CN113372029A

CN113372029A - Low-carbon type super-sulfate cement, preparation method thereof and cement mortar

Info

Publication number: CN113372029A
Application number: CN202110834212.XA
Authority: CN
Inventors: 王烨; 刘勇; 向梦琪; 李琪鹏; 陈高祥; 田开元; 郑云天; 罗建洪; 梁玉祥; 孟宪章; 万红伶; 童武兵
Original assignee: Pangang Metallurgical Material Co ltd
Current assignee: Pangang Metallurgical Material Co ltd
Priority date: 2021-07-21
Filing date: 2021-07-21
Publication date: 2021-09-10
Anticipated expiration: 2041-07-21
Also published as: CN113372029B

Abstract

The invention provides low-carbon type super-sulfate cement, a preparation method thereof and cement mortar. The low-carbon type super-sulfate cement provided by the invention comprises the following components in percentage by mass: 10 to 40 percent of titanium gypsum; 15% -30% of cement clinker; 20 to 40 percent of mineral powder; 5 to 10 percent of steel slag; 5 to 10 percent of titanium extraction tailings; 1-5% of vanadium slag; 2 to 10 percent of fly ash; 0.5 to 1 percent of excitant; 0.5 to 1 percent of water reducing agent. The invention adopts titanium gypsum, steel slag, titanium extraction tailings, vanadium slag and other industrial solid wastes to match with cement clinker, mineral powder, fly ash, an excitant and a water reducing agent in a certain proportion, wherein the use amount of the titanium gypsum is more than 10 percent, a large amount of the titanium gypsum and other industrial waste residues are utilized, the pollution of industrial wastes to the environment is reduced, meanwhile, the early mechanical property of the material can be improved, and the 28d chloride ion diffusion coefficient is also reduced.

Description

Low-carbon type super-sulfate cement, preparation method thereof and cement mortar

Technical Field

The invention relates to the field of inorganic materials, in particular to low-carbon type super-sulfate cement, a preparation method thereof and cement mortar.

Background

Along with the rapid development of society, the importance of environmental protection is increasingly prominent, and the reduction of the use amount of the conventional ordinary portland cement is one of the main solutions for realizing the double-carbon target.

The method for reducing the use amount of the cement mainly comprises two types, namely, the proportion of the cement in the concrete is reduced, namely, the proportion of mineral admixture or industrial waste residue in the cement concrete is improved, and a novel cementing material is developed. The super-sulfate cement is a green hydraulic novel cementing material prepared based on the compound excitation effect of alkali and sulfate on the potential activity of slag, wherein the proportion of the cement is low, the two solving modes are met, the production energy consumption and the CO emission are low, and the green sustainable development of the cement industry is facilitated.

Super Sulfate Cement (SSC) is prepared from 75-85% of granulated blast furnace slag and 10-20% of sulfateHydraulic binders, which are obtained by grinding together or separately an alkali component (clinker, calcium hydroxide, etc.)% 1-5% of an activator (gypsum, etc.), (industrial by-product) are also called slag sulfate cements or gypsum-slag cements. The SSC production process does not need to carry out two-grinding and one-burning of the traditional cement, fully utilizes industrial wastes, has small clinker consumption, saves the cement, and greatly reduces the consumption of resources and energy and CO₂The building material is an economical, energy-saving, environment-friendly and low-carbon building material. The production and use of the super-sulfate cement are researched in China as early as 50 years of the last century, but the cement has the problems of slow coagulation, easy surface dusting and the like in research and application, and the application of the cement is hindered. The special cement for the pavement base is developed by using gypsum, slag and a small amount of alkaline activator according to the sulfate excitation principle by Zhongming Kai et al of the university of Wuhan theory of engineering in the early 90 s. Since the early hydration heat of the super-sulfate cement is low, the application of the super-sulfate cement in mass concrete has natural advantages. In 2013, the China-built commercial concrete Co Ltd and Wuhan university adopt super sulfate to prepare large-volume concrete, and the slump, the expansion degree and the fluidity of the concrete meet the construction requirements.

CN 101423343A discloses a steel slag super-sulfate cement and a preparation method thereof, the super-sulfate cement comprises, by weight, 20-80% of steel slag, 5-65% of slag and/or fly ash, 5-25% of a sulfate activator, 1-10% of cement clinker or calcium hydroxide and 0.05-3% of an alkaline activator, the most main component of the super-sulfate cement is the steel slag, the hydration activity of the steel slag is poor, the caking property with other components is weak, and the performances such as compressive strength and the like are poor.

