A method for preparing spherical silicon micro-powder by plasma

Abstract

The application discloses a kind of spherical silicon micro powder plasma preparation method, step 1: material preparation, including silicon source, solvent and surfactant;Step 2: solution preparation, silicon source is dissolved in solvent, forms silicon source solution, and adds surfactant;Step 3: plasma preparation, silicon source solution is injected into plasma reactor, plasma reactor is heated and pressurized, and plasma is formed under the excitation of high-frequency electromagnetic field;Step 4: precipitation and separation, after reaction, the solution is taken out from plasma reactor, and precipitation and separation are carried out, and the spherical silicon micro powder obtained by separation is dried.The spherical silicon micro powder obtained by the application has been successfully produced electronic grade spherical silicon micro powder through repeated tests, meets the production demand of high-end electronic products, the product balling rate reaches 99.9%, the dispersity is high, the production energy consumption is low and the safety is high, and the particle size is controllable.

Description

TECHNICAL FIELD

[0001] The application relates to a plasma preparation method of spherical silicon micro powder and belongs to the technical field of preparation of spherical silicon micro powder. BACKGROUND

[0002] The spherical silicon micro powder is widely applied in many fields such as catalysts, paints and electronic materials. At present, a plurality of methods for preparing the spherical silicon micro powder have been proposed, including a sol-gel method and a gas phase deposition method. However, in the existing methods, the spherical silicon micro powder has problems of high cost, complex process and uneven particle size distribution.

[0003] Therefore, a plasma preparation method of spherical silicon micro powder is needed to solve the above problems. SUMMARY

[0004] The application aims to provide a plasma preparation method of spherical silicon micro powder to solve the problems in the background art.

[0005] A plasma preparation method of spherical silicon micro powder comprises the following steps:

[0006] Step 1: material preparation, including a silicon source, a solvent and a surfactant, wherein the amount ratio of the silicon source, the solvent and the surfactant is 100g: 180-220ML: 10-15g;

[0007] Step 2: solution preparation, the silicon source is dissolved in the solvent to form a silicon source solution, and the surfactant is added;

[0008] Step 3: plasma preparation, the silicon source solution is injected into a plasma reactor, the plasma reactor is heated and pressurized, and the plasma is formed under the excitation of a high-frequency electromagnetic field;

[0009] Step 4: precipitation and separation, the reacted solution is taken out from the plasma reactor, and precipitation and separation are carried out, the spherical silicon micro powder obtained by separation is dried, and the spherical silicon micro powder is obtained.

[0010] Further, the silicon source is a silicate.

[0011] Further, the silicon source is sodium silicate.

[0012] Further, the solvent is an organic solvent.

[0013] Further, the solvent is n-hexane or dimethylbenzene.

[0014] Further, the surfactant is CTAB.

[0015] Further, the temperature of the plasma reactor is 500-600℃, and the pressure is 12-15kPa.

[0016] Further, the frequency of the high-frequency electromagnetic field is 150-180MHz.

[0017] Further, the separated spherical silicon micropowder in step 5 is dried, and the drying temperature is 80℃, and the duration is at least 12 hours.

[0018] Beneficial effects: The plasma preparation method of the spherical silicon micropowder of the present application prepares the spherical silicon micropowder through plasma reaction, which is simple, low in cost, high in preparation efficiency, and narrow in particle size distribution, and is suitable for large-scale production. By adjusting the solution composition, plasma parameters, and drying conditions, etc., the morphology and size of the spherical silicon micropowder are controlled. Embodiment

[0019] The present application will be further illustrated below in conjunction with specific examples, which should be understood as merely illustrating the present application and not limiting the scope of the present application. After reading the present application, those skilled in the art can make various equivalent modifications to the present application, which fall within the scope defined by the appended claims. Example

[0020] The plasma preparation method of the spherical silicon micropowder comprises the following steps:

[0021] Step 1: Material preparation

[0022] Prepare the required raw materials and reagents. Preparation: 100g of sodium silicate Na2SiO3 as a silicon source, 180mL of n-hexane as a solvent, and 10g of CTAB (cetyltrimethylammonium bromide) as a surfactant.

