CN113979716B - Preparation method of magnesium oxysulfate cementing material adopting silicon dioxide aerogel and building component - Google Patents

Abstract

The invention provides a magnesium oxysulfide cementitious material using silica aerogel, a preparation method and a building component. The magnesium oxysulfide gelling material using silica aerogel of the present invention includes A component and B component, wherein: A component includes 1 part of magnesium sulfate heptahydrate, 8 to 12 parts of light-burned magnesium oxide in molar ratio and 15~22 parts of water, and the content of active magnesium oxide in lightly burned magnesium oxide is 55%~65%; B component includes modifier and aerogel; modifier is citric acid, tartaric acid and sodium malate. One, or a mixture of citric acid and tartaric acid, citric acid is 0.7% to 0.8% of the mass of light-burned magnesium oxide, tartaric acid and sodium malate are both 1.3% to 1.8% of the mass of light-burned magnesium oxide; Less than 6% of the mass of calcined magnesium oxide. The magnesium oxysulfide cementitious material using silica aerogel of the present invention helps to improve the mechanical properties and thermal insulation performance of the magnesium oxysulfide cementitious building materials.

Description

Preparation method and building of magnesium oxysulfide cementitious material using silica aerogel member

technical field

The invention relates to the technical field of building materials, in particular to a preparation method of a magnesium oxysulfide gelling material using silica aerogel. In addition, the present invention also relates to a building element.

Background technique

As a new type of building material, magnesium oxysulfide cementitious material is mainly made of light-burned magnesium oxide and magnesium sulfate heptahydrate solution. It has the properties of light weight, good volume stability, high flexural strength, fire resistance, thermal insulation and other properties. Applications are becoming more and more widespread. The difference of various components will have a significant impact on the performance of the magnesium oxysulfide cementitious material; and when preparing the magnesium oxysulfide cementitious material, due to the different molar proportions of the raw materials and the amount of chemical reagents added, the obtained sulfur The physical properties of the oxymagnesium cementitious material will change, and the magnesium oxysulfide cementitious material prepared by the existing preparation method has high thermal conductivity, and low physical properties such as flexural resistance, compression resistance, softening coefficient and the like.

Aerogel is a form of solid matter, the least dense solid in the world. There are many types of aerogels, including silicon-based, carbon-based, sulfur-based, metal oxide-based or metal-based, etc. The most common is silicon aerogel. Since the fine nano-network structure of silica aerogel effectively limits the propagation of localized thermal excitation, its solid-state thermal conductivity is 2-3 orders of magnitude lower than the corresponding glassy materials, and it is the solid-state material with the lowest thermal conductivity. Become a new type of thermal insulation material. Because the aerogel material is a new type of nanomaterial, it has a porous network skeleton structure, a large specific surface area, and the internal density of the material is extremely low because more than 90% of the volume is air, which leads to thermal conductivity. The coefficient is extremely low, and aerogel has the advantages of green energy saving and light weight when used as a building engineering material.

With the rapid development of my country's economy, the demand for building materials is becoming more and more strong. Due to the serious pollution and high energy consumption of traditional building materials, there is a stronger demand for new building materials according to the requirements of resource conservation and environmental friendliness. Magnesium cementitious materials are known as "green engineering building materials in the 21st century", as a new type of green composite material with good thermal insulation effect.

However, in the preparation of the existing magnesium oxysulfide cementitious materials, there is a lack of methods and related researches for adding aerogels; this leads to insufficient thermal insulation and thermal insulation formation of the existing magnesium oxysulfide cementitious materials. Adding aerogel to the cementitious material will easily lead to the weakening of the mechanical properties of the material. Therefore, it is necessary to conduct in-depth research on the addition process of aerogel and related modifiers in the magnesium oxysulfide cementitious material.

SUMMARY OF THE INVENTION

In view of this, the present invention aims to provide a preparation method of a magnesium oxysulfide cementitious material using silica aerogel, so as to improve the mechanical properties and thermal insulation properties of the magnesium oxysulfide cementitious building materials.

