VACUUM APPARATUS FOR PRODUCING A SILICON-BASED MATERIAL

Abstract

The invention relates to an apparatus for the production of a silicon-based material from quartz and a reducing agent, the apparatus comprising: a reaction chamber (1) for carrying out a chemical reaction with the reactants, the reaction chamber including a sealed enclosure, a tank, and an arc furnace; a condensation chamber (2) for solidifying a chemical compound contained in a gas from the reaction chamber (1); and a gas conveying line (3) between the reaction chamber (1) and the condensation chamber (2), notable in that the condensation chamber (2) further comprises a vibrator for generating vibrations in a lateral wall (212) of the condensation chamber (2). Figure to be published with the abbreviation: Fig. 2

Description

Title of the invention: APPARATUS FOR PRODUCING A SILICON-BASED MATERIAL UNDER VACUUM FIELD OF THE INVENTION

[0001] The present invention relates to the general technical field of the production of a silicon-based material such as silicon (II) monoxide and / or silicon, in particular of 3N purity (99.9% purity) or higher (4N (99.99%), 5N (99.999%), 6N (99.999%), etc.).

[0002] More specifically, the invention relates to the continuous production - as opposed to batch production (or "batch", according to the terminology used in the field of industrial processes) - of a silicon-based material by chemical reduction of quartz in a device including an arc furnace.

[0003] BACKGROUND OF THE INVENTION

[0004] The chemical reaction of reducing quartz at high temperature can be implemented to obtain different silicon-based materials, in particular depending on the reducing agents used in the context of this reaction.

[0005] For example, the reduction of quartz with: • a carbon-based material allows the production of silicon, • silicon allows the production of silicon monoxide.

[0006] 1. Production of silicon

[0007] The production of metallic silicon is generally based on the carbo-thermal reduction of quartz at high temperature and atmospheric pressure.

[0008] This thermal reduction of quartz can be achieved by chemically reducing the quartz in the presence of carbon-based reducing agents in an electric arc furnace where a high temperature arc heats the reactants (quartz and reducing agents).

[0009] This makes it possible to produce so-called “metallurgical grade” silicon (or “MG-Si” acronym for the Anglo-Saxon expression “Metallurgical Grade Silicon”) with a maximum purity of 98-99%.

[0010] Metallurgical grade silicon can be used: • as an alloying element – ​​for example in the aluminium and steel industry – or • as a precursor - for example in the photovoltaic industry (solar panels), for silicones and for energy storage (lithium battery).

[0011] Technological developments in the fields of photovoltaics and energy storage have led to metallurgical grade silicon becoming a material strategic.

[0012] Therefore, the supply of high purity metallurgical grade silicon at a reasonable cost has become a necessity.

[0013] However, conventional devices and methods for producing metallurgical silicon have numerous drawbacks such as a high content of impurities.

[0014] To overcome this drawback, it is possible to use a raw material (quartz) with high purity. However, this solution increases the production cost of the metallurgical silicon produced.

[0015] Document US 11,267,714 proposes another solution consisting of implementing the carbothermic reduction of quartz at high temperature under vacuum. Carrying out the carbothermic reduction of quartz under vacuum makes it possible to promote the evaporation of impurities present in the reactants (quartz and reducing agents) as well as in the newly produced liquid metallurgical grade silicon.

[0016] With reference to [Fig.l], the apparatus according to US 11,267,714 comprises an electric arc furnace FA and a sealed enclosure E containing the arc furnace FA. This arrangement (sealed enclosure E containing the arc furnace FA) makes it possible to control the pressure at which the carbothermic reduction of quartz is carried out.

[0017] However, the alternative embodiments of the apparatus described in US 11,267,714 have certain limitations which make it difficult to use the solution according to US 11,267,714 on an industrial scale for the production of silicon.

[0018] 2. Production of silicon monoxide (II)

[0019] Silicon monoxide (SiO) can be obtained by partial chemical reduction of silicon dioxide (SiO2) in the presence of silicon (Si) according to the following reaction:

[0020] SiO2 + Si 2 SiO?

