JPH0531487B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a technology for refining chalcogenide raw materials, and is capable of continuously removing impurities such as oxygen and hydrogen contained in chalcogenide raw materials without exposing them to the outside air. Especially metals that are used as raw materials for electronic materials and infrared transparent glass.
The present invention relates to a method and apparatus for purifying chalcogenide raw materials that are effective for removing oxygen impurities, etc. in Te. [Prior Art] Conventionally, chalcogenide raw materials, particularly metallic Te, have been purified by a method in which surface oxides are removed by acid washing with hydrochloric acid, nitric acid, or a mixed acid, and a distillation purification method by heating. A purification method using acid washing can only remove impurities on the surface, but cannot remove impurities contained inside the raw material. Refining by distillation refining method can remove heavy metal elements with different melting points and impurities with different vapor pressures from the target material. However, when this method is applied to refining metallic Te, it is possible to remove heavy metal elements with different melting points and impurities with different vapor pressures from the target material. ) and Te oxide (melting point: 452.2°C), there is almost no difference in melting point, and there is also no difference in vapor pressure, so they cannot be sufficiently separated and purified. Reductive refining using carbonaceous substances utilizes the difference in free energy of formation of oxides, and when chalcogenide glass is remelted with quartz alpules,
This method uses an ampoule that has been coated with carbon in advance, and mixes fine carbon powder in chalcogenide glass and melts it, removing oxygen impurities as carbon monoxide. However, with this method, there is a concern that fine carbon powder may remain in the glass. S, which is a chalcogenide element other than metal Te,
Methods for removing oxyhydrogen impurities in Se include S ₂ Cl ₂ ,
Heat treatment in an active atmosphere using SeCl ₂ is known. This method involves bubbling chloride, which is liquid at room temperature, with angone gas, and heat-treating by bringing the generated vapor into contact with the crude raw material, but it is limited in that chalcogenide chloride, which is liquid at room temperature, must be used. There is. [Problems to be solved by the invention] As mentioned above, the conventional refining methods each have their advantages and disadvantages, and in particular when targeting metal Te, the conventional acid washing method, distillation refining method and Even if carbon reduction methods are combined, sufficient purification cannot be achieved, especially when carbon reduction methods are used.
There was a high possibility that operational impurities would be mixed into the raw materials. [Means for Solving the Problems] The present invention has been made to eliminate the above problems, and involves reducing chalcogenide raw materials in a carbon crucible in the presence of carbon fibers and/or fine carbon powder. It was discovered that these problems could be solved by distilling the mixture at the same time. Furthermore, we have discovered that oxyhydrogen impurities can be removed more effectively by heat-treating chalcogenide vapor in a chlorine compound active atmosphere. The present invention also provides an apparatus capable of continuously refining a chalcogenide raw material, which purification apparatus comprises: (a) a carbon-based crucible in which the chalcogenide raw material is accommodated together with carbon fibers and/or fine carbon powder; (b) an anhydrous quartz container in which a chlorine compound is housed;
(c) a purified chalcogenide recovery device consisting of an anhydrous quartz container equipped with a cooling means for condensing the evaporated chalcogenide vapor; , are connected through an anhydrous quartz conduit, and a carrier gas supplied from an inert gas source and flowing through the anhydrous quartz conduit converts the chalcogenide vapor generated in the device (a) into the chlorine generated in the device (b). It is characterized in that it is transferred to the device (c) while being brought into contact with the compound vapor. In the present invention, a carbon-based crucible means a crucible made of carbon as well as a crucible made of other materials, such as a quartz crucible coated with carbon. In addition, the carbon fiber mixed in the chalcogenide raw material is preferably about 7 to 8 μ in diameter, 6000 filaments, and 2 to 4 m in length, and fine carbon powder is
It is desirable that the size is less than 200 meters. and,
The amount of carbon fiber and/or carbon fine powder used is preferably about 4 to 8 wt% based on the raw material. [Function] According to the present invention, when a chalcogenide raw material is heated and melted in a carbon-based crucible, the melt evaporates while being reduced by the coexisting reducing agent (carbon fiber and/or carbon fine powder). At this time, since the reducing agent is not entrained in the chalcogenide vapor,
By condensing the chalcogenide vapor, a purified chalcogenide raw material that does not contain oxyhydrogen impurities and is not contaminated with a reducing agent can be obtained. It is also possible to remove oxyhydrogen impurities, especially OH, by passing the chalcogenide vapor through an active atmosphere of chlorine compounds, such as in the presence of tellurium chloride vapor, prior to condensation.
You can get even better results. Furthermore, the chalcogenide raw material purification device of the present invention includes:
Since the continuous reduction treatment, distillation purification treatment, and heat treatment in an active atmosphere of chlorine compounds can be performed on raw materials containing metallic Te and its oxides with no difference in melting point and vapor pressure, oxyhydrogen It is suitable for preparing high-purity raw materials that do not contain impurities such as. [Example] A lump of metallic Te with a purity of 99.999% was used as a starting material for purification. After cleaning the metal Te with hydrochloric acid,
It was washed with water and alcohol, and dried in vacuum. As the Te chloride compound for the active atmosphere, a powder with a purity of 99.99% was used. Metal Ge (purity 99.99999%) powder also metal Te
Prepared after washing in the same manner as above. High purity carbon crucible for carbon reduction treatment (purity 99.999%, capacity 10
cm ³ ), carbon fiber (fiber diameter 7-8μ, number of filaments
6000, length 2-4 m) and fine carbon powder (200 mesh or less, 400-800 mg) are heated to
Heat treated to ℃. The argon flow rate during this treatment was 3/min, and the heating time was 5 hours. After that, a carbon crucible and carbon fiber (2 m) or carbon fine powder (400 mg) were placed in a carbon crucible at 10 ^-6 Torr (temperature 250
The container was evacuated for 2 hours at a temperature of 10.degree. Setting raw materials in a carbon crucible and chlorinating them in anhydrous quartz container B
All of the Te compounds were set in a vacuum glove box, and each container was taken out after closing the container, set as shown in FIG. 1, and attached to an electric furnace (not shown). Each quartz container was washed with hydrofluoric acid, thoroughly washed with water, and subjected to deaeration heat treatment before use. The temperature conditions of the carbon reduction processing section and distillation section 4, the active atmosphere processing section 3, the purified raw material recovery section 5, and the Te chloride compound distillation section 7 are shown in the table below.