In order to achieve the above object, the technical scheme of the present invention is achieved in this way:

A magnesium oxysulfide cementitious material using silica aerogel, comprising A component and B component, wherein:

The A component comprises 1 part of magnesium sulfate heptahydrate, 8 to 12 parts of light-burned magnesium oxide and 15 to 22 parts of water in molar ratio, and the content of active magnesium oxide in the light-burned magnesium oxide is 55% to 65%;

The B component includes a modifier and aerogel; the modifier is one of citric acid, tartaric acid and sodium malate, or a mixture of citric acid and tartaric acid, and the citric acid is light-burned magnesium oxide quality 0.7%～0.8% of the tartaric acid and the sodium malate are 1.3%～1.8% of the quality of light-burned magnesia; and the aerogel is less than 6% of the quality of light-burned magnesia.

Further, the aerogel adopts silica aerogel.

Further, the content of the citric acid is 0.75% of the quality of the light-burned magnesium oxide, and the content of the tartaric acid and the sodium malate are both 1.5% of the quality of the light-burned magnesium oxide.

Further, the content of the active magnesium oxide in the light-burned magnesium oxide is 57.8%.

Compared with the prior art, the present invention has the following advantages:

The material studied in the present invention takes magnesium oxysulfide gelling material as the main raw material, and then adds silica aerogel to form magnesium oxysulfide composite gelling material, and simultaneously adds different modifiers to change the properties. The material will have performance characteristics such as light weight, thermal insulation and low thermal conductivity under constant temperature and humidity conditions.

In addition, by incorporating silica aerogel, the thermal insulation performance of magnesium oxysulfide cementitious materials can be improved; the incorporation of silica aerogel can improve the thermal insulation performance of magnesium oxysulfide cementitious materials. At the same time, by setting a reasonable and quantitative amount of silica aerogel, the flexural strength, compressive strength and water resistance of the composite material can maintain the performance of the magnesium oxysulfide cementitious material to a certain extent, so it can be used for The improvement of thermal insulation performance of magnesium oxysulfide material provides a good foundation.

Another object of the present invention is to propose a preparation method, which is used for the preparation of the magnesium oxysulfide cementitious material using silica aerogel of the present invention, and comprises the following steps:

s1. According to proportioning, magnesium sulfate heptahydrate and water are mixed into magnesium sulfate heptahydrate solution, and modifier and aerogel are poured into this magnesium sulfate heptahydrate solution and fully stirred to generate mixed solution;

s2. Add the light-burned magnesium oxide required by the ratio into the mixed solution, and fully stir to form a slurry with uniform viscosity;

s3. inject the slurry into a mold coated with a release agent, remove air bubbles in the slurry, and cure the slurry in an environment with a temperature of 20° C.-30° C. and a humidity of 60%-70% for 22 to 26 hours. Demoulding to obtain semi-finished products;

s4. The finished product is obtained after curing the semi-finished product in an environment with a temperature of 20°C-30°C and a humidity of 60%-70% for 7 days.

Further, the mold is a cast iron mold, and the mold release agent is paraffin or oil.

Further, in step s3, the air bubbles in the slurry are removed by shaking, and the surface of the slurry in the mold is scraped and rolled.

Further, in step s3, the ambient temperature of the curing reaction is 25°C, the humidity is 65%, and the reaction time is 24 hours; in step s5, the ambient temperature for curing is 25°C, and the humidity is 65%.

Further, the light-burned magnesia powder is light-burned magnesia powder.

Compared with the prior art, the present invention has the following advantages:

The present invention adopts the above-mentioned preparation method, which is not only convenient for operation and implementation in construction, but also can generate magnesium oxysulfide cementitious materials with excellent mechanical properties and thermal insulation properties. Using the prepared magnesium oxysulfide cementitious material in partition walls or plug-in buildings can improve the thermal insulation performance of the magnesium oxysulfide cementitious material, and can make full use of the high mechanical strength and water resistance of the magnesium oxysulfide cementitious material. It has the characteristics of good performance and long service life; thereby improving the performance of wall insulation and building, it has good economic and social significance.

In addition, the present invention also proposes a building component, which adopts the magnesium oxysulfide cementitious material of the present invention using silica aerogel, and is prepared by the above-mentioned preparation method. The building component of the present invention has the technical advantages of the above-mentioned magnesium oxysulfide cementitious material of silica aerogel.