[0021] To produce silicon monoxide (SiO) by carrying out this reaction, a mixture of silicon (Si) and silicon dioxide (SiO2) is heated to a sublimation temperature of silicon(II) monoxide (SiO). When the reaction occurs at atmospheric pressure, the sublimation temperature is 1600°C. When the reaction occurs in a vacuum, the sublimation temperature is significantly lower, about 1200°C.

[0022] This allows the generation of a gas containing silicon monoxide (SiO) by chemical reduction. This gas is then cooled to a temperature below 800°C. The cooling of the gas containing silicon monoxide (SiO) is carried out quickly to limit the risks of restructuring, by disproportionation, of silicon monoxide (SiO) in the form of silicon (Si) and silicon dioxide (SiO2).

[0023] The rapid cooling of the gas containing silicon monoxide (SiO) induces, by condensation, the formation of an amorphous material, (SiO)n.

[0024] Such a glassy material based on silicon monoxide (SiO) is available as commercially, and can be used for various applications in the fields of optics or optoelectronics (deposition of SiO layer on a support), or in the field of lithium-based rechargeable batteries (manufacture of anodes in particular).

[0025] Although not yet realized, the apparatus according to US 11,267,714 could be suitable for the production of silicon monoxide (SiO).

[0026] However, the alternative embodiments of the apparatus described in US 11,267,714 have certain limitations which make it difficult to use the solution according to US 11,267,714 on an industrial scale for the production of silicon monoxide.

[0027] An aim of the present invention is to provide a method and a device allowing the continuous production of a silicon-based material, such as silicon (Si) and / or silicon monoxide (SiO).

[0028] More specifically, an aim of the present invention is to propose one (or more) improvement(s) to the apparatus according to US 11,267,714 to facilitate its use on an industrial scale for the production of a silicon-based material, such as silicon monoxide.

[0029] BRIEF DESCRIPTION OF THE INVENTION

[0030] To this end, the invention provides an apparatus for producing a silicon-based material (such as silicon and / or silicon monoxide) from reactants, said reactants comprising quartz and at least one reducing agent in which the apparatus comprises: • a reaction chamber for carrying out a chemical reaction using the reactants, said reaction chamber comprising: • a sealed enclosure connected to at least one suction pump to generate a vacuum inside the enclosure when the suction pump is activated, • an electric arc furnace housed inside the sealed enclosure to heat the reagents, • a tank intended to contain the reagents, • a condensation chamber for solidifying a chemical compound contained in the gas from the reaction chamber, said condensation chamber including: • a precipitation box defining a space for the solidification of the chemical compound contained in the gas coming from the reaction chamber, said precipitation box comprising at least one lateral partition, • a cooling system for cooling the gas from the reaction chamber, said cooling system being in thermal contact with the side wall, and • an extraction nozzle for collecting the solidified chemical compound, said extraction nozzle being connected to the precipitation box, • a conveying pipe for circulating the gas between the reaction chamber and the condensation chamber, said conveying pipe being connected to the enclosure on the one hand, and to the precipitation box on the other hand, remarkable in that the condensation chamber further comprises a vibrator associated with the side partition to induce the generation of vibrations in said side partition.

[0031] As will become clear in the following, the presence of a vibrator for generating vibrations in the side partition makes it easier to detach the silicon-based material likely to be deposited on said side partition. This improves the efficiency of the apparatus according to the invention by limiting the risk of depositing a thick layer of material on the side partition, such a thick layer reducing the efficiency of the cooling of the gas coming from the reaction chamber, and therefore of the apparatus.

[0032] Preferred but non-limiting aspects of the apparatus according to the invention are the following: • the side partition may have the shape of a truncated cone, a generator of the side partition forming a non-zero angle with a vertical axis; • the vibrator can be a mechanical vibrator; • the mechanical vibrator can be configured to exert a force on the lateral partition along a main axis inclined at a non-zero angle relative to the lateral partition, said non-zero angle being greater than 45° and less than 135°, preferably between 60° and 120°, in particular of the order of 90°; • the mechanical vibrator may extend outside the side partition, said mechanical vibrator being mechanically connected to the side partition by a mechanical connecting means, such as a rod in contact on the one hand with the side partition, and on the other hand with the mechanical vibrator; • the vibrator can be an acoustic vibrator; • the acoustic vibrator may comprise a plurality of transducers arranged on an internal face and / or on an external face of the partition, said transducers having respective resonance frequencies; • the side partition may comprise a layer of non-stick material such as a ceramic layer, or a fluoropolymer layer, or a layer of metal oxides; • the power supply system may include: • a receiving bowl intended to contain a reserve of reagents, a distribution channel for the circulation of reagents between the receiving bowl and the tank, and at least two valves to allow or stop the circulation of reagents between the receiving bowl and the tank; the extraction nozzle may include: a truncated funnel composed of a truncated side wall, a larger diameter upper edge of the truncated side wall being connected to the side partition, and a tube mounted on a lower edge of smaller diameter of the truncated side wall, at least two valves to allow or prevent the circulation of the silicon-based material between the truncated funnel and the outside of the condensation chamber. Brief description of the drawings

