CN108483956B - Quick-hardening sulphoaluminate cement and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of cement, and particularly relates to fast hardening sulphoaluminate cement and a preparation method thereof. The cement provided by the invention comprises the following components in percentage by weight: 5-20% of dry desulfurization ash; 60-85% of sulphoaluminate cement clinker; 5-20% of gypsum; 5-25% of limestone; 0-3% of a coagulation regulator. According to the invention, the dry desulfurization ash is added into the cement, so that the problem of disposal of the byproduct desulfurization ash in the dry desulfurization process is solved, the resource utilization of the dry desulfurization ash is realized, and the use amounts of gypsum and limestone can be saved, thereby greatly reducing the production cost of the cement; meanwhile, the addition of the dry desulfurization ash can also greatly improve the early strength and the later strength of the cement and overcome the problem of the later strength shrinkage of the cement; in addition, after the cement provided by the invention is prepared into mortar or concrete, the phenomena of 'sand forming' and 'powder falling' cannot occur in the curing process.

Description

Quick-hardening sulphoaluminate cement and preparation method thereof

Technical Field

The invention belongs to the field of cement, and particularly relates to fast hardening sulphoaluminate cement and a preparation method thereof.

Background

In recent years, dry desulfurization processes, particularly circulating fluidized bed dry desulfurization processes, have the characteristics of water saving and energy saving, and are popular with more and more users. In 2009, the national ministry of environmental protection specifically lists the dry desulfurization process technology of the flue gas circulating fluidized bed in the catalog of environmental protection technologies encouraged by the nation in 2009. At present, the dry desulfurization process of the circulating fluidized bed, particularly the upgraded dry ultra-clean technology, is comprehensively popularized and applied all over the country. The main components of the desulfurized fly ash generated by the dry desulfurization process are calcium sulfite hemihydrate, calcium sulfate, calcium carbonate, fly ash and the like, the water content is low, and the desulfurized fly ash belongs to general industrial solid wastes. With the wide popularization of the dry desulfurization process in China, the problems of disposal and utilization of the dry desulfurization ash are gradually highlighted.

The quick hardening sulphoaluminate cement has the advantages of high strength, early strength, frost resistance, impermeability and the like, is mainly used for winter engineering, rush repair and rush construction, marine engineering, road and bridge engineering, concrete, cement products and the like, and has wider market fields. The traditional quick hardening sulphoaluminate cement is mainly prepared by adding a proper amount of gypsum and limestone into sulphoaluminate cement clinker taking anhydrous calcium sulphoaluminate and dicalcium silicate as main mineral components and grinding, and has the characteristics of early strength, high strength, frost resistance, seepage resistance and the like. Although the early strength of the quick-hardening sulphoaluminate cement is high, the problem of later strength retraction is often existed.

Disclosure of Invention

In view of the above, the invention aims to provide a quick-hardening sulphoaluminate cement and a preparation method thereof, and the cement provided by the invention realizes resource utilization of dry desulphurization ash and has higher later strength.

The invention provides a quick-hardening sulphoaluminate cement, which comprises the following components in percentage by weight:

preferably, the content of calcium sulfite in the dry-method desulfurized ash is more than or equal to 30 wt%, the content of calcium carbonate is more than or equal to 15 wt%, and the water content is less than or equal to 2 wt%.

Preferably, the median particle size of the dry desulfurization ash is less than or equal to 20 mu m.

Preferably, the 3CaO 3Al in the sulphoaluminate cement clinker₂O₃·CaSO₄(iii) 2 CaO. SiO in an amount of 55 to 75 wt%₂8-37 wt%, 4 CaO. Al₂O₃·Fe₂O₃The content of (A) is 3-10 wt%, and the content of free CaO is 0-0.2 wt%.

Preferably, the stacking density of the sulphoaluminate cement clinker is 700-850 g/L, and the loss on ignition is 0-0.3 wt%.

Preferably, the sulphoaluminate cement clinker is prepared by the following method:

and mixing gypsum, bauxite and limestone, and calcining to obtain the sulphoaluminate cement clinker.