Description of drawings

The accompanying drawings that form a part of the present invention are used to provide a further understanding of the present invention, the schematic embodiments of the present invention and their descriptions are used to explain the present invention, and the azimuth words such as front and rear, upper and lower, etc. involved are only used to indicate The relative positional relationship does not constitute an improper limitation of the present invention. In the attached image:

Fig. 1 is the preparation flow chart of the preparation method of the magnesium oxysulfide gelation using silica aerogel according to the second embodiment of the present invention;

Fig. 2 is the electron microscope scanning diagram of the citric acid-modified magnesium oxysulfide cementitious material described in Example 2 of the present invention;

Fig. 3 is the scanning electron microscope view of the tartaric acid-modified magnesium oxysulfide cementitious material described in the second embodiment of the present invention;

FIG. 4 is a scanning electron microscope view of the magnesium oxysulfide gelled composite material of the silica aerogel according to the second embodiment of the present invention.

Detailed ways

It should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other under the condition of no conflict.

The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

Example 1

This embodiment relates to a magnesium oxysulfide cementitious material using silica aerogel, which helps to improve the mechanical properties and thermal insulation properties of the magnesium oxysulfide cementitious building material. The magnesium oxysulfide gel using silica aerogel includes A component and B component, wherein:

The molar ratio of component A includes 1 part of magnesium sulfate heptahydrate, 8-12 parts of light-burned magnesium oxide and 15-22 parts of water; and the content of active magnesium oxide in the light-burned magnesium oxide is 55% to 65% .

The B component includes modifiers and aerogels. Among them, the modifier is one of citric acid, tartaric acid and sodium malate, or a mixture of citric acid and tartaric acid; the dosage of various modifiers is: citric acid is 0.7%~0.8% of the mass of light-burned magnesium oxide , tartaric acid and sodium malate are 1.3%~1.8% of the mass of light-burned magnesium oxide. The dosage of aerogel is less than 6% of the mass of light-burned magnesium oxide.

Based on the above-mentioned overall proportioning principle, the aerogel preferably adopts silica aerogel. The preferred dosage of each modifier is: the content of citric acid is 0.75% of the mass of light-burned magnesia, and the content of tartaric acid and sodium malate are both 1.5% of the mass of light-burned magnesia. Meanwhile, the content of active magnesia in the light-burned magnesia is preferably about 57.8%.

In the preparation of the above-mentioned aerogel magnesium oxysulfide gelling material, the silica aerogel can be obtained from the aerogel manufacturer. Aerogel has low thermal conductivity, good thermal insulation performance, low density, lightweight material, and energy saving.

As a preferred setting, among the preparation components of the above-mentioned magnesium oxysulfide cementitious material, the light-burned magnesium oxide in this embodiment adopts a purity of 80%-85%, an activity of 55%-65%, and a fineness of 200 mesh. A commercially available product can be used; for example, a commercially available 200-mesh light-burned magnesia product with a purity of 83% and an activity of 60% is used. When the magnesium sulfate heptahydrate and water of the present embodiment prepare the magnesium sulfate heptahydrate solution, preferably the magnesium sulfate heptahydrate with a purity of 95%-99% is used.

In the preparation of magnesium oxysulfide gelation, the selection of the modifier can be one of tartaric acid, citric acid and sodium malate, or a mixture of the two modifiers of tartaric acid and citric acid. At the same time, as a preferred example of the composition of the modifier of the present embodiment, in the modifier, the content of citric acid is 0.75% of the quality of the light-burned magnesium oxide powder, and the content of tartaric acid is the light-burned magnesium oxide powder. 1.5% of the mass, and the content of sodium malate is 1.5% of the mass of the light-burned magnesia powder. In the specific preparation of the modifier, the mixture of tartaric acid, citric acid, sodium malate and citric acid and tartaric acid can be fully mixed with the magnesium sulfate heptahydrate solution by stirring and mixing.

In this embodiment, the content of the silica aerogel is less than 6% of the mass of the light-burned magnesia powder, for example, it can be 1%, 2%, 4%, or 6%. In the specific preparation of the aerogel, the silica aerogel is fully mixed with the modifier and the magnesium sulfate heptahydrate solution by stirring and mixing.

It should be noted that, the specific contents of the above-mentioned components in the magnesium oxysulfide cementitious material of the present embodiment can be adaptively selected in practical applications, as long as they meet the requirements of the overall weight ratio composition.