[0033] Other advantages and characteristics of the apparatus and method for producing a silicon-based material according to the invention will emerge more clearly from the following description of several variant embodiments, given as non-limiting examples, from the attached drawings in which: [Fig.l] is a schematic representation of a prior art silicon production apparatus, [Fig.2] is a schematic representation of an apparatus for producing silicon-based material according to the invention, [Fig.3] is a schematic representation of a reaction chamber of the production apparatus illustrated in [Fig.2], [Fig.4] is a schematic representation of a condensation chamber of the production apparatus illustrated in [Fig.2]. DETAILED DESCRIPTION OF THE INVENTION

[0034] We will now describe different examples of embodiment of the invention with reference to the figures.

[0035] 1. General

[0036] With reference to [Fig.2], the apparatus according to the invention comprises: a reaction chamber 1, a condensation chamber 2, and a delivery pipe 3.

[0037] The reaction chamber 1 allows the implementation of the quartz reduction reaction at high temperature. Depending on the nature of the reducing agents, this reaction allows the formation of gaseous silicon monoxide and / or liquid silicon. • in the presence of reducing agents such as silicon, the reaction chamber allows the formation of gaseous silicon monoxide, • in the presence of carbon-based reducing agents, the reaction chamber allows the formation of silicon.

[0038] In the following, the invention will be presented with reference to the production of silicon monoxide from quartz and a reducing agent such as silicon, it being understood that the invention can also be used: • for the production of silicon, or • for the production of both silicon and solid silicon monoxide.

[0039] The condensation chamber 2 makes it possible to cool the gases coming from the reaction chamber 1.

[0040] Advantageously, the reaction chamber 1 and the condensation chamber 2 are distinct and separate, said chambers being connected via the conveying pipe 3. This makes it possible in particular to use reaction and condensation chambers 1, 2 of different shapes and dimensions. This also makes it possible to reduce the height of the apparatus.

[0041] The conveying pipe 3 allows the circulation of gases between the reaction chamber 1 and the condensation chamber 2. It may comprise one (or more) pipe(s) connected on the one hand to the reaction chamber 1, and on the other hand to the condensation chamber 2.

[0042] In certain embodiments, the apparatus may further comprise a thermally insulating structure associated with the conveying pipe 3. Such a thermally insulating structure allows: • to reduce heat losses during the passage of gases from reaction chamber 1 to condensation chamber 2, and • to limit parasitic condensation of silicon monoxide on the internal face(s) of the pipe(s) of the delivery line 3 (which reduces the material yield of the reaction and can cause blockage of the line 3).

[0043] Since such a thermally insulating structure is known to those skilled in the art, it will not be described in more detail below. This thermally insulating structure may, for example, be composed of a thick ceramic lining of aluminum oxide (alumina or silicon carbide) arranged around or inside the conveying pipe 3.

[0044] 2. Reaction chamber

[0045] The reaction chamber 1 allows: • on the one hand to contain the reagents - namely the quartz and the agent(s) reducer(s) - used for the production of the silicon-based material, and • on the other hand, heating said reagents at high temperature to induce the partial chemical reduction reaction of the quartz in order to obtain the gas containing the silicon-based material.

[0046] With reference to [Fig.3], the reaction chamber 1 comprises: • an arc furnace 11, • a waterproof enclosure 12, • a reagent supply system 13, and • a tank 14 intended to contain the reagents, • the arc furnace 11 and the tank 14 being housed in the enclosure 12.