[Table] In the purification process, the raw material is kept at the reduction temperature for one hour in the carbon reduction treatment section 4, and then heated to the distillation temperature. Thereafter, while maintaining the same temperature, argon was flowed from the distillation argon gas inlet 1 at a flow rate of 500 ml/min. At this time, the chloride that started distilling by heating
Argon is flowed into the Te compound distillation section 7 from the argon gas introduction section 10 for Te chloride compound at a flow rate of 300 ml/min, and
open it. The activated Te chloride compound vapor from the Te chloride compound vapor inlet 2 and the reductively distilled metal Te vapor are heated in an active atmosphere treatment section 3 formed of an anhydrous quartz conduit while being in contact with each other, and the treated metal Te is heated. It accumulates in the refined raw material recovery section 5. unreacted chloride
Te compound vapor and chlorine gas are trapped in trap 6. The above purification is performed on the metal Te raw material to which a Te oxide compound has been added so that the oxygen content is 500 ppm, and chalcogenide glass with a composition of Ge ₁₇ Te ₈₃ is melted using the vacuum sealing method from the purified metal Te and metal Ge. Then, it was quenched in ice water to make glass. A double-sided polished sample (thickness: 2 mm) was prepared from this glass block, and its infrared transmittance was measured. Figure 2 shows the results of transmittance measurement. Chalcogenide glass using purified metallic Te raw material has
Since impurities in metallic Te are completely removed,
No absorption due to impurities is observed (see solid line), but absorption is observed in glass made from unrefined raw materials (see dotted line). [Effects of the Invention] As described above, by using the purification method and apparatus of the present invention, it is possible to effectively purify tellurium metal, which has no significant difference in melting point or vapor pressure between the target raw material and its impurities. I can do it. Moreover, since continuous purification is possible, efficiency is greatly improved. In addition, raw materials from which oxyhydrogen impurities have been removed have high value as electronic materials. In particular, it can effectively remove oxyhydrogen impurities that cause absorption in the infrared region, so it can be used to purify infrared-transparent chalcogenide glass raw materials.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a purification apparatus of the present invention.
FIG. 2 is a graph showing the infrared transmission curve of Ge ₁₇ Te ₈₃ chalcogenide glass, where the solid line shows the case where purified metallic Te is used and the dotted line shows the case where it is not purified. 1... Argon gas introduction part for distillation, 2... Chlorination
Te compound vapor inlet, 3... active atmosphere processing section,
4...Carbon reduction and distillation section, 5...Refined raw material receiving section, 6...Trap, 7...Te chloride compound distillation section, 8...Carbon crucible, 9...Kotuku, 10...
Argon gas introduction part for Te chloride compound, 11...
Kotoku for introducing Te chloride compound vapor.

Claims (1)

[Scope of Claims] 1. A method for purifying a chalcogenide raw material, which comprises distilling and refining the chalcogenide raw material in the presence of carbon fibers and/or fine carbon powder while undergoing reduction treatment in a carbon-based crucible. 2. A method for purifying a chalcogenide raw material, which comprises distilling the chalcogenide raw material while undergoing reduction treatment in a carbon crucible in the presence of carbon fibers and/or fine carbon powder, and passing the resulting vapor into a chlorine compound active atmosphere. . 3 (a) A chalcogenide raw material consisting of an anhydrous quartz container that removably houses a carbon-based crucible in which the chalcogenide raw material is housed together with carbon fibers and/or fine carbon powder, and a heating means attached to the container. (b) an anhydrous quartz container containing a chlorine compound;
(c) a purified chalcogenide recovery device consisting of an anhydrous quartz container equipped with a cooling means for condensing the evaporated chalcogenide vapor; , are connected through an anhydrous quartz conduit, and a carrier gas supplied from an inert gas source and flowing through the anhydrous quartz conduit converts the chalcogenide vapor generated in the device (a) into the chlorine generated in the device (b). An apparatus for purifying a chalcogenide raw material, in which chalcogenide raw material is transferred to apparatus (c) while being brought into contact with compound vapor.