Process and device for producing silicon powder by continuously electrolyzing glass

Abstract

The invention provides a process and a device for producing silicon powder by continuously electrolyzing glass, relates to the technical field of electrolytic silicon, and aims to solve the problem that the current electrolytic silicon process cannot continuously electrolyze, calcium oxide reacts with silicon dioxide in the glass to generate silicate, and the silicate contained in the glass is combined to jointly generate ionization in fused salt to generate silicon powder. Silicon exists in fused salt in the form of silicate, silicate ions are mainly consumed in the electrolysis process to generate silicon elementary substances, and the fused salt is a medium for transferring oxygen ions, so that the problem that silicon oxide is dissolved in the fused salt is solved, electrolytic silicon preparation can be continuously carried out, the obtained product is pure silicon, doped silicon dioxide is reduced, and the yield is increased. The product is scraped, cleaned and dried to obtain high-purity micron-sized silicon powder, and a raw material for preparing silicide can be obtained without adding a grinding process.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic silicon, and in particular to a process and device for producing silicon powder by continuous electrolytic glass. Background Art

[0002] Silicides have a wide range of applications in various fields. At present, the industrial method for preparing silicon is to reduce SiO2 by carbon heat at 1700°C and remove oxygen by producing CO2. The traditional silicon smelting method relies on a high-temperature smelting process, which has a series of problems such as high energy consumption, low purity, low production efficiency, and environmental pollution. The purity of silicon produced by this process is relatively low, and it needs to be further improved through refining. Mechanical grinding is required to obtain micron-level silicon powder, which further increases energy consumption. The high-cost preparation method results in high prices for high-purity silicon and silicon powder, which further leads to high production costs for silicon nitride, limiting the widespread application of other materials such as silicon nitride produced using high-purity fine silicon powder.

[0003] As an emerging method of silicon extraction, electrolytic silicon technology shows good application prospects. Molten salt electrolysis, also known as molten salt electro-deoxidation, is an electrochemical process route for directly electrolyzing solid metal oxides / non-metal oxides in high-temperature molten salt to prepare metals / non-metals or alloys. The mechanism of this process is: at high temperature, voltage is applied to the anode and cathode, so that the cathode oxide is reduced to a single substance or alloy by electrons, and the oxygen ions removed from the cathode oxide migrate to the graphite anode through the molten salt, and then lose ions to become O2 or oxygen ions react with graphite to generate CO or CO2. When applying electrolytic silicon technology, silicon is mostly prepared by a high-purity quartz molten salt electro-deoxidation process. The quartz sheet is wound on a molybdenum rod with molybdenum wire or the silicon dioxide powder is mixed with a conductive material and compacted and sintered with molybdenum wire as the cathode, and the graphite rod is used as the anode. The molten CaCl2 is used as the electrolyte, and a certain voltage is applied to form a closed loop to electrolyze the cathode oxide, and finally prepare elemental silicon. However, this method cannot guarantee that the silica cannot be completely electrolyzed into silicon, because as the electrolysis proceeds, the silica in the center becomes increasingly difficult to contact with the molten salt, and it is impossible to know whether it has been completely electrolyzed, which will eventually result in the center part not being electrolytically deoxidized. Therefore, the current electrolytic silicon process has the problems of expensive raw materials, inability to sustain electrolysis, incomplete electrolysis, and inconvenient collection of products. Summary of the invention

[0004] The purpose of the present invention is to provide a process and device for producing silicon powder by continuous electrolysis of glass in view of the defects of the prior art. Calcium oxide reacts with silicon dioxide in glass to form silicate, which is ionized in molten salt together with silicate contained in glass. Silicon is converted into silicate (mainly SiO4 4- and SiO3 2-) exists in the molten salt in the form of electrolysis. The electrolysis process mainly consumes silicate ions to generate silicon element, and the molten salt is the medium for transferring oxygen ions, thus solving the problem of silicon oxide dissolving in molten salt, making it possible to continuously carry out electrolytic silicon production, and the obtained product is pure silicon with less doped silicon dioxide. After the product is scraped, cleaned and dried, high-purity micron-level silicon powder can be obtained, and the raw material for preparing silicide can be obtained without adding a grinding process.

