CN113248165A - Alkali slag cement and preparation method thereof - Google Patents
Alkali slag cement and preparation method thereof Download PDFInfo
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- CN113248165A CN113248165A CN202110400010.4A CN202110400010A CN113248165A CN 113248165 A CN113248165 A CN 113248165A CN 202110400010 A CN202110400010 A CN 202110400010A CN 113248165 A CN113248165 A CN 113248165A
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B12/00—Cements not provided for in groups C04B7/00 - C04B11/00
- C04B12/005—Geopolymer cements, e.g. reaction products of aluminosilicates with alkali metal hydroxides or silicates
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Abstract
The alkali slag cement comprises the following raw materials in percentage by mass: 95-97% of cementing material and 3-5% of excitant, wherein the cementing material consists of slag and molecular sieve industrial slag mud, and the mass percentage of the slag and the molecular sieve industrial slag mud is (70-80%): (20-30%), the exciting agent is composed of sodium hydroxide and barium hydroxide, the mass percentage of the sodium hydroxide and the barium hydroxide is (40-60%): (40% to 60%). The alkali slag cement has good performance, and the preparation method can effectively utilize the molecular sieve industrial slag mud to prepare the alkali slag cement with good performance, reduce the landfill treatment of the molecular sieve industrial slag mud, and reduce the pollution of the molecular sieve industrial slag mud to the natural environment.
Description
Technical Field
The invention relates to the technical field of building materials, in particular to alkali slag cement and a preparation method thereof.
Background
Cement concrete has been widely used in various places of human life as a bulk structural material. However, portland cement used in concrete is a sustainable challenge because it consumes a lot of resources and energy in the production process and emits more substances polluting the environment. Meanwhile, due to global climate change, one of the focuses of the development of the cement industry in the world today is how to reduce the emission of carbon dioxide. Therefore, it is imperative to develop low carbon cements to make up for the deficiencies of conventional portland cements.
The alkali slag cement is a gelled material prepared by grinding an alkali metal compound and granulated blast furnace slag together or by preparing the ground slag with a solution of the alkali metal compound. Compared with silicate cement, the alkali slag cement has absolute advantages in the aspects of mechanical property, frost resistance, impermeability, high temperature resistance, chemical erosion resistance and the like. More importantly, the cement is a typical low-carbon cement with simple production process, a large amount of industrial wastes can be digested, the emission of carbon dioxide can be reduced by 40-80%, however, the practical application of the cement is limited to a certain extent due to the high price of the alkali-activating agent used for producing the alkali slag cement.
The molecular sieve industrial residue sludge is yellow white or gray solid waste remained after a related enterprise synthesizes and extracts a molecular sieve product. At present, a small part of the molecular sieve industrial slag mud is used as a binder of the baked bricks by production enterprises, but as the demand of the molecular sieve industrial slag mud is less, most of the molecular sieve industrial slag mud is subjected to landfill treatment. Because the industrial slag mud of the molecular sieve is strong in alkalinity, the landfill treatment can cause great harm to the surrounding environment.
With the increasing storage of the industrial residue sludge of the molecular sieve, the damage of the industrial residue sludge to the natural environment is more serious, so how to carry out harmless or resource treatment on the industrial waste is an important subject in front of scientific and technological workers.
Disclosure of Invention
The invention aims to provide alkali slag cement and a preparation method thereof, wherein the alkali slag cement is prepared by taking the molecular sieve industrial slag mud as a raw material, so that the molecular sieve industrial slag mud can be effectively recycled, and the pollution of landfill treatment on the natural environment by the molecular sieve industrial slag mud is reduced.
The technical scheme adopted by the invention to solve the technical problems is as follows:
the alkali slag cement comprises the following raw materials in percentage by mass:
95% -97% of cementing material;
3 to 5 percent of excitant;
the cementing material consists of slag and molecular sieve industrial slag mud, and the mass percentage of the slag to the molecular sieve industrial slag mud is 70-80%: 20 to 30 percent.
Further, the specific surface area of the cementing material is not less than 350 m 2/kg.
Further, the activator is composed of sodium hydroxide and barium hydroxide.
Further, the mass percentage of the sodium hydroxide and the barium hydroxide is 40% -60%: 40 to 60 percent.
Further, the fineness of the exciting agent is controlled to be not more than 10% of the residue of a square-hole sieve with the size of 80 mu m.