CN 103435279A discloses a titanium slag-doped super-sulfate cement and a preparation method thereof, wherein the titanium slag-doped super-sulfate cement comprises, by weight, 20-50 parts of granulated blast furnace slag, 20-50 parts of titanium slag and 10-30 parts of a composite activator, wherein the composite activator comprises an alkaline activator, a sulfate activator and an aluminate activator, and is prepared by batching, calcining and grinding, and the super-sulfate cement takes the titanium slag as one of main components, so that the raw material cost is reduced, but the components are weaker in binding property, need complex activator components and have higher requirements on the activator components.

CN 111302677A provides a super-sulfate cement and a preparation method thereof, wherein the super-sulfate cement comprises the following components in percentage by mass: 40-60% of first slag; 10-30% of second slag; 2-8% of general cement; 10-25% of gypsum; 0.5 to 2 percent of alkaline excitant; 3-10% of limestone; wherein the first slag and the second slag have different particle size distributions. The basic raw material of the super-sulfate cement is added with alkaline excitant, limestone and other components, and the porosity of the super-sulfate cement is reduced and the alkalinity is improved by promoting the dispersion, dissolution and hydration of slag or the reaction with the slag so as to enhance the anti-permeation and anti-carbonization performance of the super-sulfate cement; the compactness of the super-sulfate cement is improved and the anti-carbonization performance is further improved by grading the particle size of the raw slag material. However, the gypsum is mainly natural gypsum, and the exploitation is forbidden at present, so the cost is high.

The prior art also introduces titanium gypsum into the super sulfate cement. The yield of titanium dioxide in China is increased from 29 ten thousand tons in 2000 to 351 ten thousand tons in 2020, the production process mainly adopts a sulfuric acid method, a large amount of titanium gypsum which takes calcium dihydrate as a main component is produced in the production process, the titanium gypsum produced by 1t of titanium dioxide produced by the sulfuric acid method is about 6-10 t, and the annual emission of titanium gypsum in China is about 3000 ten thousand. But because calcium sulfate particles are fine, the free water content is high, the titanium gypsum resource utilization difficulty is high, the comprehensive utilization cost is high, and the market competition is weak.

For example, CN 111205002A relates to a high-toughness super-sulfate cement and a preparation method thereof, mainly overcomes the defects in the prior art, and provides a high-toughness super-sulfate cement with high strength, high toughness and high durability and a preparation method thereof, wherein the high-toughness super-sulfate cement comprises, by weight, 65-90% of slag, 10-25% of gypsum, 1-15% of an exciting agent, 1-10% of an admixture, 0-3% of a fiber and 0-1% of a coagulation adjusting type water reducing agent. The high-toughness super-sulfate cement prepared by the method improves the sulfate erosion resistance, the bending deflection resistance and the shrinkage rate to a certain extent. However, the maximum consumption of the titanium gypsum in the invention is 10%, the gypsum needs 5 times of water washing, is calcined at 140 ℃ for 4 hours, needs lime for neutralization and aging for 72 hours, and has the advantages of water consumption, energy consumption, long process and high cost, and the problem of slow early strengthening of the super-sulfate cement is not mentioned and solved.

Disclosure of Invention

In view of the above, the present invention aims to provide a low-carbon type super-sulfate cement, a preparation method thereof, and cement mortar. The low-carbon type super-sulfate cement provided by the invention can greatly utilize titanium gypsum and other industrial waste residues, reduce the pollution of industrial waste to the environment and improve the early mechanical property.

The invention provides low-carbon type super-sulfate cement which comprises the following components in percentage by mass:

preferably, the particle size of the titanium gypsum is below 100 meshes.

Preferably, the water content of the titanium gypsum is less than or equal to 20 wt%.

Preferably, the water reducing agent is a polycarboxylic acid water reducing agent.

Preferably, the activator is NaOH.

Preferably, the granularity of the titanium extraction tailings is below 100 meshes;

the granularity of the steel slag is below 100 meshes;

the particle size of the vanadium slag is below 100 meshes.

Preferably, the mineral powder is s95 mineral powder.