[0005] The first object of the present invention is to provide a process for producing silicon powder by continuous electrolytic glass, which adopts the following scheme:

[0006] include:

[0007] The solid waste glass powder, calcium oxide powder and alkali metal chloride are mixed and heated to melt to form molten salt;

[0008] Inserting the cathode and the anode into the molten salt respectively and applying electricity for electrolysis;

[0009] During the electrolysis process, silicate ions in the molten salt generate electricity to produce silicon and deposit on the cathode, and gas is produced on the anode;

[0010] The silicon deposited on the cathode is collected.

[0011] Furthermore, the alkali metal chloride salt adopts a single CaCl2 system or a mixed system of multiple alkali metal chloride salts.

[0012] Furthermore, the added amount of the solid waste glass is 10%-20% of the total weight of the molten salt, and the calcium oxide accounts for 0-2% of the total mass ratio of calcium oxide and the solid waste glass.

[0013] Furthermore, the anode is made of graphite or a coating is provided on the outside of the anode.

[0014] Furthermore, after the electrolysis is completed, the silicon powder is scraped from the cathode in a space with the same temperature environment as the electrolytic cell, or the cathode is removed and soaked after cooling, and the silicon powder is scraped after soaking.

[0015] Furthermore, after collecting the silicon deposited on the cathode, a gas-solid fluidized bed reactor is used to react the silicon powder in a high-temperature nitrogen environment to produce silicide.

[0016] The second object of the present invention is to provide a device for producing silicon powder by continuous electrolysis of glass, comprising:

[0017] an electrolytic cell for containing molten salt;

[0018] Anode, suspended in the electrolytic cell by an anode fixture;

[0019] The cathode is connected to a lifting mechanism and is suspended in the electrolytic cell by the lifting mechanism;

[0020] A scraping mechanism, including a scraper, is arranged on the cathode lifting path to scrape off the attached matter on the cathode;

[0021] The collecting mechanism comprises a collecting plate and a conveying channel. The collecting plate is slidably mounted at one end of the conveying channel and is connected to the conveying channel. The collecting plate can be inserted under the cathode to receive the attachments scraped off by the cathode.

[0022] Furthermore, a stirrer is arranged in the electrolytic cell, the stirrer is located between the anode and the cathode, and the electrolytic cell is connected to a raw material bin.

[0023] Furthermore, the scraping mechanism also includes a moving mechanism, which drives the scraper to move along the movement direction of the lifting mechanism.

[0024] Furthermore, a cavity is formed in the electrolytic cell, and a cavity for the collecting plate to probe into is provided above the molten salt, and the cavity can accommodate the cathode after being lifted by the lifting mechanism.

[0025] Compared with the prior art, the present invention has the following advantages and positive effects:

[0026] (1) In order to solve the problem that the current electrolytic silicon process cannot sustain electrolysis, calcium oxide reacts with silicon dioxide in glass to form silicates, which are then ionized in molten salt together with the silicates in glass. Silicon is converted into silicate (mainly SiO4 4- and SiO3 2- ) exists in the molten salt in the form of electrolysis. The electrolysis process mainly consumes silicate ions to generate silicon element, and the molten salt is the medium for transferring oxygen ions, thus solving the problem of silicon oxide dissolving in molten salt, making it possible to continuously carry out electrolytic silicon production, and the obtained product is pure silicon with less doped silicon dioxide. After the product is scraped, cleaned and dried, high-purity micron-level silicon powder can be obtained, and the raw material for preparing silicide can be obtained without adding a grinding process.