[0023] Step 2: Solution preparation

[0024] Dissolve the silicon source in the solvent to form a silicon source solution, and add the surfactant to the silicon source solution to control the morphology and size of the spherical silicon micropowder, and stir the solution to ensure uniform mixing.

[0025] Step 3: Plasma preparation

[0026] Inject the silicon source solution into the plasma reactor, heat the plasma reactor to 500℃ and pressurize to 12kPa, and use a 180MHz high-frequency electromagnetic field to excite, forming a plasma in the plasma reactor.

[0027] Step 4: Precipitation and separation

[0028] The solution after reaction is taken out of the plasma reactor, and precipitation and separation are carried out. The spherical silicon powder is precipitated from the solution by centrifugation. Then, the spherical silicon powder is separated from impurities such as solvents and surfactants through filtration and washing steps.

[0029] Step 5: Drying and particle size control

[0030] The spherical silicon powder is dried in a vacuum dryer, with a temperature setting of 80°C and a duration of 12 hours.

[0031] Through scanning electron microscope (SEM) observation, electron grade spherical silicon powder is formed, with a product sphericity rate of more than 99.9%, high dispersity, low energy consumption and high safety, and particle size control is realized. Embodiment

[0032] The plasma preparation method of the spherical silicon powder comprises the following steps:

[0033] Step 1: Material preparation

[0034] Prepare the required raw materials and reagents. Preparation: 100g of sodium silicate Na2SiO3 as the silicon source, 220mL of n-hexane as the solvent, and 12g of CTAB (cetyltrimethylammonium bromide) as the surfactant.

[0035] Step 2: Solution preparation

[0036] Dissolve the silicon source in the solvent to form a silicon source solution, and add the surfactant to the silicon source solution to control the morphology and size of the spherical silicon powder. Stir the solution to ensure uniform mixing.

[0037] Step 3: Plasma preparation

[0038] Inject the silicon source solution into the plasma reactor, heat the plasma reactor to 600°C and pressurize to 15kPa, and use a 150MHz high-frequency electromagnetic field to excite, forming a plasma in the plasma reactor.

[0039] Step 4: Precipitation and separation

[0040] The solution after reaction is taken out of the plasma reactor, and precipitation and separation are carried out. The spherical silicon powder is precipitated from the solution by centrifugation. Then, the spherical silicon powder is separated from impurities such as solvents and surfactants through filtration and washing steps.

[0041] Step 5: Drying and particle size control

[0042] The spherical silicon powder is dried in a vacuum dryer, with a temperature setting of 80°C and a duration of 12 hours.

[0043] After scanning electron microscope (SEM) observation, electron grade spherical silicon micro powder is formed, the product balling rate is more than 99.9%, the dispersion is high, and the production energy consumption is low and the safety is high, and the particle size is controlled. Embodiment

[0044] The plasma preparation method of spherical silicon micro powder comprises the following steps:

[0045] Step 1: material preparation

[0046] Prepare the required raw materials and reagents. Preparation: 100g of sodium silicate Na2SiO3 as a silicon source, 180mL of dimethylbenzene as a solvent, and 15g of CTAB (cetyltrimethylammonium bromide) as a surfactant.

[0047] Step 2: solution preparation

[0048] Dissolve the silicon source in the solvent to form a silicon source solution, and add the surfactant to the silicon source solution to control the morphology and size of the spherical silicon micro powder, and stir the solution to ensure uniform mixing.

[0049] Step 3: plasma preparation

[0050] Inject the silicon source solution into the plasma reactor, heat the plasma reactor to 550℃ and pressurize to 13kPa, and use a 160MHz high-frequency electromagnetic field to excite, forming a plasma in the plasma reactor.

[0051] Step 4: precipitation and separation

[0052] Take out the reacted solution from the plasma reactor, and perform precipitation and separation. By centrifugal method, the spherical silicon micro powder is precipitated from the solution. Then, through the steps of filtration and washing, the spherical silicon micro powder is separated from the impurities such as solvent and surfactant.

