Spherical micron-sized grinding medium as well as preparation method and application thereof

Abstract

The embodiment of the invention relates to a spherical micron-sized grinding medium as well as a preparation method and application thereof. The spherical micron-sized grinding medium is micron-sized spherical particles of silicon carbide; wherein the Dv50 of the spherical micron-sized grinding medium is 1-99 microns, the true density is greater than or equal to 2.2 g / cm < 3 >, the powder compaction density is greater than or equal to 0.8 g / cm < 3 >, and the sphericity is greater than or equal to 0.9; the spherical micron-sized grinding medium is used in ball-milling equipment or a ball-milling process. The spherical micron-sized grinding medium provided by the embodiment of the invention has the advantages of small particle size, narrow size distribution, high hardness, high strength, good wear resistance and the like, and can meet the requirement on grinding of superfine powder.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding media for ball mills, and in particular to a spherical micron-sized grinding medium, a preparation method thereof, and an application thereof. Background Art

[0002] There are two major trends in the development of the current powder industry: high purity and high fineness. Among them, ultrafine powders generally refer to a series of ultrafine materials from the micron level, submicron level to above 100 nanometers. After the material is pulverized into ultrafine powders, due to the small volume of the powder particles and narrow particle size distribution, they have characteristics such as high surface activity, high strength of the sintered body, fast dissolution rate, and fast chemical reaction rate, and thus are widely used in fields such as chemical engineering, high-speed rail, aerospace, new energy, and new materials.

[0003] The commonly used powder preparation processes are mainly two categories: chemical methods and physical methods. The powders prepared by chemical synthesis have good fineness, but the purity may not be good. The ball milling method, as a physical method, is widely used in the powder industry.

[0004] To achieve high purity and high fineness of powders, high-quality grinding media are essential. For grinding media, it is usually required to have less loss and pollution, high fineness of powders, and narrow particle size distribution, etc. In the industry, for the ultrafine grinding and dispersion of high-purity powders, zirconia ceramic materials such as zirconia microspheres, zirconia balls, zirconia columns, and zirconia beads are usually used according to different materials, working conditions, and requirements.

[0005] However, the sizes of the current zirconia beads on the market are usually above 0.1 mm, which cannot meet the higher technical requirements of current ultrafine powders. Although the minimum preparation size that can be achieved by current zirconia beads is 50 μm, it is prepared by the drop-forming method, with high technical requirements and difficult process control, and it is not universal. Summary of the Invention

[0006] The purpose of the present invention is to provide a spherical micron-sized grinding medium, a preparation method thereof, and an application thereof, which can meet the requirements of ultrafine powder grinding and high hardness, high strength, and good wear resistance of the ball milling medium.

[0007] To this end, in the first aspect, an embodiment of the present invention provides a spherical micron-sized grinding medium, and the spherical micron-sized grinding medium is a micron-sized spherical particle of silicon carbide; wherein, the Dv50 of the spherical micron-sized grinding medium is 1-99 μm, the true density ≥ 2.2 g / cm 3 , the powder compaction density ≥ 0.8 g / cm 3 , and the sphericity ≥ 0.9;

[0008] The spherical micron-sized grinding medium is used in ball milling equipment or processes.

[0009] Preferably, the spherical micron-sized grinding medium is a crystalline material with a grain size of 1-100 nm.

[0010] Preferably, in the spherical micron-sized grinding medium, by mass ratio, the silicon element accounts for 40%-60%, and the carbon element accounts for 60%-40%.

[0011] In a second aspect, an embodiment of the present invention provides a method for preparing a spherical micron-sized grinding medium, and the preparation method includes:

[0012] Hydrothermally treat the carbon-containing polymer to obtain a spherical carbonization precursor, and perform carbonization treatment on the spherical carbonization precursor to obtain a spherical hard carbon matrix;

[0013] Perform pore-forming treatment on the spherical hard carbon matrix to obtain micron-sized spherical porous carbon;

[0014] Using the micron-sized spherical porous carbon as a substrate, introduce a silicon-containing gas as a silicon source into the reaction furnace through a protective gas for chemical vapor deposition to obtain a spherical silicon-carbon composite material;

[0015] Put the spherical silicon-carbon composite material into a reaction device and perform heat treatment at a temperature not lower than 1000 °C to obtain spherical silicon carbide particles with a Dv50 of 1-99 μm, which are the spherical micron-sized grinding medium.