[0027] (2) Directly using solid waste glass as a silicon source, utilizing the glass in solid waste, saving production costs and protecting the environment; using glass in solid waste as a raw material, which is mainly composed of silicates and silicon dioxide, the silicon in the glass can exist in the form of silicate ions in molten salt under high temperature conditions without the addition of other substances. The electrolysis process mainly consumes silicate ions to generate silicon elements, and only needs to regularly pour glass into it to continuously produce high-purity silicon powder.

[0028] (3) The continuous electrolytic glass production silicon powder device can continuously produce high-purity silicon powder with a particle size of less than 15 microns. It does not require grinding or other treatments, and can be directly processed to produce silicon nitride and other downstream silicon-based materials, achieving low-energy production. The use of a gas-solid fluidized bed reactor can effectively increase the gas-solid contact area and improve the reaction efficiency, solving the problem that the silicon powder at the bottom of the fixed bed cannot be converted into silicon nitride due to failure to contact with nitrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 It is a schematic diagram of the process of producing silicon powder by continuous electrolysis of glass in Examples 1 and 2 of the present invention.

[0031] Figure 2 1 is a particle size analysis diagram of the silicon powder produced by electrolysis in Examples 1 and 2 of the present invention.

[0032] Figure 3 Schematic diagram of a gas-solid fluidized reactor for preparing silicon nitride in Examples 1 and 2 of the present invention.

[0033] Figure 4 It is a schematic diagram of the structure of the device for producing silicon powder by continuous electrolysis of glass in Example 2 of the present invention.

[0034] Figure 5 It is a cross-sectional view of the device for producing silicon powder by continuous electrolysis of glass in Example 2 of the present invention.

[0035] Figure 6 It is a cross-sectional view of scraping the electrolysis product in Example 2 of the present invention.

[0036] Figure 7 yes Figure 6 Enlarged view of point A in the middle.

[0037] Figure 8 It is a schematic diagram of the structure of the collection and transmission components in Examples 1 and 2 of the present invention.

[0038] Among them, 1. lifting mechanism; 2. raw material bin; 3. agitator; 4. anode fixture; 5. electrolytic cell; 6. collecting bin; 7. conveying channel; 8. cathode fixture; 9. cathode; 10. collecting plate; 11. scraper; 12. receiving tank; 13. anode. DETAILED DESCRIPTION

[0039] Example 1

[0040] In a typical embodiment of the present invention, Figure 1-Figure 3 As shown, a process for producing silicon powder by continuous electrolytic glass is given.

[0041] The current electrolytic silicon method cannot guarantee that silicon dioxide cannot be completely electrolyzed into silicon, because as the electrolysis proceeds, the silicon dioxide in the center becomes increasingly difficult to contact the molten salt, and it is impossible to know whether it has been completely electrolyzed, so the center part will eventually not be electrolyzed and deoxidized. Therefore, the current electrolytic silicon process has the problems of expensive raw materials, inability to sustain electrolysis, incomplete electrolysis, and inconvenient product collection. Based on this, the present embodiment provides a continuous electrolytic glass production silicon powder process, which directly uses solid waste glass as a silicon source, and calcium oxide reacts with silicon dioxide in the glass to form silicates, which are combined with the silicates contained in the glass to be ionized in the molten salt. The electrolysis process mainly consumes silicate ions to generate silicon element, and the molten salt is the medium for transferring oxygen ions, thereby solving the problem of silicon oxide dissolving in the molten salt, so that the electrolytic silicon production can be carried out continuously, and the obtained silicon is attached to the cathode 9, which is convenient for collection.

[0042] like Figure 1-Figure 3 As shown, the process of producing silicon powder by continuous electrolytic glass includes:

[0043] The solid waste glass powder, calcium oxide powder and alkali metal chloride are mixed and heated to melt to form molten salt;

[0044] Insert the cathode 9 and the anode 13 into the molten salt respectively, and apply electricity for electrolysis;

[0045] During the electrolysis process, silicate ions in the molten salt are electrified to produce silicon and deposit on the cathode 9, and gas is produced on the anode 13;

[0046] The silicon deposited on the cathode 9 is collected.