The invention also provides a preparation method of the low-carbon type super-sulfate cement in the technical scheme, which comprises the following steps:

mixing and ball-milling titanium gypsum, cement clinker, mineral powder, steel slag, titanium extraction tailings, vanadium slag, fly ash, an excitant and a water reducing agent to obtain the low-carbon type super-sulfate cement.

The invention also provides cement mortar which is prepared by mixing and grinding cement materials, sand and water;

the cement material is the low-carbon type super-sulfate cement in the technical scheme.

Preferably, the mass ratio of the sand to the cement material is 2.5-3.5;

the ratio of the mass of the water to the total mass of the cement material and the sand is 0.5-0.6;

in the mixing and grinding:

the adopted ball milling media are Millpebs grinding media and spherical media;

the mass ratio of the Millpebs grinding medium to the spherical medium is 0.2-0.5;

the ball material ratio of the mixed grinding is 0.1-0.5.

The invention adopts titanium gypsum, steel slag, titanium extraction tailings, vanadium slag and other industrial solid wastes to match with cement clinker, mineral powder, fly ash, an activator and a water reducing agent according to a certain proportion, wherein the use level of the titanium gypsum is more than 10 percent, and the use level of other slag materials is more than 11 percent, thereby greatly utilizing the titanium gypsum and other industrial wastes, reducing the pollution of the industrial wastes to the environment, simultaneously improving the early mechanical property (namely 3d strength) of the material and reducing the 28d chloride ion diffusion coefficient.

Experimental results show that the 3d flexural strength of the low-carbon type super-sulfate cement provided by the invention reaches more than 6.5MPa, and the 3d compressive strength reaches more than 8 MPa; the 28d flexural strength reaches more than 11MPa, and the compressive strength reaches more than 45 MPa. The chloride ion diffusion coefficient of 28d cement is 1.5 multiplied by 10^-12The following.

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 schematic illustration of two mixed ball milling media;

FIG. 2 is a schematic flow diagram illustrating the preparation of a low-carbon type super-sulfate cement according to an embodiment of the present invention;

FIG. 3 is a macro-topography of the cement mortar sample of example 1;

FIG. 4 is a SEM microstructure of a cement mortar sample of example 1;

FIG. 5 is a schematic illustration of the formation of a hardened slurry structure;

FIG. 6 is a macro-topography of the cement mortar sample of example 2;

FIG. 7 is a SEM microstructure of a cement mortar sample of example 2;

FIG. 8 is a macro-topography of the cement mortar sample of example 3;

FIG. 9 is a SEM microstructure of a cement mortar sample of example 3.

Detailed Description

The titanium gypsum is industrial waste residue produced in the process of generating titanium dioxide by a sulfuric acid method. In the invention, the titanium gypsum is preferably pretreated titanium gypsum; the pretreatment comprises the following steps: drying, grinding and screening. The invention controls the water content of the titanium gypsum to be less than or equal to 20 wt% by drying. The granularity of the titanium gypsum is controlled below 100 meshes by grinding and screening, namely the granularity of the powder is controlled to be less than or equal to the granularity corresponding to 100 meshes, the granularity corresponding to 100 meshes is controlled to be 150 mu m, namely the granularity of the titanium gypsum is controlled to be less than or equal to 150 mu m. The larger the mesh number of the sieve is, the smaller the corresponding powder particle size is, and the particle size of the titanium gypsum is controlled to be less than 100 meshes, namely the mesh number of the sieve is more than 100 meshes. More preferably, the particle size of the titanium gypsum is 100-120 μm.

In the invention, the mass ratio of the titanium gypsum in the raw material is 10-40%. The higher the addition amount of waste residues such as titanium gypsum and the like in cement is, the more easily the mechanical property and the like of materials are influenced, even if the titanium gypsum is introduced into cement ingredients in the prior art, the common usage amount is below 5 percent and at most 10 percent, and complex treatment (such as washing, calcining, neutralizing, aging and the like) is required to be carried out, but in the invention, through selection and allocation of various components, the addition amount of the titanium gypsum can reach more than 10 percent, the titanium gypsum does not need to be subjected to complex and special pretreatment, and only simple treatment of drying and grinding is carried out, so that the utilization rate of the titanium gypsum is greatly improved, and the environmental protection pressure and the treatment pressure of solid waste are reduced. In some embodiments of the invention, the amount of titanium gypsum is 20%, 30% or 40%.

