Process for the production of a cement substitute

Patent metadata

Field	Value
Publication number	US-2024400447-A1
Application number	US-202218694607-A
Country	US
Kind code	A1
Filing date	Nov 22, 2022
Priority date	Nov 22, 2021
Publication date	Dec 5, 2024
Grant date	—

Abstract

A process for the manufacturing of a cement substitute may include: mixing an alkaline aluminosilicate containing material with at least one aluminosilicate hydrate containing material, and heating the thus obtained mixture to a calcination temperature of below 800° C. to form a calcined product comprising a reactive amorphous phase having the alkali ions bound therein. The process may further comprise a step of cooling the calcined product to a desired temperature. A cement substitute is obtainable by this process. The cement substitute includes a reactive amorphous phase of co-calcined alkali aluminosilicate containing material and aluminosilicate hydrate, containing material having alkali ions bound therein. The alkali ions are preferably sodium ions.

First claim

1 . A process for the manufacturing of a cement substitute, the process comprising the following steps:
a) mixing an alkaline aluminosilicate containing material with at least one aluminosilicate hydrate containing material to obtain a mixture, and b) heating the mixture to a calcination temperature of below 800° C. to form a calcined product comprising a reactive amorphous phase having the alkali ions bound therein.

2 . The process according to claim 1 , wherein the mixture is heated to a calcination temperature of below 775° C.

3 . The process according to claim 1 , wherein the mixture is calcinated at a calcination time of less than 75 minutes.

4 . The process according to claim 1 , wherein the calcined product contains maximum 5 wt. % of a crystalline phase.

5 . The process according to claim 1 , wherein the alkaline aluminosilicate containing material is an aluminum sludge.

6 . The process according to claim 5 wherein the aluminum sludge is a bauxite residue comprising at least one of sodalite and cancrinite.

7 . The process according to claim 1 , wherein the alkaline aluminosilicate containing material is a sodium aluminosilicate containing material.

8 . The process according to claim 1 , wherein the aluminosilicate hydrate containing material comprises a kaolin group clay material.

9 . The process according to claim 8 wherein the kaolin group clay material is kaolinite.

10 . The process according to claim 1 , wherein the weight ratio of the alkaline aluminosilicate containing material versus the aluminosilicate hydrate containing material varies from 1 to 15.

11 . The process according to claim 1 , wherein at least one of heating to the calcining temperature is carried out according to a controlled temperature-time regime.

12 . The process according to claim 11 wherein heating of the mixture is carried out at a heating rate of 2 to 50° C./min.

13 . A cement substitute obtainable by the process according to claim 1 .

14 . A cement substitute comprising a reactive amorphous phase of co-calcined alkali aluminosilicate containing material and aluminosilicate hydrate containing material, having alkali ions bound therein.

15 . The cement substitute according to claim 14 , wherein the alkali ions are sodium ions.

16 . A cement composition comprising the cement substitute obtained from the process according claim 1 .

17 . A mortar or cement composition containing the cement composition according to claim 16 .

18 . The mortar or cement composition according to claim 17 , wherein at least 20 wt. % of the cement is substituted by the cement substitute.

19 . The process according to claim 1 , wherein the mixture is heated to a calcination temperature of 600° C. to 800° C.

20 . The process according to claim 4 , wherein the calcined product contains maximum 2.5 wt. % of a crystalline phase, based on the total weight of the calcinated product.

Assignees

• Vito Nv

Inventors

• Peys Arne
• Quaghebeur Mieke
• Snellings Ruben

Classifications

• C04B28/26

  Silicates of the alkali metals · CPC title

• C04B28/06

  Aluminous cements (monolithic refractories or refractory mortars C04B35/66) · CPC title

• C04B7/12

  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 title

• Y02P40/10

  Production of cement, e.g. improving or optimising the production methods; Cement grinding · CPC title

• C04B20/04

  Heat treatment · CPC title