Preferably, the calcining temperature is 1200-1400 ℃; the calcining time is 30-50 min.

Preferably, the gypsum comprises dihydrate gypsum and/or anhydrite.

Preferably, the set control agent is a retarder or a set accelerator.

The invention provides a preparation method of the quick-hardening sulphoaluminate cement, which comprises the following steps:

a) mixing and grinding sulphoaluminate cement clinker, gypsum and limestone to obtain first powder;

b) mixing and sorting the first powder and the dry desulphurization ash to obtain second powder;

c) and mixing the second powder with a coagulation regulator to obtain the quick-hardening sulphoaluminate cement.

Compared with the prior art, the invention provides the rapid hardening sulphoaluminate cement and the preparation method thereof. The cement provided by the invention comprises the following components in percentage by weight: 5-20% of dry desulfurization ash; 60-85% of sulphoaluminate cement clinker; 5-20% of gypsum; 5-25% of limestone; 0-3% of a coagulation regulator. According to the invention, the dry desulfurization ash is added into the cement, so that the problem of disposal of the byproduct desulfurization ash in the dry desulfurization process is solved, the resource utilization of the dry desulfurization ash is realized, and the use amounts of gypsum and limestone can be saved, thereby greatly reducing the production cost of the cement; meanwhile, the addition of the dry desulfurization ash can also greatly improve the early strength and the later strength of the cement and overcome the problem of the later strength shrinkage of the cement; in addition, after the cement provided by the invention is prepared into mortar or concrete, the phenomena of 'sand forming' and 'powder falling' cannot occur in the curing process. The experimental results show that: the compressive strength of the cement provided by the invention after 28 days of curing is more than or equal to 48MPa, and the phenomena of 'sand forming' and 'powder falling' of mortar or concrete prepared by the cement can not occur in the curing process.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a comparative graph showing the plastering effect of various cement mortars provided in example 5 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a quick-hardening sulphoaluminate cement, which comprises the following components in percentage by weight:

the cement provided by the invention comprises dry desulfurization ash, sulphoaluminate cement clinker, gypsum, limestone and a thickening time control agent. The dry desulfurization ash is a byproduct produced by a dry flue gas desulfurization process, mainly comprises calcium sulfite hemihydrate, calcium carbonate, calcium sulfate, fly ash and the like, and belongs to general industrial solid wastes. In one embodiment provided by the present invention, the content of calcium sulfite in the dry desulfurized ash is preferably not less than 30 wt%, and specifically may be 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 57 wt%, 60 wt%, or 65 wt%. In one embodiment provided by the present invention, the content of calcium carbonate in the dry desulfurized ash is preferably not less than 15 wt%, and specifically may be 15 wt%, 18 wt%, 20 wt% or 25 wt%. In one embodiment provided by the invention, the content of calcium hydroxide in the dry desulfurized fly ash is preferably 5-20 wt%, and specifically can be 10 wt%. In one embodiment provided by the invention, the content of calcium oxide in the dry desulfurized fly ash is preferably 1-5 wt%, and specifically can be 2 wt%, 2.5 wt% or 3 wt%. In one embodiment provided by the invention, the content of magnesium oxide in the dry desulfurized ash is preferably 0.5-4 wt%, and specifically may be 1 wt%, 1.5 wt%, or 2 wt%. In one embodiment provided by the invention, the content of calcium chloride in the dry desulfurized fly ash is preferably 2-8 wt%, and specifically can be 4 wt%, 4.5 wt% or 5 wt%. In one embodiment provided by the invention, the content of calcium fluoride in the dry desulfurized fly ash is preferably 0.5-3 wt%, and specifically can be 1 wt%. In an embodiment provided by the present invention, the content of the fly ash in the dry desulfurization ash is preferably 2 to 8 wt%, and specifically may be 5 wt%, 5.5 wt%, or 6 wt%, and the main components of the fly ash are silicon dioxide, aluminum oxide, and ferric oxide. In one embodiment provided by the present invention, the water content of the dry desulfurization ash is preferably less than or equal to 2 wt%, and specifically may be 0.5 wt%, 0.9 wt%, 1 wt%, or 1.5 wt%. In one embodiment provided by the present invention, the median particle size of the dry desulfurized fly ash is preferably less than or equal to 20 μm, and specifically may be 10 μm, 15 μm or 20 μm. In one embodiment provided by the invention, the density of the dry desulfurization ash is preferably 0.5-1.5 g/mL, and specifically can be 0.7g/mL, 0.9g/mL, 1g/mL or 1.2 g/mL. In the present invention, the content of the dry desulfurization ash in the cement is 5 to 20 wt%, specifically 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, 14 wt%, 14.5 wt%, 15 wt%, 15.5 wt%, 16 wt%, 16.5 wt%, 17 wt%, 17.5 wt%, 18 wt%, 18.5 wt%, 19 wt%, 19.5 wt%, or 20 wt%.