A preparation method of alkali slag cement comprises the following preparation steps:
respectively drying the slag and the molecular sieve industrial slag mud, then proportioning the slag and the molecular sieve industrial slag mud according to the required proportion, and then grinding the mixture until the specific surface area is not less than 350 m2Per kg, obtaining a cementing material;
step two, mixing sodium hydroxide and barium hydroxide according to a required proportion, and then grinding the mixed materials until the residue of a square-hole sieve with the size of 80 mu m is not more than 10% to obtain an exciting agent;
and step three, mixing the cementing material and the exciting agent according to the required proportion and uniformly mixing to obtain the alkali slag cement.
The invention has the beneficial effects that:
1. the invention uses the molecular sieve industrial slag mud for preparing the alkali slag cement, the prepared cement has good performance in the aspects of setting time, compressive strength and the like, a new scheme is provided for resourcefully treating a large amount of molecular sieve industrial slag mud, and the harm of landfill treatment of the molecular sieve industrial slag mud to the environment is avoided.
2. The invention uses the molecular sieve industrial slag mud as the raw material for preparing the alkali slag cement, and compared with the cost of slag, the cost of the molecular sieve industrial slag mud is almost zero, thereby greatly reducing the production cost of the alkali slag cement, being beneficial to the popularization and the application of the alkali slag cement, and further being beneficial to the resource treatment of the molecular sieve industrial slag mud.
3. The invention uses the molecular sieve industrial residue mud as a raw material for preparing the alkali slag cement, and because the molecular sieve industrial residue mud is the waste left after a molecular sieve product is extracted from clay, sodium silicate, aluminum hydroxide, activated alumina, potassium chloride, sodium chloride, calcium chloride, potassium hydroxide, sodium hydroxide and the like serving as raw materials by related enterprises, the contained sodium silicate, potassium hydroxide and sodium hydroxide can serve as a part of alkaline excitant in the process of preparing the alkali slag cement, so that the use amount of the excitant required to be added is reduced, the production cost of the alkali slag cement is further reduced, the popularization and the application of the alkali slag cement are facilitated, and the resource treatment of the molecular sieve industrial residue mud is further facilitated.
4. The dissolution speed of alkali in the molecular sieve industrial slag mud is low, and the alkali is used together with an additional alkaline exciting agent, so that compared with the single use of the added exciting agent, the alkali slag cement coagulation time can be flexibly adjusted, the alkali slag cement is more beneficial to popularization and application, and more recycling treatment of the molecular sieve industrial slag mud is facilitated.
5. The alkaline excitant of the invention is mixed with barium hydroxide, which can effectively excite the activity of slag and improve the sulfate resistance of the alkaline slag cement.
Detailed Description
The invention will be further described with reference to specific examples for the purpose of facilitating an understanding of the technical means, the inventive features and the objectives obtained, but the scope of the invention as claimed should not be limited to the scope described in the detailed description.
It is to be noted that unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which this application belongs.
The invention provides alkali slag cement which comprises the following raw materials in percentage by mass: 95-97% of cementing material and 3-5% of excitant, wherein the cementing material consists of slag and molecular sieve industrial slag mud, and the mass percentage of the slag and the molecular sieve industrial slag mud is (70-80%): (20-30%); the activator can be composed of sodium hydroxide and barium hydroxideThe mass percentage of (40-60%): (40% -60%), wherein the mass percentage of NaOH in the sodium hydroxide is not less than 96%, and Ba (OH) in the barium hydroxide2The mass percentage of the component (A) is not less than 98 percent.
Specifically, the specific surface area of the cementing material consisting of the slag and the molecular sieve industrial slag is not less than 350 m2The fineness of the exciting agent is controlled to be not more than 10 percent of the residue of a square-hole sieve with the particle size of 80 mu m.
The chemical components of the slag and the molecular sieve industrial slag mud used in the embodiment of the invention are shown in Table 1, wherein the mass coefficient of the slag is 1.82, and the technical requirements provided by GB/T203-.
TABLE 1 chemical composition of slag and molecular Sieve Industrial slag sludge (% by weight)
The invention also provides a preparation method of the alkali slag cement, which comprises the following preparation steps:
respectively drying the slag and the molecular sieve industrial slag mud, then proportioning the slag and the molecular sieve industrial slag mud according to the required proportion, and then grinding the mixture until the specific surface area is not less than 350 m2Per kg, obtaining the cementing material;
grinding the exciting agent until the sieve residue of the 80-micron square-hole sieve is not more than 10% for standby application, wherein the exciting agent can be mixed powder of sodium hydroxide and barium hydroxide according to a certain proportion, and when the exciting agent is used, the mixed powder is ground until the sieve residue of the 80-micron square-hole sieve is not more than 10% to obtain the standby exciting agent;
and step three, mixing the cementing material and the exciting agent according to the required proportion and uniformly mixing to obtain the alkali slag cement.
