Aqueous suspensions including an aluminous cement and binding compositions
Stabilized aqueous suspensions include aluminous cement and/or calcium sulfoaluminous cement and binding compositions including the aqueous suspension in combination with organic binders, which are stable at room temperature and at high temperature as well as methods for preparing the same are described.
1. A stabilized aqueous suspension, comprising:
from 50% to 70% by weight, relative to the total weight of said aqueous suspension at least one hydraulic binder comprising aluminous cement and/or calcium sulfoaluminous cement and at least one blocking agent comprising a phosphorus-containing compound selected from the group consisting of metaphosphoric acid, phosphorous acid, phosphoric acid, phosphonic acids and any compound which may form any of these compounds by reacting with water, said suspension comprising from 0.1% to 20% by weight of phosphorus-containing compound relative to the aluminous cement and/or calcium sulfoaluminous cement total weight,
from 30% to 50%, by weight, relative to the total weight of said aqueous suspension of water, and
from 0 to 5%, by weight, relative to the total weight of said aqueous suspension of additional additives,
wherein said stabilized aqueous suspension is stabilized for at least two months at a temperature from about 15° C. to 55° C.
2. The stabilized aqueous suspension according to claim 1 , wherein compounds which may form metaphosphoric acid, phosphorous acid, phosphoric acid or phosphonic acids are selected from the group consisting of: phosphorus pentoxyde, pyrophosphoric acid, tripolyphosphoric acid, amino trimethylene phosphonic acid, 2-aminoethyl phosphonic acid, 1-hydroxy ethylidene-1,1-diphosphonic acid, ethylene diamine tetramethylene phosphonic acid, tetramethylene diamine tetramethylene phosphonic acid, hexamethylene diamine tetramethylene phosphonic acid, diethylene triamine pentamethylene phosphonic acid, phosphonobutane tricarboxylic acid, N-(phosphonomethyl)iminodiacetic acid, 2-carboxyethyl phosphonic acid, and 2-hydroxy phosphonocarboxylic acid.
3. The stabilized aqueous suspension according to claim 1 , wherein said aqueous suspension has a pH value lower than 9.
4. The stabilized aqueous suspension according to claim 1 , wherein the aluminous cement is an alumina high-content aluminous cement with an alumina content of more than 60% by weight relative to the aluminous cement total weight and the suspension comprises from 0.5 to 20% by weight of a phosphorus-containing compound relative to the alumina high-content aluminous cement total weight.
5. The stabilized aqueous suspension according to claim 1 , wherein the aluminous cement is an alumina intermediate-content aluminous cement with an alumina content ranging from 45 to 60% by weight relative to the aluminous cement total weight and the suspension comprises from 2 to 20% by weight of a phosphorus-containing compound relative to the alumina intermediate-content aluminous cement total weight.
6. The stabilized aqueous suspension according to claim 1 , wherein the aluminous cement is an alumina low-content aluminous cement with an alumina content of less than 45% by weight relative to the aluminous cement total weight and the suspension comprises from 5 to 20% by weight of a phosphorus-containing compound relative to the alumina low-content aluminous cement total weight.
7. The stabilized aqueous suspension according to claim 1 , wherein said aqueous suspension further comprises another blocking agent selected from carboxylic acids.
8. The stabilized aqueous suspension according to claim 1 , wherein said aqueous suspension comprises by weight relative to the total weight of said aqueous suspension:
from 55 to 65% of aluminous cement,
from 35 to 45% of water, and
from 0 to 5% of additional additives.
9. The stabilized aqueous suspension according to claim 4 , wherein the aluminous cement has the following chemical composition, by weight relative to the aluminous cement total weight:
Al 2 O 3 : >60%,
CaO: >25%,
SiO 2 : <5%, and
Fe 2 O 3 : <10%.
10. The stabilized aqueous suspension according to claim 1 , wherein the hydraulic binder further comprises calcium sulphates.