In the present invention, the cement clinker is preferably PO 42.5. The source of the cement clinker is not particularly limited, and the cement clinker can be a general commercial product. In the present invention, the particle size of the cement clinker is 100 mesh or less. The corresponding relation between the powder particle size and the screen mesh number is consistent with the above, namely the particle size of the cement clinker is controlled to be less than or equal to 150 μm, and more preferably 100-120 μm. In the invention, the mass ratio of the cement clinker in the raw materials is 15-30%; in some embodiments of the invention, the mass ratio is 15% or 20%.

In the invention, the mineral powder is preferably mineral powder with the national standard s 95. The source of the mineral powder is not particularly limited, and the mineral powder is a general commercial product. In the invention, the granularity of the mineral powder is below 100 meshes. The corresponding relationship between the powder particle size and the mesh number of the sieve is consistent with the above, namely the particle size of the mineral powder is controlled to be less than or equal to 150 μm, and more preferably 100-120 μm. In the invention, the mass ratio of the mineral powder in the raw materials is 20-40%; in some embodiments of the invention, the mass ratio is 20%, 25% or 30%.

In the present invention, the steel slag is preferably crushed and sieved before use. In the invention, the granularity of the steel slag is below 100 meshes. The corresponding relationship between the powder particle size and the mesh number is consistent with the above, i.e. the particle size of the steel slag is controlled to be less than or equal to 150 μm, and more preferably 100-120 μm. In the invention, the mass ratio of the steel slag in the raw materials is 5-10%; in some embodiments of the invention, the mass ratio is 5% or 10%.

In the invention, the titanium extraction tailings are preferably crushed and sieved before use. In the invention, the granularity of the titanium extraction tailings is below 100 meshes. The corresponding relation between the powder particle size and the screen mesh number is consistent with the above, namely the particle size of the titanium extraction tailings is controlled to be less than or equal to 150 μm, and more preferably 100-120 μm. In the invention, the mass ratio of the titanium extraction tailings in the raw materials is 5-10%; in some embodiments of the invention, the mass ratio is 10%.

In the invention, the vanadium slag is preferably crushed and sieved before use. In the invention, the particle size of the vanadium slag is below 100 meshes. The corresponding relation between the powder particle size and the screen mesh number is consistent with the above, namely the particle size of the vanadium slag is controlled to be less than or equal to 150 μm, and more preferably 100-120 μm. In the invention, the mass ratio of the vanadium slag in the raw materials is 1-5%; in some embodiments of the invention, the mass ratio is 5%.

In the invention, the titanium extraction tailings, the steel slag and the vanadium slag are preferably mixed, crushed and screened, namely, the three materials are mixed together and crushed and screened, and the granularity of the mixed powder is controlled to be below 200 meshes.

In the invention, the granularity of the fly ash is preferably 45-80 μm. In the invention, the mass ratio of the fly ash in the raw material is 2-10%; in some embodiments of the invention, the mass ratio is 3% or 5%.

In the present invention, the activator is preferably NaOH. In the invention, the mass ratio of the exciting agent in the raw materials is 0.5-1%; in some embodiments of the invention, the mass ratio is 1%.

In the present invention, the water reducing agent is preferably a polycarboxylic acid water reducing agent, more preferably a 301A type polycarboxylic acid water reducing agent, and is commercially available from sichuan cuisine. In the invention, the mass ratio of the water reducing agent in the raw materials is 0.5-1%; in some embodiments of the invention, the mass ratio is 1%.

The types, the amounts and the like of the raw materials are consistent with those in the technical scheme, and are not described in detail herein.

The ball milling medium adopted by the mixed ball milling is preferably stainless steel balls. The ball-to-material ratio of the ball mill is preferably 0.2; the ball-material ratio refers to the mass ratio of the ball-milling medium to the powder to be ball-milled. The rotation speed of the ball milling is preferably 220-300 r/min, and the ball milling time is preferably 1-2 h. And performing ball milling treatment to obtain the low-carbon type super-sulfate cement.

