High-specific-strength hollow glass microsphere for full-ocean-depth use, and preparation method therefor

Abstract

The present invention belongs to the technical field of glass microsphere preparation, and discloses a high-specific-strength hollow glass microsphere for full-ocean-depth use, and a preparation method therefor. The hollow glass microsphere consists of the following components in percentage by mass: 70-80% of SiO2, 1-5% of Al2O3, 8-15% of B2O3, 1-3% of ZnO, 4-10% of Na2O, 0.5-2% of Li2O, 5-10% of CaO, 0.5-2% of SO3, and 0.5-1% of ZrO2, with the balance being 0-1% of R2O3. The hollow glass microsphere obtained in the present invention has a true density of 0.40-0.46 g / cm3, a d(50) particle size of less than or equal to 20 µm, a d(90) particle size of less than or equal to 35 µm, a d(97) particle size of less than or equal to 45 µm, a floating rate of greater than or equal to 99%, a compressive strength of greater than or equal to 110 MPa (10 min), and a breakage rate of less than or equal to 20%. The microsphere has good performance, can be applied at a full ocean depth, and has significant application value.

Description

High specific strength hollow glass microsphere for full depth of sea and preparation method thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of glass microsphere preparation, and particularly relates to a high specific strength hollow glass microsphere for full depth of sea and a preparation method thereof. BACKGROUND

[0002] The hollow glass microsphere is a kind of hollow glass ball with small size, and has the advantages of light weight, heat insulation, sound insulation, high and low temperature resistance, good electric insulation and thermal stability, corrosion resistance and the like. The density thereof is generally 0.10-0.70 g / cm 3 , and the particle size range is generally 5-200 μm. The hollow glass microsphere can be used as a new type of filling material in resin, and is widely applied to deep sea buoyancy material, heat insulation material and the like. The hollow glass microsphere can also be used to produce low-density cement slurry, drilling fluid and the like, so as to solve the problems of deep well cementing and drilling. The hollow glass microsphere can also be used as a special functional material, such as aerospace ablation material, hydrogen storage material, electromagnetic shielding material and the like, and has a wide application prospect.

[0003] When the hollow glass microsphere is applied to the solid buoyancy material, the hollow glass microsphere is combined with other resins, and is prepared into the solid buoyancy material by vacuum pouring and the like. In use, the material will be subjected to loads such as tension, compression, shear, bending and impact. In the deep sea environment, the material will also be subjected to all-around hydrostatic pressure strength (the water pressure increases by 1 MPa for every 100 m increase in water depth). In the actual application process, the deformation rate and water absorption rate of the material after being subjected to the specified hydrostatic pressure for a period of time (such as 24 h) are generally investigated, which requires that the volume damage rate of the hollow glass microsphere under the certain hydrostatic pressure be low. Therefore, only the hollow glass microsphere with high compressive strength can be applied to the field. Therefore, the water hydrostatic pressure strength of the hollow glass microsphere becomes one of the most critical performance indexes in the actual application.

[0004] The water hydrostatic pressure strength is one of the key important indexes for characterizing the performance of the hollow glass microsphere. In the actual application, the volume damage rate of the hollow glass microsphere under the certain water hydrostatic pressure strength is generally used to characterize the water hydrostatic pressure strength. This is because the hollow glass microsphere is a hollow glass ball with hollow structure, and will be perforated and broken under the certain water hydrostatic pressure strength, resulting in the decrease in volume. With the increase in water hydrostatic pressure strength, the damage rate will also gradually increase. According to the different application fields, the acceptance of the damage rate is also different. Generally, the water hydrostatic pressure strength corresponding to the hollow glass microsphere with a damage rate not greater than 20% is taken as the water hydrostatic pressure strength of the sample.

