WO2012064047A2

WO2012064047A2 - Apparatus for manufacturing fine powder of high purity silicon

Info

Publication number: WO2012064047A2
Application number: PCT/KR2011/008342
Authority: WO
Inventors: 시마무네타카유키; 카토켄지; 사카타토요아키
Original assignee: 타운마이닝 컴퍼니., 리미티드; 씨.에스.라보레토리 인 테크놀로지 리미티드
Priority date: 2010-11-11
Filing date: 2011-11-11
Publication date: 2012-05-18
Also published as: KR101525859B1; WO2012064047A3; JP2012101997A; KR20130097219A; JP5574295B2

Abstract

The present invention relates to an apparatus for manufacturing a fine powder of high purity silicon, and the apparatus for manufacturing a fine powder of high purity silicon is characterized by comprising: (1) a device for supplying zinc gas by heating and evaporating metallic zinc above the boiling point of zinc; (2) a device for supplying liquid silicon tetrachloride from among the zinc gases;(3) a device for generating a reactive gas containing silicon particles by reaction through mix-stirring of the zinc gas and the liquid silicon tetrachloride; (4) a device for precipitating a portion of the gaseous component while simultaneously growing the generated silicon particles as the reactive gas temperature is lowered to between 300^oC and 800^oC; (5) a device for obtaining solid silicon by evaporation of water and heating to above 950 degrees while simultaneously maintaining precipitation; and (6) a device for exhaust gas for discharging off exhaust gas that includes un-reacted gases, etc. and includes evaporated water.

Description

【Specification】

[Name of invention]

High Purity Silicon Fine Powder Manufacturing Equipment

[Technical Field]

The present invention relates to an apparatus for producing high purity silicon fine powder. More specifically, silicon fine powder having high purity and fine crystals, which can be mainly used as a negative electrode material for a lithium ion battery, a raw material for high purity silicon nitride, a solar cell material, or other raw material for silicon compounds. It relates to a manufacturing apparatus that can provide.

[Technique to become background of invention]

High purity silicon is known to be used for electronic devices, such as single crystal silicon wafers, and ultra high purity products of about 11 nine. Also, depending on the type of impurity element, it is also used for solar cells, which are rapidly expanding in recent years. Need high degree of purity. Therefore, in connection with the production of silicon, studies have been conducted to grow the crystals of silicon to be produced so that impurities are not contained. In other words, as a typical silicon production process, a so-called Siemens method is known in which trichlorosilane is reduced to hydrogen and the resulting silicon is grown on the substrate for a predetermined time. However, this technique is a good way to obtain ultra-pure silicon, but because the energy consumption is very large and the production rate is slow, inevitably large equipment is required, and the manufacturing cost is very high.

On the other hand, various silicone manufacturing methods which change the raw material used or differ from a manufacturing condition are proposed (nonpatent literature 1). However, these conventional methods have a problem that the raw material is special or that the raw silicon compound is unstable and explosive, and thus has not been widely used.

In addition, metallurgical methods for plasma melting using high purity silicon of about 4 atoms as a raw material, or methods for volatilizing impurities and purifying them by electron beam melting are known. And, high purity by the above method A method of obtaining high purity silicon by adding a one-way arching technique in the process of uneven silicon and moving only impurities to the ends has been proposed.

However, these methods can obtain ultra-high-purity chalcones, but there is a problem in that the practical use is not easily expanded in that the raw material silicon is high purity and expensive, and there are few suitable silicon sources. In addition, since the said silicon is all performed in order to obtain dense high-purity silicon in block form, it did not correspond to the objective of this invention. In recent years, the method of reducing silicon tetrachloride to zinc is mainly examined from the viewpoint of energy saving. That is, the production of silicon by the zinc reduction method of silicon tetrachloride was first proposed around 1950, and many technical proposals have been made since then, and some are known to be commercialized. However, it is known that such a method is a high temperature process and it is difficult to maintain its operating conditions, and it is difficult to further treat zinc chloride generated.

Accordingly, various studies have been made. For example, Patent Document 1 and Patent Document 2 propose a method of obtaining silicon by blowing silicon tetrachloride into a liquid zinc surface. This method is characterized in that the silicon can be produced at a relatively low temperature, but in reality, it is not easy to separate the solid phase silicon from the liquid layer zinc and the gaseous reaction product zinc chloride, and impurities of the liquid layer zincation are common in the silicon. It has a problem that the separation is very difficult.

In addition, several proposals have been made with respect to a method of reducing silicon tetrachloride gas to zinc gas and producing silicon on the furnace wall of the reaction furnace. In patent document 3, the mixing ratio of gas is specifically determined, precipitation is controlled, and the growth of crystal | crystallization is promoted. In addition, as a method for facilitating the deposition and extraction of silicon to the furnace wall, Patent Document 4 proposes to use a release material for the wall in the semi-ungjok. However, there is a problem that the batch process increases the chance of introducing impurities into the formed silicon, and the removal and separation of silicon tetrachloride, which is a reaction gas, is difficult. And all of these methods The focus is on growing the crystals of the resulting silicon to the maximum possible.

In addition, in order to grow the formed silicon crystal larger, the patent literature

5 shows that the reaction between silicon tetrachloride gas and zinc gas is carried out under special conditions in an inert carrier gas atmosphere. In Patent Document 6, a silicon seed crystal plate is placed in a reaction chamber, or such a wall is made to grow needle-shaped silicon therein. However, these also cannot escape from the batch process, and even if improved, it was very difficult to prevent the entry of impurities. All of these methods then focus on making the particles as large as possible to achieve high purity of silicon.