[0047] 2.1. Arc furnace

[0048] The arc furnace 11 makes it possible to heat the reactants at high temperature (in particular greater than or equal to 1200°C) to induce the chemical reduction reaction of the quartz in order to produce the gas containing the silicon monoxide (II).

[0049] For the formation of an electric arc allowing the heating of the reactants (quartz and reducing agent), the arc furnace 11 comprises electrodes 111, 112 supplied either from a direct current source or from an alternating current source. Each electrode 111, 112 may consist of a cylindrical graphite bar extending vertically.

[0050] The arc furnace 11 may comprise: • one (or more) mobile electrode(s) 111 held by one (or more) support(s) (not shown), the (or each) mobile electrode 111 being able to be introduced into the enclosure 12 by passing (each) through a through-orifice provided in the enclosure 12, • one (or more) fixed electrode(s) 112 housed in the bottom of the tank 14.

[0051] The support(s) holding the movable electrode(s) 111 make it possible to vary the distance between the ends of the fixed and movable electrode(s) to control the quantity of energy transferred to the reagents contained in the tank 14.

[0052] As indicated previously, each electrode 111, 112 is connected to a direct current source or to an alternating current source. One of the advantages of a direct current power supply is that the electrodes are not subject to the electromagnetic effects that the electrodes of a furnace powered from an alternating current source undergo.

[0053] In the case of a direct current power supply: • the movable electrode(s) 111 can be connected to the positive pole of the direct current source to form an anode, • the fixed electrode(s) 112 can be connected to the negative pole of the direct current source and form a cathode.

[0054] Since the arc furnace 11 is of a type known per se to those skilled in the art, its operation will not be described in more detail below.

[0055] 2.2. Enclosure

[0056] The sealed enclosure 12 makes it possible to define an enclosed space in which it is possible to generate a depression or obtain an inert atmosphere, that is to say a space in which it is possible to reduce the pressure to a value lower than atmospheric pressure.

[0057] To reduce the pressure in the enclosure, the reaction chamber 1 comprises one (or more) suction pump(s) (not shown) connected to the enclosure 12 to generate a vacuum in the enclosure 12 by suction.

[0058] Reducing the pressure in the enclosure 12 to a value lower than atmospheric pressure makes it possible to limit the temperature necessary for initiating the chemical reduction reaction of the quartz.

[0059] Such an enclosure 12 may have different shapes and be made from different materials to ensure this function. Thus, in the context of the present invention, the term "watertight enclosure" means a compartment composed of at least one wall 121 - for example made of steel - on either side of which there is a pressure difference. Thus, the watertight enclosure makes it possible to delimit two zones (i.e. an internal zone and an external zone) between which there is a pressure difference.

[0060] The sealed enclosure 12 comprises one (or more) through orifice(s), possibly for the passage: • one (or more) gas injection channel(s) 122, each channel 122 being able to be connected to a gas supply source (such as argon and nitrogen), • one (or more) suction channel(s) 123 which can be connected to a suction pump to enable the generation of a vacuum inside the enclosure 11, • one (or more) evacuation channel(s) 124 intended to be connected to the supply pipe 3 for the transfer of the gas from the reaction chamber 1 to the condensation chamber 2, • one (or more) of the electrodes 111, • electrical connection means (such as an electrically conductive cable, for example for the electrical connection of a sensor contained in the enclosure, etc.), • a casting channel (or channels) 144, etc.

[0061] The enclosure 12 is configured to withstand temperatures greater than or equal to 1000°C, in particular between 1200°C and 1800°C.

[0062] In certain embodiments, the reaction chamber 1 may comprise a thermally insulating structure associated with the enclosure 12 to reduce heat losses in the housing. Such a thermally insulating structure may be composed of a thick ceramic lining of aluminum oxide (alumina or silicon carbide) disposed around or inside the enclosure 12.

[0063] 2.3. Power supply system

[0064] The reagent supply system 13 makes it possible to fill the tank 14 with quartz and reducing agent(s).

[0065] The power supply system 13 comprises: • a receiving bowl 131 intended to contain a reserve of quartz and reducing agent(s), • a distribution channel 132 for the circulation of quartz and the reducing agent(s), and • two (or more than two) sealed valves 133a, 133b to allow or stop the circulation of quartz and the reducing agent(s).

