High belite-containing sulfoaluminous clinker, method for the production and the use thereof for preparing hydraulic binders

1. A sulphoaluminate clinker, comprising as a phasic formulation, compared with the total weight of clinker:

5 to 25% of a calcium aluninoferrite phase with a formulation corresponding to the general formula C2AXF(1−X), with X comprised between 0.2 and 0.8;

15 to 35% of a calcium sulphoaluminate phase yee' limit (C4A3$);

40 to 75% belite (C2S), wherein C represents CaO, A represents Al 2 O 3 , F represents Fe 2 O 3 , S represents SiO 2 and $ represents SO 3 ;

from 0.01 to 10% of one or several minor phases selected from the group consisting of calcium sulphates, alkali sulphates, perovskite, calcium aluminates, gehlenite, free lime and periclase, and/or a vitreous phase, and

one or several secondary elements selected from the group consisting of sulphur, magnesium, sodium, potassium, boron, phosphorus, zinc, manganese, titanium, fluorine, chlorine, present in the following quantities:

from 3 to 10% of sulphur expressed as sulphuric anhydride,

up to 5% of magnesium expressed as magnesium oxide,

up to 5% of sodium expressed as sodium oxide,

up to 5% of potassium expressed as potassium oxide,

up to 3% of boron, expressed as boron oxide,

up to 7% of phosphorus expressed as phosphoric anhydride,

up to 5% of zinc, manganese, titanium or mixtures thereof, expressed as oxides of these elements,

up to 3% of fluoride, chloride, or mixtures thereof, expressed as calcium fluoride and calcium chloride, the total content of said one or several secondary elements being less than or equal to 15%.

2. A sulphoaluminate clinker according to claim 1 , comprising one or several secondary elements in the following quantities, by weight compared to the total weight of the clinker:

from 4 to 8% of sulphur expressed as sulphuric anhydride,

from 1 to 4% of magnesium, expressed as magnesium oxide,

from 0.1 to 2% of sodium, expressed as sodium oxide,

from 0.1 to 2% of potassium, expressed as potassium oxide,

up to 2% of boron, expressed as boron oxide,

up to 4% of phosphorus expressed as phosphoric anhydride,

up to 3% of zinc, manganese, titanium or mixtures thereof, expressed as oxides of these elements, and

up to 1% of fluoride, chloride, or mixtures thereof, expressed as calcium fluoride and calcium chloride.

3. A sulphoaluminate clinker according to claim 1 , comprising the following secondary elements, in the following quantities, by weight compared to the total weight of the clinker:

from 0.2 to 1% of sodium, expressed as sodium oxide,

from 0.2 to 1% of potassium, expressed as potassium oxide,

from 0.2 to 2% of boron, expressed as boron oxide, and

a fluorine plus chlorine content less than or equal to 1%, expressed as calcium fluoride and chloride.

4. A sulphoaluminate clinker according to claim 1 , comprising at least the following main oxides present in the relative proportions expressed as % of the total weight of the clinker:

CaO: 50 to 61%

Al 2 O 3 : 9 to 22%

SiO 2 : 15 to 25%

Fe 2 O 3 : 3 to 11%.

5. A sulphoaluminate clinker according to claim 1 , wherein the belite phase of the clinker is partially or totally crystallised in the α′ form.

6. A sulphoaluminate clinker according to claim 1 , wherein the belite phase of the clinker in the α′ form accounts for at least 50% by weight of the clinker.

7. A sulphoaluminate clinker according to claim 1 , comprising an accelerator or retarder of setting and/or hardening.

8. A production method of a clinker according to claim 1 , comprising:

a) preparing a raw mix comprising at least one raw material or a mixture of raw materials able by clinkerisation to provide the phases C2AXF(1−X), with X comprised between 0.2 and 0.8, C4A3$ and C2S;

b) adding to and mixing into the raw mix at least one additive supplying a secondary element selected from the group consisting of sulphur, magnesium, sodium, potassium, boron, phosphorus, zinc, manganese, titanium, fluorine, chlorine, or mixtures thereof, in quantities effective to provide said clinker;

c) calcining the mixture at a temperature of 1150° C. to 1350° C. for at least 15 minutes in an atmosphere that is sufficiently oxidising to avoid the calcium sulphate being reduced to sulphur dioxide.