[0005] Hollow glass microsphere research began in the 1950s, and in the 1980s, it was applied in various fields, and domestic hollow glass microsphere research started late, developed from the 1990s, and achieved a breakthrough in 2015, mastered the preparation method of high-performance hollow glass microspheres, but high specific strength hollow glass microspheres for full sea depth are still blank, at present, all countries in the world are developing in the direction of ultra-light, high-strength and ultra-fine, but high specific strength hollow glass microspheres: density in 0.40-0.46g / cm 3 , the water static pressure strength of the sample in 110-120MPa is still blank in the world.

[0006] SUMMARY

[0007] The purpose of the present application is to make up for the deficiency in the prior art that the density of the prepared hollow glass microspheres is 0.40-0.46g / cm 3 , and the water static pressure strength is far from 110MPa, which cannot meet the needs of future space deep-sea major engineering, and to provide a high specific strength hollow glass microsphere for full sea depth and a preparation method thereof.

[0008] The purpose of the present application can be achieved by the following technical solutions:

[0009] A high specific strength hollow glass microsphere for full sea depth, the raw material components include SiO270-80%, Al2O31-5%, B2O38-15%, ZnO 1-3%, Na2O 4-10%, Li2O 0.5-2%, CaO 5-10%, SO30.5-2%, ZrO20.5-1%, and other R2O30-1% by mass percentage.

[0010] Among them, R2O3 is any one or more of Fe2O3, Y2O3, La2O3 and Ce2O3.

[0011] Further, the hollow glass microspheres are composed of the following raw materials by mass percentage: SiO272%, Al2O32%, B2O310%, ZnO 1.8%, Na2O 5%, Li2O 1.5%, CaO 5.8%, SO31%, ZrO20.5%, Fe2O30.3%, Y2O30.1%.

[0012] The present application also provides a preparation method of a high specific strength hollow glass microsphere for full sea depth, comprising the following steps:

[0013] 1) according to the above ratio, each raw material is weighed and mixed uniformly, and then is put into a special cold-top electric smelting furnace for smelting. The cold-top electric smelting furnace only has a melting pool without a clarifying pool, which can reduce the discharge of the foaming agent during glass melting, which is just opposite to the traditional glass smelting furnace provided with a clarifying and homogenizing pool to increase the discharge of bubbles; the smelting temperature is 1550-1650℃, the smelting time is 6-7 hours for one furnace, and the smelted glass liquid is directly connected to a water quenching pool;

[0014] 2) the smelted glass is water quenched, dried, roughly broken, ground and classified, secondarily sintered, collected, pressure-optimized, elutriated, secondarily dried, precisely classified and modified and reinforced to obtain a super-light, super-fine and super-high-pressure hollow glass microsphere.

[0015] Specifically, the specific process of the above step 2) is as follows:

[0016] (1) the broken glass after water quenching is dried at 150-400℃ for 2-4 hours, the dried broken glass is roughly broken into particles of 0.5-1mm, and then is subjected to high-energy grinding, modification and dispersion and classification to obtain suitable glass powder, wherein the particle size of the ground and classified glass powder is controlled to be d(10)≥1.5μm, d(50)=6±2μm and d(90)≤15μm.

[0017] (2) the classified glass powder is sent into a secondary sintering furnace, the furnace has a diameter of 2-3m and is provided with multiple burners to uniformly control the temperature field of the furnace to avoid the phenomenon that the flame of a single burner is not dispersed, the glass powder is not sufficiently sintered and foamed or is over-sintered, which leads to a low yield of the hollow glass microsphere or a high density of the hollow glass microsphere.

[0018] (3) the hollow glass microsphere after secondary sintering is collected, and a water static pressure resisting equipment is used to pre-treat the prepared hollow glass microsphere: the target pressure resisting strength is increased to 40-80MPa in 1-2 hours, and the pressure is maintained for 3-5 hours to remove the hollow glass microspheres with low pressure resisting strength such as eccentricity and multiple cavities.

[0019] (4) the pressure-optimized hollow glass microspheres are elutriated by using the buoyancy of water, the solid glass microspheres, the broken hollow glass microsphere fragments and part of the hollow glass microspheres with a density greater than 1.0g / cm 3 sink to the bottom of the water, and the hollow glass microspheres floating on the water surface are collected.