Patent Document 7 shows that silicon tetrachloride gas, which is a raw material, is formed in a cylindrical shape around a silicon tetrachloride gas nozzle by blowing a zinc tetrachloride gas from the nozzle in a lower zinc gas atmosphere. Although the patent document defines the flow rate of gas substantially, the Example shows that manufacturing is carried out by controlling reaction by sending a lean gas. In addition, the above patent documents show that relatively large equipment can be used to make large crystals, and that crystals can be grown without contacting the inner surface of the reaction column by growing crystals around the nozzle. Accordingly, although the above-mentioned patent document shows that high-purity crystals do not contain impurities, this method not only synthesizes a large amount of fine crystals in a short time, but also grows crystals on the contrary with the same zinc reduction method.

Regarding the problem of the previously known method, the present inventors have proceeded to examine the high temperature process by the turning melting method as a method of continuously producing silicon without producing silicon in the furnace wall of the reaction furnace. Related contents were implemented in inventions, such as the following patent document 8, patent document 9, patent document 10, patent document 11, patent document 12, and the like. Accordingly, by the above inventions In addition, it is possible to continuously operate without being affected by the furnace wall of the reactor, which makes it possible to give the product silicon good performance.

However, this method also requires a high temperature of more than 120 CTC, typically around 1410 ^° C, which is the melting point of silicon. It was.

In addition, since the reaction device itself forms a cyclone, there is a problem in that it becomes large in size, and because the reaction temperature is very high, problems in durability of the material constituting the reaction furnace are likely to occur. There is a problem that it is difficult to secure device materials. In order to solve these problems, the present inventors performed the vapor phase reaction method similarly in Patent Document 13, but succeeded in extracting silicon as a single crystal fiber by specifying reaction conditions. In addition, while purifying the high purity of the silicon thus produced, it was extracted with a melt to further improve efficiency.

However, in order to form such fibrous single crystals, high concentrations of zinc and silicon tetrachloride must be reacted at a high temperature. However, since the pressure change of the semi-autumn is relatively large, it is found that the control of the conditions is strict for practical use. In addition, a problem has been found that sometimes the concentration of impurities tends to be high because of high temperature reaction. And all of the above methods are conditions that do not cause the formation of fine powder because crystal growth is given priority, and silicon fine powder could not be extracted from them.

In this way, the silicon crystals were generated in the reaction apparatus and then melted, thereby enabling continuous operation. On the other hand, in order to generate the crystals, conditions such as temperature and atmosphere were strict and the durability of the apparatus could be caused. In addition, deviations easily occur in the crystals to be produced, and in the separation process from the gas, crystals in which growth is sometimes unsatisfactory often occur in the exhaust gas. On the other hand, as a method of growing the crystal to be produced in a substantially constant state as shown in Patent Document 6 Although it is considered to have a seed crystal, this operation is difficult to coincide with this object of making a fine crystal at the same time.

On the other hand, the present inventors found that the reaction of reducing zinc tetrachloride by zinc was very fast, and examined the manufacturing conditions and apparatus for greatly expanding the production capacity while using a smaller apparatus. That is, liquid silicon tetrachloride was supplied in a high concentration of gaseous zinc to realize silicon production conditions that were very high. (Patent Document 15, Patent Document 16, Patent Document 17). In these inventions, it was found that the reaction zone became small, and the silicon, which was the reaction product, grew while changing into silicon crystals in the intermediate before becoming complete silicon (Non-Patent Document 2).

In the above processes, silicon crystals are obtained by separation of the reaction gas and silicon by a crystal growth unit, a cyclone, and the like, and, if necessary, through a fusion process. During this process, the physical separation of gaseous and solid-phase silicon should result in at least some degree of crystal growth between them, and the resulting silicon will involve some growth of the particles, even without dissolution. There was a problem. However, since purity is a problem for solar cells, it was rather desirable that the particles be larger.

There exists a method of using a so-called fluidized bed as a method of generating silicon on a seed crystal only continuously (nonpatent literature 1). However, when zinc chloride is present in the system as the reaction gas, separation and recovery of the reaction gas becomes difficult, and thus there is a problem that formation of the fluidized bed itself is difficult.

In addition, the above methods are all aimed at obtaining high purity / ultra high purity silicon, and there is no known method for obtaining fine crystals while maintaining high purity.

[Patent Document 1] Japanese Patent Application Laid-Open No. 11-060228

[Patent Document 2] Japanese Patent Application Laid-Open No. 11-092130

[Patent Document 3] Japanese Patent Publication 2003-095633

[Patent Document 4] Japanese Patent Publication 2003-095632 [Patent Document 5] Japanese Patent Application Laid-Open No. 2004-196643

[Patent Document 6] Japanese Unexamined Patent Publication 2003-095634

[Patent Document 7] Japanese Patent Laid-Open No. 2003-095634

[Patent Document 8] Japanese Patent Application Laid-Open No. 2004-210594

[Patent Document 9] Japanese Patent Publication 2003-342016

[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-010472

[Patent Document 11] Japanese Unexamined Patent Publication No. 2004-035382

[Patent Document 12] Japanese Patent Laid-Open No. 2004-099421

[Patent Document 13] Japanese Patent Laid-Open No. 2006-290645

[Patent Document 14] Japanese Patent Laid-Open No. 2006-298740

[Patent Document 15] Japanese Patent Laid-Open No. 2008-81387

[Patent Document 16] Japanese Patent Laid-Open 2008—115066

[Patent Document 17] Japanese Patent Laid-Open No. 2008-115455

[Patent Document 18] Japanese Patent Publication 2009—13042

[Nonpatent Literature 1] Silicon 24 (1994)

[Non-Patent Document 2] Annual Report, Nagoya Institute of Technology and Ceramics-based Engineering Research Center, vol7 17 (2007)

[Content of invention]

Problem to be solved

The present invention is to provide a high-purity silicon micropowder manufacturing apparatus capable of obtaining ultra-high-purity silicon having a fine particle shape and high efficiency and a large amount using minimal energy.