The low-carbon type super sulfate cement provided by the invention is formed by matching industrial solid wastes such as titanium gypsum, steel slag, titanium extraction tailings, vanadium slag and the like with cement clinker, mineral powder, fly ash, an exciting agent and a water reducing agent in a certain proportion, and when the cement paste is prepared by using the low-carbon type super sulfate cement paste, Fe in the titanium gypsum and an alkaline exciting agent begin to hydrate and the Fe in the titanium gypsum and the aluminum phase C in the fly ash begin to hydrate₃A and iron phase C₄AF with Ca dissolved in the liquid phase²⁺Ions and SO₄ ^2-Forming ettringite from the ionized water; c in cement clinker₃S and C₂S hydrates to form C-S-H gel and Ca is released²⁺Ions; hydrolyzing slag (steel slag, titanium extraction tailings and vanadium slag) to release Ca²⁺Ions; in Ca of ore powder²⁺And SO₄ ^2-Under the double excitation of (1), starting hydrolysis to form C-S-H gel and ettringite; providing Al by fly ash³⁺To form a gelled phase C3A; under the coordination of the polycarboxylic acid water reducing agent and the alkali activator, the early strength of the material is improved. With the continuous progress of hydration reactions, various hydration products gradually fill the space originally occupied by water, and solid particles gradually approach. Because of the mutual lapping of the needle-shaped and rod-shaped crystals of the ettringite, the cross-over of a large number of foil-shaped and fibrous C-S-H crystals is particularly realizedSo that the originally dispersed solid particles and hydration products are connected to form a firmly combined and compact whole body in a three-dimensional space, thereby leading the set cement to be more and more compact and continuously improving the strength; the residual titanium gypsum is tightly wrapped by the thick hydration product layer and is not dissolved any more, so that the cement has good hydraulicity.

According to the invention, through the formula design, the specific raw materials are matched in a certain proportion, so that under the condition of utilizing a large amount of titanium gypsum and other industrial waste residues, the early mechanical property (namely 3d strength) of the material can be improved, and the 28d chloride ion diffusion coefficient is also reduced. In the comprehensive utilization means of gypsum in the prior art, the investment and energy consumption for preparing sulfuric acid and co-producing cement by using gypsum are high; the doping amount of the gypsum used as a cement coagulant is limited, and the additional value is low; the SSC technology for producing the clinker by using the titanium gypsum is expected to realize the digestion of a large amount of titanium gypsum, calcium and sulfur resources and the purpose of in-plant circulation. According to the invention, titanium gypsum can be used in a large amount to produce standard high-sulfate cement, and simultaneously the titanium gypsum, the titanium extraction tailings and further other industrial waste residues such as steel slag and the like are digested, so that the problem of waste residue treatment of enterprises is solved, and the produced SSC has a wide market space.

The invention also provides cement mortar which is prepared by mixing and grinding cement materials, sand and water; the cement material is the low-carbon type super-sulfate cement in the technical scheme.

In the present invention, the sand is preferably standard sand. The mass ratio of the sand to the cement material is preferably 2.5-3.5, and more preferably 3.22. The mass ratio to the total mass of the cement material and the sand is 0.5 to 0.6.

In the invention, in the mixing and grinding, the adopted ball-milling media are new heterogeneous media Millpebs grinding media and spherical media; wherein, the spherical medium is preferably a stainless steel ball. The mixing medium of the new heterogeneous medium and the spherical medium is shown in figure 1, and figure 1 is a schematic diagram of two mixed ball milling media. In the invention, the mass ratio of the Millpebs grinding media and the spherical media is preferably 0.2-0.5. In the invention, the ball-to-material ratio of the ball mill is 0.1-0.5; the ball-material ratio refers to the mass ratio of the ball-milling medium to the powder to be ball-milled (namely the total amount of the cement material and the standard sand). In the invention, the rotation speed of ball milling is preferably 220-300 r/min, and the ball milling time is preferably 60-120 min. And performing ball milling treatment to obtain cement mortar.

The invention adopts the new anisotropic medium and the spherical medium which are matched in a certain proportion as ball milling media, ball milling is carried out on the new anisotropic medium and the spherical medium in a certain proportion with materials, the cross section of powder can be increased, the activity is improved, the dispersed solid particles and hydration products are connected by the added materials to form a three-dimensional firmly-combined and compact whole, thereby leading the set cement to be more and more compact, the strength to be continuously improved, the residual titanium gypsum is tightly wrapped by a thick hydration product layer and is not dissolved any more, and leading the cement to have good hydraulicity. Meanwhile, different from other standard cement sample preparation ingredients (namely weighing → stirring → adding standard sand → adding water → injection molding), the invention adds a mixing and grinding ingredient technology after the materials are taken and weighed, and mixes and grinds the weighed cement materials, sand and water again, thereby greatly improving the later stability of the cement sample preparation.