[0066] The receiving bowl 131 comprises a bottom in which a through-light is provided connected to one end of the distribution channel 132, the other end of the distribution channel 132 opening into the tank 14.

[0067] The two valves (hereinafter referred to as first and second valves) 133a, 133b are mounted on the distribution channel 132. A controller (not shown) makes it possible to control the valves from a deactivated state to an activated state (and from an activated state to a deactivated state): • each valve blocking the passage of reagents (quartz + reducing agent(s)) between the receiving bowl 131 and the tank 14 in the deactivated state, • each valve allowing the passage of reagents (quartz + reducing agent(s)) between the receiving bowl 131 and the tank 14 in the activated state.

[0068] The first and second valves 133a, 133b define a sealed compartment C between the receiving bowl 131 and the tank 14 (and more generally between the exterior and the interior of the enclosure 12).

[0069] To fill compartment C, the controller activates the first valve 133a and deactivates the second valve 133b. The reagents (quartz + reducing agent(s)) flow by gravity from the receiving bowl 131 to compartment C. When compartment C is filled with reagents, the controller deactivates the first valve 133a, then activates the second valve 133b. The reagents flow by gravity from compartment C to the tank 14. Once the compartment is emptied, the controller deactivates the second valve 133b and a new filling cycle can be initiated (activation of the first valve 133a for filling compartment C, etc.). The presence of two valves 133a, 133b makes it possible to maintain the enclosure 12 at a pressure lower than atmospheric pressure during the filling of the tank 14.

[0070] 2.4. Tank

[0071] The tank 14 may consist of a graphite carcass coated externally with a refractory lining. Alternatively, the tank 14 may be made of alumina, silica, metal or silicon carbide (SiC).

[0072] The tank 14 (or crucible) is intended to contain the reagents, but also the products and / or by-products resulting from the chemical reduction reaction of the quartz.

[0073] The tank 14 comprises a bottom 141, one (or more) side wall(s) 142, and an upper opening 143. A-A' is denoted by A-A', a longitudinal central axis of the reaction chamber 1 which is vertical when the apparatus is placed on a horizontal flat surface.

[0074] In the following, the description is oriented by considering that the terms “upper” and “high” correspond to a direction generally parallel to the axis A-A' and going from the bottom 141 towards the opening 143, while the terms “lower” and “lower” correspond to an opposite direction.

[0075] The bottom 141 of the tank 14 may comprise a stud projecting towards the inside of the tank 14. More precisely, the stud projects from the bottom 141 and extends along the axis A-A' towards the opening 143. The stud may be made of an electrically conductive material and constitute one of the electrodes of the arc furnace (typically the fixed electrode). Alternatively, the bottom 141 may be devoid of a stud and comprise only a circular recess through which one of the electrodes of the arc furnace is mounted. As a further variant, the bottom 141 of the tank 14 may be devoid of a stud and of a circular recess, in particular in the case where the electrode (or electrodes) of the arc furnace is (are) mounted above the tank 14.

[0076] The tank 14 also comprises a pouring channel (or several channels) 144 for discharging the reaction products and / or by-products contained in the tank 14 to an external pocket intended to receive it for subsequent storage. A closure system - such as a nozzle or a plug made of carbon material - may be provided for closing the pouring channel (or channels) at the end of the chemical reduction reaction of the quartz.

[0077] 3. Condensation chamber

[0078] The condensation chamber 2 makes it possible to solidify the silicon monoxide (II) contained in the gas coming from the reaction chamber 1.

[0079] The condensation chamber 2 comprises a precipitation box 21, a cooling system 22, a vibrator 23 and an extraction nozzle 24.

[0080] 3.1. Precipitation box

[0081] The precipitation box 21 may be cylindrical in shape. It comprises, for example, an upper partition 211, a side partition 212 and possibly a lower partition.

[0082] The upper partition 211 comprises a through orifice 213 connected to the conveying pipe 3 to allow the introduction - into the precipitation chamber 21 - of the gas coming from the reaction chamber 1.

[0083] Advantageously, the lateral partition 212 (or all the partitions) of the precipitation box 21 may comprise a layer of smooth non-stick material such as a ceramic layer, or a layer of metal oxides or a layer of fluoropolymer. This makes it possible to promote / simplify the detachment of the solidified silicon monoxide deposited on the internal face of the lateral partition 212.