[0047] Specifically, the implementation steps of the process for producing silicon powder by continuous electrolytic glass are described.

[0048] Constructing a chloride molten salt system, wherein the molten salt in the system is mainly composed of alkali metal chloride salts, such as CaCl2, MgCl2, NaCl, KCl, LiCl and other alkali metal chloride salts, or a combination of multiple salts;

[0049] Adding solid waste glass and calcium oxide powder into the chloride molten salt system in proportion;

[0050] A mixture of alkali metal chloride, calcium oxide and solid waste glass is mixed and added into an alumina crucible, and a cathode 9 and an anode 13 are inserted into the molten salt during the electrolysis stage;

[0051] The electrolysis product can be continuously obtained by using a continuous electrolysis glass silicon production device.

[0052] In addition, the product can be acid-washed, water-washed and dried to obtain relatively uniform high-purity micron-sized silicon powder, which can then be used to produce downstream silicon-based materials, such as reacting the prepared silicon powder in a high-temperature nitrogen environment to produce silicon nitride powder.

[0053] In the above process, glass slag is added to a single or multiple alkali chloride molten salt system, the temperature is raised to 50-100°C above the melting point of the alkali chloride system, an inert gas is introduced to accelerate the mixed dissolution, and the cathode 9 and the anode 13 are inserted into the molten salt during the electrolysis stage. During the electrolysis process, silicate ions obtain electrons on the cathode 9 to produce silicon and deposit on the cathode 9, while oxygen ions lose electrons on the anode 13 to produce oxygen or carbon-containing gas. The product is scraped from the cathode 9, and after water washing, acid washing, and drying, a relatively uniform high-purity silicon powder can be obtained, and then downstream silicon-based materials can be produced, for example, the prepared silicon powder is reacted in a high-temperature 1400°C nitrogen environment to produce silicon nitride powder.

[0054] In other optional embodiments, downstream silicon-based materials produced using high-purity silicon powder include silicon nitride, single crystal silicon, polycrystalline silicon, silicon-carbon composite materials, silicon-aluminum alloys, silicone rubber and the like.

[0055] like Figure 3 As shown, the obtained high-purity silicon powder is subjected to a silicon powder direct nitridation method to generate silicon nitride powder. The method is to react the high-purity silicon powder with nitrogen at 1200-1400°C. The reactor uses a gas-solid fluidized bed, which can effectively increase the gas-solid contact area and improve the reaction efficiency, thus solving the problem that the silicon powder at the bottom of the fixed bed cannot be converted into silicon nitride due to failure to contact with nitrogen.

[0056] Among them, when the molten salt system is CaCl2 alone, the solubility of oxygen ions is the largest, but the molten salt temperature is higher, at 800℃-850℃; multiple combinations can lower the melting point, and only melting the glass into liquid can also allow electrolysis to proceed.

[0057] It is understandable that when the yield requirement is high, a single CaCl2 system can be used. If energy saving is the priority, a mixed system of multiple alkali metal chlorides can be used. The lowest melting point of the CaCl2-MgCl2-NaCl system is 416°C, and the electrolysis temperature can be set to 650°C at this time.

[0058] The solubility of oxygen ions in CaCl2 is the highest, and in the binary molten salt system, the solubility of oxygen ions in CaCl2-LiCl is the highest, and the solubility of oxygen ions in CaCl2-MgCl2 is the lowest. The solubility of oxygen ions decreases with the increase of the addition amount of non-CaCl2 chloride salts.

[0059] The amount of solid waste glass added is 10%-20% of the total weight of the molten salt, and calcium oxide accounts for 0-2% of the total mass of calcium oxide and glass. This is because the glass itself contains silicate components, and silicate will generate alkali metal oxides after electrolysis. The alkali metal oxides will continue to react with the remaining silicon dioxide to generate silicates, allowing the electrolysis reaction to continue; and the additional addition of calcium oxide can increase the silicate content in the molten salt to a certain extent, which can increase the reaction rate.