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

In the following examples, the cement clinker is PO42.5 and the main component is SiO₂、Al₂O₃And CaO, available from Pan Steel group. The mineral powder is s95 mineral powder and is purchased from a Huaying purifying material. The fineness of the fly ash is three levels. The water reducing agent is a polycarboxylic acid water reducing agent 301A type purchased from Sichuan ferrum family.

In the following examples, the main components of raw materials such as titanium gypsum are shown in Table 1.

TABLE 1 Main Components of raw materials such as titanium Gypsum

Composition (wt%)	SiO₂	CaO	Na₂O	MgO	TiO₂	Al₂O₃	Fe₂O₃	SO₃	V₂O₅	Others
											Titanium gypsum	1.89	34.6	0.2	1.5	2.3	1.2	10.2	40.2	\	7.7
Titanium extraction tailings	21.3	35.2	0.5	9.5	11.0	8.9	2.5	\	\	11.1
											Steel slag	9.7	48.3	\	9.0	\	2.0	31.0	\	\	\
Vanadium slag	18.9	3.6	\	1.2	8.6	1.8	35.2	\	16.4	14.3
											Fly ash	53.1	2.7	\	2.3	\	30.0	2.9	\	\	9.0

Example 1

Referring to fig. 2, raw material treatment and preparation of low-carbon type super-sulfate cement are performed, and fig. 2 is a schematic flow chart of the preparation of the low-carbon type super-sulfate cement according to the embodiment of the invention.

1. Raw material treatment:

and (3) carrying out filter pressing, drying, ball milling and 100-mesh sieving on the titanium gypsum to obtain the titanium gypsum powder with the water content of 20 wt% and the granularity of 100 meshes.

Mixing and ball-milling the titanium extraction tailings, the steel slag and the vanadium slag, and sieving the mixture by a 200-mesh sieve to obtain 200-mesh powder.

And (4) sieving the mineral powder with a 100-mesh sieve to obtain the mineral powder with the 100-mesh sieve.

And (3) sieving the cement clinker by using a 300-mesh sieve to obtain the cement clinker with 300 meshes.

2. The low-carbon type super-sulfate cement comprises the following raw materials:

20% of titanium gypsum, 20% of cement clinker, 30% of mineral powder, 10% of steel slag, 10% of titanium extraction tailings, 5% of vanadium slag and 5% of fly ash.

Mixing and grinding ingredients: putting the raw materials into a ball mill, wherein the ball milling medium is stainless steel, the ball-material ratio is 0.2, and ball milling is carried out for 1h at the rotating speed of 300r/min to obtain the low-carbon type super-sulfate cement material.

3. Preparing cement mortar:

according to the method of national standard GB/T175-2008 'cement mortar strength test method', the low-carbon type super-sulfate cement material is mixed with water and standard sand, stirred, placed into a mold, maintained and tested for the breaking strength and the compressive strength.

Wherein, the process for preparing cement mortar is as follows:

proportioning according to the mass ratio of standard sand to cement material of 3.22, adding water according to the mass ratio of water to the proportioning of 0.5, wherein the ball milling media are a new heterogeneous medium (Millpebs grinding media) and a spherical medium (stainless steel balls), and the mass ratio of the two media is 0.2; the ball-material ratio is 0.5, and the cement mortar is obtained by mixing and grinding for 3min at the rotating speed of 350 r/min.

4. And (3) characterization and detection:

the macro-morphology and the microstructure of the sample are tested, and the results are respectively shown in fig. 3 and fig. 4, fig. 3 is the macro-morphology diagram of the cement mortar sample of the example 1, and fig. 4 is the SEM microstructure diagram of the cement mortar sample of the example 1, so that the structure is dense, and the gaps are filled with abundant hydration products such as C-S-H gel and the like to form a slurry structure with a compact structure. The formation of the hardened slurry structure is shown in fig. 5, and fig. 5 is a schematic diagram of the formation of the hardened slurry structure; the reactions that occur include: 3CaO + Al₂O₃+3CaSO₄+26H₂O→C₃A·3CaSO₄·32H₂O，CaO+SiO₂+H₂O→C-S-H。

The mechanical properties and the chloride ion diffusion coefficient of the material were tested, and the results are shown in table 1.