The magnesium oxysulfide cementitious material of the silica aerogel of this embodiment uses the magnesium oxysulfide cementitious material as the main raw material, and then adds silica aerogel to form the magnesium oxysulfide composite cementitious material. By adding different modifiers to change the properties, the composite material will have the performance characteristics of light weight, thermal insulation and low thermal conductivity under constant temperature and humidity conditions. The incorporation of silica aerogel can improve the thermal insulation performance of magnesium oxysulfide cementitious materials, and at the same time, by setting a reasonable and quantitative amount of silica aerogel, the flexural strength, The compressive strength and water resistance can maintain the properties of the magnesium oxysulfide cementitious material to a certain extent, so it can provide a good foundation for the improvement of the thermal insulation performance of the magnesium oxysulfide material.

Embodiment 2

The present embodiment relates to a preparation method of a magnesium oxysulfide cementitious material using silica aerogel and a building component, which are convenient for operation and implementation in construction, and can both generate oxysulfide with excellent mechanical properties and thermal insulation properties. Magnesium cementitious material.

The method is used for the preparation of the magnesium oxysulfide gelling material using silica aerogel provided in Example 1, and includes the following steps:

s1. According to proportioning, magnesium sulfate heptahydrate and water are mixed into magnesium sulfate heptahydrate solution, and modifier and aerogel are poured into this magnesium sulfate heptahydrate solution and fully stirred to generate mixed solution;

s2. Add the light-burned magnesium oxide required by the ratio into the mixed solution, and fully stir to form a slurry with uniform viscosity;

s3. Inject the slurry into the mold coated with the release agent, remove the bubbles in the slurry, cure and react for 22 to 26 hours in an environment with a temperature of 20°C-30°C and a humidity of 60%-70%, and then release the mold to obtain semi-finished products;

s4. After curing the semi-finished product for 7 days in an environment with a temperature of 20°C-30°C and a humidity of 60%-70%, the finished product is obtained.

Based on the above-mentioned overall preparation process requirements, the following specific operation forms can be used in the preparation of magnesium oxysulfide gel.

First, the mold is prepared and a layer of release agent is applied to the mold. For example, use a triple cast iron mold with a size of 40mm x 40mm x 160mm; the release agent can be paraffin or oil.

After that, prepare the required raw materials of various components; wherein, the light-burned magnesium oxide is preferably light-burned magnesium oxide powder; and the magnesium oxide active hydration detection method is used to detect the activity of the light-burned magnesium oxide to ensure the activity of the light-burned magnesium oxide. The content of magnesium oxide meets the requirements. Weigh active magnesium oxide, magnesium sulfate heptahydrate, citric acid, tartaric acid, sodium malate and aerogel respectively, and weigh the corresponding proportion of water.

After that, the dissolving operation is performed. The magnesium sulfate heptahydrate is fully stirred and dissolved in water at room temperature to form a magnesium sulfate solution (that is, a magnesium sulfate heptahydrate solution). First, a certain modifier is poured into the magnesium sulfate solution and stirred at a slow speed to form a mixed solution. Mechanical and other properties are measured, and then silica aerogel is added and thermal conductivity is measured to ensure that the material meets the mechanical and thermal performance requirements required by the building.

According to the different types of aerogels and modifiers added to the magnesium sulfate solution, as well as the different amounts of aerogels added, various types of mixed solutions can be generated. For example, the modifier uses citric acid, tartaric acid, sodium malate or a mixture of citric acid and tartaric acid, and the amount of the added aerogel can be 1%, 2%, 6%, etc. of the mass of the light-burned magnesium oxide powder. In this way, many different mixed solutions can be formed.

For example, a certain mass of light-burned magnesium oxide powder is poured into the mixed solution generated by mixing magnesium sulfate solution with different modifiers such as citric acid, tartaric acid or sodium malate, and the mixture is fully stirred with a stirrer at room temperature. Three kinds of slurries A, B, and C were respectively formed (the three groups of example products in the following Example 1 adopted these three kinds of slurries). Pour a certain mass of light-burned magnesium oxide powder into a solution of citric acid and a mixture of citric acid and tartaric acid, respectively, and add them to the mixed solution containing silica aerogel, and stir them at room temperature with a stirrer. The three types of slurries, D and E, were formed by fully stirring them (the two groups of example products in the following Example 2 used these three types of slurries). . The above-mentioned slurries need to be fully stirred until the viscosity is uniform. Different slurries have certain differences in mechanical properties and thermal insulation properties, and can be flexibly adjusted and selected according to the performance needs of the building frame.

