JPS6293302A - Production of metal by way of ultrafine particle - Google Patents

Abstract

PURPOSE:To efficiently obtain high-purity metal by ejecting a low boiling metallic compd. to a hydrogen reducing and reduced pressure area, subjecting the compd. to cooling to enduce ultrafine metallic particles and capturing such particles. CONSTITUTION:A vapor seed (SiCl3) is formed when SiCl4 and H2 are put into a heat-resistant vessel 1 and are heated by an electric heater or direct fire, etc. Such vapor seed is ejected through a nozzle 3 from the vessel 1 at a supersonic velocity to the reduced pressure area in a reduced pressure vessel 2 and is expanded by which the ultrafine silicon particles are deposited. The ultrafine silicon particles are captured by axially sliding a capturing bar 4 while rotating the same. The metallic silicon is thus obtd. The similar effect is obtd. with (Al-Cl system), (Ca-Cl system), (Ta-Cl system), etc. as well by the similar treatment. The ultrafine metallic particles are easily obtd. by the above-mentioned device. The high-purity metallic silicon is obtd. by capturing the ultrafine particles at a good yield.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a method for precipitating ultrafine metal particles from a low-boiling metal compound.
! , relates to a method for producing metal using ultrafine particles that efficiently captures this.

<Prior Art> The utility value of high-purity silicon used as semiconductor elements in fields such as semiconductor technology is increasing.

Conventionally, the Siemens method has been known as a method for industrially producing high-purity silicon. In this manufacturing method, a silicon core provided in a Pel Jar is heated with electricity, and trichlorosilane (SzHCla) and a water system (+-12) are fed into the Pel Jar, and the silicon core is highly heated by aqueous reduction or thermal decomposition. This method deposits pure silicon.

<Problems to be solved by the invention> Even with the Siemens method, which is considered to be an advantageous method using current quantities, there were 27 problems as listed below.

■High f+Ii 1~Riku ``1 Lucilan (S
+HCJ! 3) → Dimension ↑ → is easy 1 piece silicon tetrachloride <5
Because it converted to IC1a), process control was extremely strict. This silicon tetrachloride has low industrial utility value because it requires very high quality conditions of 1800'C or higher even if hydrogen reduction is attempted.

■The silicon core is heated with electricity, but since the silicon core has a property that its electrical resistance decreases as the temperature rises, a large current is required for heating, increasing power consumption. The optimum operating temperature for this manufacturing method is 111 atm, which is around 1600°C, but it is difficult to achieve this altitude, and even if temperatures up to 1600'C are achieved, radiant heat loss from the silicon core to the Pelger is high. It becomes very large and the power consumption becomes very high. For this reason, it was necessary to operate under strict control, using expensive trichlorosilane, and operating at a temperature of about 1100° C. and low pressure at the risk of poor yield.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a method for producing metal using ultrafine particles, which can also produce high-purity silicon without requiring expensive 1-lychlorosilane or large amounts of electric power. The purpose is to

Means for Solving the Problems〉 The method for producing metal via ultrafine particles according to the present invention involves heating a low-boiling metal compound in a state mixed with hydrogen to partially hydrogen-reduce the low-boiling metal. A step of creating a vapor species that is stable at high temperatures consisting of a compound, and injecting the vapor species into a reduced pressure area at supersonic speed to cause a disproportionation reaction and internal quenching.V) Similar to the above?
Metals in Jli point compounds are precipitated as ultrafine particles! ! 1104 (, gastrointestinal
It is characterized in that the step of taking in the Iti'1 minute*\'/-f is 1;1^λ.

The process of producing vapor species from the low-boiling point metal compound of silicon tetrachloride snow involves lowering the metal compound by hydrogen reduction, so it can be carried out with a relatively low amount of heat. 7111 The heating means can also be of various types, such as an open flame, in addition to the one using electric power. Therefore, the step of precipitating ultrafine metal particles from the vapor species is carried out by ejecting the vapor species at a supersonic velocity in the reduced H range.
l! ! Only the power of a vacuum pump is required to achieve 1. Furthermore, the precipitated ultrafine metal particles emit 6 at supersonic speed.
If a given human body collides with the trapping material with a low force, it will be efficiently captured by the trapping material.

<Example> Examples of the present invention are shown below.

(To-1-S + -CI2 system) This example uses St C1, which is a low boiling point metal compound with a boiling point of about 30'C.
In this method, metallic silicon is produced in one step from a to ultrafine silicon particles.

First, S + 014 and I2 were mixed and heated to 1300°C.
When heated further, as seen from the chemical potential diagram shown in Figure 2, S + C14 transforms into 5ICls and hydrogen j
! The type of steam that was generated is a matter of concern.