[0020] (5) the elutriated hollow glass microspheres are filtered, dried and precisely classified by using an air flow sieve, and the particle size is controlled to be d(50)≤20μm, d(90)≤35μm and d(97)≤45μm.

[0021] (6) the silane coupling agent is mixed with anhydrous ethanol in a ratio of 1:1, stirred for 10-30 minutes, and then slowly dripped into the hollow glass bead dry modification stirrer, the mass ratio of the silane coupling agent to the hollow glass bead is 1:500-1:1000, the temperature is controlled at 60-80 DEG C, and the time is controlled at 1-2 hours, so as to realize the surface of the hollow glass bead coated with a layer of silane coupling agent, and the effect of modification and enhancement is achieved.

[0022] In the application, B2O3 is a glass forming oxide, can play a role of fluxing, reduce the melting temperature of the glass, accelerate the melting of the glass, inhibit the excessive rise of the thermal expansion coefficient of the glass, and improve the thermal stability and chemical stability of the glass;

[0023] ZnO is used to reduce the softening point of the glass, and adjust the thermal expansion coefficient to a suitable range, so as to ensure the acid resistance of the glass powder;

[0024] SiO2 is the main component of forming glass silicon oxygen tetrahedron and connecting to constitute the glass network structure, can reduce the thermal expansion coefficient of the glass, improve the thermal stability, chemical stability, hardness and mechanical strength of the glass, and is a necessary component to obtain high acid resistance, when the content of SiO2 is too large, the melting temperature of the glass will be increased, and crystallization may be caused;

[0025] Al2O3 can reduce the crystallization tendency of the glass, improve the chemical stability, thermal stability, mechanical strength and hardness of the glass, and in the case that the content of alkali metal in the glass is relatively large and the network fracture is relatively serious, the intermediate oxide (such as Al2O3) is added to make the fractured silicon oxygen tetrahedron re-connect and make the structure of the glass more stable;

[0026] ZrO2 can improve the hardness and chemical stability of the glass, and reduce the thermal expansion coefficient of the glass;

[0027] Li2O and Na2O can improve the melting property when the glass is melted, and reduce the softening point of the glass;

[0028] The rare earth oxide has a significant effect on improving the bending strength, elastic modulus and strain point of the glass, reduces the brittleness of the glass, greatly increases the fracture toughness, and can reduce the high temperature viscosity of the glass.

[0029] The beneficial effects of the application are as follows:

[0030] The full-sea-depth high specific strength hollow glass bead of the application is ultra-light, high-strength and ultra-fine, the true density is 0.40-0.46 g / cm 3 , the particle size distribution d(50) is ≤20 μm, d(90) is ≤35 μm, d(97) is ≤45 μm, the floating rate is ≥99%, and the hydrostatic pressure strength is 110-120 MPa, and the performance is far superior to similar products at home and abroad. Attached Figure Description

[0031] The invention will now be further described with reference to the accompanying drawings.

[0032] Figure 1 is a microscope image of the high specific strength hollow glass microspheres for full ocean depth prepared in Example 1. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] (1) Weigh the raw materials according to the following mass percentages: SiO2 72%, Al2O3 2%, B2O3 10%, ZnO 1.8%, Na2O 5%, Li2O 1.5%, CaO 5.8%, SO3 1%, ZrO2 0.5%, Fe2O3 0.3%, Y2O3 0.1%; Weigh the raw materials according to the above proportions, mix them evenly, and put them into a specially cooled top electric melting furnace for melting. There is only a melting pool and no refining pool, which reduces the discharge of foaming agent during glass melting. This is the opposite of the traditional glass melting furnace which has a refining and homogenizing pool to increase the discharge of bubbles. The melting temperature is 1600℃, and the melting time is 7 hours to produce one batch of material. The melted glass is directly connected to the water quenching pool.

[0036] (2) The water-quenched glass was dried at 200℃ for 2.5 hours. The dried glass was coarsely crushed into 0.5-1mm particles, and then crushed, modified, dispersed and classified by a high-energy mill to obtain suitable glass powder. The particle size of the glass powder after grinding and classification was controlled at d(10)≥1.5μm, d(50)=6±2μm, and d(90)≤15μm.