[0016] Preferably, the Dv50 of the spherical porous carbon is 1-99 μm; the pores of the spherical porous carbon are nano-pores.

[0017] Preferably, the carbon-containing polymer includes one or more of glucose, sucrose, polyvinylpyrrolidone, starch, polyvinylidene fluoride, phenolic epoxy resin, or polyvinyl chloride;

[0018] The temperature of the carbonization treatment is 400-1500 °C, and the heat preservation time is 0.5-20 h;

[0019] The specific pore-forming process includes: placing the spherical hard carbon matrix in a reaction furnace, heating to 800-1500 °C, introducing a pore-forming gas, and reacting for 1-20 h to obtain a spherical porous composite hard carbon material with a three-dimensional conductive structure inside the particles, which is the spherical hard carbon matrix; wherein the pore-forming gas is a combination of one or more of carbon dioxide, oxygen, and water vapor, and the flow rate is 1-10 L / min.

[0020] Preferably, the silicon-containing gas includes one or more of silane, propylsilane, dichlorosilane, trichlorosilane, and tetrachlorosilane; the protective gas includes one or two of nitrogen or argon;

[0021] The temperature of the vapor deposition is 500°C - 1500°C, and the time is 1 hour - 20 hours;

[0022] The temperature of the heat treatment is 1000°C - 1500°C, and the time is 10 hours - 30 hours.

[0023] Preferably, during the heat treatment, covalent bonds are formed between silicon and carbon in the silicon-carbon composite material to form silicon carbide.

[0024] In a third aspect, an embodiment of the present invention provides a ball milling device, and the ball milling medium used in the ball milling device is the spherical micron-sized grinding medium described in the first aspect above of the present invention.

[0025] In a fourth aspect, an embodiment of the present invention provides a ball milling process, and the ball milling process uses the spherical micron-sized grinding medium described in the first aspect above of the present invention as the ball milling medium to perform ball milling treatment on materials.

[0026] The spherical micron-sized grinding medium provided by the embodiment of the present invention is spherical silicon carbide formed under high-temperature and oxygen-free conditions, and has the advantages of small particle size, narrow size distribution, high hardness, high strength, good wear resistance, etc., and is suitable for the fine chemical industry field. Its preparation process is stable, and the prepared grinding balls have excellent grinding performance. Using the spherical micron-sized grinding medium provided by the present invention for ball milling of materials can effectively meet the technical requirements of ultra-fine powder grinding in the current fine chemical industry field. Description of the Drawings

[0027] Figure 1 It is a flow chart of the preparation method of the spherical micron-sized grinding medium provided by the embodiment of the present invention;

[0028] Figure 2 It is a comparison diagram of the scanning electron microscope (SEM) results of the spherical micron-sized grinding medium for grinding materials prepared in Example 1 and Comparative Example 1 of the present invention.

[0029] Figure 3 It is a schematic diagram of the particle size distribution of the spherical micron-sized grinding medium prepared in Example 1 of the present invention;

[0030] Figure 4 It is a SEM image of the spherical micron-sized grinding medium prepared in Example 1 of the present invention;

[0031] Figure 5 It is a SEM image of the spherical micron-sized grinding medium prepared in Example 1 of the present invention after being pressed under a pressure of 5t. Detailed Embodiments

[0032] The technical solutions of the present invention will be further described in detail below with reference to the drawings and embodiments.

[0033] An embodiment of the present invention provides a spherical micron-sized grinding medium for ball milling equipment or processes. The spherical micron-sized grinding medium is micron-sized spherical particles of silicon carbide. Among them, the Dv50 of the spherical micron-sized grinding medium is 1 - 99 μm, the true density is ≥ 2.2 g / cm 3 , and the powder compaction density is ≥ 0.8 g / cm 3 , and the sphericity is ≥ 0.9. The spherical micron-sized grinding medium is a crystalline material with a grain size of 1 - 100 nm.

[0034] In the spherical micron-sized grinding medium, by mass ratio, the silicon element accounts for 40% - 60%, and the carbon element accounts for 60% - 40%.

[0035] The spherical micron-sized grinding medium of the present invention is obtained through the following preparation method. The main steps are as Figure 1 , including:

[0036] Step 110: Hydrothermally treat the carbon-containing polymer to obtain a spherical carbonization precursor, and perform carbonization treatment on the spherical carbonization precursor to obtain a spherical hard carbon matrix.