[Measures of problem]

The present invention provides a device for supplying zinc gas by heating and evaporating metal zinc above the boiling point of zinc, (2) a device for supplying liquid silicon tetrachloride in the zinc gas, and (3) the zinc gas. And mixing and stirring the silicon tetrachloride to form a reaction gas containing silicon particles, and (4) growing the silicon particles produced by lowering the temperature of the reaction gas to 3oo ^° C to 8 (xrc). And (5) mechanisms for precipitating together with some of the gas components At the same time maintaining the precipitate, the precipitate is heated to 950 ^° C or more, volatilization of the evaporate to obtain a solid silicon, and (6) to discharge the exhaust gas containing the evaporate and non-aerated gas out of the system An apparatus for producing high purity silicon fine powder, comprising an exhaust gas mechanism.

By using the apparatus for producing high purity silicon fine powder, in the process of producing silicon by reducing silicon tetrachloride with zinc, it is possible to react at a very high concentration despite the disproportionation reaction, and the silicon nucleus is selectively produced. Under the conditions, silicon is produced, and as a result, a large amount of fine powder silicon is simultaneously produced, and the silicon of the fine powder can be efficiently obtained by partially precipitating the silicon together with the raw material zinc and the semi-aerated zinc.

In the gas reaction as in the present invention, it is generally known that increasing the concentration of the source gas promotes nucleation of the reaction product, resulting in smaller crystal grains. The method of supplying and reacting liquid silicon tetrachloride in the zinc gas utilized by the present inventors is the highest concentration as reaction performed under normal pressure, and is the most preferable form in order to obtain microcrystals. Accordingly, the present invention has been achieved for the purpose of obtaining fine grain crystals of high purity silicon with high efficiency and high yield while maintaining such conditions.

In other words, zinc gas can be obtained by boiling, evaporating and evaporating a liquid or solid zinc metal directly from the mechanism 1 for supplying zinc gas, thereby obtaining a zinc gas having a boiling temperature of almost zinc gas. In addition, it can be heated to the required reaction temperature 1050 ^° C to 1300 ^° C. At this time, there is no need for atmospheric gas, but in order to smooth the flow of the gas in the system and to prevent the closing in the middle, argon gas can be additionally used, and thus slightly pressurized.

However, the amount of gas used or the degree of pressurization should be not so great, for example, if the pressure is up to lOOOOPa degree (pressure of lni, such as water). Suffice. In the case of a semi-ungular pipe thickness of about 25 kPa, the amount of argon is preferably about 50 ml / (min) to 1000 ml / (min).

The apparatus for supplying the zinc gas includes a gasification unit for gasifying a high purity solid or liquid zinc quantitatively from the boiling point of zinc to 1300 ^° C .; And an adjusting unit for heating the generated zinc gas and adjusting the temperature. The zinc gas may be quantitatively supplied by adjusting the temperature.

On the other hand, in the heated heated zinc gas, silicon tetrachloride having a boiling point of about 56.4 ^° C. can be supplied as a liquid in the mechanism 2 for supplying silicon tetrachloride. The supply of silicon tetrachloride may be performed by dropping in the flow of zinc gas from the top using gravity, or spraying silicon tetrachloride in the flow of zinc gas.

The mechanism (2) for supplying liquid silicon tetrachloride into the zinc gas includes: a passage portion of zinc gas supplied and passed through the zinc gas supply mechanism; And a supply part for quantitatively spraying or dropping liquid silicon tetrachloride in the passage part.

In addition, the silver content of the association part of the silicon tetrachloride and the flow of zinc gas is

It is preferably 1050 r to 1300 ° C, more preferably may be iioo ° c to i2oor. That is, the temperature of the passage portion of the zinc gas of the supply mechanism of silicon tetrachloride can be maintained ^at 1050 ^° C to 1300 ^° C. However, the actual temperature of the associated portion may be slightly lower than the above range.

When the temperature of the associating portion is less than 1050 ^° C., the silicon or silicon precursor produced by the reaction is easily precipitated, and the silicon or silicon precursor is precipitated at the associating portion of zinc and silicon tetrachloride, which may interfere with continuous operation. There is a possibility. Therefore, the temperature of the associating part is preferably high, but at 1300 ^° C or higher, problems due to the durability of quartz glass or silicon carbide sintered body, which are commonly used, or problems of excessive energy consumption are caused. Left. In the associating portion, zinc and silicon tetrachloride associate with gas-liquid or gas-gas, and at least partially react, and the gas containing partially produced silicon or silicon precursor produces a reaction gas having stirring means therein. It is guided by the mechanism (3) to perform, and the reaction continues to complete. The agitation means used here are completely agitated with zinc and silicon tetrachloride and are sufficiently agitated. Utensils may be used. For example, a randomly placed baffle plate or a pipe called a square mixer, which divides the gas into half, breaks it longitudinally and half of it by shearing, and combines it in one cycle. It is possible to use a mechanism of stirring and mixing repeatedly. By these things, a perfect mix was obtained without pressure loss.

That is, (3) the mechanism for generating a reaction gas containing silicon particles by the mixed stirring reaction of the zinc gas and silicon tetrachloride, is a cylindrical body maintained at a temperature of 1050 ^° C to 1250 ^° C., It may include elements that turbulent gas.