9. A production method for a sulphoaluminate clinker according to claim 8 , wherein the raw materials used in the production are selected from the group consisting of phosphate limestone, magnesium limestone, clays, fly ash, hearth ash, fluidised bed ash, laterite, bauxite, red mud, slag, clinker, gypsum, desulphogypsum, phosphogypsum, desulphurisation mud, industrial scoriae, and mixtures thereof.

10. A production method of a clinker according to claim 8 , wherein the clinker obtained is then ground with or without calcium sulphate, in the form of gypsum, or hemihydrate, or anhydrite, until a Blaine specific surface of over 3000 cm 2 /g is obtained.

11. A hydraulic binder comprising a mixture of clinker according to claim 1 and source materials of calcium sulphate and/or calcium oxide.

12. A binder according to claim 11 , comprising as much as 30% by weight of the total weight of the binder, of at least one material selected from the group consisting of limestone, pozzolana, fly ash and blast furnace slag.

13. A binder according to claim 11 , comprising as much as 15% by weight of the total weight of the binder, of a material selected from the group consisting of gypsum, anhydrites and hemihydrates.

14. A binder according to claim 11 , comprising at least one setting retarder selected from the group consisting of gluconates, saccharides, retarders of the phosphoric acid or carboxylic acid type or mixtures thereof.

15. A binder according to claim 11 , comprising at least one dispersing agent selected from the group consisting of polynaphthalene sulphonates, polymelamine sulphonates, hydroxycarboxylic acids, (poly)acrylic acids, their derivatives and their corresponding salts, derivatives of phosphonic acid, and mixtures thereof.

16. A binder according to claim 11 , wherein, in use, the binder is adapted to produce a slurry, mortar or cement.

17. A sulphoaluminate clinker according to claim 1 , wherein, when added with water and mixed with source materials including at least calcium sulphate and/or calcium oxide, said clinker is adapted to provide a settable composition having a 1 day mechanical strength, as hardened, greater than about 20 MPa.

18. A sulphoaluminate clinker according to claim 17 , wherein, when added with water and mixed with source materials including at least calcium sulphate and/or calcium oxide, said clinker is adapted to provide a settable composition having a 28 day mechanical strength, as hardened, greater than about 30 MPa.

19. A sulphoaluminate clinker, comprising as a phasic formulation, compared with the total weight of clinker:

5 to 25% of a calcium aluminoferrite phase with a formulation corresponding to the general formula C2AXF(1−X), with X comprised between 0.2 and 0.8;

15 to 35% of a calcium sulphoaluminate phase yee' limit (C4A3$);

40 to 75% belite (C2S), wherein C represents CaO, A represents Al 2 O 3 , F represents Fe 2 O 3 , S represents SiO 2 and $ represents SO 3 ;

from 0.01 to 10% of one or several minor phases selected from the group consisting of calcium sulphates, alkali sulphates, perovskite, calcium aluminates, gehlenite, free lime and periclase, and/or a vitreous phase, and

additives comprising at least sodium and boron present in the following quantities, by weight as compared to the total weight of the clinker: from 0.1 to 5% of sodium expressed as sodium oxide and from 0.2 to 3% of boron, expressed as boron oxide, the total content of said additives being less than or equal to 15%,

wherein, when added with water and mixed with source materials including at least calcium sulphate and/or calcium oxide, said clinker is adapted to provide a settable composition having a 1 day mechanical strength, as hardened, greater than about 20 MPa.

20. A sulphoaluminate clinker according to claim 19 , wherein, when added with water and mixed with source materials including at least calcium sulphate and/or calcium oxide, said clinker is configured to provide a settable composition having a 28 day mechanical strength, as hardened, greater than about 30 MPa.

21. A sulphoaluminate clinker according to claim 19 , wherein the additives comprise from 0.1 to 5% of potassium, expressed as potassium oxide.