[0037] Specifically, the carbon-containing polymer includes one or more of glucose, sucrose, polyvinylpyrrolidone, starch, polyvinylidene fluoride, phenolic epoxy resin, or polyvinyl chloride.

[0038] Hydrothermally treat the carbon-containing polymer, then wash and filter until the filtrate is transparent and colorless, and then dry to obtain a spherical carbonization precursor.

[0039] Carry out carbonization treatment on the spherical carbonization precursor at 400 - 1500 °C for a holding time of 0.5 - 20 h, and crush and classify the product of the carbonization treatment to obtain a hard carbon matrix with a particle size of 1 μm - 99 μm.

[0040] Step 120: Perform pore-forming treatment on the spherical hard carbon matrix to obtain micron-sized spherical porous carbon.

[0041] Specifically, place the spherical hard carbon matrix in a reaction furnace, heat it to 800 - 1500 °C, introduce pore-forming gas, and react for 1 - 20 h to obtain a spherical porous composite hard carbon material with a three-dimensional conductive structure inside the particles, which is the spherical hard carbon matrix. Among them, the pore-forming gas is a combination of one or more of carbon dioxide, oxygen, and water vapor, and the flow rate is 1 - 10 L / min.

[0042] The formed spherical porous carbon is a porous carbon microsphere containing through holes. The microsphere size is micron-sized, the Dv50 is 1 - 99 μm, and the pore size is nanometer-sized.

[0043] Step 130: Using micron-sized spherical porous carbon as the substrate, introducing a silicon-containing gas as the silicon source into the reaction furnace through a protective gas for chemical vapor deposition to obtain spherical silicon-carbon composite materials.

[0044] The silicon-containing gas includes one or more of silane, propylsilane, dichlorosilane, trichlorosilane, and tetrachlorosilane; the protective gas includes one or both of nitrogen or argon; the temperature of the chemical vapor deposition is 500°C - 1500°C, and the time is 1 hour - 20 hours.

[0045] Step 140: Placing the spherical silicon-carbon composite materials into a reaction device and performing heat treatment at a temperature not lower than 1000°C to obtain spherical silicon carbide particles with a Dv50 of 1 - 99 μm, which are spherical micron-sized grinding media.

[0046] Specifically, the temperature of the heat treatment is 1000°C - 1500°C, and the time is 10 hours - 30 hours.

[0047] During the heat treatment process, covalent bonds are formed between silicon and carbon in the silicon-carbon composite materials to form silicon carbide.

[0048] The spherical micron-sized grinding media prepared by the present invention are micron-sized spherical silicon carbide formed under high-temperature and oxygen-free conditions, having the advantages of small particle size, narrow size distribution, high hardness, high strength, good wear resistance, etc., and are suitable for the fine chemical industry field. Its preparation process is stable, and the prepared grinding balls have excellent grinding performance. Using the spherical micron-sized grinding media provided by the present invention for material ball milling can effectively meet the technical requirements of ultrafine powder grinding in the current fine chemical industry field.

[0049] To more clearly illustrate the purpose and advantages of the present invention, the present invention will be further described below in conjunction with embodiments. In addition, the embodiments described in the present invention are only partial embodiments. All other embodiments obtained by those skilled in the art without creative efforts based on the embodiments described in the present invention fall within the protection scope of the present invention. Additionally, it should be understood that these embodiments are only for more detailed description and should not be construed as limiting the present invention in any form, that is, it is not intended to limit the protection scope of the present invention.

[0050] Example 1

[0051] This example provides a spherical silicon carbide micron-sized grinding media and its preparation process, which are as follows.

[0052] Step 1: Heating glucose at 100°C for 5 hours for solidification treatment to obtain a carbonization precursor;

[0053] Step 2: Place the carbonization precursor into the reaction device, heat it up to 900 °C, and keep it at this temperature for 8 hours to carbonize the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm.

[0054] Step 3: Perform pore-forming treatment on the spherical hard carbon matrix to obtain a spherical porous carbon material. The gas source used is carbon dioxide, and the gas flow rate is 9 L / min. The temperature for pore-forming is 800 °C, and the time is 25 hours.

[0055] Step 4: Place 1 kg of the spherical porous carbon as the substrate in the furnace cavity of the reaction furnace. Among them, the particle size Dv50 of the spherical porous carbon is 10 μm.

