Method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials

Abstract

This invention discloses a method for preparing hollow glass microsphere precursors using byproducts of hollow glass microsphere production as raw materials. Byproduct A generated during the preparation of the hollow glass microsphere precursor and fine powder (byproduct B) generated during the high-temperature spheroidization process of hollow glass microsphere production are mixed evenly and placed in a square crucible. The mixture is then sintered in a roller kiln or sintering furnace to obtain sintered materials in block or large particle form. The sintered material is then crushed to obtain small particles of 0.5-2 mm. These crushed particles are further pulverized and classified to obtain hollow glass microsphere precursors that meet the requirements for high-temperature hollow spheroidization. This invention features a simple process flow and low energy consumption. It utilizes an air atmosphere for oxidizing atmosphere sintering, eliminating the need for deliberately filling other gases to control the sintering atmosphere, thus effectively controlling the particle size and particle size distribution of the prepared hollow glass microsphere precursors.

Description

Technical Field

[0001] This invention belongs to the field of inorganic new material preparation technology, specifically relating to a method for preparing hollow glass microsphere precursors, which is particularly suitable for the recycling and reuse of by-products in the production process of hollow glass microspheres. Background Technology

[0002] In recent years, with the expanding applications of high-performance hollow glass microspheres in deep-sea buoyancy materials, aerospace, and new energy vehicles, the market demand for both the production volume and product performance of high-performance hollow glass microspheres has increased significantly. Various hollow glass microsphere manufacturers have been developing and optimizing their preparation methods, with currently disclosed methods mainly including solid-phase powder methods and soft chemical methods.

[0003] Solid-phase powder method and soft chemical method both involve the preparation of hollow glass microsphere semi-finished product (precursor) and the high-temperature hollow spheroidization of hollow glass microsphere.

[0004] Patents CN101068753A and CN101704632A both mention that the hollow glass microsphere precursors produced by the solid-phase powder method are mainly prepared through steps such as melting, water quenching, pulverizing, and classification. During the pulverizing and classification processes to collect the precursors of the target particle size, a significant amount of fine powder byproducts will inevitably be generated. Patent CN102583973A mentions that the hollow glass microsphere precursors produced by the soft chemical method are prepared by a spray drying process. During the collection of the precursors of the target particle size, a significant amount of fine powder byproducts will also be generated.

[0005] During the high-temperature hollow spheroidization process of hollow glass microspheres, a large amount of fine powder byproducts that fail to form spheres are generated and collected in the dust removal device.

[0006] Byproduct A, generated during the preparation of hollow glass microsphere precursors, typically has a particle size (D50) of 0.1-5 μm. Its composition is similar to that of general hollow glass microsphere precursors, but due to its extremely fine particle size, it cannot be directly sintered into hollow glass microspheres. It generally accounts for 5%-10% of the precursors, and can even reach 20% when preparing high-end hollow glass microsphere products requiring a narrow particle size distribution. The conventional method is to incorporate it into the raw materials for recycling.

[0007] The fine powder (byproduct B) produced during the high-temperature spheroidization process typically contains 40%-70% B2O3, 10%-50% SiO2, 1%-10% CaO, and 5%-25% NaO. It generally accounts for about 10% of the finished hollow glass microspheres. The conventional treatment method is to mix it back into the raw materials for recycling.

[0008] Byproduct A generated during the preparation of the aforementioned precursors and byproduct B generated during the high-temperature hollow spheroidization process can account for 15%-30% of the total materials in the preparation of hollow glass microspheres. Adding them to the raw materials to carry out the complete product preparation process again not only consumes a lot of energy, but also causes fluctuations in the product formula and affects the product performance.

[0009] To address the aforementioned problems, this invention provides a method for preparing hollow glass microsphere precursors using byproducts from the hollow glass microsphere production process. The method directly utilizes byproducts from the hollow glass microsphere production process for precursor preparation. The prepared precursor has a particle size D50 of 10-40 μm and can be directly hollowed into spheres to produce hollow glass microsphere products with satisfactory performance. Currently, no related patents or literature reports have been found in China. Summary of the Invention

[0010] The purpose of this invention is to address the problem of recycling byproducts generated during the existing hollow glass microsphere preparation process. It provides a method for preparing hollow glass microsphere precursors using these byproducts as raw materials. The prepared precursors have a particle size (D50) of 10-40 μm and can be directly hollowed into spheres to produce hollow glass microsphere products with satisfactory performance. Compared to traditional byproduct recycling methods, this method has advantages such as low energy consumption and simple preparation, and the prepared precursors have controllable particle size and excellent performance.

[0011] To achieve the above-mentioned objectives of the present invention, the method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials is implemented by the following steps;

[0012] 1) Mixing: Byproduct A generated during the preparation of hollow glass microspheres precursor and fine powder-byproduct B generated during the high-temperature spheroidization process of hollow glass microspheres production are mixed evenly;

[0013] The proportions based on 100% of the total mass of raw materials are: By-product A 75%-95%, By-product B 5%-25%;

[0014] The mass percentage of each chemical component in by-product A is as follows: SiO2 60%-80%, Na2O 6%-18%, CaO 5%-14%, B2O3 5%-15%, Al2O3 0%-3%, MgO 0%-3%, ZnO 0%-3%, P2O5 0%-3%, SO3 0%-2%, with the balance being 0-5%. The particle size D50 of by-product A is generally in the range of 0.1-5μm.