In the present invention, the sulphoaluminate cement clinker is produced by calcination of sulphoaluminate cement raw meal, including, but not limited to, gypsum, bauxite and limestone. In the present invention, the sulphoaluminate cement clinker is preferably prepared according to the following method: and mixing gypsum, bauxite and limestone, and calcining to obtain the sulphoaluminate cement clinker. In the preparation method provided by the invention, the mixing mode is preferably that gypsum, bauxite and limestone are sequentially crushed and ground; the calcination temperature is preferably 1200-1400 ℃, and specifically can be 1200 ℃, 1250 ℃, 1300 ℃, 1350 ℃ or 1400 ℃; the calcination time is preferably 30-50 min, and specifically can be 30min, 35min, 40min, 45min or 50 min. In the present invention, the mineral composition in the sulphoaluminate cement clinker comprises 3CaO 3Al₂O₃·CaSO₄、2CaO·SiO₂、4CaO·Al₂O₃·Fe₂O₃And free CaO. Wherein the 3CaO 3Al₂O₃·CaSO₄The content in the sulphoaluminate cement clinker is preferably 55-75 wt%, and specifically can be 55 wt%, 56 wt%, 57 wt%, 58 wt%, 59 wt%, 60 wt%, 61 wt%, 62 wt%, 63 wt%, 64 wt%, 65 wt%, 66 wt%, 67 wt%, 68 wt%, 69 wt%, 70 wt%, 71 wt%, 72 wt%, 73 wt%, 74 wt% or 75 wt%; the 2CaO SiO₂The content in the sulphoaluminate cement clinker is preferably 8-37 wt%, specifically 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, or 37 wt%; the 4 CaO. Al₂O₃·Fe₂O₃The content of the sulphoaluminate cement clinker is preferably 3-10 wt%, and specifically can be 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt% or 10 wt%; the content of the free CaO in the sulphoaluminate cement clinker is preferably 0-0.2 wt%, and specifically can be 0.05 wt%, 0.1 wt%, 0.15 wt% or 0.2 wt%. In the invention, the bulk density of the sulphoaluminate cement clinker is preferably 700-850 g/L, and specifically can be 700g/L, 710g/L, 720g/L, 730g/L, 740g/L, 750g/L, 760g/L, 770g/L, 780g/L, 790g/L, 800g/L, 810g/L, 820g/L, 830g/L, 840g/L or 850 g/L; the ignition loss of the sulphoaluminate cement clinker is preferably 0-0.3 wt%, and specifically can be 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt% or 0.3 wt%. In the present invention, the content of the sulfoaluminate cement clinker in the cement is 60 to 85 wt%, specifically 60 wt%, 60.5 wt%, 61 wt%, 61.5 wt%, 62 wt%, 62.5 wt%, 63 wt%, 63.5 wt%, 64 wt%, 64.5 wt%, 65 wt%, 65.5 wt%, 66 wt%, 66.5 wt%, 67 wt%, 67.5 wt%, 68 wt%, 68.5 wt%, 69 wt%, 69.5 wt%, 70 wt%, 70.5 wt%, 71 wt%, 71.5 wt%, 72 wt%, 72.5 wt%, 73 wt%, 73.5 wt%, 74 wt%, 74.5 wt%, 75 wt%, 75.5 wt%, 76 wt%, 76.5 wt%, 77 wt%, 77.5 wt%, 78 wt%, 78.5 wt%, 79 wt%, 79.5 wt%, or 80 wt%.