[0056] Step 5: Introduce nitrogen with a flow rate of 2 L / min into the reaction furnace as the protective gas, heat it up at a rate of 5 °C / min. After heating up to 500 °C, introduce dichlorosilane gas with a flow rate of 2 L / min as the silicon source, and the introduction time is 2 h. Then cool it down to room temperature and discharge to obtain a spherical silicon-carbon composite material.

[0057] Step 6: Perform heat treatment on the obtained spherical silicon-carbon composite material. Place the spherical silicon-carbon composite material in the reaction furnace, introduce nitrogen as the protective gas, and the nitrogen flow rate is 2 L / min. Heat it up to 1000 °C, keep it at this temperature for 10 h, then cool it down to room temperature and discharge, and spherical micron-sized silicon carbide grinding media can be obtained.

[0058] Example 2

[0059] This example provides a spherical silicon carbide micron-sized grinding media and its preparation process, which is as follows.

[0060] Step 1: Heat glucose at 100 °C for 5 hours for solidification treatment to obtain a carbonization precursor.

[0061] Step 2: Place the carbonization precursor into the reaction device, heat it up to 900 °C, and keep it at this temperature for 8 hours to carbonize the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm.

[0062] Step 3: Perform pore-forming treatment on the spherical hard carbon matrix to obtain a spherical porous carbon material. The gas source used is carbon dioxide, and the gas flow rate is 9 L / min. The temperature for pore-forming is 800 °C, and the time is 25 hours.

[0063] Step 4: Place 1 kg of the spherical porous carbon as the substrate in the furnace cavity of the reaction furnace. Among them, the particle size Dv50 of the spherical porous carbon is 10 μm.

[0064] Step 5: Introduce nitrogen with a flow rate of 1 L / min into the reaction furnace as the protective gas, heat it up at a rate of 5 °C / min. After heating up to 1500 °C, introduce silane gas with a flow rate of 1.5 L / min as the silicon source, and the introduction time is 1 h. Then cool it down to room temperature and discharge to obtain a spherical silicon-carbon composite material.

[0065] Step 6: Heat-treat the obtained spherical silicon carbide composite material. Place the spherical silicon carbide composite material in a reaction furnace, introduce nitrogen gas as the protective gas with a nitrogen gas flow rate of 1 L / min, heat up to 1050 °C, hold for 18 h, then cool to room temperature and discharge the material to obtain spherical micron-sized silicon carbide grinding media.

[0066] Example 3

[0067] This example provides a spherical silicon carbide micron-sized grinding media and its preparation process, which are as follows.

[0068] Step 1: Heat glucose at 100 °C for 5 hours for curing treatment to obtain a carbonization precursor.

[0069] Step 2: Place the carbonization precursor in a reaction device, heat up to 900 °C, hold for 8 hours to perform carbonization treatment on the carbonization precursor, and obtain a 15-μm spherical hard carbon matrix.

[0070] Step 3: Perform pore-forming treatment on the spherical hard carbon matrix to obtain a spherical porous carbon material. The gas source used is carbon dioxide, and the gas flow rate is 9 L / min; the temperature for pore-forming is 800 °C, and the time is 25 hours.

[0071] Step 4: Place 1 kg of spherical porous carbon as the substrate in the reaction furnace cavity, where the Dv50 of the spherical porous carbon is 10 μm.

[0072] Step 5: Introduce nitrogen gas with a flow rate of 3 L / min as the protective gas into the reaction furnace, heat up at a rate of 5 °C / min, after heating up to 500 °C, introduce silane and trichlorosilane gases with a flow rate of 5 L / min as the silicon source, and introduce them for 18 h, then cool to room temperature and discharge the material to obtain a spherical silicon carbide composite material.

[0073] Step 6: Heat-treat the obtained spherical silicon carbide composite material. Place the spherical silicon carbide composite material in a reaction furnace, introduce nitrogen gas as the protective gas with a nitrogen gas flow rate of 3 L / min, heat up to 1100 °C, hold for 28 h, then cool to room temperature and discharge the material to obtain spherical micron-sized silicon carbide grinding media.

[0074] Example 4

[0075] This example provides a spherical silicon carbide micron-sized grinding media and its preparation process, which are as follows.