[0015] The mass percentage of each chemical component in the by-product B is as follows: B2O3 40%-70%, SiO2 10%-50%, CaO 1%-10%, Na2O 5%-25%, with the balance being 0-5%.

[0016] 2) Sintering: Place the uniformly mixed material from step 1) into a square crucible, and place the square crucible in a roller kiln or sintering furnace for sintering to obtain blocky or large granular sintered material.

[0017] Before placing the square crucible in the roller kiln or sintering furnace for sintering, the material should be compacted in the square crucible as much as possible to increase the amount of material per unit volume and increase the surface contact between by-product A and by-product B.

[0018] 3) Crushing: The sintered material obtained in step 2) is crushed to obtain small particles of 0.5-2mm.

[0019] 4) Crushing and classifying: The small particles crushed in step 3) are crushed and classified to obtain hollow glass microsphere precursors that meet the requirements of high-temperature hollow spheroidization.

[0020] Furthermore, the sintering temperature in step 2) is generally controlled in the range of 300-800℃, with 500-800℃ being the preferred range; the sintering atmosphere is air, and the sintering time is generally 30-360 minutes.

[0021] Furthermore, in step 1), it is preferable to use a VC mixer or a high-speed mixer for mixing.

[0022] Furthermore, in step 3), it is preferable to use a jaw crusher or a double roll crusher, or a combination of jaw crusher and double roll crusher, as the crushing equipment.

[0023] Furthermore, in step 4), the pulverizing equipment adopts air jet milling or a combination of air jet milling and Raymond milling, and in step 4), the classifying equipment adopts cyclone classifier.

[0024] By synergistically controlling the raw material ratio and process parameters of each step, the particle size D50 of the prepared hollow glass microsphere precursor can be in the range of 10-40 μm.

[0025] The hollow glass microsphere precursor prepared by the method of this invention, after subsequent high-temperature hollow spheroidization, can produce hollow glass microsphere products with performance comparable to those of hollow glass microspheres prepared by normal production processes.

[0026] This invention employs a method of mixing byproduct A generated during precursor preparation with byproduct B generated during high-temperature hollow spheroidization. By utilizing the low melting temperature of byproduct B due to its high boron content, byproduct A is regranulated at a relatively low temperature of 300-800℃, ensuring that its particle size meets the requirements for high-temperature hollow spheroidization of hollow glass microspheres. This successfully achieves the recycling of byproducts A and B, and is characterized by low energy consumption and a simple process.

[0027] Compared with the prior art, the method of preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials in this invention has the following beneficial effects after adopting the above technical solution:

[0028] (1) The byproduct A generated during the preparation of the precursor and the byproduct B generated during the high-temperature hollow spheroidization process are directly processed and utilized. Compared with adding them into the raw materials and re-melting or spray drying granulation, the process is simple and the low-temperature sintering granulation process at 300-800℃ has significantly lower energy consumption, which can significantly reduce energy consumption.

[0029] (2) The raw materials only use by-products A and B generated during the production of hollow glass microspheres. The composition is simple, and the low-temperature sintering process is simple to operate, which is very beneficial to the processing operation.

[0030] (3) Using an air atmosphere for oxidizing atmosphere sintering, there is no need to deliberately fill other gases to control the sintering atmosphere. This is low-cost and can remove some impurities in the material that are not required for glass formation.

[0031] (4) This method can effectively control the particle size and particle size distribution of the prepared hollow glass microsphere precursor, and prepare hollow glass microspheres with different densities and particle sizes. Detailed Implementation

[0032] To describe the present invention, the method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials is further described in detail below with reference to embodiments. However, the present invention is not limited to the embodiments. Example 1

[0033] (1) Weigh 95% of by-product A generated during the preparation of the precursor and 5% of by-product B generated during the high-temperature hollow spheroidization process, and mix them thoroughly in a VC mixer.

[0034] (2) The uniformly mixed material is loaded into a square crucible and compacted. It is then placed in a roller kiln for sintering at 800°C for 30 minutes in an air atmosphere. After cooling, it is taken out.

[0035] (3) The above materials are crushed by a jaw crusher to obtain materials with a particle size of 2 mm, and then pulverized and classified by a Raymond mill to obtain hollow glass microsphere precursors with the target particle size.

[0036] (4) The prepared hollow glass microspheres have a particle size D50 of 40 μm and good precursor properties. After subsequent high-temperature hollow spheroidization, hollow glass microspheres with properties comparable to those of hollow glass microspheres prepared by normal production process can be prepared. Example 2

[0037] (1) Weigh 75% of by-product A generated during the preparation of the precursor and 25% of by-product B generated during the high-temperature hollow spheroidization process, and mix them thoroughly in a high-speed mixer.