[0084] Furthermore, the lateral partition 212 of the precipitation box 21 may have a truncated cone shape. In particular, the generatrix of the lateral partition 212 may have a non-zero angle (in particular between 1 and 45°) with the vertical axis A-A'. This also makes it possible to promote / simplify the detachment of the solidified silicon monoxide deposited on the internal face of the lateral partition 212.

[0085] 3.2. Cooling system

[0086] The condensation chamber 2 also comprises a cooling system 22 composed for example of one (or more) heat exchanger(s) in which a heat transfer fluid circulates.

[0087] The integration of a cooling system 22 makes it possible to rapidly cool the gas coming from the reaction chamber 1 in order to solidify the silicon monoxide (II) on the internal face of the side partition 212.

[0088] This rapid cooling of the gas makes it possible to limit the risks of restructuring, by disproportionation, of silicon monoxide (SiO) in the form of silicon (Si) and silicon dioxide (SiO2).

[0089] In the embodiment illustrated in [Fig.4], the cooling system 22 comprises a coil 221 surrounding the side partition 212 over its entire height. A heat transfer fluid 222 - such as water - circulates in the coil 221.

[0090] This makes it possible to reduce the temperature of the gas containing silicon monoxide (II) • from a temperature of 1200°C to a temperature below 800°C when the device is used at a pressure below atmospheric pressure, or • from a temperature of 1600°C to a temperature below 800°C when the device is used at atmospheric pressure.

[0091] The cooling of the gas induces the solidification of the silicon monoxide contained therein. This solidified silicon monoxide is deposited on the internal face of the lateral partition 212 of the precipitation box 21.

[0092] 3.3. Vibrator

[0093] In order to ensure the efficiency of the gas cooling, the condensation chamber 2 also comprises a vibrator 23 configured to generate vibrations on the surface of the side partition 212. The generation of vibrations makes it possible to detach the solidified silicon monoxide (II) deposited on the internal face of the side partition 212.

[0094] Thus, the presence of a vibrator 23 makes it possible to limit the thickness of the layer of silicon monoxide “d” deposited on the internal face of the precipitation box in order to ensure effective cooling of the gas contained in the condensation chamber 2: in fact, the deposition of too thick a layer of silicon monoxide on the internal face of the lateral partition would prevent the effective transfer of heat between the inside and the outside of the condensation chamber, which would prevent the rapid cooling of gas containing silicon monoxide (II).

[0095] The vibrator 23 may be of the acoustic type, that is to say a system converting electrical energy into acoustic energy, for example in the ultrasonic range.

[0096] Alternatively, the vibrator 23 may be of the mechanical type, that is to say a mechanical system generating vibrations using a rotary, linear or electromagnetic mechanism.

[0097] 3.3.1. Acoustic vibrator

[0098] In the case of an acoustic vibrator, the latter comprises one (or more) transducer(s) and one (or more) generator(s) remote from the transducer(s) to supply the transducer(s) with electrical energy.

[0099] Each transducer is composed of: • a ceramic made from a homogeneous or piezocomposite material • and possibly an adjustment module (not shown).

[0100] Each transducer constitutes a resonant element, like a tuning fork. The transducer(s) may be arranged on the internal face or (preferably on) the external face of the side partition 212.

[0101] In the embodiment illustrated in [Fig.4], the vibrator 23 comprises a plurality of transducers arranged on the external face of the lateral partition 212, and more precisely around the cooling system 22.

[0102] According to the invention, each transducer produces, in the lateral partition 212, waves with a frequency between 20 kHz and 5 MHz, preferably of the order of 100 kHz. This makes it possible to promote the detachment of the solidified silicon monoxide (II) deposited on the internal face of the lateral partition 212.

[0103] Advantageously, the waves are well distributed in the precipitation box 21 thanks to the fact that the transducers are placed homogeneously on the lateral partition 212. To obtain a homogeneous acoustic field, small transducers, i.e. less than 10 cm and preferably between 2 cm and 5 cm, can be used. This allows optimal paving. The shape of each transducer can, for example, be circular, square or polygonal.