[0076] Step 1: Heat glucose at 100 °C for 5 hours for curing treatment to obtain a carbonization precursor.

[0077] Step 2: Place the carbonization precursor into the reaction device, heat it up to 900 °C, and keep it at this temperature for 8 hours to carbonize the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm;

[0078] Step 3: Perform pore-forming treatment on the spherical hard carbon matrix to obtain a spherical porous carbon material; the gas source used is carbon dioxide, and the gas flow rate is 9 L / min; the temperature for pore-forming is 800 °C, and the time is 25 hours;

[0079] Step 4: Place 1 kg of spherical porous carbon as the substrate in the reaction furnace cavity, where the Dv50 of the spherical porous carbon is 9 μm.

[0080] Step 5: Introduce nitrogen with a flow rate of 4.5 L / min into the reaction furnace as the protective gas, heat it up at a rate of 5 °C / min, and after heating up to 1350 °C, introduce silicoethane and dichlorosilane gases with a flow rate of 5 L / min as the silicon source, and the introduction time is 10 h. Then cool it down to room temperature and discharge to obtain a spherical silicon-carbon composite material.

[0081] Step 6: Perform heat treatment on the obtained spherical silicon-carbon composite material. Place the spherical silicon-carbon composite material in the reaction furnace, introduce nitrogen as the protective gas with a nitrogen flow rate of 4.5 L / min, heat it up to 1200 °C, keep it at this temperature for 14 h, then cool it down to room temperature and discharge, and spherical micron-sized silicon carbide grinding media are obtained.

[0082] Example 5

[0083] This example provides a spherical micron-sized silicon carbide grinding media and its preparation process, which are specifically as follows.

[0084] Step 1: Heat glucose at 100 °C for 5 hours for curing treatment to obtain a carbonization precursor;

[0085] Step 2: Place the carbonization precursor into the reaction device, heat it up to 900 °C, and keep it at this temperature for 8 hours to carbonize the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm;

[0086] Step 3: Perform pore-forming treatment on the spherical hard carbon matrix to obtain a spherical porous carbon material; the gas source used is carbon dioxide, and the gas flow rate is 9 L / min; the temperature for pore-forming is 800 °C, and the time is 25 hours;

[0087] Step 4: Place 1 kg of spherical porous carbon as the substrate in the reaction furnace cavity, where the Dv50 of the spherical porous carbon is 10 μm.

[0088] Step 5: Introduce nitrogen gas with a flow rate of 4.5 L / min into the reaction furnace as a protective gas, heat it up at a rate of 5 °C / min. After heating up to 1450 °C, introduce silicoethane gas with a flow rate of 5 L / min as a silicon source, and the introduction time is 12 h. Then cool it down to room temperature and discharge the material to obtain a spherical silicon-carbon composite material.

[0089] Step 6: Heat-treat the obtained spherical silicon-carbon composite material. Place the spherical silicon-carbon composite material in the reaction furnace, introduce nitrogen gas as a protective gas, with a nitrogen flow rate of 4.5 L / min, heat it up to 1300 °C, keep it at this temperature for 20 h, then cool it down to room temperature and discharge the material, thus obtaining spherical micron-sized silicon carbide grinding media.

[0090] Example 6

[0091] This example provides a spherical micron-sized silicon carbide grinding media and its preparation process, which are as follows.

[0092] Step 1: Heat glucose at 100 °C for 5 hours for solidification treatment to obtain a carbonization precursor.

[0093] Step 2: Put the carbonization precursor into the reaction device, heat it up to 900 °C, and keep it at this temperature for 8 hours to conduct carbonization treatment on the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm.

[0094] Step 3: Perform pore-forming treatment on the spherical hard carbon matrix to obtain a spherical porous carbon material; the gas source used is carbon dioxide, and the gas flow rate is 9 L / min; the temperature for pore-forming is 800 °C, and the time is 25 hours.

[0095] Step 4: Place 1 kg of spherical porous carbon as a substrate in the furnace cavity of the reaction furnace, where the Dv50 of the spherical porous carbon is 11 μm.

[0096] Step 5: Introduce nitrogen gas with a flow rate of 2 L / min into the reaction furnace as a protective gas, heat it up at a rate of 5 °C / min. After heating up to 600 °C, introduce tetrachlorosilane gas with a flow rate of 3.5 L / min as a silicon source, and the introduction time is 20 h. Then cool it down to room temperature and discharge the material to obtain a spherical silicon-carbon composite material.

