Ultra-light mineral foam

Patent metadata

Field	Value
Publication number	US-2020247722-A1
Application number	US-201615780783-A
Country	US
Kind code	A1
Filing date	Dec 5, 2016
Priority date	Dec 4, 2015
Publication date	Aug 6, 2020
Grant date	—

Abstract

A process for the production of a mineral foam includes separately preparing a slurry of cement and an aqueous foam, wherein the cement slurry includes water and Portland cement as well as calcium silicate hydrate crystallization seeds; contacting the slurry of cement with the aqueous foam to obtain a slurry of foamed cement; and casting the slurry of foamed cement and leave it to set.

First claim

1 . A process for the production of a mineral foam comprising the following steps:
(i) separately preparing a slurry of cement and an aqueous foam, wherein the cement slurry comprises water and Portland cement as well as calcium silicate hydrate crystallization seeds; (ii) contacting the slurry of cement with the aqueous foam to obtain a slurry of foamed cement; (iii) casting the slurry of foamed cement and leave it to set, wherein the mineral foam is substantially free of particles with a mean diameter D50 <2 μm.

2 . The process according to claim 1 , wherein the calcium silicate hydrate crystallization seeds comprise calcium silicate hydrate particles.

3 . The process according to claim 1 , wherein the calcium silicate hydrate crystallization seeds are present in the form of an aqueous suspension.

4 . The process according to claim 1 , wherein the calcium silicate hydrate crystallisation seeds are present in an amount of 0.5-7% in dry calcium silicate hydrate by weight of Portland cement.

5 . The process according to claim 1 , wherein the D50 of bubbles of the aqueous foam prepared in step (i) is less than or equal to 400 μm.

6 . The process according to claim 1 , wherein step (ii) comprises the introduction of the slurry of cement and the aqueous foam into a static mixer to obtain the slurry of foamed cement.

7 . The process according to claim 1 , wherein a W/C ratio (wt/wt ratio) of 0.28-0.35 is used in step (i).

8 . The process according to claim 1 , wherein the Portland cement is a cement of the type CEM I, CEM II, CEM III, CEM IV or CEM V.

9 . The process according to claim 1 , wherein the Portland cement has a specific surface (Blaine) of 3000-10000 cm 2 /g.

10 . The process according to claim 1 , wherein the cement slurry comprises a water reducer.

11 . The process according to claim 1 , wherein the slurry of foamed cement comprises at least one supplementary mineral component.

12 . A method comprising utilizing calcium silicate hydrate crystallization seeds for enhancing the mechanical stability and/or reducing the collapse of a slurry of foamed cement, said slurry of foamed cement being obtained by
(i) separately preparing a slurry of cement and an aqueous foam, wherein the cement slurry comprises water and Portland cement as well as calcium silicate hydrate crystallization seeds; and (ii) contacting the slurry of cement with the aqueous foam to obtain the slurry of foamed cement.

13 . Use method according to claim 12 , wherein the calcium silicate hydrate crystallisation seeds are present in an amount of 0.5-7% in dry calcium silicate hydrate by weight of Portland cement.

14 .- 18 . (canceled)

19 . The process according to claim 4 , wherein the calcium silicate hydrate crystallisation seeds are present in an amount of 0.5-5% in dry calcium silicate hydrate by weight of Portland cement.

20 . The process according to claim 19 , wherein the calcium silicate hydrate crystallisation seeds are present in an amount of 0.7-3% in dry calcium silicate hydrate by weight of Portland cement.

21 . The process according to claim 9 , wherein the Portland cement has a specific surface (Blaine) of 3500-6000 cm 2 /g.

22 . The process according to claim 10 , wherein the water reducer is a plasticiser or super-plasticiser.

23 . The process according to claim 11 , wherein the at least one supplementary mineral component is a supplementary cementitious material.

24 . The process according to claim 11 , wherein the at least one supplementary mineral component is selected from calcium carbonate, silica, ground glass, solid or hollow glass beads, glass granules, expanded glass powders, silica aerogels, silica fume, granulated blast furnace slags, ground sedimentary siliceous sands, fly ash or pozzolanic materials or mixtures thereof.

25 . The method according to claim 13 , wherein the calcium silicate hydrate crystallisation seeds are present in an amount of 0.5-5% in dry calcium silicate hydrate by weight of Portland cement.

26 . The method according to claim 25 , wherein the calcium silicate hydrate crystallisation seeds are present in an amount of 0.7-3% in dry calcium silicate hydrate by weight of Portland cement.

Assignees

• Holcim Technology Ltd

Inventors

• Bost Pascal
• Sabio Serge
• Chaumilliat Christine
• Lombois-Burger Hélène

Classifications

• C04B14/04 Primary

  Silica-rich materials; Silicates · CPC title

• C04B38/10 Primary

  by using foaming agents (C04B38/02 takes precedence){or by using mechanical means, e.g. adding preformed foam} · CPC title

• C04B28/04 Primary

  Portland cements · CPC title

• C04B22/00863

  Calcium silicate hydrate · CPC title

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title