The gas turbulent element may consist of baffle plates placed at uneven intervals or may be square mixers.

The reaction gas containing the silicon precursor and silicon generated in this way flows in the mechanism 3, and reaction further advances. This reaction material is sent to a mechanism (4) which grows silicon particles maintained ^{at a} temperature of 30 ^° C. to 800 ^° C. and at the same time precipitates together with a part of the gaseous component, and at least the reaction gas at least half of zinc gas and zinc chloride. A part and the silicon which generate | occur | produce are united and precipitate. As a result, very fine silicon particles before crystal growth precipitate with zinc chloride or zinc gas.

The produced precipitate is in a state containing very fine particles because it is co-precipitation with zinc chloride or zinc. Sedimentation of silicon by the above-mentioned silver is performed in a very short time, and is maintained at about 0.5 seconds to about 2 seconds at a portion maintained ^at 300 ^° C. to 800 ^° C., and passes through a vertical tube maintained at the temperature. It can be almost completely precipitated silicon. The silicon precipitated through this temperature portion volatilizes the evaporate maintained at 950 ^° C. or higher, and reaches a holding tank, which is a mechanism (5) for obtaining solid silicon. The volatiles such as zinc and zinc chloride are separated and removed to obtain high purity. Only silicon fine particles remain. In this case, unreacted silicon tetrachloride, such as zinc or zinc chloride, is discharged from the exhaust gas apparatus, so that the exhaust gas components are usually treated and recovered.

If necessary, further stabilization can be achieved by making the mechanism 4 which grows the silicon particles and precipitates together with a part of the gas as an inclined tube instead of the vertical type. If the slope is inclined ^at 30 ^° to 90 ^° with respect to the horizontal, and the silver content of the inclined portion is kept at 300 ^° C to 800 ^° C, preferably 500 ^° C to 750 ^° C, silicon, zinc chloride and zinc are integrally formed therein. At the same time it precipitates almost instantaneously, at the same time, the product slides down the inclined portion slowly, taking time to fall into the silicon holding tank, where the volatiles are volatilized to remain as pure silicon. The inclination of the inclined portion is preferably about 30 ^° to 90 ^° with respect to the horizontal, and the holding time can be changed by the angle.

Here, if the inclination of the inclined tube is less than 30 ^° , the fall of the product silicon is likely to be incomplete, and sometimes stays, which may cause closure. However, the proximity time becomes shorter, and the holding time becomes shorter and unevenness tends to occur depending on the conditions. Therefore, it is necessary to determine the inclination angle according to the use and production capacity.

That is, the apparatus for producing a precipitate at least partially by lowering the temperature of the reaction gas (300) to 300 ^° C to 800 ^° C, is maintained at a temperature of 300 ^° C to 800 ^° C and 30 ^° to 90 ^° with respect to the horizontal It can be a tube inclined into. The apparatus (4) generates a precipitate containing silicon in the spectral and inner wall portions, while maintaining the precipitate at the bottom of the product and the inner wall of the tubular body. It may be characterized in that it is heated to 950 ^° C. or higher, and volatilized evaporates are sent to a mechanism for obtaining solid silicon. (5) The apparatus for warming the precipitate above 950 ^° C. and volatizing the evaporate to obtain solid silicon comprises: an element receiving a gas comprising a precipitate containing silicon from the apparatus for lowering the temperature; Silicone holding containers; And an element for exhausting the exhaust gas.

In addition, the mechanism (5) may be characterized in that the bottom of the silicone holding container is heated from the bottom with a heater maintained at a temperature of loocrc to iioo ^° c.

The apparatus for manufacturing high purity silicon fine powder may further include an extraction element for extracting silicon generated in the silicon holding container even during reaction.

The element for discharging the exhaust gas can be connected to the processing mechanism of the exhaust gas.

On the other hand, the high-purity silicon fine powder production apparatus, as well as for solar cells (solar cell), in particular, fine powder high-purity silicon as a lithium ion battery negative electrode or silicon nitride raw material, the moisture of the power required for the current silicon production In addition, it is a manufacturing apparatus for manufacturing in the state of fine powder which has not been reported before, and it is a technology that will be an important means to solve the future energy problem, global warming problem by CO ₂ . In particular, since it has the possibility of greatly improving the characteristics of the current lithium ion secondary battery, it is considered to be very widely used for manufacturing secondary battery raw materials for hybrid and electric vehicles which are expected to be greatly expanded in the future.

【Effects of the Invention】

According to the present invention, by supplying silicon tetrachloride in the liquid phase in a high temperature and high concentration of zinc gas and reacting with vigorous stirring in a high state of silver, silicon is produced by silicon tetrachloride, which is part of zinc zinc, which is a reaction product, and zinc chloride which is a reaction product. By coagulating together at 30 CTC to 800 ^° C., fine silicon particles can be stably obtained with high yield. In addition, the agglomerated product at this temperature is maintained at a temperature above the boiling point of zinc in the holding tank. By evaporating the volatile products mainly comprising zinc and zinc chloride, fine particles of high purity silicon can be obtained in high yield.

[Brief Description of Drawings]

1 shows a conceptual diagram of a manufacturing apparatus of one embodiment of the invention. 2 shows a conceptual diagram of a manufacturing apparatus of an embodiment of the present invention, in which a precipitate of silicon is used as an inclined tube.

3 is a conceptual diagram illustrating a manufacturing apparatus of an embodiment of the present invention, in which an exhaust gas treatment unit is provided with a water circulation mechanism.

