Ultra-light mineral foam

Patent metadata

Field	Value
Publication number	US-2018354854-A1
Application number	US-201615780931-A
Country	US
Kind code	A1
Filing date	Dec 5, 2016
Priority date	Dec 4, 2015
Publication date	Dec 13, 2018
Grant date	—

Abstract

A process for the production of a mineral foam includes (i) separately preparing a slurry of cement and an aqueous foam, wherein the cement slurry includes water and Portland cement; (ii) contacting the slurry of cement with the aqueous foam to obtain a slurry of foamed cement; (iii) adding an aluminum salt source before or during step (ii); and (iv) 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; (ii) contacting the slurry of cement with the aqueous foam to obtain a slurry of foamed cement; (iii) adding an aluminum salt source before or during step (ii); (iv) casting the slurry of foamed cement and leave it to set, wherein the mineral foam is substantially free of particles with a diameter D50<2 μm.

2 . The process according to claim 1 , wherein aluminum sulphate is used as said aluminum salt source.

3 . The process according to claim 1 , wherein the aluminum salt source is added to the aqueous foam before contacting the aqueous foam with the cement slurry in step (ii).

4 . The process according to claim 2 , wherein aluminum sulphate is added in an amount of 0.15-5% in dry aluminum sulphate by weight of cement.

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

6 . The process according to claim 1 , 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 an aluminum salt source, being 1 aluminum sulphate in the form of an aluminum sulphate solution, 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; (ii) contacting the slurry of cement with the aqueous foam to obtain a slurry of foamed cement; and (iii) adding an aluminum salt source before or during step (ii).

13 . The method according to claim 12 , wherein aluminum sulphate is added in an amount of 0.15-5% in dry aluminum sulphate by weight of cement.

14 .- 18 . (canceled)

19 . The process according to claim 2 , wherein the aluminum sulphate is in the form of an aluminum sulphate solution.

20 . The process according to claim 2 , wherein aluminum sulphate is added in an amount of 0.25-3% in dry aluminum sulphate by weight of cement.

21 . The process according to claim 20 , wherein aluminum sulphate is added in an amount of 0.5-2.5% in dry aluminum sulphate by weight of cement.

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

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

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

25 . 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

26 . The method according to claim 13 , wherein aluminum sulphate is added in an amount of 0.25-3% in dry aluminum sulphate by weight of cement.

27 . The method according to claim 26 , wherein aluminum sulphate is added in an amount of 0.5-2.5% in dry aluminum sulphate by weight of cement.

Assignees

• Holcim Technology Ltd

Inventors

• Chaumilliat Christine
• Blachier Christian
• Perez Nicalas
• Ferreint Lilian

Classifications

• C04B22/148

  Aluminium-sulfate · CPC title

• C04B2111/52

  Sound-insulating materials · CPC title

• C04B28/04 Primary

  Portland cements · CPC title

• C04B2111/40

  Porous or lightweight materials · CPC title

• C04B38/10

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