JP2006169067A - Method and system for purifying silicon carbide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and system for producing purified silicon carbide from silica sand and coke. <P>SOLUTION: The purification method of silicon carbide is characterized in that silicon carbide is purified by charging a mixture of coke and silica sand into a jet gas furnace, then heating the mixture to 800-1,200°C by blowing a jet gas flame onto the mixture from above by using a jet gas burner, and separating oxygen in the silica sand. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a silicon carbide purification method and system for purifying silicon carbide by continuously heating a mixture of silica sand and coke, and purifying the silicon carbide.

  Conventionally, in order to purify silicon carbide, a silicon carbide refining method in which a mixture of silica sand and coke is inserted into a hot-air heating furnace and heated electrically is generally used.

Moreover, the collection | recovery which has a cyclone type container with the crude silicon carbide powder obtained by making the reducing gas containing metal silicon, the oxidizing gas containing oxygen, and the hydrocarbon react, the gas containing carbon, and the acidic gas containing oxygen A silicon carbide powder collecting method is proposed which is introduced into the apparatus and heated at 500 ° C. to 800 ° C. to burn and remove carbon to obtain a purified silicon carbide powder and to collect this. Has been.
JP-A 63-195106

  Among the known techniques, the method of using electric heat not only has a low efficiency, but also has a problem that the purification efficiency is low when the mixing of silica sand and coke is insufficient.

  In the invention of Patent Document 1, since crude silicon carbide is first purified, the second processing is an essential requirement, and thus there is a problem of efficiency reduction.

  The present invention uses a jet gas composed of a mixture of hydrogen and oxygen for combustion and can be reduced by hydrogen, so that it can be purified efficiently and solves the conventional problems.

  That is, the invention of the method is that a mixture of coke and silica sand is fed into a ZET gas furnace, a ZET gas flame is blown from above with a ZET gas burner, heated to 800 ° C. to 1200 ° C., oxygen of the silica sand is separated and silicon carbide is separated. A method for refining silicon carbide characterized by refining, wherein a mixture of coke and silica sand is sent to a zet gas furnace, a zet gas flame is blown from above with a zet gas burner, and the mixture is heated to 800 ° C. to 1200 ° C. This is a method for purifying silicon carbide characterized in that silicon carbide is purified by separating the oxygen, hydrogen is separated from exhaust gas, calcium carbonate is purified using the remaining carbon dioxide gas, and then released.

  The invention of the system is a silicon carbide refining system characterized by combining a mixing means of silica sand and coke, a silicon carbide zet gas furnace equipped with a zet gas burner, and an exhaust treatment means. The jet gas is blown out to generate a jet gas flame, the mixing means is a powder mixer, and the exhaust treatment means is a heat exchanger, a cyclone and a hydrogen separator.

  Since the zet gas used in the above is electrolyzed through the permeation membrane, rainwater, industrial water or tap water can be used. The water is electrolyzed to produce hydrogen gas and oxygen gas, which are mixed.

  Since combustion of the zet gas is a phase change from gas to liquid, a normal explosion phenomenon (Explosion) does not occur, and a pseudo explosion phenomenon (Implosion) occurs. Implosion generates a vacuum around the heat source, but is safe because energy does not diffuse outside.

  Further, since it is a mixed gas of hydrogen gas and oxygen gas, there is no risk of environmental deterioration even if it leaks into the air, and there is no risk of combustion if it diffuses. Naturally, it becomes water by combustion, so there is no emission of harmful substances.

When the control object is irradiated with a Zet gas flame, it becomes extremely high temperature (1000 ° C. to 4000 ° C.) and dissolves all objects, but there is no risk of transferring to other objects. Also, since the zet gas itself contains oxygen, it will continue to burn even in places where there is no air. Furthermore, it has the characteristics shown in Table 1.

  As described above, zet gas has characteristics as compared with fossil fuel or fossil gas, and therefore heats the target product to the target temperature and does not discharge pollutants. Therefore, it is optimal as a heat source for refining silicon carbide.

  According to this invention, since a mixture of silica sand and coke is heated with a jet gas flame, the reduction of silica sand and the combination with carbon are performed instantaneously, and there is no condition for mixing other materials, so high purity silicon carbide There is an effect that can. The silicon carbide of this invention is 0.999.

In the present invention, as shown in FIG. 1, silica sand powder having a particle size of 0.1 mm to 10 mm and coke powder having the same particle size are charged into a mixer at a ratio (volume) of 1: 1 and mixed sufficiently (for example, 5 This is put into a hydrogen atmosphere zet gas furnace, and a zet gas flame is blown from above and heated at 800 ° C. to 1000 ° C. to burn and discharge CO ₂ and H ₂ . Therefore, H ₂ is recovered with a separation membrane and treated with CO ₂ .