Fig. 4 shows a conceptual diagram of a manufacturing apparatus of one embodiment of the invention, in which a mechanism for continuously extracting silicon from a silicon holding container is provided.

[Specific contents for implementation of the invention]

The present invention will be described in more detail with reference to the drawings. That is, Figure 1 is a case in which a device for growing the silicon particles generated by lowering the temperature of the reaction gas containing silicon to 300 ^° C to 800 ^° C and at the same time to precipitate with a part of the gas component is a vertical tube, Figure 2 is the precipitation It is the case that the mechanism to make is inclined tube. 3 is a case where a cooling fan is provided for temperature control of the settling mechanism. Moreover, the idea of the schematic diagram of the waste gas processing mechanism was shown. Figure 4 is to keep the precipitate warmed to 950 ^° C or more to volatilize the evaporate, inclined to the bottom of the mechanism to obtain a solid silicon, and to process while moving the generated silicon to enable continuous operation. 1, zinc wire or molten zinc is supplied from the zinc supply part 1. As shown in FIG. In this case, if a fixed amount of zinc can be supplied, a zinc melting furnace can send a fixed amount of zinc to a pump or the like. The method of supplying a zinc wire is particularly preferable for a compact apparatus due to its ease of handling and easy transfer of quantitatively. It is a way. In addition, according to the conveyance here, it can supply and supply atmospheric gas for pressurization and atmosphere adjustment as needed. The zinc wire or zinc melt sent in this way is supplied from the zinc supply port (1), and Zinc vapor is generated by heating and evaporating with a zinc evaporator (2). Here, zinc is vaporized above the boiling point of zinc by a direct heater. This results in an atmosphere containing only some argon gas but substantially only zinc gas. This zinc gas is heated to the required temperature in the gas heating section (3). Usually 1300 ^° C is good at 105C C, in particular 1100 ^° C to 1200 ^° C is suitable. It is sent to the mechanism 4 which supplies the silicon tetrachloride heated and controlled in this way. Since the boiling point of silicon tetrachloride is about 57.6 ^° C, ^'normal equilibrium in the gas, but, in this case so as to dropping from silicon tetrachloride supply port 41 is supplied in a liquid state. Of course, it can be supplied as a liquid drop as it is, but spray or black can also be supplied as a shower type. The method of supply is not particularly specified, and it is preferable to supply a fixed amount by a tube pump or a diaphragm pump. In the case of a large amount, a pressure is applied to the silicon tetrachloride holding unit to flow through the flowmeter, and the flow rate is adjusted by a valve. In either case, silicon tetrachloride is supplied in this section in the liquid phase.

The supplied silicon tetrachloride immediately starts the reaction with zinc gas and starts the production of the silicon precursor and the silicon, and at the same time an element for turbulizing the gas therein in a mechanism (5) for producing the reaction gas containing silicon particles. The reaction can be carried out simultaneously while the reaction is sufficiently stirred by (51), and the temperature can be lowered in the mechanism (6) that grows the silicon particles and simultaneously precipitates them with a part of the gas component, thereby producing the silicon and some unreacted zinc and Zinc chloride unites and precipitates, and it moves to the mechanism (7) which obtains solid silicon. In addition, in maintaining the temperature of the precipitation mechanism 6, the temperature may be maintained by providing different angle elements (for example, FIGS. 3 and 300) such as not only heating the heater but also introducing external air.

For this reason, in the conventional cyclone system, the silicon | silicone below ΙΟμηι which is difficult to precipitate, especially submicron microparticles | fine-particles, precipitates in the mechanism 7 which obtains solid silicon. Here, the base is heated above the loocrc, and the wall is slightly lower than it, but kept above the boiling point of zinc, to volatilize and evaporate volatile zinc or zinc chloride, There is little and the production silicon can be kept in high purity. In addition, the heating can always be carried out, if necessary, the temperature. It is also possible to keep it low and to heat the temperature above 1000 ^° c intermittently. Also, if the temperature of the outside bottom of the apparatus by at least 1000 ^° c, for some fine particles of silicone makes it a throw escape from the exhaust mechanism 8 along with evaporation, such as zinc chloride, the ambient temperature at that point is 1000 ^° c or less is preferable.

Although the exhaust gas mechanism 8 is not specifically designated, it is maintained here above the boiling point of zinc so that precipitation may not occur in the middle of a gas pipe, and the exhaust gas processing part 9 after that can fully reduce temperature and precipitate it as a solid. Alternatively, in the case of contact with zinc chloride solution, if there is unbanung silicon tetrachloride, it is precipitated with silicon oxide as 'SiCl ₄ + 2H ₂ 0 ^ Si0 ₂ + 4HC1', and zinc chloride and zinc are dissolved in zinc chloride solution It can also be processed by successive extraction.

In Fig. 2, the principle is the same as in Fig. 1, but in Fig. 1, the mechanism 6 which grows silicon particles and precipitates together with a part of the gaseous components is used as a vertical pipe, but instead it is an inclined pipe 61. In order to reliably deposit a precipitate composed of silicon, zinc chloride and / or zinc, the temperature of the lower temperature is lengthened, the cornering and precipitation are performed more reliably, and the silicon particles grow appropriately to yield Can be made higher. In addition, since a certain amount of time is maintained at the intermediate temperature, at least a portion of the volatiles mainly containing zinc chloride can be removed while being precipitated therein. There is little volatilization of zinc and zinc chloride, and the fall of the silicon microparticles | fine-particles accompanying it to the exhaust gas part is further reduced, and it is effective for the improvement of efficiency. In addition, of course, the silicon of finer particles is surely obtained.