After completing the preparation of the slurry, inject it into the mold, wait for 24 hours for curing and molding to demould, and obtain a semi-finished product; then put it into a constant temperature and humidity curing box for 7 days and 28 days of curing, and then the finished product can be obtained. When the mould is placed on the building frame, the finished product forms the building element of the building.

It should be pointed out that after the above-mentioned slurry is injected, the air bubbles in the slurry should be removed by means of vibration, etc., and the surface of the slurry in the mold should be scraped and rolled.

Meanwhile, preferably, the ambient temperature of the curing reaction is 25°C, the humidity is 65%, and the reaction time is 24 hours; in step s5, the ambient temperature for curing is 25°C, and the humidity is 65%.

Through the above preparation method, magnesium oxysulfide gel with good mechanical properties and thermal insulation properties can be obtained. The above preparation method is not only convenient for operation and implementation in construction, but also can generate magnesium oxysulfide cementitious materials with excellent mechanical properties and thermal insulation properties. Using the prepared magnesium oxysulfide cementitious material in partition walls or plug-in buildings can improve the thermal insulation performance of the magnesium oxysulfide cementitious material, and can make full use of the high mechanical strength and water resistance of the magnesium oxysulfide cementitious material. It has the characteristics of good performance and long service life; thereby improving the performance of wall insulation and building, it has good economic and social significance.

In addition, the present invention also proposes a building component, which is prepared by the above-mentioned preparation method using the magnesium oxysulfide gel of the present invention using silica aerogel. The building component of the present invention has the technical advantages of the above-mentioned magnesium oxysulfide cementitious material of silica aerogel.

Hereinafter, the preparation method of this embodiment will be further elaborated with reference to specific examples and comparative examples, and the related properties of the manufactured products will be tested and inspected.

[Example 2.1]

The magnesium oxysulfide cementing material of the present embodiment adopts the following ratio: wherein the molar ratio of lightly burned magnesium oxide powder, magnesium sulfate heptahydrate, and water is 10:1:18, and the active magnesium oxide in the lightly burned magnesium oxide powder is 10:1:18. The content is 57.8%. The modifier adopts citric acid, tartaric acid and sodium malate to carry out respectively, and form three groups of embodiment products; wherein, the content of citric acid is 0.75% of the quality of light-burned magnesia powder, forming group 1 product; the content of tartaric acid is light 1.5% of the mass of the calcined magnesia powder forms group 2 products; the content of sodium malate is 1.5% of the mass of the light calcined magnesia powder to form group 3 products.

In this example, the glass fiber magnesia cementitious material wave tile and ridge tile (JC/T747-2002) can be used as the testing standard, and the flexural strength, compressive strength, and thermal conductivity are measured after curing for 28 days, and the softening coefficient is measured after immersion in water for 7 days. , respectively carry out the test of three groups of embodiment products.

According to the aforementioned preparation steps, the magnesium oxysulfide cementitious material of the present embodiment is obtained, and the ambient temperature of the curing reaction is 25°C, the humidity is 65%, and the reaction time is 24 hours; the ambient temperature for curing is 25°C, and the humidity is 65°C %, and the test results are shown in Table 1 below.

Table 1. Test results of the embodiment

The test results in Table 1 show that among the three modifiers used in the present invention, 0.75% citric acid and 1.5% tartaric acid have a large degree of improvement in the strength properties of the magnesium oxysulfide cementitious material. Fig. 2 and Fig. 3 are the scanning electron microscope images of the citric acid and tartaric acid-modified magnesium oxysulfide cementitious materials; it can be seen that the modifiers of citric acid and tartaric acid have an effect on the strength properties of the magnesium oxysulfide aerogel composites. significant impact.

[Example 2.2]

The magnesium oxysulfide cementing material of the present embodiment adopts the following ratio: wherein the molar ratio of lightly burned magnesium oxide powder, magnesium sulfate heptahydrate, and water is 10:1:18, and the active magnesium oxide in the lightly burned magnesium oxide powder is 10:1:18. The content is 57.8%. In this embodiment, the modifiers used are respectively citric acid and a mixture of citric acid and tartaric acid to form two groups of embodiment products; those using a citric acid modifier are group 1 products, and a mixture of citric acid and tartaric acid is used as Modifiers are group 2 products. At the same time, according to the above preparation steps, a quantitative amount of aerogel is added to obtain the magnesium oxysulfide aerogel composite material of this embodiment. Wherein, the content of citric acid is 0.75% of the mass of light-burned magnesia powder, the content of tartaric acid is 1.5% of the mass of light-burned magnesia powder, and the content of aerogel is 1% of the mass of light-burned magnesia powder.

