CN110255951B

CN110255951B - Barium-based chloride ion curing agent and preparation method and application thereof

Info

Publication number: CN110255951B
Application number: CN201910290304.9A
Authority: CN
Inventors: 谭洪波; 邓秀峰; 张迅; 聂康峻; 李懋高; 马保国
Original assignee: Wuhan University of Technology WUT
Current assignee: Wuhan University of Technology WUT
Priority date: 2019-04-11
Filing date: 2019-04-11
Publication date: 2021-11-02
Anticipated expiration: 2039-04-11
Also published as: CN110255951A

Abstract

The invention provides a barium-based chloride ion curing agent and a preparation method and application thereof, wherein the barium-based chloride ion curing agent is mainly prepared from the following components in parts by weight through a wet grinding process: barium residue: 220-250 parts of grinding aid: 50-80 parts of ionic cosolvent: 18-25 parts of a dispersion stabilizer: 25-35 parts of water: 610 and 687 parts. The barium-based chloride ion curing agent takes barium slag as a main raw material, adopts a wet grinding process, improves the fineness of the barium slag, increases the specific surface area of the barium slag and ensures that Ba in the barium slag is contained²⁺Fully dissolved out in wet-grinding liquid phase environment, and Ba in barium slag²⁺The barium sulfate can generate stable barium sulfate sediment with replaced sulfate ions, the content of the sulfate ions in the solution is reduced, and further the AFm can be promoted to be converted into Kuzel's salt, Friedel's salt and a solid solution thereof, so that the barium sulfate has high chloride ion curing rate, the 3d and 28d chloride ion curing rates can be improved by more than 20%, a new direction is provided for the resource utilization of the barium slag, the resource utilization rate of the barium slag is greatly improved, and the additional value of the barium slag product is improved.

Description

Barium-based chloride ion curing agent and preparation method and application thereof

Technical Field

The invention relates to the technical field of chloride ion curing agents, and particularly relates to a barium-based chloride ion curing agent and a preparation method and application thereof.

Background

In reinforced concrete, the steel bar is usually in a high-alkaline (pH is generally higher than 12.5) concrete pore solution environment, a passivation film with the thickness of about 2-10 nm is formed on the surface of the steel bar, and the chemical component of the film is Fe₃O₄-γFe₂O₃The surface roughness of the passive film is defective, so the film can be firmly combined with the surface of the steel bar, thereby the steel bar has the corrosion resistance. However, when chloride ions intrude into the reinforced concrete system and the content exceeds a certain value, it results in steelThe surface of the reinforcing steel bar is subjected to depassivation reaction and further strong electrochemical corrosion, so that the corrosion of the reinforcing steel bar is induced, and the durability and the service life of the reinforced concrete are damaged. The relevant literature shows that the calcium sulphoaluminate monosulfide hydrate (AFm) in the cement product has good curing effect on chloride ions, and the curing mechanism can be summarized as follows: under the condition of the existence of chloride ions, sulfate ions and water molecules between the AFm layers are subjected to ion exchange with chloride ions in a solution, and are converted into Kuzel's salt, Friedel's salt and a solid solution thereof, so that the chloride ions are cured, and therefore, the chloride ion curing agent commonly used at present is basically developed based on the principle, but the curing efficiency of the chloride ion curing agent on the chloride ions is low.

The barium slag is solid waste discharged in the process of producing barium salt by refining barite, mainly contains acid-soluble barium and water-soluble barium, has toxicity and is dangerous waste. If the barium residues are stacked for a long time, not only a large amount of land is occupied, but also spontaneous combustion is easy to occur under the condition of sunshine and high temperature, toxic gas is discharged, leachate containing sulfide is produced to pollute water body through rainwater infiltration, and meanwhile barium sulfide and acid-soluble barium in the waste residues can generate a harmful effect on soil. At present, with the development of chemical industry, the yield of barium-containing waste residue in China is more and more large and reaches 40 ten thousand in 2006, and with the development of production, the yield of barium carbonate reaches 30 ten thousand in 2009, which is only produced by Guizhou Hongxing development corporation, and is also increased year by year. Because the treatment approach is limited, the treatment approach is mainly stacking at present, and the accumulated stacking of the barium slag in China is over ten thousand tons, so that the method has very important significance if the barium slag is used for preparing the chloride ion curing agent to prevent the steel bar from being corroded.

Disclosure of Invention

In view of the above, the present invention aims to provide a barium-based chloride ion curing agent to solve the problem of low resource utilization rate of the existing barium slag.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the barium-based chloride ion curing agent is prepared by the following components in parts by weight through a wet grinding process: barium residue: 220-250 parts of grinding aid: 50-80 parts of ionic cosolvent: 18-25 parts of a dispersion stabilizer: 25-35 parts of water: 610 and 687 parts.

Optionally, the grinding aid comprises limestone flour.