Sacρ4 gas phase) -1-1/2H2 (gas phase) → S+
+l! s (gas phase) + HC1 (gas phase) Next, when this high-temperature vapor species is rapidly cooled to below 1200'C and the chlorine partial pressure (PCI22) is lowered, a disproportionation reaction (D r 5proport+onat
ton React+on), silicon is precipitated as ultrafine particles.

Sr CJ23 (gas phase) → 1/4S+ (same phase) +3
/4S+ (,24 (gas phase) Here, when attempting to directly reduce Sr Ce4 with hydrogen to SI, the dotted line in the figure indicates the boundary of the range where this water = 5- elemental reduction is possible. →, it is presumed that an extremely high temperature condition of 1800° C. or higher is required, but in this example, a relatively low waterlogging condition fF of 1300° C. is sufficient, which is useful in practice.

The series of steps described above can be carried out using an apparatus as shown in FIG. Of course, this device is a heat-resistant container 1.
A depressurized container 2 whose inside is depressurized by a vacuum pump or the like is connected by a nozzle 3, and a trap rod 4 made of the same material (silicon in this case) as the ultrafine metal particles deposited in the depressurized container 2 is used as a decoy. It is provided to be movable and rotatable.

Therefore, step 1 of creating the vapor species described above. L, heat-resistant container 1
This can be easily carried out by placing SiCβ4 and 1-12 inside and heating it with an electric heater or an open flame.

In addition, in the step of rapidly cooling the vapor species, the vapor species is ejected from the heat-resistant container 1 through the nozzle 3 into the reduced pressure area in the reduced pressure container 2 at supersonic speed 1! This can be easily carried out by inflating and opening. In other words, by substituting the relational expression that holds true in the case of uI combined rate expansion, the relational expression between pressure and temperature 1 is r-1.Since r-1/r~1/4, 1/100
1/3 internal quenching can be obtained with a reduced pressure of .

In addition, from the viewpoint of preventing pressure loss during ejection, it is preferable to use a nozzle 3 with small flow resistance.In carrying out this step, the steam species is insulated and expanded slowly. Therefore, a passage pipe may be used instead of the nozzle 3.

In addition, the capture of the precipitated ultrafine particles is extremely high [4], since they may be knocked into the ultrafine net element or the trapping rod 4 by the human suspension given by the ejection, and the chamber is reduced. Coupled with the low pressure inside No. 2, extremely high yields can be achieved without being affected by air currents, etc. And this catching stick 4
A high-purity metal silicon material can be obtained by rotating the material N and moving it once in the axial direction. It should be noted that efficiency can be further improved by radially arranging a plurality of units consisting of the heat-resistant container 1 and the nozzle 3 so that a plurality of strips of ultrafine particles are driven from each unit into the trap rod.

By carrying out the same steps using the same apparatus as in the above embodiment, metals can also be produced from other low-boiling point metal compounds via metal ultrafine particles with similar efficiency.

(+-1-1!-Cρ system) According to this Example 1, metal aluminum "
It is a manufacturer of kumu.

First, AlG23 (1-12) was kneaded at 1800°.
When heated above C, a vapor species in which AlCl3 is hydrogen-reduced to AlCl2 is obtained as shown in the chemical potential diagram shown in FIG.

AIC; fls (gas phase) + 1/2H2 (gas phase) → A
lG12 (gas phase) 10HCβ (gas phase) Next, when this high-temperature vapor species is rapidly cooled to below 900'C and the chlorine partial pressure (PCI22) is lowered, as shown in Figure 3,
Due to the disproportionation reaction, aluminum is precipitated as ultrafine droplets.

AlCl2 (gas phase) → 1/3i (liquid phase) + 2/3A
, eCfs (gas phase) (HGa C1 system) In this example, ultra-r
Metallic gallium is produced using l1 particle Keishan.

First, GaCl3 is 1-12! ■Gozaichi 1! Te 580
'J, sea urchin, and G shown in Figure 14.
A vapor species is obtained by converting aCl30→Gin into GaCl1 (hydrogen) ψ.

GaC1a (gas phase) + 1-h (gas phase) → GaC, I2 (gas phase) + 2l-1 (d! (gas phase)) Next, this vapor species is rapidly cooled to below 330°C and the chlorine partial pressure is lowered. As shown in FIG. 4, gallium is precipitated as ultrafine droplets by a disproportionation reaction.

GaCl2 (gas phase) →2/3 Ga (liquid phase)
+1/3Ga C13 (AN phase) In this example, both products are in liquid phase, so
In order to reduce the hardness of the force by -11, it is necessary to perform phase separation after one turn.

(HTa-Cl system) In this example, ultrafine particles of tantalum are soaked in '#A from TaCρ5, which is a low boiling point metal compound.

First, knead acI5 with 1-12) to 1040°
Heat to above C and heat to ac15 as shown in Figure 5.
The vapor species obtained by hydrogen reduction of T a to C14 are expressed as follows.