[0097] Step 6: Heat-treat the obtained spherical silicon-carbon composite material. Place the spherical silicon-carbon composite material in the reaction furnace, introduce nitrogen gas as a protective gas, with a nitrogen flow rate of 2 L / min, heat it up to 1400 °C, keep it at this temperature for 25 h, then cool it down to room temperature and discharge the material, thus obtaining spherical micron-sized silicon carbide grinding media.

[0098] Example 7

[0099] This example provides a spherical micron-sized silicon carbide grinding media and its preparation process, which are as follows.

[0100] Step 1: Glucose is heated at 100 °C for 5 hours for solidification treatment to obtain a carbonization precursor;

[0101] Step 2: The carbonization precursor is placed in a reaction device, heated to 900 °C, and held for 8 hours to perform carbonization treatment on the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm;

[0102] Step 3: The spherical hard carbon matrix is subjected to pore-forming treatment to obtain a spherical porous carbon material; the gas source used is carbon dioxide, and the gas flow rate is 9 L / min; the temperature for pore-forming is 800 °C, and the time is 25 hours;

[0103] Step 4: 1 kg of spherical porous carbon is placed as a substrate in the reaction furnace cavity, where the Dv50 of the spherical porous carbon is 10 μm.

[0104] Step 5: Nitrogen with a flow rate of 1 L / min is introduced into the reaction furnace as a protective gas, and the temperature is raised at a rate of 5 °C / min. After the temperature reaches 800 °C, silane gas with a flow rate of 1.5 L / min is introduced as a silicon source, and the introduction time is 10 h. Then, the temperature is lowered to room temperature for discharging to obtain a spherical silicon-carbon composite material.

[0105] Step 6: The obtained spherical silicon-carbon composite material is subjected to heat treatment. The spherical silicon-carbon composite material is placed in a reaction furnace, nitrogen is introduced as a protective gas, the nitrogen flow rate is 1 L / min, the temperature is raised to 1500 °C, held for 10 h, and then lowered to room temperature for discharging, thus obtaining spherical micron-sized silicon carbide grinding media.

[0106] Example 8

[0107] This example provides a spherical micron-sized silicon carbide grinding medium and its preparation process, which are as follows.

[0108] Step 1: Glucose is heated at 100 °C for 5 hours for solidification treatment to obtain a carbonization precursor;

[0109] Step 2: The carbonization precursor is placed in a reaction device, heated to 900 °C, and held for 8 hours to perform carbonization treatment on the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm;

[0110] Step 3: The spherical hard carbon matrix is subjected to pore-forming treatment to obtain a spherical porous carbon material; the gas source used is carbon dioxide, and the gas flow rate is 9 L / min; the temperature for pore-forming is 800 °C, and the time is 25 hours;

[0111] Step 4: 1 kg of spherical porous carbon is placed as a substrate in the reaction furnace cavity, where the Dv50 of the spherical porous carbon is 10 μm.

[0112] Step 5: Introduce argon gas with a flow rate of 5 L / min into the reaction furnace as a protective gas, heat it at a rate of 5 °C / min, and after heating to 800 °C, introduce silane gas with a flow rate of 8 L / min as a silicon source for 10 h, then cool it to room temperature and discharge to obtain a spherical silicon-carbon composite material.

[0113] Step 6: Heat-treat the obtained spherical silicon-carbon composite material. Place the spherical silicon-carbon composite material in the reaction furnace, introduce argon gas as a protective gas with an argon flow rate of 5 L / min, heat it to 1200 °C, keep it at this temperature for 14 h, then cool it to room temperature and discharge to obtain spherical micron-sized silicon carbide grinding media.

[0114] Example 9

[0115] This example provides a spherical micron-sized silicon carbide grinding media and its preparation process, which are as follows.

[0116] Step 1: Heat glucose at 100 °C for 5 h for curing treatment to obtain a carbonization precursor.

[0117] Step 2: Place the carbonization precursor in the reaction device, heat it to 900 °C, and keep it at this temperature for 8 h to perform carbonization treatment on the carbonization precursor to obtain a spherical hard carbon matrix with a diameter of 15 μm.

[0118] Step 3: Perform pore-forming treatment on the spherical hard carbon matrix to obtain a spherical porous carbon material; the gas source used is carbon dioxide, and the gas flow rate is 9 L / min; the temperature for pore-forming is 800 °C, and the time is 25 h.