The CO ₂ treatment passes a suitable catalyst to form, for example, CaCO ₃ , or separates into C ₂ and O ₂ and releases the gas. This point uses the prior art.

  In the present invention, an appropriate amount of silica sand and coke are fed to the mixer 2 by the powdered silica sand 30 and the coke 31 feeding devices 1 and 1, and the mixture is uniformly mixed by the mixer 2. Is fed into the zet gas furnace 3.

  The jet gas furnace 3 has a plurality of jet gas burners 4 and 4 at the upper part, and jet gas flames 5 and 5 are blown from the burner to heat the mixture to 800 ° C. to 1000 ° C. to generate silicon carbide. . The zet gas furnace 3 is supplied with hydrogen in advance so as to maintain a hydrogen atmosphere.

  Since the zet gas flame 5 is generated by the combustion of hydrogen and oxygen, it burns to generate water vapor, and this water vapor, carbon dioxide gas and hydrogen are discharged.

  Therefore, after the exhaust gas is cooled by the heat exchanger 9, hydrogen is recovered by the separation cylinder 6 having a separation membrane and supplied to the zet gas furnace, carbon is separated from the water vapor and carbon dioxide gas, and the water vapor and oxygen are released to the outside. . Therefore, the influence on the outside world is very small (a part of carbon dioxide is emitted).

  The jet gas used in the present invention is generated by electrolyzing water with the jet gas generator 7 and is used by distributing it to a necessary place with the distributor 8.

  The zet gas is composed of a mixed gas of hydrogen gas and oxygen gas, and has the characteristics as shown in Table 1. Therefore, it exhibits a sufficient effect for the production of this silicon carbide, and the production and purification can be performed in a single process. It can be carried out.

  Referring to FIG. 3, the electrolysis apparatus for generating the jet gas according to the present invention will be described. In the electrolytic cell 10, a large number of electrode plates 11, 11 are installed in parallel, and each electrode plate 11, 11 is a conductive plate 12, 12a forms a positive pole and a negative pole, respectively.

  One end of a water supply pipe 13 is connected to the lower part of the electrolytic cell 10, a pump 18 is interposed in the water supply pipe 13, and the other end is connected to the electrolytic water tank 14.

  The upper end of the electrolytic cell 10 is connected to the base end of a drain pipe 15, and the other end of the drain pipe 15 is connected to a separation rod 16 inside the upper part of the electrolytic water tank 14. A mixed gas discharge pipe 17 is connected to the upper part of the electrolytic water tank 14. In the figure, 24 is a water level measurement chamber, 25 is a supply / exhaust pipe, 26 is a water level gauge, 27 is an electromagnetic valve, 28 is a water supply pipe, 29 is a communication hole, and 32 is a sensor.

  Therefore, when each electrode plate 11, 11 is energized and the pump 18 of the water supply pipe 13 is started, the electrolyzed water in the electrolyzed water tank 14 flows as indicated by arrows 20, 21, 22 and is electrolyzed and generated. Hydrogen gas, oxygen gas and water are taken out from the drain pipe 15 as shown by an arrow 19, separated from the gas and water by a separation rod 16, and sent from a discharge pipe 17 to a distributor 8 as shown by an arrow 23 ( 2), distribution is performed from the distributor 8 to a necessary place.

  The above-described embodiment is an example, and other electrolysis apparatuses can be used.

The block diagram of the Example of this invention. Similarly schematic diagram. (A) Explanatory drawing which carried out the cross section of the electrolyzer similarly, (b) The partially expanded perspective view which similarly shows the connection of an electrode plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding device 2 Mixer 3 Zet gas furnace 4 Zet gas burner 5 Zet gas flame 6 Separation cylinder

Claims (6)

  It is characterized in that a mixture of coke and quartz sand is fed into a zet gas furnace, a zet gas flame is blown from the top with a zet gas burner, heated to 800 ° C. to 1200 ° C., oxygen in the quartz sand is separated and silicon carbide is purified. Method of purified silicon carbide.   A mixture of coke and silica sand is fed into a zet gas furnace, and a zet gas flame is blown from the top with a zet gas burner, heated to 800 ° C. to 1200 ° C., oxygen in the silica sand is separated to purify silicon carbide, and hydrogen from the exhaust A method for purifying silicon carbide, characterized in that calcium carbonate is purified using the remaining carbon dioxide gas, and then released.   A silicon carbide refining system comprising a combination of silica sand and coke mixing means, a silicon carbide zet gas furnace equipped with a zet gas burner, and an exhaust treatment means.   The silicon carbide purification system according to claim 3, wherein the jet gas burner blows the jet gas to generate a jet gas flame.   4. The silicon carbide refining system according to claim 3, wherein the mixing means is a powder particle mixer.   The silicon carbide refining system, wherein the exhaust treatment means is a heat exchanger, a cyclone and a hydrogen separator.

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