1-acI2h (gas phase) + 1/2t-12 (gas phase) -T
aC4!4 (gas phase) + 1-ICI (gas phase) Next, this vapor species is rapidly cooled to 870'C to 800°C and the chlorine partial pressure is lowered to initiate a disproportionation reaction as shown in Figure 5. tantalum is precipitated as ultrafine particles.

TaCj4 (gas phase) → 115Ta (solid phase) + 415Ta
Cj5 (gas phase) In addition, in the 11th disproportionation reaction of this example, from FIG. Ta
(in the same phase) and Ta C15 (in the gas phase), thus achieving the above disproportionation reaction.

(1''-T+-CI2 system) In this example, ultrafine titanium particles are produced from T+ C, +24, which is a low boiling point metal compound.

First, mix T1Cf14 with 1-12 and
T+C as shown in Figure 6.
A vapor species is obtained by aqueous reduction of 14 to T+ Cp3.

T+ C14 (gas phase) -+-1/2L12 (gas phase) →
T + 013 (gas phase) -+-LI C (1 (gas phase)
Next, this vapor type was rapidly cooled to 820° Cl gas and the partial pressure of chlorine was lowered to obtain the temperature shown in Figure 6.
For the disproportionation reaction, ultrafine particles of J, Lee-1-IC, and 2 were added.

T+ C1s (gas phase) →1/2-1-+ C, &
, z (gas phase) -+-1/2-I + C, C2 (solid phase) In addition, the same as this (1-+Cf5 (gas phase) condenses on 1,1, TT+ Cf12-1-+ CQ s (7')
? ! By combining these, we can obtain an ultra-fine IRt, but this 1
T+C, C3 (in phase) in compound 17 has a temperature of 800 to 90
Disproportionation reaction is carried out at 0℃, chlorine content FF-10at, rn or less! By doing so, T+C12 can be obtained.

T+ Cl23 (solid phase) → Ding + Cβ2 (in phase) +
1/2T+ C, +24 (gas phase) Next, a sintered body of ultrafine titanium particles is obtained by subjecting T+ (12 to a non-restriction reaction at a temperature of 970° C. or higher).

-r+(12 (in-phase) → 1/3T+ (solid phase) +2/
3Ti Cρ3 (vapor phase) Note that this example can be similarly applied to tungsten chloride, and ultrafine sintered tungsten particles can also be obtained from tungsten chloride.

<Reference example> (+-1-C-0 system) In order to serve as a reference when further developing the present invention, this reference example does not show an example of a system in which the disproportionation reaction proceeds only by rapid cooling. This method produces ultrafine carbon particles from CO2, a low-boiling compound.

First, when CO2 is mixed with To 12 and heated to 800° C. or higher, a vapor species in which CO2 is hydrogen-reduced to CO is obtained, as can be seen from the chemical potential diagram shown in FIG.

CO2 (vapor phase) t1-f2 (vapor phase) → Co (vapor phase) 7t-120 (vapor phase) Next, this high-temperature vapor species is rapidly cooled to below 680°C and the FJf partial pressure (PO2) is lowered. From FIG. 7, it is determined that J-carbon is precipitated as ultrafine particles in the unrestricted chemically formed core. This is a correct judgment in terms of equilibrium theory, but it is not correct in terms of speed theory.

2CO (gas phase) → C (same phase) 10C02 (gas phase) In other words, in this case, (alGO (gas phase) exists stably even at room temperature, so the speed of the immobilization reaction is very slow. In order to improve this, U e N N
For example, a small amount of ferrocene (Fe (C5t-15) 2 ) is added to the heat resistant container 1 and the heat content M is converted into an aerosol! ? ! This is achieved by keeping it cloudy.

<Effects of the Invention> According to the present invention, ultrafine metal particles can be easily produced, and the ultrafine particles can be captured with a high yield and have a high purity (-14 = 1). Therefore, when the present invention is applied to silicon production,
If S+CI4 can be set to 0:1, and a large amount of stress can be reduced, inefficient electrical heating can also be omitted.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an apparatus for implementing the present invention, FIGS. 2 to 6 are chemical potential diagrams corresponding to the embodiments, and FIG. 7 is a chemical potential diagram of a reference example. Patent Applicant Kosai Midori Akira Noriyuki Co., Ltd.
Hakuheungrei's attorney, Dobe (and 1 other person), Tears L

Claims (1)

[Claims] A step of heating a low-boiling point metal compound in a mixed state with hydrogen to produce a vapor species stable at high temperatures consisting of a partially hydrogen-reduced low-boiling point metal compound, and ejecting the vapor species at supersonic speed into a reduced pressure region. a step of precipitating the metal in the low boiling point compound as ultrafine particles through a disproportionation reaction and internal quenching;
A method for manufacturing metal using ultrafine particles, comprising the step of capturing the flying ultrafine particles into a trapping material provided in the reduced pressure area.