[0037] (3) The graded glass powder is fed into a secondary sintering furnace with a furnace diameter of 2.1m and three burners at the bottom. The furnace temperature field is uniformly controlled to avoid the flame of a single burner furnace not being dispersed. The fully dispersed glass particles are in a molten state and spheroidize under the action of surface tension. At the same time, during the spheroidization process, the gas dissolved in the glass is released. After rapid cooling and collection, hollow glass microspheres are obtained.

[0038] (4) Collect the glass microspheres after secondary sintering, and use a water-resistant isostatic pressing device to pre-treat the prepared hollow glass microspheres: 2 hours, up to a target compression strength of 60 MPa, and keep pressure for 3 hours, to remove hollow glass microspheres with low compression strength due to eccentricity, multiple cavities, etc.;

[0039] (5) The glass microspheres after compression optimization are floated and selected by using the buoyancy of water, and the solid glass microspheres, the broken hollow glass microsphere fragments after compression, and part of the hollow glass microspheres with a density greater than 1.0 g / cm 3 sink to the bottom of the water, and the hollow glass microspheres floating on the water surface are obtained;

[0040] (6) The hollow glass microspheres after floating and selection are filtered, dried, and precisely graded by using an air flow sieve, with a particle size controlled at d(50)≤20 μm, d(90)≤35 μm, and d(97)≤45 μm;

[0041] (7) KH560 is mixed with anhydrous ethanol at a ratio of 1:1, stirred for 30 minutes, and then slowly dripped into a hollow glass microsphere dry modification stirrer, with a mass ratio of KH560 to hollow glass microspheres of 1:600, a temperature controlled at 80°C, and a time controlled at 1.5 hours, so as to realize the coating of a layer of KH560 on the surface of the hollow glass microspheres, and achieve the effect of modification and enhancement.

[0042] As shown in FIG. 1, it is a microscope image of the hollow glass microspheres prepared in the embodiment.

[0043] Comparative Example 1

[0044] (1) The raw materials SiO272%, Al2O32%, B2O310%, ZnO 1.8%, Na2O 5%, Li2O 1.5%, CaO 5.8%, SO31%, ZrO20.5%, Fe2O30.3%, and Y2O30.1% are weighed according to the mass percentage, mixed uniformly, and put into a traditional crucible kiln for melting, with a melting temperature of 1600°C and a melting time of 7 hours for one furnace charge, and the melted glass liquid is directly connected to a water quenching pool;

[0045] (2) The broken glass after water quenching is dried at 200°C for 2.5 hours, the dried broken glass is coarsely broken into particles of 0.5-1 mm, and then high-energy grinding, modification dispersion, and grading are performed to obtain suitable glass powder, with a particle size of the ground and graded glass powder controlled at d(10)≥1.5 μm, d(50)=6±2 μm, and d(90)≤15 μm;

[0046] (3) The graded glass powder is sent into a traditional single-burner hollow-spheroidizing furnace for reheating. At this time, the glass particles in a molten state are spheroidized under the action of surface tension. In the process of spheroidization, the gas originally dissolved in the glass is released due to changes in temperature, pressure and atmosphere, and is collected after rapid cooling, thereby obtaining the hollow glass microsphere product;

[0047] (4) The hollow-spheroidized glass microspheres are collected, and an anti-water static pressure device is used to pretreat the prepared hollow glass microspheres against pressure: 2 hours are used to increase the target anti-pressure strength to 60 MPa, and 3 hours are used for pressure keeping, so as to exclude hollow glass microspheres with low anti-pressure strength such as eccentricity and multiple cavities;

[0048] (5) The glass microspheres after anti-pressure optimization are floated and selected by using the buoyancy of water. The solid glass microspheres, the broken hollow glass microsphere fragments and part of the hollow glass microspheres with a density greater than 1.0 g / cm 3 sink to the bottom of the water, and the hollow glass microspheres floating on the water surface are obtained;