[0060] The reaction of electrons generated at the cathode 9 does not consume the cathode 9 during the electrolysis process. Graphite, metals or metal oxides that are resistant to high temperature and salt corrosion can be used as the cathode 9. In order to prevent other ions from entering the molten salt and interfering with the purity of silicon, graphite is used as the anode 13. The reaction process will cause certain losses to the anode 13 and generate oxygen, carbon dioxide and carbon monoxide gases. In order to avoid environmental pollution caused by the product gas of the anode 13, an electrode with a SnO2 or RuO2 coating can be used as the anode 13.

[0061] In addition, the cathode 9 and the anode 13 can be distributed in a rod-to-rod structure, a rod-to-tube structure or a plate-to-plate structure, and the electrolysis rate mainly depends on parameters such as electrode area, electrolysis voltage, and electrode spacing. In this embodiment, the electrolysis temperature during electrolysis is 650° C.-850° C., and the electrolysis voltage is -1.90V to -3.00V.

[0062] For the silicon powder attached to the cathode 9, there are two ways to obtain the silicon powder from the electrode after the electrolysis. One is to scrape the product silicon powder in a space with the same temperature as the electrolytic cell 5, because at this temperature, the molten salt in the gaps of the silicon powder is still in liquid state, and the silicon powder will not be strongly adhered to the electrode, and the silicon powder can be easily scraped off without damaging the electrode, and the electrode can be immediately moved back to the electrolytic cell 5 to continue working; the other is to scrape the product silicon powder at room temperature or non-high temperature environment. The main steps are to move the electrode and the product to an oxygen-free environment for preliminary cooling, cooling to below 500°C, and then moving to room temperature for cooling again. When it is cooled to below 80°C, the product part on the electrode is placed in water and soaked for 30 minutes to dissolve the metal salt adhering to the silicon powder in water, and the product can be easily scraped or washed.

[0063] The pickling solution used for cleaning the product is 0.1M hydrochloric acid, which is used to remove a small amount of metal impurities generated during electrolysis. If the purity requirement is not high, this step can be omitted. Water washing is divided into primary water washing and secondary water washing. In order to remove some soluble ions, the secondary water washing uses deionized water or water with less impurities for washing; the primary water washing can use the filtered water from the previous primary water washing and secondary water washing, which can effectively reduce the consumption of water resources.

[0064] The purity of the silicon powder obtained after cleaning and drying can reach more than 99.9%, and 90% of the powder particle size is below 15 microns.

[0065] Specific, combined Figure 1-Figure 3 As shown, waste glass is used as raw material, which is cleaned and crushed into small particles of 20 mesh. 20.0g of broken glass and 200.0g of anhydrous calcium chloride are weighed and poured into a graphite crucible with an inner diameter of 60mm. During electrolysis, the graphite crucible is used as the anode 13, and a graphite rod with a diameter of 8mm is inserted as the cathode 9. The graphite rod is placed coaxially with the crucible. The heating rate of the whole heating process is 4℃ / min. First, the temperature is raised to 350℃, kept warm for 1h, and the moisture is removed; then the temperature is raised to 850℃, kept warm and electrolysis is carried out. In the electrolysis stage, a pre-electrolysis voltage of -1.80V is first carried out, and electrolysis is carried out for 1h to remove some impurities; then the voltage is raised to -1.90V, electrolysis is carried out for 3h, and the electrolysis current is 700mA; the purity of the elemental silicon product in this example is 99.95%, and 90% of the powder particle size is below 15 microns. The laser particle size analysis chart is shown in Figure 2 .

[0066] Example 2

[0067] In another typical embodiment of the present invention, Figure 1-Figure 8 As shown, a device for producing silicon powder by continuous electrolysis of glass is provided, which is applied to the process for producing silicon powder by continuous electrolysis of glass as in Example 1.