[0104] Preferably, each transducer has its own resonance frequency. The fact that the natural frequencies of the transducers are different prevents standing waves from being established in the precipitation box 21. This has the advantage of improving the acoustic homogeneity in the precipitation box 21.

[0105] As indicated above, each transducer may also comprise an adjustment module, which may be an electronic power card. In this case, the piezoelectric ceramic of the transducer is powered by the electronic power card providing it with an alternating voltage corresponding to its own vibration mode.

[0106] 3.3.2. Mechanical vibrator

[0107] In the case of a mechanical vibrator, this may comprise a core (or weight) mounted mobile in linear translation (along said main axis) on two aligned bearings, and moved by the action of a periodic and alternating electromagnetic field.

[0108] Such a mechanical vibrator is configured to exert an axial force (i.e. directed along a main axis (or direction)) on the lateral partition 212, this force being invariable over time.

[0109] Advantageously, the main axis along which the force is exerted may be inclined relative to the lateral partition 212 to be vibrated, by an angle greater than 45° and less than 135°, preferably between 60° and 120°, in particular close to 90°. This makes it possible to promote the detachment of the solidified silicon (II) monoxide deposited on the internal face of the lateral partition 212.

[0110] The mechanical vibrator may be arranged outside the precipitation box 21 and in particular around the cooling system 22 extending opposite the external face of the lateral partition 212. In this case, the mechanical vibrator is connected to the lateral partition 212 by a mechanical connection means, such as one (or more) rod(s) in contact on the one hand with the external face of the lateral partition 212, and on the other hand with the mechanical vibrator.

[0111] The use of an electromagnetic type mechanical vibrator makes it possible to propose a vibration generation solution with a very low cost.

[0112] Such mechanical vibrators further have the following advantages: • they are compact, • they are of low mass, • they are robust, • they allow continuous operation; and • they are capable of applying relatively significant forces to the precipitation box 21 - via the mechanical connection means - for example of the order of a few tens of newtons.

[0113] 3.4. Extraction nozzle

[0114] The extraction nozzle 24 makes it possible to collect the silicon monoxide (II) powder detached from the side partition 212.

[0115] Advantageously, the extraction nozzle 24 can be positioned under the precipitation box 21 to recover the detached silicon monoxide (II) powder falling by gravity.

[0116] The extraction nozzle 24 comprises: • a truncated funnel 241 composed of a truncated side wall of which: • the upper edge defines a large diameter upper base fixed to the side partition 212 (or to the lower partition if the precipitation box 21 includes such a lower partition), and • the lower edge defines a lower base of smaller diameter, and • a tube 242 mounted at the lower base of the funnel 241.

[0117] The extraction nozzle 24 also comprises two (or more than two) sealed valves 243a, 243b to allow or stop the circulation of the solidified silicon monoxide (II) powder between the truncated funnel 241 and the outside of the condensation chamber 2. The valves 243a, 243b are mounted on the tube 242.

[0118] A controller (not shown) makes it possible to control the valves 243a, 243b from a deactivated state to an activated state (and from an activated state to a deactivated state): • each valve 243a, 243b blocking the passage of the silicon monoxide (II) powder between the funnel 241 and an external container in the deactivated state, • each valve 243a, 243b allowing the passage of the silicon monoxide (II) powder between the funnel 241 and the external container in the activated state.

[0119] The two valves 243a, 243b - hereinafter referred to as "first valve" and "second valves" - define a sealed compartment CE between the funnel 241 and the external container 5 (and more generally between the exterior and the interior of the condensation chamber 2).

[0120] For filling the compartment CE, the controller activates the first valve 243a and deactivates the second valve 243b. The silicon monoxide (II) powder flows by gravity from the funnel 241 to the compartment CE. When the compartment CE is filled with powder, the controller deactivates the first valve 243a, then activates the second valve 243b. The powder flows by gravity from the compartment CE to the external container 5. Once the compartment CE is emptied, the controller deactivates the second valve 243b and a new filling cycle can be initiated (activation of the first valve 243a for filling the compartment CE, etc.). The presence of two valves 243a, 243b makes it possible to maintain the precipitation box 21 at a pressure lower than atmospheric pressure during the filling of the external container.