[0049] (6) The floated and selected hollow glass microspheres are filtered, dried and precisely graded by using an air flow sieve, so as to control the particle size to be d(50)≤20 μm, d(90)≤35 μm and d(97)≤45 μm;

[0050] (7) KH560 is mixed with anhydrous ethanol at a ratio of 1:1, stirred for 30 minutes, then slowly dripped into a hollow glass microsphere dry modification stirrer, the mass ratio of KH560 to hollow glass microspheres is 1:600, the temperature is controlled at 80℃, and the time is controlled at 1.5 hours, so as to realize the coating of a layer of KH560 on the surface of the hollow glass microspheres, thereby achieving the effect of modification and enhancement.

[0051] Comparative Example 2

[0052] (1) The raw materials are weighed according to the following mass percentage: SiO272%, Al2O32%, B2O310%, ZnO 1.8%, Na2O 5%, Li2O 1.5%, CaO 5.8%, SO31%, ZrO20.5%, Fe2O30.3%, Y2O30.1%; the raw materials are weighed according to the above ratio, mixed uniformly, and put into a specially designed cold-top electric melting furnace for melting. Only a melting pool is provided without a clarifying pool, which reduces the release of the foaming agent during glass melting, and is just opposite to the traditional glass melting furnace provided with a clarifying and homogenizing pool to increase the release of bubbles. The melting temperature is 1600℃, the melting time is 7 hours for one furnace, and the molten glass liquid is directly connected to a water quenching pool;

[0053] (2) The water-quenched cullet is dried at 200°C for 2.5 hours, the dried cullet is roughly broken into 0.5-1mm particles, and then the glass powder is obtained by high-energy grinding, modification dispersion, and grading, with the particle size of the ground and graded glass powder controlled at d(10)≥1.5μm, d(50)=6±2μm, and d(90)≤15μm;

[0054] (3) The graded glass powder is fed into a secondary sintering furnace with a hearth diameter of 2.1m and three burners arranged below the hearth to uniformly control the temperature field of the hearth, so as to avoid the dispersion of the flame of a single burner, and the glass particles in a molten state are spheroidized under the action of surface tension, and at the same time, the gas dissolved in the glass is released in the process of spheroidization, and the hollow glass microspheres are obtained by rapid cooling, collection, and drying.

[0055] The same glass batch is used in the above embodiment and two comparative examples, and the glass is melted in different furnaces and sintered in different secondary sintering furnaces. The difference lies in that the glass is melted in the cold-top electric melting furnace specially made according to the application in Example 1, the secondary sintering furnace with a large hearth and multiple burners, and the hollow glass microspheres with high specific strength for full sea depth are obtained by compression optimization, precise grading, and modification enhancement, as shown in FIG. 1; the glass is melted in the traditional crucible furnace in Comparative Example 1, the hollow spheroidization furnace with a single burner, and the hollow glass microspheres are obtained by compression optimization, precise grading, and modification enhancement; the glass is melted in the cold-top electric melting furnace specially made according to the application in Comparative Example 2, the secondary sintering furnace with a large hearth and multiple burners, and the hollow glass microspheres are obtained by rapid cooling, collection, and drying, but without compression optimization, precise grading, and modification enhancement, as shown in Table 1. It can be seen that the hollow glass microspheres with high specific strength for full sea depth and the preparation method thereof can fully meet the requirements of future space deep-sea major projects in terms of density, hydrostatic strength, and other performance indicators.

[0056] Table 1: Effect comparison of examples and comparative examples

[0057] The above content is only an example and description of the application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific embodiments, as long as they do not deviate from the application or exceed the scope defined by the present claims, and they should belong to the protection scope of the application.

Claims

1. A hollow glass microsphere having high specific strength for full ocean depth, characterized by, The raw material components include SiO270-80%, Al2O31-5%, B2O38-15%, ZnO 1-3%, Na2O 4-10%, Li2O 0.5-2%, CaO 5-10%, SO30.5-2%, ZrO20.5-1%, and other R2O30-1% by mass percentage. R2O3 is any one or more of Fe2O3, Y2O3, La2O3, and Ce2O3.