11. The stabilized aqueous suspension according to claim 1 , wherein the aqueous suspension solid content is higher than 50%.
12. A method for preparing a stabilized aqueous suspension according to claim 1 , comprising the following steps of:
introducing water into a mixing tank,
stirring,
adding the phosphorus-containing compound,
optionally adding the one or more dispersant(s),
adding the one or more hydraulic binder(s),
maintaining the stirring and,
optionally adding the other components,
stirring for at least 5 minutes.
13. A method for retarding for at least two months at a temperature ranging from about 15° C. to 55° C. the setting of a stabilized aqueous suspension comprising:
from 50% to 70%, by weight, relative to the total weight of said aqueous suspension of at least one hydraulic binder, the hydraulic binder comprising at least one aluminous cement,
from 30% to 50%, by weight, relative the total weight of said aqueous suspension of water, and
from 0 to 5%, by weight, relative to the total weight of said aqueous suspension of additional additives,
said method comprising: adding to said aqueous suspension, at least one phosphorus-containing compound selected from the group consisting of metaphosphoric acid, phosphorous acid, phosphoric acid, phosphonic acids and any compound which may form any of metaphosphoric acid, phosphorous acid, phosphoric acid, and phosphonic acids by reacting with water, said phosphorus-containing compound representing from 0.1 to 20% by weight relative to the aluminous cement total weight.
14. A binding composition comprising:
(i) a stabilized aqueous suspension according to claim 1 , and
(ii) at least one organic binder.
15. The stabilized aqueous suspension according to claim 9 , wherein the aluminous cement has the following chemical composition, by weight relative to the aluminous cement total weight:
Al 2 O 3 : ranging from 60-75%,
CaO: ranging from 25-50%,
SiO 2 : <4%, and
Fe 2 O 3 : <5%.
16. The stabilized aqueous suspension according to claim 7 , wherein said aqueous suspension comprises a combination of:
at least one phosphonic acid,
at least one compound selected from the group consisting of metaphosphoric acid, phosphorous acid, phosphoric acid and any compound which may form any of these compounds by reacting with water, and
at least one carboxylic acid.
17. The stabilized aqueous suspension according to claim 3 , wherein said aqueous suspension has a pH value lower than 8.
18. The stabilized aqueous suspension according to claim 3 , wherein said aqueous suspension has a pH value lower than 7.
19. The stabilized aqueous suspension according to claim 3 , wherein said aqueous suspension has a pH value lower than 6.5.
20. The stabilized aqueous suspension according to claim 1 , wherein the phosphorous containing compound has a pka of less than 9.
21. The stabilized aqueous suspension according to claim 1 , wherein the phosphorous containing compound has a pka of less than 8.
22. The stabilized aqueous suspension according to claim 1 , wherein the phosphorous containing compound has a pka of less than 7.
23. The stabilized aqueous suspension according to claim 1 , wherein the phosphorous containing compound has a pka of less than 6.8.
24. The stabilized aqueous suspension according to claim 10 , wherein the hydraulic binder comprises by weight, relative to the aqueous suspension total weight, from 5 to 30% of calcium sulphates.
25. The stabilized aqueous suspension according to claim 10 , wherein the hydraulic binder of the aqueous suspension comprises by weight relative to the total weight of the hydraulic binder-forming components:
from 0 to 50% of calcium sulphates, and
from 50 to 100% of aluminous cement.
26. The stabilized aqueous suspension according to claim 25 , wherein the hydraulic binder of the aqueous suspension comprises by weight relative to the total weight of the hydraulic binder-forming components:
from 1 to 35% of calcium sulphates, and
from 50 to 99% of aluminous cement.
27. The stabilized aqueous suspension according to claim 25 , wherein the hydraulic binder of the aqueous suspension comprises by weight relative to the total weight of the hydraulic binder-forming components:
from 5 to 30% of calcium sulphates, and
from 70 to 95% of aluminous cement.