Example 2

1. Raw material treatment: the same as in example 1.

30% of titanium gypsum, 15% of cement clinker, 25% of mineral powder, 10% of steel slag, 10% of titanium extraction tailings, 5% of vanadium slag, 3% of fly ash, 1% of water reducing agent and 1% of NaOH activator.

Mixing and grinding ingredients: the same as in example 1.

3. Preparing cement mortar: the same as in example 1.

4. And (3) characterization and detection:

the results of the macro-morphology and the microstructure of the sample are respectively shown in fig. 6 and fig. 7, fig. 6 is the macro-morphology diagram of the cement mortar sample of example 2, and fig. 7 is the SEM microstructure diagram of the cement mortar sample of example 2, and it can be seen that the structure is dense, and the gaps are filled with abundant hydration products such as C-S-H gel, etc., to form a slurry structure with a compact structure.

Example 3

1. Raw material treatment: the same as in example 1.

40% of titanium gypsum, 15% of cement clinker, 20% of mineral powder, 5% of steel slag, 10% of titanium extraction tailings, 5% of vanadium slag, 3% of fly ash, 1% of water reducing agent and 1% of NaOH activator.

Mixing and grinding ingredients: the same as in example 1.

3. Preparing cement mortar: the same as in example 1.

4. And (3) characterization and detection:

the results of the macro-morphology and the microstructure of the sample are respectively shown in fig. 8 and fig. 9, fig. 8 is the macro-morphology diagram of the cement mortar sample of example 3, and fig. 9 is the SEM microstructure diagram of the cement mortar sample of example 3, and it can be seen that the structure is dense, and the voids are filled with abundant hydration products such as C-S-H gel, etc., to form a slurry structure with a compact structure.

TABLE 1 Properties of Cement mortar test pieces obtained in examples 1 to 3

The test results in table 1 show that the specific formulation design of the invention, the addition of titanium extraction tailings, steel slag and vanadium slag in example 1, does not affect the 28d mechanical properties of the material, and the 3d early strength is good. In the example 2, the exciting agent and the water reducing agent are introduced to be matched with other components, the mechanical property of 28d is basically not influenced, but the early strength of 3d is obviously improved. The content of the titanium gypsum in the example 3 is increased to 40%, and compared with the example 1, the 28d compressive strength is reduced to some extent, but the use standard can be reached, but the 3d flexural strength is obviously improved. Meanwhile, the 28d cement chloride ion diffusion coefficient of the obtained super-sulfuric acid cement is less than 1.5 multiplied by 10^-12Watch, watchShowing good resistance to chloride ion permeability.

The foregoing examples are provided to facilitate an understanding of the principles of the invention and their core concepts, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention. The scope of the invention is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that approximate the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. The low-carbon type super-sulfate cement is characterized by comprising the following components in percentage by mass:

2. the low-carbon type super sulfate cement according to claim 1, wherein the titanium gypsum has a particle size of 100 mesh or less.

3. The low-carbon type super sulfate cement according to claim 1, wherein the titanium gypsum has a water content of 20 wt% or less.

4. The low carbon type super sulfate cement of claim 1, wherein the water reducer is a polycarboxylic acid water reducer.

5. The low carbon-type super sulfate cement of claim 1, wherein the activator is NaOH.

6. The low-carbon type super-sulfate cement according to claim 1, wherein the titanium extraction tailings have a particle size of 100 meshes or less;

the granularity of the steel slag is below 100 meshes;

the particle size of the vanadium slag is below 100 meshes.

7. The low-carbon super-sulfate cement according to claim 1, wherein the ore powder is s95 ore powder.

8. A method for preparing the low-carbon type super sulfate cement according to any one of claims 1 to 7, comprising the following steps:

9. The cement mortar is characterized by being prepared by mixing and grinding cement materials, sand and water;

the cement material is the low-carbon type super-sulfate cement as defined in any one of claims 1-7.

10. The cement mortar of claim 1, wherein the mass ratio of the sand to the cement material is 2.5-3.5;

in the mixing and grinding:

the adopted ball milling media are Millpebs grinding media and spherical media;

the ball material ratio of the mixed grinding is 0.1-0.5.