2. The high specific strength hollow glass microsphere for full depth of sea according to claim 1, characterized in that, The hollow glass microbeads are composed of the following raw materials by mass percentage: SiO272%, Al2O32%, B2O310%, ZnO 1.8%, Na2O 5%, Li2O 1.5%, CaO 5.8%, SO31%, ZrO20.5%, Fe2O30.3%, and Y2O30.1%.

3. The method for preparing high specific strength hollow glass microspheres for full ocean depth according to any one of claims 1-2, characterized in that, The method comprises the following steps: 1) The raw materials are weighed according to the above-mentioned proportions, mixed uniformly, and put into a specially-made cold-top electric melting furnace for melting, the cold-top electric melting furnace has only a melting pool but no clarifying pool, the melting temperature is 1550-1650°C, the melting time is 6-7 hours for one furnace, and the melted glass liquid is directly connected to a water quenching pool; 2) The melted glass is water quenched, dried, roughly broken, ground and classified, secondarily sintered, collected, pressure-resistant selected, elutriated, secondarily dried, precisely classified, and modified and reinforced to obtain a super-light, super-fine, and super-high-pressure hollow glass microbead.

4. The method according to claim 3, wherein the hollow glass microspheres have a specific gravity of 0.3 to 0.

6. The process of step 2) is specifically as follows: (1) The broken glass after water quenching is dried at 150-400°C for 2-4 hours, the dried broken glass is roughly broken into 0.5-1mm particles, and then the particles are subjected to high-energy grinding, modification and dispersion, and classification to obtain suitable glass powder; (2) The classified glass powder is sent into a secondary sintering furnace, the furnace has a diameter of 2-3m and is provided with multiple burners for uniformly controlling the temperature field of the furnace; (3) The glass microbeads after secondary sintering are collected, and the prepared hollow glass microbeads are subjected to pressure-resistant pretreatment by using a water-resistant isostatic pressing device; (4) The anti-pressing preferred glass microbeads are floated and selected by the buoyancy of water. The solid glass microbeads, the broken hollow glass microbead fragments and the hollow glass microbeads with the density greater than 1.0 g / cm 3 are all sunk to the bottom of water, and the hollow glass microbeads floating on the water surface are obtained. (5) The elutriated hollow glass microbeads are filtered, dried, and precisely classified by using an air flow screen; (6) A layer of silane coupling agent is coated on the surface of the hollow glass microbeads.

5. The method of claim 4, wherein the hollow glass microspheres have a specific gravity of 0.40 or less. In step (1), the particle size of the glass powder after grinding and classification is controlled to be d(10)≥1.5μm, d(50)=6±2μm, and d(90)≤15μm.

6. The method of claim 4, wherein the hollow glass microspheres have a specific gravity of 0.40 or less. In step (3), the time is 1-2 hours, the target pressure strength is increased to 40-80MPa, and the pressure is maintained for 3-5 hours to remove the hollow glass microbeads with low pressure strength.

7. The method according to claim 4, wherein the hollow glass microspheres have a specific gravity of 0.40 or less. In step (5), the particle size of the precisely classified glass microbeads is controlled to be d(50)≤20μm, d(90)≤35μm, and d(97)≤45μm.

8. The method according to claim 4, wherein the hollow glass microspheres have a specific gravity of 0.40 or less. In step (6), the specific operation is as follows: the silane coupling agent and anhydrous ethanol are mixed at a ratio of 1:1, stirred for 10-30 minutes, then slowly dripped into a dry modification stirrer of the hollow glass microbeads, the mass ratio of the silane coupling agent to the hollow glass microbeads is 1:500-1:1000, the temperature is controlled to be 60-80°C, and the time is controlled to be 1-2 hours, so that a layer of silane coupling agent is coated on the surface of the hollow glass microbeads to play a role of modification and reinforcement.

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