3 is a schematic view in the case where the treated water is passed through the exhaust gas treatment unit. In other words, by circulating the zinc chloride aqueous solution to the bottom of the exhaust gas treatment unit, zinc chloride which is an exhaust gas component coming in from the top is Soluble in aqueous solution. In the case of Mibanung's zinc and silicon tetrachloride, silicon tetrachloride reacts immediately with water to form hydrochloric acid and silicon oxide, and since the aqueous solution is acidic with the produced hydrochloric acid, zinc is also dissolved to form an aqueous zinc chloride solution. . In addition, if a little hydrochloric acid is added to this circulating water, zinc can be completely dissolved without unreacted silicon tetrachloride, and all the exhaust gas can be made into a zinc chloride solution. This may be purified to obtain zinc chloride, or may be sent to a diaphragm electrolytic cell as it is to recover zinc as metal zinc.

FIG. 4 is the same as FIG. 1 until the mechanism 6 that grows the silicon particles and precipitates with some of the gaseous components is the same as that of FIG. 1, but tilts the bottom of the mechanism 7 to obtain the solid silicon beneath it. The volatiles are volatilized while being moved by the sediment falling from the apparatus of 6) and transferred to a lower vessel or a dissolving mechanism 400 in which only silicon is placed on the way, and continuously extracted or dissolved therefrom as a melt. It can also be extracted.

The invention is explained in more detail in the following examples. However, the following examples are only for exemplifying the present invention, and the contents of the present invention are not limited to the following examples.

In addition, although the apparatus of the Example is mostly made of quartz glass, of course, ceramic materials, such as silicon carbide, can also be used with the enlargement.

Example 1

The apparatus shown in FIG. 1 was test-made. In other words, the zinc evaporation tank (gasification part) has a cylinder with a diameter of 150 腿 and a height of 35 腿, and a cylinder on the opposite side of the cylinder and a zinc supply port attached to the cylinder at a 45 ^° height direction with an inner diameter of 4 瞧 at one end of the cylinder. A quartz glass tube having a gas flow passage having an outer diameter of 30 mm and horizontally installed, and a glass tube having an outer diameter of 30 mm and a length of 600 tnm having a vertical pipe having an inner diameter of 10 mm at a portion of 50 mm on one side connected to the gas flow passage with a zinc gas are zinc gas. As a heating (adjustment section), a vertical pipe was erected at the other stage and installed as a silicon tetrachloride supply mechanism. Moreover, it was set as the mechanism which generate | occur | produces the reaction gas by installing the semi-conducting tube of quartz glass of outer diameter 30mm and length 1000mm in a horizontal direction. In this semi-ungung tube, four square mixers of 125 길이 in length and 23 직경 in diameter were placed on the silicon tetrachloride supply mechanism side. On the opposite side of the quartz tetrafluoride feed mechanism of the semi-ungung tube made of quartz glass, a quartz glass vertical tube having an outer diameter of 35 mm and a height of 600 mm falling at right angles is formed and the lower side thereof has a diameter of 160 mm x height of 200 mu m. The container (silicone holding container) was attached. -The cover part of the quartz glass container is provided with an inlet (element receiving gas) and an exhaust gas pipe from the vertical pipe (element for exhausting gas), and an exhaust gas pipe made of quartz glass having an outer diameter of 25 mm is mounted thereon. Another stage was connected to a drum can made of stainless steel (SUS304). The drum can was filled with argon gas and used for exhaust gas treatment. However, pressure was not applied and back pressure was not generated.

The zinc evaporation tank was placed in contact with the upper and lower sides of the glass cylinder to place a heating plate made of iron chromium wire heating elements. In addition, the lower surface of the quartz glass container was also provided in such a manner that the heating surface was in close contact. Another part controlled the temperature by placing a heater to surround these cylinders.

The zinc to be fed was to continuously send a pure zinc (99.995 mass% zinc) wire having a diameter of 2 mm 3 at 10 m 3 / sec continuously. Silicon tetrachloride was continuously supplied at 0.25 g / sec by a tube pump at the top. In addition, the start of operation was to start supplying zinc first, and then to start supplying silicon tetrachloride after 30 seconds. Further, argon gas was supplied at a rate of 200 ml / min from the branch pipe of the zinc wire portion.

The silver content of each part was 1100 ^° C of zinc evaporation tank, 1KXTC of zinc gas heating part, 120CTC of silicon tetrachloride supply device (zinc gas passing part), and the temperature of the reaction tube was 1100 ^° C of the square mixer insert part, and the rest of the semi-finished pipe ( The latter half) was set at 1050 ^° C. The vertical tube was 700 ^° C. to 750 ^′ C, the silicone holding vessel was at the bottom 1050 ^° C. and the side wall was 95 CTC. In the supply of silicon tetrachloride, the calculation was over 17% of zinc. After 20 minutes of continuous operation, 45.2 g of brown, fine powder silicon was obtained. Having a peak where the measured particle size distribution of the silicon bar, 5μ particle size ^η ι and 15μπι, average particle size was found that fine particles formed of silicon ΙΟμ ^η ι below.

The yield of silicon was 91% relative to the theoretical value. The presence of hydrochloric acid odor in the exhaust gas section left some of the uncoated spots under these conditions, partially escaped in the exhaust gas, and partially gathered in the pipe.