In the present invention, the gypsum includes, but is not limited to, dihydrate gypsum and/or anhydrite. Wherein the SO of the dihydrate gypsum₃The content is preferably more than or equal to 35 wt%, and can be 38 wt% or 40 wt%; SO of said anhydrite₃The content is preferably 45 wt% or more. In the present invention, the content of the gypsum in the cement is 5 to 20 wt%, specifically 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, or 20 wt%.

In the invention, the limestone has medium advantagesOptionally contains CaO and Al₂O₃、SiO₂And MgO, wherein the content of CaO in the limestone is preferably equal to or more than 50 wt%, and can be specifically 52 wt% or 55 wt%; the Al is₂O₃The limestone content is preferably less than or equal to 2 wt%, and may be, in particular, 0.5 wt%, 1 wt%, 1.5 wt%, or 2 wt%; the SiO₂The limestone content is preferably less than or equal to 5 wt.%, and may be, in particular, 0.5 wt.%, 1 wt.%, 1.5 wt.%, 2 wt.%, 2.5 wt.%, 3 wt.%, 3.5 wt.%, 4 wt.%, 4.5 wt.% or 5 wt.%; the content of MgO in limestone is preferably not more than 3 wt%, and specifically may be 0.5 wt%, 0.6 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, or 3 wt%. In the present invention, the limestone content in the cement is 5 to 25 wt%, specifically 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, or 25 wt%.

In the present invention, the set retarder is a retarder or a set accelerator, wherein the set retarder includes, but is not limited to, boric acid; the set accelerator includes, but is not limited to, lithium carbonate. In the present invention, the content of the set control agent in the cement is 0 to 3 wt%, specifically 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, or 3 wt%.

The invention also provides a preparation method of the quick-hardening sulphoaluminate cement, which comprises the following steps:

a) mixing and grinding sulphoaluminate cement clinker, gypsum and limestone to obtain first powder;

b) mixing and sorting the first powder and the dry desulphurization ash to obtain second powder;

c) and mixing the second powder with a coagulation regulator to obtain the quick-hardening sulphoaluminate cement.

In the method for preparing the rapid hardening sulphoaluminate cement, sulphoaluminate cement clinker, gypsum and limestone are mixed and ground firstly. Wherein the grinding temperature is preferably less than 80 ℃; the grinding time is preferably 50-100 min, and specifically can be 60min, 70min, 80min or 90 min. And obtaining first powder after grinding.

And after the first powder is obtained, mixing and sorting the first powder and the dry-method desulfurized fly ash. The dry desulfurization ash is preferably pre-homogenized for a period of time before use, and the pre-homogenization time is preferably 12-36 hours, and specifically can be 12 hours, 18 hours, 24 hours, 28 hours, 30 hours or 36 hours. And after mixing and sorting, collecting powder meeting the required fineness, namely second powder. The fineness of the second powder is preferably more than or equal to 350m²A dose of 450 to 600 m/kg²/kg。

And after the second powder is obtained, mixing the second powder with a coagulation regulator to obtain the quick-hardening sulphoaluminate cement.

According to the invention, the dry desulfurization ash is added into the cement, so that the problem of disposal of the byproduct desulfurization ash in the dry desulfurization process is solved, the resource utilization of the dry desulfurization ash is realized, and the use amounts of gypsum and limestone can be saved, thereby greatly reducing the production cost of the cement; meanwhile, the addition of the dry desulfurization ash can also greatly improve the early strength and the later strength of the cement and overcome the problem of the later strength shrinkage of the cement; in addition, after the cement provided by the invention is prepared into mortar or concrete, the phenomena of 'sand forming' and 'powder falling' cannot occur in the curing process.

In the preparation method of the rapid hardening sulphoaluminate cement provided by the invention, sulphoaluminate cement clinker, gypsum and limestone are mixed and ground firstly, and then are mixed and sorted with the dry desulphurization ash, so that the problems of material sticking and grinding, yield reduction and the like caused by the participation of the dry desulphurization ash in the mixed grinding can be effectively avoided.