[0038] (2) The mixed material is loaded into a square crucible and compacted. It is then placed in a sintering furnace for sintering at 300°C for 180 minutes in an air atmosphere. After cooling, it is taken out.

[0039] (3) The above material is crushed by a double roller crusher to obtain a material with a particle size of 0.5 mm. Then, the material is crushed and classified by an air jet mill to obtain a hollow glass microsphere precursor with the target particle size.

[0040] (4) The prepared hollow glass microspheres have a particle size D50 of 10 μm and good precursor properties. After subsequent high-temperature hollow spheroidization, hollow glass microspheres with properties comparable to those of hollow glass microspheres prepared by normal production process can be prepared. Example 3

[0041] (1) Weigh 90% of by-product A generated during the preparation of the precursor and 10% of by-product B generated during the high-temperature hollow spheroidization process, and mix them thoroughly in a high-speed mixer.

[0042] (2) The uniformly mixed material is loaded into a square crucible and compacted, and then placed in a roller kiln for sintering. Sintering is carried out at 500°C for 360 minutes in an air atmosphere, and then cooled and removed.

[0043] (3) The above material is crushed by a jaw crusher to obtain material with a particle size of 1 mm, and then the hollow glass microsphere precursor with the target particle size is obtained by crushing and classifying by an air jet mill.

[0044] (4) The prepared hollow glass microspheres have a particle size D50 of 30 μm and good precursor properties. After subsequent high-temperature hollow spheroidization, hollow glass microspheres with properties comparable to those of hollow glass microspheres prepared by normal production process can be prepared. Example 4

[0045] (1) Weigh 85% of by-product A generated during the preparation of the precursor and 15% of by-product B generated during the high-temperature hollow spheroidization process, and mix them thoroughly in a high-speed mixer.

[0046] (2) The uniformly mixed material is loaded into a square crucible and compacted. It is then placed in a roller kiln for sintering at 600°C for 240 minutes in an air atmosphere. After cooling, it is taken out.

[0047] (3) The above material is crushed by a double roller crusher to obtain material with a particle size of 1 mm, and then the hollow glass microspheres with the target particle size are obtained by crushing and classifying by an air jet mill.

[0048] (4) The prepared hollow glass microspheres have a particle size D50 of 25 μm and good precursor properties. After subsequent high-temperature hollow spheroidization, hollow glass microspheres with properties comparable to those of hollow glass microspheres prepared by normal production process can be prepared.

[0049] The material ratios, upper and lower limits of process parameters, and range values ​​involved in this invention can all achieve the present invention, and will not be listed one by one here.

Claims

1. A method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials, characterized in that... The following steps are adopted; 1) Mixing: Byproduct A generated during the preparation of hollow glass microspheres precursor and fine powder-byproduct B generated during the high-temperature spheroidization process of hollow glass microspheres production are mixed evenly; The proportions based on 100% of the total mass of raw materials are: By-product A 75%-95%, By-product B 5%-25%; The mass percentage of each chemical component in the by-product A is as follows: SiO2 60%-80%, Na2O 6%-18%, CaO 5%-14%, B2O 35%-15%, Al2O 30%-3%, MgO 0%-3%, ZnO 0%-3%, P2O 50%-3%, SO 30%-2%, and the balance 0-5%. The mass percentage of each chemical component in the by-product B is as follows: B2O3 40%-70%, SiO2 10%-50%, CaO 1%-10%, Na2O 5%-25%, and the balance 0-5%. 2) Sintering: Place the uniformly mixed material from step 1) into a square crucible, and place the square crucible in a roller kiln or sintering furnace for sintering to obtain sintered material in block or large particle shape. 3) Crushing: The sintered material obtained in step 2) is crushed to obtain small particles of 0.5-2mm. 4) Crushing and classifying: The small particles crushed in step 3) are crushed and classified to obtain hollow glass microsphere precursors that meet the requirements of high-temperature hollow spheroidization.

2. The method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials as described in claim 1, characterized in that: The particle size D50 of the by-product A is in the range of 0.1-5 μm.

3. The method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials as described in claim 1, characterized in that: In step 2), the sintering temperature is controlled in the range of 300-800℃, the sintering atmosphere is air, and the sintering time is 30-360min.

4. The method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials as described in claim 3, characterized in that: The sintering temperature in step 2) is controlled within the range of 500-800℃.

5. The method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials as described in claim 1, 2, 3, or 4, characterized in that: The mixing equipment in step 1) is a VC mixer or a high-speed mixer.

6. The method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials as described in claim 5, characterized in that: The crushing equipment in step 3) is a jaw crusher or a double roll crusher, or a combination of jaw crusher and double roll crusher.

7. The method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials as described in claim 6, characterized in that: In step 4), the pulverizing equipment uses air jet milling or a combination of air jet milling and Raymond milling, and the classifying equipment in step 4) uses cyclone classifier.

8. The method for preparing hollow glass microsphere precursors using hollow glass microsphere by-products as raw materials as described in claim 7, characterized in that: By synergistically controlling the raw material ratio and process parameters of each step, the particle size D50 of the prepared hollow glass microsphere precursor can be in the range of 10-40 μm.