[0119] Step 4: Place 1 kg of spherical porous carbon as a substrate in the furnace cavity of the reaction furnace, where the Dv50 of the spherical porous carbon is 10 μm.

[0120] Step 5: Introduce argon gas with a flow rate of 2.5 L / min into the reaction furnace as a protective gas, heat it at a rate of 5 °C / min, and after heating to 1200 °C, introduce propylsilane gas with a flow rate of 5 L / min as a silicon source for 4 h, then cool it to room temperature and discharge to obtain a spherical silicon-carbon composite material.

[0121] Step 6: Heat-treat the obtained spherical silicon-carbon composite material. Place the spherical silicon-carbon composite material in the reaction furnace, introduce argon gas as a protective gas with an argon flow rate of 2.5 L / min, heat it to 1250 °C, keep it at this temperature for 15 h, then cool it to room temperature and discharge to obtain spherical micron-sized silicon carbide grinding media.

[0122] Example 10

[0123] This example provides a spherical micron-sized silicon carbide grinding media and its preparation process, which are as follows.

[0124] Step 1: Glucose was heated at 100 °C for 5 hours for solidification treatment to obtain a carbonization precursor;

[0125] Step 2: The carbonization precursor was placed in a reaction device, heated to 900 °C, and held for 8 hours to perform carbonization treatment on the carbonization precursor, obtaining a spherical hard carbon matrix with a diameter of 15 μm;

[0126] Step 3: The spherical hard carbon matrix was subjected to pore-forming treatment to obtain a spherical porous carbon material; the gas source used was carbon dioxide, and the gas flow rate was 9 L / min; the temperature for pore-forming was 800 °C, and the time was 25 hours;

[0127] Step 4: 1 kg of the spherical porous carbon was used as a substrate and placed in the reaction furnace cavity, where the Dv50 of the spherical porous carbon was 10 μm.

[0128] Step 5: Argon with a flow rate of 2.5 L / min was introduced into the reaction furnace as a protective gas, and the temperature was raised at a rate of 5 °C / min. After the temperature reached 1350 °C, silane and dichlorosilane gases with a flow rate of 6 L / min were introduced as silicon sources, and the introduction time was 4 h. Then, the temperature was lowered to room temperature for discharging to obtain a spherical silicon-carbon composite material.

[0129] Step 6: The obtained spherical silicon-carbon composite material was subjected to heat treatment. The spherical silicon-carbon composite material was placed in the reaction furnace, and argon was introduced as a protective gas with an argon flow rate of 2.5 L / min. The temperature was raised to 1250 °C, held for 16 h, and then lowered to room temperature for discharging, thus obtaining spherical micron-sized silicon carbide grinding media.

[0130] Comparative Example 1

[0131] Taking commercially available zirconia balls with a size of 2 - 3 μm as grinding media as a comparative example.

[0132] The grinding media prepared in Example 1 and the grinding media in Comparative Example 1 were compared. They were respectively used to perform 2 h of grinding treatment on nano-silicon (Dv50 = 800 nm), and the scanning electron microscope images (SEM) of the ground materials are as shown in Figure 2 a (Example 1) and 2b (Comparative Example 1).

[0133] From Figure 2 the comparison, it can be seen that the spherical micron-sized silicon carbide material prepared by the present invention grinds nano-silicon to about 100 nm, while the zirconia balls can only reduce the size to about 200 nm. The spherical micron-sized silicon carbide material prepared by the present invention can grind nano-scale materials to a smaller size.

[0134] The Dv50 of the spherical micron-sized silicon carbide grinding media obtained in the above examples was tested, and the results are shown in Table 1 below.

[0135] Serial number Dv50 / μm Example 1 10.51 Example 2 10.76 Example 3 9.82 Example 4 8.90 Example 5 10.71 Example 6 11.20 Example 7 9.88 Example 8 10.20 Example 9 10.44 Example 10 10.52

[0136] Table 1

[0137] As can be seen from Table 1, the preparation method of the spherical micron-sized grinding medium provided by the present invention has good stability and repeatability.

[0138] The particle size distribution of the spherical micron-sized grinding medium prepared in Example 1 of the present invention was tested, and the results are as Figure 3 shown. It can be seen that the particle size distribution of the spherical micron-sized grinding medium prepared by the present invention is concentrated.