The experimental results show that: the specific surface area of the cement provided by the invention is more than 540m²And/kg, the compressive strength after curing for 3 days is more than or equal to 44MPa, the compressive strength after curing for 28 days is more than or equal to 48MPa, and the phenomena of 'sand forming' and 'powder falling' of mortar or concrete prepared by the cement can not occur in the curing process.

For the sake of clarity, the following examples are given in detail.

In the following examples, the gypsum used was dihydrate gypsum (SO)₃Content 38 wt%);

the CaO content of the limestone powder is 52 wt%, and Al₂O₃1 wt% of SiO₂The content is 3 wt%, and the MgO content is 0.6 wt%;

the adopted sulphoaluminate cement clinker is prepared from gypsum, bauxite and limestone according to the mass ratio of 43: 36: 21 is obtained by calcining at 1300 ℃ for 40min after mixing and grinding, and 3CaO 3Al in cement clinker₂O₃·CaSO₄With a content of 67 wt%, 2 CaO. SiO₂Has a content of 27 wt%, 4 CaO. Al₂O₃·Fe₂O₃The content of (A) was 6 wt%, the content of free CaO was 0.05 wt%, the bulk density was 790g/L, and the loss on ignition was 0.1 wt%;

the adopted dry desulfurization ash is a dry desulfurization byproduct pre-homogenized for 36 hours, and comprises 57 wt% of calcium sulfite, 18 wt% of calcium carbonate, 10 wt% of calcium hydroxide, 2.5 wt% of calcium oxide, 1.5 wt% of magnesium oxide, 4.5 wt% of calcium chloride and fly ash (SiO)₂+Al₂O₃+Fe₂O₃)5.5 wt% and 1 wt% of calcium fluoride, which total 100 wt%. The water content was 0.9 wt%, the median particle diameter was 15 μm, and the density was 0.9 g/mL.

The adopted setting regulator is boric acid or lithium carbonate.

Example 1

1) Designing components:

2) preparation:

according to the composition design, the natural gypsum, the limestone powder and the sulphoaluminate cement clinker are added into a mill together for mixing and grinding (the temperature in the mill is less than 80 ℃), after grinding for 70min, the dry desulfurization ash is added into the materials in proportion before the materials enter a powder selecting system, and the materials are mixed and sorted to collect the fineness (450-600 m) meeting the requirement²/kg) powder, and mixing with a coagulation regulator to prepare the dry desulfurized fly ash quick-hardening sulphoaluminate cement.

Example 2

1) Designing components:

2) preparation:

according to the composition design, the natural gypsum, the limestone powder and the sulphoaluminate cement clinker are added into a mill together for mixing and grinding (the temperature in the mill is less than 80 ℃), after grinding for 70min, the dry desulfurization ash is added into the materials in proportion before the materials enter a powder selecting system, and the materials are mixed and sorted to collect the fineness (450-600 m) meeting the requirement²/kg) powder, and mixing with a coagulation regulator to prepare the dry desulfurized fly ash quick-hardening sulphoaluminate cement.

Example 3

1) Designing components:

2) preparation:

according to the composition design, the natural gypsum, the limestone powder and the sulphoaluminate cement clinker are added into a mill together for mixing and grinding (the temperature in the mill is less than 80 ℃), after grinding for 70min, the dry desulfurization ash is added into the materials in proportion before the materials enter a powder selecting system, and the materials are mixed and sorted to collect the fineness (450-600 m) meeting the requirement²/kg) powder, and mixing with a coagulation regulator to prepare the dry desulfurized fly ash quick-hardening sulphoaluminate cement.

Comparative example

1) Designing components:

2) preparation:

according to the component design, the natural gypsum, the limestone powder and the sulphoaluminate cement clinker are added into a mill together for mixing and grinding (the temperature in the mill is less than 80 ℃), the materials are separated in a powder separation system after being ground for 70min, and the fineness (450-600 m) meeting the requirement is collected²/kg) powder, and mixing with a coagulation regulator to prepare the dry desulfurized fly ash quick-hardening sulphoaluminate cement.