[0068] A device for continuously electrolyzing glass to produce silicon powder, comprising:

[0069] An electrolytic cell 5, for containing molten salt;

[0070] The anode 13 is suspended in the electrolytic cell 5 by the anode fixture 4;

[0071] The cathode 9 is connected to the lifting mechanism 1 and is suspended in the electrolytic cell 5 by the lifting mechanism 1;

[0072] The scraping mechanism includes a scraper 11, which is arranged on the lifting path of the cathode 9 to scrape off the attached matter on the cathode 9;

[0073] The collecting mechanism includes a collecting plate 10 and a conveying channel 7. The collecting plate 10 is slidably mounted on one end of the conveying channel 7 and is connected to the conveying channel 7. The collecting plate 10 can be inserted under the cathode 9 to receive the attachments scraped off by the cathode 9.

[0074] like Figure 4-Figure 8 As shown, in this embodiment, the cathode 9 is connected to the lifting mechanism 1 through the cathode fixture 8. The lifting mechanism 1 can be a cylinder, an electric cylinder, an electric telescopic rod, etc., and the output end is connected to the cathode fixture 8. One end of the cathode fixture 8 is connected to the cathode 9, and the other end passes through the top of the electrolytic cell 5 and is connected to the output end of the lifting mechanism 1. Both the cathode 9 and the anode 13 can be made of carbon blocks.

[0075] An agitator 3 is arranged in the electrolytic cell 5 , and the agitator 3 is located between the anode 13 and the cathode 9 . The agitator 3 can adopt a blade-type stirring structure. The electrolytic cell 5 is connected to the raw material bin 2 , and the raw material bin 2 can put solid waste glass powder and calcium oxide powder into the electrolytic cell 5 .

[0076] The scraping mechanism also includes a moving mechanism, which drives the scraper 11 to move along the moving direction of the lifting mechanism 1. The scraper 11 can be stored in the receiving groove 12 and can be taken out by the moving mechanism. The moving mechanism can use a linear drive element such as a cylinder, an electric cylinder, and an electric telescopic rod, which can drive the scraper 11 to move relative to the cathode 9, thereby scraping and collecting the silicon deposited on the surface of the cathode 9.

[0077] A cavity is formed in the electrolytic cell 5 , and a cavity is provided above the molten salt for the collecting plate 10 to probe into. The cavity can accommodate the cathode 9 lifted by the lifting mechanism 1 , and the cathode 9 is scraped and cleaned by the scraper 11 in the cavity.

[0078] The electrolysis stage Figure 5 As shown, at this time, the cathode 9 and the anode 13 are both placed in the molten salt, the cathode 9 and the anode 13 are both in a low position, the collection plate 10 is retracted into the conveying channel 7, the scraper 11 is retracted to the storage place above, the raw material bin 2 releases the raw material into the molten salt of the electrolytic cell 5 at a uniform speed according to the electrolysis situation, and the stirrer 3 stirs continuously to accelerate the dissolution of the raw material, and also plays a role in driving away the bubbles on the surface of the anode 13. The presence of bubbles on the surface of the anode 13 will reduce the contact area between the electrode and the molten salt, which is not conducive to the electrolysis. At the same time, the oxygen component in the bubbles will react with the anode 13 to produce carbon dioxide or carbon monoxide, thereby consuming the anode 13. In the electrolysis stage, the electrolysis product silicon will be deposited on the cathode 9. Because the electrolysis product is a loose structure and will increase the resistance of the cathode 9 to a certain extent and reduce the current density, the product needs to be scraped and collected after a period of deposition.

[0079] The product collection stage is as follows Figure 6 As shown, at this time, the cathode 9 is pulled up and separated from the molten salt, the collecting plate 10 extends out from the conveying channel 7 and is located directly below the cathode 9, and the scraper 11 pops up from the receiving groove 12 and reciprocates up and down, thereby scraping the electrolytic products. The scraped products fall into the collecting plate 10 and are transported to the collecting bin 6 through the conveying channel 7. After the collection stage is over, the collecting plate 10 and the scraper 11 are both retracted, and the cathode 9 descends into the molten salt, stops descending when it is level with the position of the anode 13, and then energized for a new round of electrolysis.