Example 1
The alkali slag cement comprises the following raw materials in percentage by mass: 95% of cementing agent and 5% of excitant. Wherein the cementing material consists of 80 weight percent of slag and 20 weight percent of molecular sieve industrial slag mud; the activator consists of 50% by weight of sodium hydroxide and 50% by weight of barium hydroxide. Specific surface of the cementing materialProduct is not less than 350 m2The fineness of the exciting agent is controlled to be not more than 10 percent of the residue of a square-hole sieve with the particle size of 80 mu m.
A preparation method of alkali slag cement comprises the following preparation steps:
respectively drying the slag and the molecular sieve industrial slag sludge, and then drying the slag and the molecular sieve industrial slag sludge according to the proportion of 80%: 20 percent of the raw materials are mixed according to mass percentage, and then the mixed materials are ground into powder with the specific surface area of 387 m2Per kg, obtaining the cementing material;
step two, mixing sodium hydroxide and barium hydroxide according to the proportion of 50%: 50 percent of the activator is prepared, and then the mixture is ground to 80 mu m square hole sieve residue of 6.3 percent to obtain the activator;
step three, mixing the cementing agent and the exciting agent according to the proportion of 95%: 5 percent of the alkali slag cement A is prepared and evenly mixed to obtain the alkali slag cement A.
Example 2
The alkali slag cement comprises the following raw materials in percentage by mass: 97% of cementing agent and 3% of excitant. Wherein the cementing material consists of 75 percent of slag and 25 percent of molecular sieve industrial slag by weight; the activator consists of 60% by weight of sodium hydroxide and 40% by weight of barium hydroxide. The specific surface area of the cementing material is not less than 350 m2The fineness of the exciting agent is controlled to be not more than 10 percent of the residue of a square-hole sieve with the particle size of 80 mu m.
An alkali slag cement and a preparation method thereof, comprising the following preparation steps:
step one, respectively drying the slag and the molecular sieve industrial slag sludge, and then drying the slag and the molecular sieve industrial slag sludge according to the proportion of 75%: 25 percent of the raw materials are mixed, and then the mixed materials are ground into 392 m of specific surface area2Per kg, obtaining the cementing material;
step two, mixing the sodium hydroxide and the barium hydroxide according to the proportion of 60%: 40 percent of the activator is prepared, and then the mixture is ground to 80 mu m square hole sieve residue of 5.6 percent to obtain the activator;
step three, mixing the cementing agent and the exciting agent according to the proportion of 97%: 3 percent of the alkali slag cement B is prepared and evenly mixed to obtain the alkali slag cement B.
Example 3
The alkali slag cement comprises the following raw materials in percentage by mass: 96% of cementing agent and 4% of excitant. Wherein the cementing material consists of 70 percent of slag and 30 percent of molecular sieve industrial slag mud by weight; the activator consists of 40% by weight of sodium hydroxide and 60% by weight of barium hydroxide. The specific surface area of the cementing material is not less than 350 m2The fineness of the exciting agent is controlled to be not more than 10 percent of the residue of a square-hole sieve with the particle size of 80 mu m.
An alkali slag cement and a preparation method thereof, comprising the following preparation steps:
step one, respectively drying the slag and the molecular sieve industrial slag mud, and then drying the slag and the molecular sieve industrial slag mud according to the proportion of 70%: 30 percent of the raw materials are mixed, and then the mixed materials are ground into powder with the specific surface area of 380 m2Per kg, obtaining the cementing material;
step two, mixing sodium hydroxide and barium hydroxide according to the proportion of 40%: mixing 60% of the raw materials in percentage by mass, and then grinding the mixed materials to obtain an exciting agent, wherein the residue of a square-hole sieve with the size of 80 mu m is 5.7%;
step three, mixing the cementing agent and the exciting agent according to the proportion of 96%: 4 percent of the alkali slag cement C is obtained by burdening and uniformly mixing.