Example 4

Physical Properties of quick hardening sulphoaluminate cements

Specific surface area tests are carried out on the quick-hardening sulphoaluminate cement products prepared in the examples 1-3 and the comparative example, and the cement setting time is checked according to the specified method of JC/T453-2001; the compressive strength of the cement mortar is tested according to the regulations of GB/T17671-2001. The test results are shown in table 1.

Table 1 results of performance testing

As can be seen from Table 1, the formulation examples of the present invention can satisfy the application properties of the rapid hardening sulphoaluminate cement of 42.5MPa class. Meanwhile, compared with the comparative example, the specific surface area of the sulphoaluminate cement can be increased, and the 3d and 28d compressive strength can be improved.

Example 5

Test of wall plastering effect of quick-hardening sulphoaluminate cement mortar

The fast hardening sulphoaluminate cement products prepared in the examples 1-3 and the comparative example and ISO standard sand are mixed by a cement mortar mixer, water is added for stirring (cement: sand: water is 6:1:1, mass ratio), and the prepared mortar is compared with plastering performance. The plastering effect is described in table 2 and shown in fig. 1.

TABLE 2 mortar plastering Performance results comparison

As can be seen from Table 2 and FIG. 1, compared with the comparative example, the cement provided by the embodiment of the present invention has significantly reduced phenomena of "sand-out" and "powder-falling" during curing after being prepared into mortar.

In conclusion, the method utilizes the industrial solid waste dry desulphurization ash to prepare the quick-hardening sulphoaluminate cement, realizes the conversion of waste resources into renewable resources, and solves the problem of comprehensive utilization of the desulphurization ash to a certain extent; and the addition of the dry desulfurization ash can also save the consumption of 20-60 percent of gypsum and 10-40 percent of limestone, reduce the development consumption of limestone and gypsum resources and environmental pollution, and has obvious advantages in production cost.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (8)

1. The quick-hardening sulphoaluminate cement comprises the following components in percentage by weight:

the content of calcium sulfite in the dry desulfurization ash is more than or equal to 30 wt%, the content of calcium carbonate is more than or equal to 15 wt%, the content of calcium hydroxide is 5-20 wt%, the content of calcium oxide is 1-5 wt%, the content of magnesium oxide is 0.5-4 wt%, the content of calcium chloride is 2-8 wt%, the content of calcium fluoride is 0.5-3 wt%, the content of fly ash is 2-8 wt%, and the water content is less than or equal to 2 wt%; the median particle size of the dry desulfurization ash is less than or equal to 20 mu m, and the density is 0.5-1.5 g/mL.

2. The cement of claim 1, wherein the sulphoaluminate cement clinker comprises 3 CaO-3 Al₂O₃·CaSO₄(iii) 2 CaO. SiO in an amount of 55 to 75 wt%₂8-37 wt%, 4 CaO. Al₂O₃·Fe₂O₃The content of (A) is 3-10 wt%, and the content of free CaO is 0-0.2 wt%.

3. The cement according to claim 1, wherein the sulfoaluminate cement clinker has a bulk density of 700 to 850g/L and a loss on ignition of 0 to 0.3 wt.%.

4. The cement according to claim 1, wherein the sulphoaluminate cement clinker is prepared according to the following method:

and mixing gypsum, bauxite and limestone, and calcining to obtain the sulphoaluminate cement clinker.

5. The cement of claim 4, wherein the calcination temperature is 1200 to 1400 ℃; the calcining time is 30-50 min.

6. Cement according to claim 1, characterized in that said gypsum comprises dihydrate gypsum and/or anhydrite.

7. The cement of claim 1, wherein the set retarder is a retarder or an accelerator.

8. A method for preparing the rapid hardening sulphoaluminate cement of any one of claims 1 to 7, comprising the following steps:

a) mixing and grinding sulphoaluminate cement clinker, gypsum and limestone to obtain first powder;

b) mixing and sorting the first powder and the dry desulphurization ash to obtain second powder;

c) and mixing the second powder with a coagulation regulator to obtain the quick-hardening sulphoaluminate cement.

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