Example 2

The silicon manufacturing apparatus shown in FIG. 2 was produced. The zinc supply to the zinc tetrachloride supply part was the same as that of FIG. 1, and the semi-ungular pipe length was 600 mm, and the square mixer similar to Example 1 was built into the part. The inclined tube which was arrange | positioned so that it might fall toward a quartz glass container with the inclination-angle at 45 ^degrees with respect to the horizontal was provided behind the half-pipe, and it connected to the quartz glass container. Since the cover part of the quartz glass container was set 600 mm lower with respect to the reaction gas generating mechanism part that is a horizontal part, the length of the inclined tube was 850 mm 3. Moreover, the outer diameter of the inclined tube was 35 mm, and the others were the same as in Example 1. In addition, the material used was silicon carbide (SiC).

The temperature was 1200 ° C (evaporator outer part) of the zinc evaporation tank, and the zinc gas heating unit was also 1200 ^° C. In addition, the silicon tetrachloride supply mechanism was 1200 ^° C., the reaction gas generating mechanism 105 (C, and the inclined tube was 500 ^° C. In the same manner as in 1, the bottom plate part was 1050 ^° C and the wall part was 950 ^° C.

The zinc wire was supplied at 15 kV / sec in the same manner as in Example 1. Silicon tetrachloride was 0.4 g / sec. Zinc and silicon tetrachloride began at the same time. The supply of zinc and silicon tetrachloride was continued for 30 minutes and stopped. After stopping supply of silicon tetrachloride and zinc, After the temperature was lowered. As a result, 106 g of silicon was obtained from the quartz glass container. This was 89.2% of theory. In addition, the amount of zinc supplied was about 9% excess with respect to silicon tetrachloride. Part of this difference was due to the occurrence of non-reflection, while on the other hand, the produced silicon was held on a part of the glass surface of the inclined portion.

Example 3

As a turbulence element of the zinc evaporation tank, the zinc supply equipment, and the gas of the reaction tower, the same apparatus as in Example 1 was prepared except that the square mixer was replaced with a baffle plate. That is, the zinc evaporation tank is of the same size, but the zinc supply part is provided with an inclined tube having a diameter of 20 mm and the outer diameter of the zinc supply part of the zinc attached to the tip is 15 mm, and the zinc liquid feeder with the liquid trap (12) Installed. The zinc supply here is to be supplied by the overflow from the zinc feeder through the liquid trap, so that a portion of 2 mm diameter zinc wire as used in Example 1 is supplied at a rate of 20 mm / sec. did.

As described above, the semiungwan tube was placed as a turbulent element of gas so that a semicircular quartz glass plate was placed at random intervals and at random angles so as to reach the entire length of 1000 mV in the apparatus. In addition, this apparatus mainly used quartz glass. As an operation condition, the temperature of the zinc evaporation tank was 1300 ^° C. Although it turns into a zinc gas of a boiling temperature substantially here, it was set as this temperature in order to generate | occur | produce a sufficient amount of zinc gas and to make it zinc gas instantaneously. In addition, the zinc gas heating unit was 1200 ^° C., and made the same temperature as the silicon tetrachloride supply mechanism. The temperature of the half-ung pipe containing the baffle plate was 1150 ^° C. On the other hand, the temperature of the vertical pipe portion is set at 600 ^° C to 650 ^° C., in order to maintain this temperature, an angle relief mechanism for receiving external air is installed in addition to the heater. Further silicone holding part is silver is a base temperature at 1000 ^° C, which was the wall temperature to 800 ^° C. In addition, a drum can made of SUS304 having a circulation mechanism of a zinc chloride aqueous solution from the outside at the bottom was used as the exhaust gas treatment / recovery mechanism. An acid-resistant paint was applied to the inside of the drum can to improve corrosion resistance. In addition, the exhaust gas accompanying silicon formation was led to the top of the drum tube in a quartz glass tube having an outer diameter of 30 mm. Furthermore, by winding the heater directly on the quartz glass tube for exhaust gas, the temperature was maintained ^at 1100 ^° C. to prevent the formation of volatiles. Moreover, the zinc chloride aqueous solution supplied to a drum can was made to circulate with the 200 1 solution tank through a several capacitor | condenser, and circulated by the magnet pump. As a circulating zinc chloride aqueous solution, 15% zinc chloride + 5% aqueous hydrochloric acid solution (mass%) was circulated. On the other hand, the level of this circulating water was set to 50 mm at the bottom in the drum tube.

The following operation was performed about this apparatus. That is, as described above, the zinc wire was supplied at 20 mm / sec, and dropping of silicon tetrachloride was started 30 seconds after the introduction of zinc into the zinc evaporation tank was confirmed. The supply amount of silicon tetrachloride was 0.5 g / sec. After 60 minutes of operation, 252 g of brown silicon fine powder was obtained. In addition, 16.77 degrees of supply zinc was excess in theory. In addition, the zinc chloride aqueous solution in the exhaust gas treating drum partially contained precipitates of silicon oxide. Accordingly, it was found that unbanung silicon tetrachloride was produced to some extent even when excess zinc was added. In addition, since the precipitates of silicon oxide were large particles, they could be easily separated by a filter cloth of about 100 scale.

Example 4

Bottom of the silicone holding container of the apparatus of Example 2 As shown in Fig. 4, the element part receiving gas at an angle of 20 degrees was inclined to the top, and a pipe of 60 mm diameter quartz glass was mounted in addition to the bottom. The length of the inclined section is 600 mm long, and the temperature gradient is made so that the uppermost silver is 1000 ^° C and the lowest silver is 2 (XTC. The lower part is also equipped with a quartz glass container filled with argon gas. The vessel had a lid at the top to allow continuous extraction of the silicon from the top .. A brown spray, thought to be a little silicone at about 15 minutes of start-up, after a silicone manufacturing test under the same conditions as in Example 2. With particles Sediment began to fall. The temperature was 200 ^° C, so these could be taken out from above.