Comparative examples
According to the usual situation, the slag is mixed with sodium silicate with a modulus of 1.2 according to a ratio of 94%: 6 percent of the raw materials are mixed, and then the mixture of the slag and the sodium silicate is ground until the specific surface area is 385 m2Per kg, a comparative alkali slag cement was obtained. The setting time, strength and sulfate erosion resistance of the cements of the above examples and comparative cements were examined, respectively, and the results are shown in Table 2.
Wherein, the detection of the cement setting time is carried out according to GB/T1346-2001 'method for detecting water consumption, setting time and stability of standard consistency of cement'; the testing of the strength of the mortar is carried out according to GB/T17671-1999 method for testing the strength of mortar (ISO method); the test of the sulfate erosion resistance is carried out according to a test method (K method) of immersion erosion resistance in GB/T749-2008 test method of cement sulfate erosion resistance, wherein the erosion solution is a sodium sulfate solution with a concentration of 3% (mass fraction).
TABLE 2 Properties of alkali-slag cements of examples and comparative alkali-slag cements
As can be seen from Table 2, the initial setting time of the alkali-slag cement is shorter than the normal construction requirement, the setting time of the alkali-slag cement is normal, the setting time of the alkali-slag cement is obviously prolonged compared with the setting time of the alkali-slag cement, the initial setting time can be prolonged by about 2-3 times, the final setting time can be prolonged by about 2-2.5 times, and the interval between the final setting time and the initial setting time can be prolonged by about 1.5 times, so that the alkali-slag cement can better meet the time requirement of each construction link, and further contributes to the popularization and application of the alkali-slag cement.
As can be seen from Table 2, in the alkali slag cement of the present application, except that the alkali slag cement C has slightly lower compressive strengths at 3d and 28d than the comparative alkali slag cement, both the alkali slag cement A and the alkali slag cement B have higher compressive strengths at 3d and 28d than the comparative alkali slag cement, where d represents days and 3d represents 3 days.
As can be seen from Table 2, the alkali-slag cement A, the alkali-slag cement B and the alkali-slag cement C have better sulfate erosion resistance than the comparative alkali-slag cement, and the sulfate erosion resistance is improved by about 7 to 24%.
Under the condition of using a smaller amount of exciting agent, the alkali slag cement is prepared by taking the molecular sieve industrial slag mud as a raw material, the alkali slag cement has better compressive strength, and better performance improvement is realized in the aspects of setting time and sulfate corrosion resistance, so that the molecular sieve industrial slag mud not only can be used as a raw material for producing the alkali slag cement, but also can be used for improving partial performance of the alkali slag cement, a new scheme is provided for harmless or resource treatment of the molecular sieve industrial slag mud, the molecular sieve industrial slag mud can be greatly recycled by utilizing a large amount of requirements of the alkali slag cement, the molecular sieve industrial slag mud is prevented from being buried and treated, and the harm to the environment is reduced.
It should be noted that the above embodiments are only for illustrating the present invention, but the present invention is not limited to the above embodiments, and any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention fall within the protection scope of the present invention.
Claims (6)
1. The alkali slag cement is characterized by comprising the following raw materials in percentage by mass:
95% -97% of cementing material;
3 to 5 percent of excitant;
the cementing material consists of slag and molecular sieve industrial slag mud, and the mass percentage of the slag to the molecular sieve industrial slag mud is 70-80%: 20 to 30 percent.
2. The alkali slag cement as set forth in claim 1, wherein the specific surface area of said binder is not less than 350 m2/kg。
3. An alkaline slag cement according to claim 1, wherein said excitant is composed of sodium hydroxide and barium hydroxide.
4. An alkaline slag cement according to claim 3, wherein the sodium hydroxide and barium hydroxide are present in an amount of 40 to 60% by weight: 40 to 60 percent.
5. Alkali slag cement according to claim 4, wherein the fineness of said exciting agent is controlled to not more than 10% by sieve residue of 80 μm square mesh.
6. A method of producing an alkali slag cement as claimed in any one of claims 1 to 5, comprising the steps of:
respectively drying the slag and the molecular sieve industrial slag mud, then proportioning the slag and the molecular sieve industrial slag mud according to the required proportion, and then grinding the mixture until the specific surface area is not less than 350 m2Per kg, obtaining a cementing material;
step two, mixing sodium hydroxide and barium hydroxide according to a required proportion, and then grinding the mixed materials until the residue of a square-hole sieve with the size of 80 mu m is not more than 10% to obtain an exciting agent;
and step three, mixing the cementing material and the exciting agent according to the required proportion and uniformly mixing to obtain the alkali slag cement.
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Application publication date: 20210813 |