[0121] 4. Conclusions

[0122] The apparatus described above allows the continuous production of a silicon-based material: • such as silicon monoxide (II) powder, or • silicon, or • silicon and silicon monoxide, or • an intermediate oxide, SiOx (0 <x<2).

[0123] The integration of a vibrator 23 makes it possible to detach the silicon monoxide (II) solidifying on the walls of the precipitation box 21 from the condensation chamber 2.

[0124] This limits the risks of disproportionation of silicon monoxide by guaranteeing rapid and efficient cooling of the gas generated in the reaction chamber.

[0125] The reader will have understood that numerous modifications can be made to the invention described above without materially departing from the new teachings and advantages described here.

Claims

Claims

1. Apparatus for producing a silicon-based material from reactants, said reactants comprising quartz and at least one reducing agent wherein the apparatus comprises: • a reaction chamber (1) for carrying out a chemical reaction using the reactants, said reaction chamber (1) comprising: • a sealed enclosure (121) connected to at least one suction pump to generate a vacuum inside the enclosure (121) when the suction pump is activated, • an electric arc furnace (11) housed inside the sealed enclosure (121) to heat the reactants, • a tank intended to contain the reagents, • a condensation chamber (2) for solidifying a chemical compound contained in the gas coming from the reaction chamber (1), said condensation chamber (2) including: • a precipitation box (21) defining a space for the solidification of the chemical compound contained in the gas coming from the reaction chamber (1), said precipitation box (21) comprising at least one lateral partition (212), • a cooling system (22) for cooling the gas coming from the reaction chamber (1), said cooling system (22) being in thermal contact with the side partition (212), and • an extraction nozzle (24) for collecting the solidified chemical compound, said extraction nozzle being connected to the precipitation box (21), • a conveying pipe (3) for the circulation of gas between the reaction chamber (1) and the condensation chamber (2), said conveying pipe (3) being connected to the enclosure (11) on the one hand, and to the precipitation box (21) on the other hand, characterized in that the condensation chamber (2) comprises in furthermore a vibrator (23) associated with the side partition (212) to induce the generation of vibrations in said side partition (212).

2. Apparatus according to claim 1, wherein the side partition (212) has a truncated cone shape, a generatrix of the side partition (212) forming a non-zero angle with a vertical axis (A-A').

3. Apparatus according to any one of claims 1 or 2, wherein the vibrator is a mechanical vibrator.

4. Apparatus according to claim 3, wherein the mechanical vibrator is configured to exert a force on the lateral partition (212) along a main axis inclined at a non-zero angle relative to the lateral partition (212), said non-zero angle being greater than 45° and less than 135°, preferably between 60° and 120°, in particular of the order of 90°.

5. Apparatus according to any one of claims 3 or 4, wherein the mechanical vibrator extends outside the side partition (212), said mechanical vibrator being mechanically connected to the side partition (212) by a mechanical connecting means, such as a rod in contact on the one hand with the side partition (212), and on the other hand with the mechanical vibrator.

6. Apparatus according to any one of claims 1 or 2, wherein the vibrator is an acoustic vibrator.

7. Apparatus according to claim 6, wherein the acoustic vibrator comprises a plurality of transducers arranged on an inner face and / or on an outer face of the side partition (212), said transducers having respective resonant frequencies.

8. Apparatus according to any one of claims 1 to 7, wherein the side wall (212) comprises a layer of non-stick material such as a ceramic layer, or a fluoropolymer layer, or a metal oxide layer.

9. Apparatus according to any one of claims 1 to 8, wherein the supply system (12) comprises: • a receiving bowl (121) intended to contain a reserve of reagents, • a distribution channel (122) for the circulation of the reagents between the receiving bowl (121) and the tank (14), and • at least two valves (123a, 123b) for authorizing or stopping the circulation of the reagents between the receiving bowl (121) and the tank (14).

10. Apparatus according to any one of claims 1 to 9, wherein the extraction nozzle comprises: • a truncated funnel composed of a truncated side wall, a larger diameter upper edge of the truncated side wall being connected to the side partition (212), and • a tube mounted on a lower edge of smaller diameter of the truncated side wall, • at least two valves to allow or prevent the circulation of the silicon-based material between the truncated funnel and the outside of the condensation chamber (2).

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