[0080] The continuous electrolytic glass production silicon powder device can continuously produce high-purity silicon powder with a particle size of less than 15 microns. It does not require grinding or other treatments, and can be directly processed to produce silicon nitride and other downstream silicon-based materials, achieving low-energy production. The use of a gas-solid fluidized bed reactor can effectively increase the gas-solid contact area, improve the reaction efficiency, and solve the problem that the silicon powder at the bottom of the fixed bed cannot be converted into silicon nitride due to failure to contact with nitrogen.

[0081] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, 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 process for producing silicon powder by continuous electrolytic glass, characterized in that: include: The solid waste glass powder, calcium oxide powder and alkali metal chloride are mixed and heated to melt to form molten salt; Inserting the cathode and the anode into the molten salt respectively and applying electricity for electrolysis; During the electrolysis process, silicate ions in the molten salt generate electricity to produce silicon and deposit on the cathode, and gas is produced on the anode; The silicon deposited on the cathode is collected.

2. The process for producing silicon powder by continuous electrolytic glass according to claim 1, characterized in that: The alkali metal chloride salt adopts a single CaCl2 system or a mixed system of multiple alkali metal chloride salts.

3. The process for producing silicon powder by continuous electrolytic glass according to claim 1, characterized in that: The added amount of the solid waste glass is 10%-20% of the total weight of the molten salt, and the calcium oxide accounts for 0-2% of the total mass ratio of the calcium oxide and the solid waste glass.

4. The process for producing silicon powder by continuous electrolytic glass according to claim 1 or 3, characterized in that: The anode is made of graphite or a coating is arranged on the outside of the anode.

5. The process for producing silicon powder by continuous electrolytic glass according to claim 1, characterized in that: After the electrolysis is completed, the silicon powder is scraped from the cathode in a space with the same temperature environment as the electrolytic cell, or the cathode is removed and soaked after cooling, and the silicon powder is scraped after soaking.

6. The process for producing silicon powder by continuous electrolytic glass according to claim 1 or 5, characterized in that: After collecting the silicon deposited on the cathode, a gas-solid fluidized bed reactor is used to react the silicon powder in a high-temperature nitrogen environment to produce silicide.

7. A device for producing silicon powder by continuous electrolysis of glass, applied to the process for producing silicon powder by continuous electrolysis of glass as claimed in any one of claims 1 to 6, characterized in that: include: an electrolytic cell for containing molten salt; Anode, suspended in the electrolytic cell by an anode fixture; The cathode is connected to a lifting mechanism and is suspended in the electrolytic cell by the lifting mechanism; A scraping mechanism, including a scraper, is arranged on the cathode lifting path to scrape off the attached matter on the cathode; The collecting mechanism comprises a collecting plate and a conveying channel. The collecting plate is slidably mounted at one end of the conveying channel and is connected to the conveying channel. The collecting plate can be inserted under the cathode to receive the attachments scraped off by the cathode.

8. The device for producing silicon powder by continuous glass electrolysis according to claim 7, characterized in that: A stirrer is arranged in the electrolytic cell, and the stirrer is located between the anode and the cathode. The electrolytic cell is connected to a raw material bin.

9. The device for producing silicon powder by continuous glass electrolysis according to claim 7, characterized in that: The scraping mechanism also includes a moving mechanism, which drives the scraper to move along the action direction of the lifting mechanism.

10. The device for producing silicon powder by continuous glass electrolysis according to claim 9, characterized in that: A cavity is formed in the electrolytic cell, and a cavity for the collecting plate to probe into is provided above the molten salt, and the cavity can accommodate the cathode lifted by the lifting mechanism.

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