Optionally, the ionic cosolvent is an aqueous solution of triethanolamine and triisopropanolamine; the mass ratio of the triethanolamine to the triisopropanolamine is (1.2-1.8) to 1; the mass fraction of the ionic cosolvent is 10%.

Optionally, the dispersion stabilizer is an aqueous solution of a polycarboxylic acid water reducing agent and sodium hexametaphosphate; the mass ratio of the polycarboxylic acid water reducing agent to the sodium hexametaphosphate is (2-3) to 1; the mass fraction of the dispersion stabilizer is 10%.

Optionally, the median particle size of the barium-based chloride ion curing agent is 200-300 nm.

The second object of the present invention is to provide a method for preparing the barium-based chloride ion curing agent, which comprises the following steps:

and mixing the barium residue, the grinding aid, the ionic dissolution promoter, the dispersion stabilizer and the water, and grinding to obtain the barium-based chloride ion curing agent.

Optionally, the amount of the ground grinding body is 2 to 3 times of the total amount of the barium residue, the grinding aid, the ionic dissolution promoter, the dispersion stabilizer and the water; the grading of the grinding body is as follows: 10 mm: 5 mm: 2.5 mm: 0.6 mm-2: 3: 4.

Optionally, the polishing speed of the polishing is 400-800 rpm.

The third purpose of the invention is to provide the application of the barium-based chloride ion curing agent in cement-based materials, wherein the cement-based materials comprise cement; the dosage of the barium-based chloride ion curing agent is 5-8% of that of the cement.

Compared with the prior art, the barium-based chloride ion curing agent has the following advantages:

1. the barium-based chloride ion curing agent takes barium slag as a main raw material, adopts a wet grinding process, improves the fineness of the barium slag, increases the specific surface area of the barium slag and ensures that Ba in the barium slag is contained²⁺In the wet millingFully dissolved out in phase environment, Ba in barium slag²⁺The barium sulfate can generate stable barium sulfate sediment with replaced sulfate ions, the content of the sulfate ions in the solution is reduced, and further the AFm can be promoted to be converted into Kuzel's salt, Friedel's salt and a solid solution thereof, so that the barium sulfate has high chloride ion curing rate, the 3d and 28d chloride ion curing rates can be improved by more than 20%, a new direction is provided for the resource utilization of the barium slag, the resource utilization rate of the barium slag is greatly improved, and the additional value of the barium slag product is improved.

2. The barium-based chloride ion curing agent takes the barium slag as a main raw material, adopts a wet grinding process to improve the fineness and increase the specific surface area, is favorable for providing crystal nucleus growth points for cement hydration products, reducing nucleation barriers, accelerating the early cement hydration process and improving the early strength of the cement-based material on one hand, and can also promote the dissolution of calcium, aluminum and silicon ions in the barium slag to enable the calcium, aluminum and silicon ions to generate a pozzolan reaction with the cement hydration products on the other hand, further improving the later strength of the cement, and the existence of the nano-grade particles can fill the pores in the set cement, the nanometer lithium slag early strength agent can improve the 3d compressive strength of the cement-based material by more than 25 percent and improve the 28d compressive strength by more than 15 percent.

3. The barium slag admixture is prepared by a wet grinding method, the preparation process is simple, the preparation process is easy to control, and in addition, a grinding aid, an ion cosolvent and a dispersion stabilizer are added in the wet grinding process, so that on one hand, the wet grinding efficiency can be further improved, the preparation energy consumption is further reduced, on the other hand, the barium-based chloride ion curing agent disclosed by the invention has good stability and dispersibility, and the flowability of slurry can be improved when the barium-based chloride ion curing agent is used for cement concrete, so that the adaptability of the slurry can be favorably improved.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in detail with reference to examples.

Table 1 shows the ratio (parts by weight) of each component in the barium-based chloride ion curing agent of examples 1 to 6 of the present invention and the fineness of the barium-based chloride ion curing agent of each example, wherein the grinding aid is limestone powder; the ionic cosolvent is an aqueous solution of Triethanolamine (TEA) and Triisopropanolamine (TIPA), and the mass fraction of the ionic cosolvent is 10%; the dispersion stabilizer is an aqueous solution of a polycarboxylate superplasticizer (PCE) and Sodium Hexametaphosphate (SHMP), and the mass fraction of the dispersion stabilizer is 10%. Table 2 shows the ratio of the ionic dissolution accelerator to the dispersion stabilizer in examples 1 to 6 of the present invention. Table 3 shows the basic physicochemical properties of the polycarboxylate superplasticizer (PCE). Table 4 shows the chemical composition of barium residue.