[Explanation of code]

I Zinc Inlet

II argon gas inlet

12 Zinc Liquid Feeder

2 zinc evaporator

3 gas heating unit

4 A mechanism for supplying silicon tetrachloride

41 Silicon tetrachloride supply port

42 Passage of zinc gas

5 Apparatus for generating reaction gas containing silicon

51 Gas Turbulence (Square Mixer)

52 Urea Turbulent Gas Disturbance

6 A mechanism for growing silicon particles and at the same time settling them together with some of the gaseous components (vertical tubes)

61 Devices for growing silicon particles and at the same time settling them together with some of the gaseous components (tilts)

7 Apparatus for obtaining solid silicon

8 exhaust gas appliance

9 Exhaust Gas Treatment

91 air exhaust

100 pump

200 Zinc Chloride Tank

300 angle elements

400 silicone extraction apparatus

Claims

[Patent Claims] [Claim 1]

(1) a mechanism for supplying zinc gas by heating and evaporating metal zinc above the boiling point of zinc; (2) a mechanism for supplying liquid silicon tetrachloride into the zinc gas; (3) the zinc gas and silicon tetrachloride. A mixture of agitating and reacting to generate a reaction gas containing silicon particles; and (4) lowering the temperature of the reaction gas to 300 ^° C. to 800 ^° C. to grow the generated silicon particles and at least a portion of the gas component. And (5) the apparatus for maintaining the precipitate and at the same time maintaining the precipitate, while at least 950 ^° C, and depositing the precipitate to volatilize the evaporate to obtain solid silicon; and (6) the evaporate. And an exhaust gas mechanism for discharging the exhaust gas containing the reaction gas to the outside of the system.

[Claim 2]

The method of claim 1,

The mechanism (1) for supplying zinc gas,

High purity solid or liquid zinc is quantitatively determined from the boiling point of zinc

A gasification unit gasifying ^at 1300 ^° C .; And

An adjusting unit for heating the generated zinc gas and adjusting a temperature;

Apparatus for producing a high-purity silicon fine powder, characterized in that for quantitatively supplying the zinc gas adjusted the temperature.

[Claim 3]

The method of claim 1,

(2) a passage for passing zinc gas, wherein the mechanism for supplying liquid silicon tetrachloride into the zinc gas is supplied from the zinc gas supply mechanism and passed therethrough; And Apparatus for producing a high-purity silicon micropowder comprising a supply unit for quantitatively spraying or dropping liquid silicon tetrachloride in the passage.

[Claim 4]

The method of claim 3,

An apparatus for producing high-purity silicon fine powder, wherein the temperature of the passage portion of the zinc gas in the supply mechanism of silicon tetrachloride is maintained at 105 CTC to 130 CTC.

[Claim 5]

The method of claim 1,

(3) The mechanism for producing a reaction gas containing silicon particles by mixing and stirring the zinc gas and silicon tetrachloride is a cylindrical body maintained at a temperature of 1050 ^° C to 1250 ^° C, the gas inside the cylindrical body Apparatus for producing high purity silicon comprising an element that turbulences.

[Claim 6]

The method of claim 5,

An apparatus for producing high purity silicon fine powder, wherein the element for turbulent gas is made of a baffle plate placed at uneven intervals.

【Claim 7】.

The method of claim 5,

A device for producing high-purity silicon fine powder, wherein the element for turbulent gas is a square mixer.

[Claim 8]

The method of claim 1, (4) The apparatus for producing high-purity silicon fine powder, wherein the apparatus for producing a precipitate at least partially by lowering the temperature of the reaction gas to 300 ^° C. to 80 CTC is maintained at a temperature of 300 ^° C. to 800 ^° C.

[Claim 9]

The method of claim 1,

(4) the apparatus for producing a precipitate at least partially by lowering the temperature of the reaction gas to 300 ^° C to 800 ^° C,

It is maintained at a temperature of 300 ^° C to 800 ^° C, the tube inclined ^at 30 ^° to 90 ^° with respect to the horizontal,

While generating a precipitate containing silicon in the crowd and the inner wall,

(5) while maintaining the sediment at the lower portion of the inner wall of the tube, the sediment is warmed above 950 ^° C, the evaporate is volatilized and sent to a device for obtaining solid silicon. Apparatus for producing high-purity silicon fine powder, characterized in that.

[Claim 10]

The method of claim 1,

(5) A mechanism for maintaining the precipitate and at the same time warming the precipitate to 950 ^° C. or higher, volatilizing the evaporate to obtain solid silicon,

An element receiving a gas comprising a precipitate containing silicon from the device for lowering the temperature;

Silicone holding container; And

Apparatus for producing high purity silicon fine powder comprising the element for discharging the exhaust gas.

[Claim 11]

The method of claim 10 (5) A mechanism for maintaining the precipitate and at the same time warming the precipitate to 950 ^° C. or higher, volatilizing the evaporate to obtain solid silicon,

Apparatus for producing a high-purity silicon fine powder, characterized in that the bottom of the silicon holding container is heated from the bottom with a heater maintained at a temperature of loocrc to nocrc.

[Claim 12]

The method according to claim 10 or 11,

(5) A mechanism for maintaining the precipitate and heating the precipitate to 95 CTC or more, volatilizing the evaporate to obtain solid silicon,

An apparatus for producing high-purity silicon fine powder, further comprising an extraction element for extracting the silicon produced in the silicon holding container even during reaction.

[Claim 13]

The method of claim 10,

The element for discharging the exhaust gas, exhaust

High purity silicon fine powder manufacturing apparatus connected.