This example also refers to the glass fiber magnesia cementitious material wave tile and ridge tile (JC/T747-2002) as the detection standard, and measures the flexural strength, compressive strength and thermal conductivity after curing for 28 days, and measures the softening coefficient after immersion in water for 7 days. . The above-mentioned two groups of embodiment products are tested, and the test results are shown in Table 2 below.

Table 2. Test results of the embodiment

The test results in Table 2 show that in the present invention, when the content of silica aerogel is the same, with the increase of the type of modifier added, its strength performance is reduced, but its thermal conductivity is reduced, and the thermal insulation effect is increased. ; Figure 4 shows the electron microscope scanning diagram of the magnesium oxysulfide aerogel composite material of this embodiment. It can be seen from the above experiments that the magnesium oxysulfide cementitious material of the present invention can effectively enhance the thermal insulation performance of the magnesium oxysulfide cementitious material by adding different amounts of aerogels on the basis of adding various modifiers.

[Comparative ratio]

On the basis of Example 2.2, this comparative example is based on the modification agent being a mixture of citric acid and tartaric acid, adding 1% and 2% of silica aerogel respectively to complete two groups of magnesium oxysulfide Preparation of gelling material products; those using 1% silica aerogel are group 1 products, and those using 2% silica aerogel are group 2 products. The magnesium oxysulfate cementitious material incorporating different amounts of silica aerogel is made from the following raw materials: light-burned magnesium oxide powder, magnesium sulfate heptahydrate, water, citric acid, tartaric acid, and aerogel, wherein , the molar ratio of light-burned magnesium oxide powder, magnesium sulfate heptahydrate, and water is 10:1:18, and the content of active magnesium oxide in the light-burned magnesium oxide powder is 57.8%, and the content of the citric acid is light-burned oxidation The mass of magnesium powder is 0.75%, the content of tartaric acid is 1.5% of the mass of the light-burned magnesium oxide powder, and the dosage of silica aerogel is 1% and 2% of the mass of the light-burned magnesium oxide powder, respectively.

In this comparative example, when preparing the magnesium oxysulfide cementitious materials incorporating different amounts of silica aerogel, the specific preparation methods mainly include:

First, coat a layer of release agent on the mold, then take the magnesium sulfate solution and modifier, and pour the modifier into the magnesium sulfate solution and stir at a slow speed to form a mixed solution. Next, the light-burned magnesium oxide powder is fully stirred with different mixed solutions to form two groups of slurries F and G with uniform viscosity; the two groups of slurries have different content of silica aerogel.

Then, inject the slurries F and G into the mold respectively to remove air bubbles, and cure and react for 24 hours in an environment with a temperature of 25°C and a humidity of 65%, and then demould to obtain a semi-finished product; The finished product was obtained after curing for 7 days and 28 days in an environment of 25°C and a humidity of 65%.

Wherein, the preparation of the modifier is the same as the above, and the above-mentioned mold release agent can also be paraffin or engine oil, and after injecting the slurry F and G into the mold respectively, it is still selected to vibrate to remove air bubbles, and is scraped and rolled slightly.

In the comparative test of the present invention, JC/T747-2002 is still used as the detection standard, and the flexural strength, compressive strength, softening coefficient and thermal conductivity are used as indicators. The test results are shown in Table 3 below.

Table 3. Test results of two groups of comparative products

As can be seen from the comparison of the above table, the magnesium oxysulfide cementitious material added with 1% of silica aerogel of the present embodiment is compared with the magnesium oxysulfide cementitious material added with 2% of silica aerogel, Its flexural strength, compressive strength and water resistance have decreased, but with the increase of the quality of silica aerogel, the thermal conductivity of the product is decreased, and the thermal insulation effect is increased; therefore, do not mix too much dioxide For silicone aerogels, the potential balance between thermal conductivity and mechanical strength should be considered in specific applications.