TABLE 1

TABLE 2

TABLE 3

Chloride ion content (%)	Alkali content (%)	Water loss (%)	pH	Solid content (%)
					0.03	3.75	30.1	7	40

TABLE 4

Composition (I)	Loss	BaO	SiO₂	Al₂O₃	Fe₂O₃	SO₃	CaO	MgO	K₂O	Na₂O
											Mass fraction/%	7.20	38.24	13.13	5.08	2.55	17.52	13.05	2.21	0.73	0.39

The barium-based chloride ion curing agent of example 1 to example 6 was prepared by the following method, specifically including the steps of:

according to the raw material formula, putting barium slag, a grinding aid, an ion cosolvent, a dispersion stabilizer and water into a grinding tank, then sealing and fixing the grinding tank on a grinding machine, cooling the grinding machine at the cooling temperature of 20 ℃ by setting the grinding speed of the grinding machine to 400rpm, grinding the materials, standing for 10min every 20min in the grinding process until the median particle size of the materials in the grinding tank is 200-300nm in order to avoid the influence of overhigh temperature of the grinding machine on the grinding efficiency of the materials, and filtering out a grinding body to obtain the barium-based chloride ion curing agent.

Wherein, the dosage of the grinding body in the grinding tank is preferably 2.5 times of the total dosage of the barium residue, the grinding aid, the ionic cosolvent, the dispersion stabilizer and the water, and the grading of the grinding body is as follows: 10 mm: 5 mm: 2.5 mm: 0.6 mm-2: 3: 4.

The barium-based chloride ion curing agent of example 1-example 6 was used in a cement-based material, in which application the cement-based material included cement; the dosage of the barium-based chloride ion curing agent is 5-8% of the dosage of the cement. It should be noted that, in cement-based materials such as concrete, in order to improve the working performance, mechanical properties and durability of the concrete, admixtures such as fly ash and mineral powder are usually added, and cement and these additional admixtures are generally referred to as cement materials, therefore, when the barium-based chloride ion curing agent of examples 1 to 6 is used in the cement-based material containing admixtures, the amount of the barium-based chloride ion curing agent is 5 to 8% of the amount of the cement materials, i.e. 5 to 8% of the barium-based chloride ion curing agent is added. Specific amounts of the barium-based chloride ion curing agents of examples 1 to 6 are shown in table 5.

The mechanical properties of the cement-based material (cement mortar) doped with the barium-based chloride ion curing agent of the examples 1-6 are tested according to the standard GB8076-2008, the chloride ion curing rate is tested according to the silver nitrate chemical titration method in the standard JTJ270-98 concrete test procedure of water transportation engineering, and the chloride ion curing rate is compared with the chloride ion curing rate of the cement-based material not doped with the barium-based chloride ion curing agent of the invention (comparative example), wherein the water-to-gel ratio of the cement-based material is 0.5. The test results are shown in table 5.

TABLE 5

As can be seen from Table 5, when the amount of the barium-based chloride ion curing agent added in examples 1 to 6 is 5 to 8%, the 3d compressive strength can be improved by more than 25%, the 28d compressive strength can be improved by more than 15%, and the 3d and 28d chloride ion curing rates can be improved by more than 20% compared with the comparative example, so that the barium-based chloride ion curing agent has large-scale popularization value.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The barium-based chloride ion curing agent is characterized by being prepared from the following components in parts by weight through a wet grinding process: barium residue: 220-250 parts of grinding aid: 50-80 parts of ionic cosolvent: 18-25 parts of a dispersion stabilizer: 25-35 parts of water: 610-687 parts; the median particle size of the barium-based chloride ion curing agent is 200-300 nm; the grinding aid comprises limestone powder; the ionic cosolvent is an aqueous solution of triethanolamine and triisopropanolamine; the mass ratio of the triethanolamine to the triisopropanolamine is (1.2-1.8) to 1; the mass fraction of the ionic cosolvent is 10 percent; the dispersion stabilizer is an aqueous solution of a polycarboxylic acid water reducing agent and sodium hexametaphosphate; the mass ratio of the polycarboxylic acid water reducing agent to the sodium hexametaphosphate is (2-3) to 1; the mass fraction of the dispersion stabilizer is 10%.

2. The method for preparing the barium-based chloride ion curing agent of claim 1, comprising the steps of:

3. The preparation method of the barium-based chloride ion curing agent according to claim 2, wherein the amount of the ground grinding body is 2 to 3 times the total amount of the barium residue, the grinding aid, the ionic dissolution promoter, the dispersion stabilizer and the water; the grading of the grinding body is as follows: 10 mm: 5 mm: 2.5 mm: 0.6mm = 2: 3: 4.

4. The method for preparing barium-based chloride ion curing agent as claimed in claim 2, wherein the grinding speed of the grinding is 400-800 rpm.

5. Use of the barium-based chloride ion curing agent of claim 1 in a cementitious material, wherein the cementitious material comprises cement; the dosage of the barium-based chloride ion curing agent is 5-8% of that of the cement.