[0053] Step 5: drying and particle size control

[0054] Dry the spherical silicon micro powder in a vacuum dryer, set the temperature to 80℃, and the duration is 12 hours.

[0055] After scanning electron microscope (SEM) observation, electron grade spherical silicon micro powder is formed, the product balling rate is more than 99.9%, the dispersion is high, and the production energy consumption is low and the safety is high, and the particle size is controlled. Embodiment

[0056] The plasma preparation method of spherical silicon micro powder comprises the following steps:

[0057] Step 1: material preparation

[0058] Prepare the required raw materials and reagents. Preparation: 100 g of sodium silicate Na2SiO3 as the silicon source, 220 mL of xylene as the solvent, and 13 g of CTAB (cetyltrimethylammonium bromide) as the surfactant.

[0059] Step 2: Solution preparation

[0060] Dissolve the silicon source in the solvent to form a silicon source solution, and add the surfactant to the silicon source solution to control the morphology and size of the spherical silicon micro-powder. Stir the solution to ensure uniform mixing.

[0061] Step 3: Plasma preparation

[0062] Inject the silicon source solution into the plasma reactor, heat the plasma reactor to a temperature of 580°C and pressurize it to 14 kPa, and use a high-frequency electromagnetic field with a frequency of 150 MHz to excite the plasma in the plasma reactor.

[0063] Step 4: Precipitation and separation

[0064] Remove the reacted solution from the plasma reactor and perform precipitation and separation. Centrifugation is used to precipitate the spherical silicon micro-powder from the solution. Then, through filtration and washing steps, the spherical silicon micro-powder is separated from impurities such as solvents and surfactants.

[0065] Step 5: Drying and particle size control

[0066] Dry the spherical silicon micro-powder in a vacuum dryer, set the temperature to 80°C, and maintain for 12 hours.

[0067] Through scanning electron microscopy (SEM) observation, electron-grade spherical silicon micro-powder is formed, with a product sphericity rate of more than 99.9%, high dispersity, low production energy consumption, high safety, and controllable particle size.

[0068] The present application prepares spherical silicon micro-powder through plasma reaction, which is simple, low-cost, high-efficiency, and narrow particle size distribution, suitable for large-scale production. By adjusting the solution composition, plasma parameters, and drying conditions, the morphology and size of the spherical silicon micro-powder can also be controlled.

[0069] The present application successfully produces electron-grade spherical silicon micro-powder through repeated experiments, meeting the production needs of high-end electronic products, with a product sphericity rate of 99.9%, high dispersity, low production energy consumption, high safety, and controllable particle size.

Claims

1. A plasma preparation method for spherical silicon powder, characterized in that: The following steps are involved: Step 1: Material preparation, including silicon source, solvent and surfactant, wherein the ratio of silicon source, solvent and surfactant is: 100g: 180-220ml: 10-15g; the silicon source is silicate; the solvent is an organic solvent; the surfactant is CTAB; Step 2: Solution preparation: dissolving the silicon source in a solvent to form a silicon source solution, and adding a surfactant; Step 3: Plasma preparation: injecting a silicon source solution into a plasma reactor, heating and pressurizing the plasma reactor, and forming a plasma under the excitation of a high-frequency electromagnetic field; the temperature of the plasma reactor is 500-600°C, the pressure is 12-15kPa; the frequency of the high-frequency electromagnetic field is 150-180MHz; Step 4: precipitation and separation, taking the reacted solution out of the plasma reactor, performing precipitation and separation, and drying the separated spherical silicon micropowder to obtain spherical silicon micropowder; In step 4, the separated spherical silicon powder is dried at a temperature of 80° C. for at least 12 hours.

2. The plasma preparation method of spherical silicon powder according to claim 1, characterized in that: The silicon source is sodium silicate.

3. The plasma preparation method of spherical silicon powder according to claim 1, characterized in that: The solvent is n-hexane or xylene.