from dispersing, rheology modifying admixtures, pigments, retarders, and accelerators.

6. The process of claim 2 , wherein the set-controlling agent is selected from a gluconate and sucrose.

7. The process of claim 2 , wherein the dispersing/viscosity-modifying agent is a polycarboxilate based material.

8. The process of claim 2 , wherein the ground calcium silicate comprises ground wollastonite, pseudo-wollastonite, rankanite, belite, and elite; the filler particles comprises ground limestone and silica; the activating-agent comprises ground lime; the set-controlling agent is a gluconate; the viscosity-modifying agent comprises a polycarboxilate based material; and the aerating agent comprises aluminum paste.

9. The process of claim 2 , wherein at the end of the curing step strength imparting components consist primarily of calcium carbonate and amorphous calcium-silicate phases, calcium-silicate hydrate gel and calcium hydroxide.

10. The process of claim 1 , further comprising after curing the pre-cured object, drying the pre-cured object to remove residual water at a temperature in the range from about 20° C. to about 110° C. for about 12 hours to about 96 hours.

11. The process of claim 1 , wherein curing the expanded mixture is performed under a pressure ranging from ambient atmospheric pressure to about 30 psi above ambient and under a CO 2 concentration ranging from about 25% to about 99.5% to produce an aerated composite material.

12. The process of claim 1 , wherein the pre-curing and further curing is carried out under a dynamic CO 2 circulating flow condition.

13. The process of claim 1 , wherein the pre-curing step is performed at a temperature in the range from about 20° C. to about 80° C. for about 1 hour to about 10 hours under a vapor comprising water and CO 2 .

14. The process of claim 13 , wherein the pre-curing step is performed at a temperature of about 60° C. for about 1 hour to about 5 hours under a vapor comprising water and CO 2 .

15. The process of claim 1 , wherein further curing the pre-cured object is performed at a temperature in the range from about 20° C. to about 80° C. for about 5 hours to about 40 hours under a vapor comprising water and CO 2 and having a pressure in the range from about ambient atmospheric pressure to about 30 psi above ambient atmospheric pressure.

16. The process of claim 15 , wherein further curing the pre-cured object is performed at a temperature in the range from about 30° C. to about 70° C. for about 10 hours to about 30 hours under a vapor comprising water and CO 2 and having a pressure in the range from about ambient atmospheric pressure to about 60 psi above ambient atmospheric pressure.

17. The process of claim 1 , wherein the ground calcium silicate is selected from wollastonite, pseudo-wollastonite, rankanite, belite, and alite.

18. The process of claim 1 , wherein the filler particles are selected from fly ash, bottom ash, slag having particle sizes ranging from about 0.5 μm to about 300 μm.

19. The process of claim 1 , wherein the filler particles are selected from limestone, miro-silica, and quartz having particle sizes ranging from about 1 μm to about 500 μm.

20. The process of claim 1 , wherein the filler particles are selected from aggregates having particle sizes ranging from about 20 μm to about 500 μm.

21. The process of claim 1 , wherein the aerating agent is selected from aluminum, iron, zinc, in powder and or paste form.

22. The process of claim 1 , wherein the aerating agent is hydrogen peroxide in liquid form.

Assignees

• Solidia Technologies Inc

Inventors

• Deo Omkar
• Vuong David
• Ravikumar Deepak
• Sahu Sadananda
• Atakan Vahit

Classifications

• C04B28/188 Primary

  the Ca-silicates being present in the starting mixture · CPC title

• Y02P40/18

  Carbon capture and storage [CCS] · CPC title

• B28B11/247

  Controlling the humidity during curing, setting or hardening · CPC title

• B28B1/50

  specially adapted for producing articles of expanded material, e.g. cellular concrete (chemical aspects {or making expanded aggregate} C04B) · CPC title

• Y10T428/249968

  Of hydraulic-setting material · CPC title