[0139] The pressure test was carried out on the spherical micron-sized grinding medium prepared in Example 1 of the present invention. Figure 4 This is the SEM image of the spherical micron-sized grinding medium prepared in Example 1 of the present invention. It can be seen that its microscopic morphology is a round sphere. Figure 5 This is the SEM image of the spherical micron-sized grinding medium prepared in Example 1 of the present invention after being pressed under a pressure of 5 tons. It can be seen that its microscopic morphology still remains a round sphere. This shows that the grinding medium prepared by the present invention has high hardness and high strength and can meet the technical requirements of ultrafine powder processing.

[0140] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A spherical micron-sized grinding medium, characterized in that, The spherical micron-sized grinding medium is micron-sized spherical particles of silicon carbide; wherein, the Dv50 of the spherical micron-sized grinding medium is 1-99 μm, the true density ≥ 2.2 g / cm 3 , and the powder compaction density ≥ 0.8 g / cm 3 , and the sphericity ≥ 0.9; The spherical micron-sized grinding medium is used in ball milling equipment or processes.

2. The spherical micron-sized grinding medium according to claim 1, wherein The spherical micron-sized grinding medium is a crystalline material with a grain size of 1 - 100 nm.

3. The spherical micron-sized grinding medium according to claim 1, characterized in that, In the spherical micron-sized grinding medium, by mass ratio, the silicon element accounts for 40% - 60%, and the carbon element accounts for 60% - 40%.

4. A method for preparing the spherical micron-sized grinding medium according to any one of claims 1-3 above, characterized in that, The preparation method includes: Hydrothermally treating the carbon-containing polymer to obtain a spherical carbonization precursor, and carbonizing the spherical carbonization precursor to obtain a spherical hard carbon matrix; Performing pore-forming treatment on the spherical hard carbon matrix to obtain micron-sized spherical porous carbon; Using the micron-sized spherical porous carbon as a substrate, introducing a silicon-containing gas as a silicon source into a reaction furnace through a protective gas for chemical vapor deposition to obtain a spherical silicon-carbon composite material; Placing the spherical silicon-carbon composite material in a reaction device and performing heat treatment at a temperature not lower than 1000 °C to obtain spherical silicon carbide particles with a Dv50 of 1 - 99 μm, which are the spherical micron-sized grinding medium.

5. The preparation method according to claim 4 above, characterized in that, The Dv50 of the spherical porous carbon is 1 - 99 μm; the pores of the spherical porous carbon are nano-pores.

6. The preparation method according to claim 4 above, characterized in that, The carbon-containing polymer includes one or more of glucose, sucrose, polyvinylpyrrolidone, starch, polyvinylidene fluoride, phenolic epoxy resin, or polyvinyl chloride; The temperature of the carbonization treatment is 400 - 1500 °C, and the heat preservation time is 0.5 - 20 h; The specific pore-forming process includes: placing the spherical hard carbon matrix in a reaction furnace, heating to 800 - 1500 °C, introducing a pore-forming gas, and reacting for 1 - 20 h to obtain a spherical porous composite hard carbon material with a three-dimensional conductive structure inside the particles, which is the spherical hard carbon matrix; wherein the pore-forming gas is a combination of one or more of carbon dioxide, oxygen, and water vapor, and the flow rate is 1 - 10 L / min.

7. The preparation method according to claim 4 above, characterized in that, The silicon-containing gas includes one or more of silane, propylsilane, dichlorosilane, trichlorosilane, and tetrachlorosilane; the protective gas includes one or both of nitrogen or argon; The temperature of the chemical vapor deposition is 500 °C - 1500 °C, and the time is 1 hour - 20 hours; The temperature of the heat treatment is 1000 °C - 1500 °C, and the time is 10 hours - 30 hours.

8. The preparation method according to claim 4 above, characterized in that, During the heat treatment process, a covalent bond is formed between silicon and carbon in the silicon-carbon composite material to form silicon carbide.

9. A ball milling device, characterized in that, The ball milling medium used in the ball milling equipment is the spherical micron-sized grinding medium according to any one of claims 1 - 3 of the present invention.

10. A ball milling process, characterized in that, The ball milling process uses the spherical micron-sized grinding medium according to any one of claims 1 - 3 of the present invention as the ball milling medium for ball milling treatment of materials.

Images