Finally, it should be noted that when 1 part of magnesium sulfate heptahydrate is used in a molar ratio, different parts such as 8, 9, 10, 12, etc. can be used for lightly burned magnesia, and 15, 17, 19, 22, etc., are used for water Different parts; the molar ratio of light-burned magnesium oxide powder, magnesium sulfate heptahydrate, and water is about 10:1:18, all of which can meet the requirements of the present invention to improve product mechanics and thermal insulation performance. Similarly, when the content of active magnesium oxide in light-burned magnesium oxide is between 55% and 65%, the purpose of improving product performance can be satisfied; the content can be 55%, 58%, 62%, 65%, or the above 57.8% used in the examples. Citric acid is within the range of 0.7%~0.8% of the mass of light-burned magnesium oxide, and tartaric acid and sodium malate are within the range of 1.3%~1.8% of the mass of light-burned magnesium oxide, which can meet the purpose of improving product performance.

To sum up the above, the preparation method of this embodiment and the building components made thereof are magnesium oxysulfate cementitious materials, and by incorporating a suitable amount of silica aerogel, the product can not only have high thermal insulation performance, but also At the same time, it also takes into account the performance of high strength. When the magnesium oxysulfide aerogel composite material prepared by the preparation method of this embodiment is used as a building component in a building partition wall and a plug-in building, the thermal insulation performance of the wall can be effectively improved, and the Other properties of the wall remain basically unchanged. In this way, while making full use of the characteristics of high mechanical strength, good water resistance and long service life of magnesium oxysulfide cementitious materials, the performance of walls and buildings can be improved, and the good thermal insulation effect of aerogel can also be achieved. Has a good application prospect.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (8)

1. The preparation method of the magnesium oxysulfate cementing material adopting the silica aerogel is characterized by comprising a component A and a component B, wherein:

the component A comprises 1 part of magnesium sulfate heptahydrate, 8-12 parts of light burned magnesium oxide and 15-22 parts of water according to the mol ratio, and the content of active magnesium oxide in the light burned magnesium oxide is 55-65%;

the component B comprises a modifier and aerogel; the modifier is citric acid or a mixture of citric acid and tartaric acid, and the aerogel is silicon dioxide aerogel; the citric acid accounts for 0.7-0.8% of the weight of the light-burned magnesia, and the tartaric acid accounts for 1.3-1.8% of the weight of the light-burned magnesia; the mass of the aerogel is 1-2% of that of the light-burned magnesia; and the number of the first and second electrodes,

the preparation method comprises the following steps:

s1. preparing magnesium sulfate heptahydrate solution from magnesium sulfate heptahydrate and water, pouring modifier and aerogel into the magnesium sulfate heptahydrate solution, and stirring to obtain mixed solution;

s2, adding light calcined magnesia with a proportioning requirement into the mixed solution, and fully stirring to form slurry with uniform viscosity;

s3., injecting the slurry into a mold coated with a release agent, removing bubbles in the slurry, and demolding after curing reaction for 22-26 hours at the temperature of 20-30 ℃ and the humidity of 60-70% to obtain a semi-finished product;

s4. curing the semi-finished product in an environment with the temperature of 20-30 ℃ and the humidity of 60-70% for 7 days to obtain the finished product.

2. The method for preparing a magnesium oxysulfate gel material using silica aerogel according to claim 1, characterized in that: the content of the citric acid is 0.75 percent of the weight of the light calcined magnesia, and the content of the tartaric acid is 1.5 percent of the weight of the light calcined magnesia.

3. The method for preparing a magnesium oxysulfate gel material using silica aerogel according to claim 1, characterized in that: the content of the active magnesium oxide in the light-burned magnesium oxide is 57.8%.

4. The method for preparing magnesium oxysulfate gelling material using silica aerogel according to any of claims 1 to 3, characterized in that: the mold is a cast iron mold, and the release agent is paraffin or engine oil.

5. The method for preparing a magnesium oxysulfate gel material using silica aerogel according to claim 4, characterized in that: in step s3, bubbles in the slurry are removed by vibration, and the surface of the slurry in the mold is scraped and rolled.

6. The method for preparing a magnesium oxysulfate gel material using silica aerogel according to claim 4, characterized in that: in step s3, the ambient temperature of the curing reaction is 25 ℃, the humidity is 65%, and the reaction time is 24 hours; in step s5, the ambient temperature for curing was 25 ℃ and the humidity was 65%.

7. The method for preparing a magnesium oxysulfate gel material using silica aerogel according to claim 4, characterized in that: the light-burned magnesia adopts light-burned magnesia powder.

8. A building component, characterized in that it is prepared by the method of any one of claims 1 to 7 for preparing magnesium oxysulfate gel material using silica aerogel.

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