JP2002079209A - Method for separating deposit from inorganic glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for separating a specified deposit efficiently from an inorganic glass as a matrix of glass moldings through a simple treatment. SOLUTION: This method for separating a deposit from an inorganic glass comprises the steps of (a) putting in a heating furnace the glass moldings composed of the inorganic glass as a matrix to which the deposit with a lower melt point or vapor pressure temperature than the inorganic glass sticks, (b) decompressing the interior of the heating furnace and (c) heating the glass moldings in the decompressed heating furnace at a specified temperature below the melt point of the inorganic glass and thereby, melt or vaporize the deposit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology related to the disposal and recycling of glass products (glass moldings) used in automobiles and buildings, and more particularly, to inorganic glass as a main component. The present invention relates to a technology for treating a glass molded article having an adhered substance having a low melting point or a low vapor pressure temperature to separate and remove the adhered substance (i.e., constituent components) from the inorganic glass.

[0002]

2. Description of the Related Art Window frames and automobiles of buildings are not limited to glass moldings made of pure inorganic glass alone, but are made of a material different from the main inorganic glass and adhered to the inorganic glass. Glass moldings containing existing components (hereinafter simply referred to as “adhesions”) are used for various applications. For example, as such a glass molding, 2
Polyvinyl butyral resin (PV
“Laminated glass” having an intermediate film made of a thermoplastic resin such as B) has been used as a windshield of an automobile or a window glass (safety glass) of a building. In addition, "Glass with defogger function" which has a thick film-like silver conductor and black ceramic which are fixed by firing on the glass surface
Is used as a rear window glass of an automobile. In addition, for example, quarter glass having a black ceramic is a typical example of the glass molded body.

By the way, from the viewpoint of saving resources and preventing environmental pollution, inorganic glass and a predetermined component of the attached substance are collected from the waste of the glass molded article having the attached substance, and the collected substance is used as another product. It is desired to reuse (recycle) it as a raw material or the like. As a prerequisite for realizing the recycling of such a glass molded body, the glass molded body that has become unnecessary and discarded is treated to separate the deposit from the main inorganic glass (typically, soda-lime glass). There is a need. That is, in order to recover the main inorganic glass portion from the glass molded article which is discarded as being unnecessary and reuse it as a raw material (glass cullet or the like) for flat glass or other glass products, the impurities which hinder such reuse, namely It is necessary to prevent the attached matter from being contained in the collected glass. Regarding this, for example, Japanese Unexamined Patent Publication No.
No. 499 discloses a method for separating an intermediate film, which comprises softening the above-mentioned intermediate film by heating the above-mentioned laminated glass, and cutting and removing the softened intermediate film from a glass substrate. I have. Further, JP-A-7-17746 and JP-A-7-17747 disclose that an interlayer film of laminated glass is impregnated with water to reduce the adhesive strength of the interlayer film to a glass plate, and thereafter, the interlayer film is made of a glass plate. There is disclosed a method for separating an intermediate film, which is characterized in that it is peeled off from an intermediate film.

[0004]

However, the conventional method for separating deposits from a glass molded body as described in the above publication is technically well-established even if it is technically established. It was not efficient enough to contribute to the promotion of recycling. That is, in the separation method characterized by cutting and removing the intermediate film softened by heating the laminated glass, the intermediate film of the heat-treated laminated glass is cut one by one using a cutting means such as a heating wire. Cutting had to be performed. For this reason, it has been difficult to quickly separate a large amount of interlayer film of laminated glass at a time. On the other hand, in the separation method characterized in that the interlayer film of the laminated glass is hydrated, it takes a long time (several hours to several days) to include a sufficient amount of water in the interlayer film to reduce the adhesive force. In addition, it was necessary to further perform a physical treatment (vibration treatment, suction treatment, etc .: see the above-mentioned publication) on the glass molded body subjected to the long-term water-containing treatment to peel off the intermediate film portion from the glass portion. . Therefore, it has been difficult to efficiently separate a large amount of interlayer film of laminated glass in a short time.

Accordingly, the present invention has been made to solve the above-mentioned problems associated with the conventional method of treating a glass molded body to separate a predetermined adhered substance. It is an object of the present invention to provide a method for efficiently separating a predetermined attached matter from inorganic glass which is a main component of a glass molded body by a treatment. Further, another aspect of the present invention is to provide a method for efficiently collecting a desired deposit and / or a main inorganic glass from a glass molded article (waste) by performing the separation method.

[0006]

Means for Solving the Problems, Functions and Effects The method of the present invention provided to achieve the above object is a method for separating extraneous matter from a main inorganic glass of a glass molded body. And (a) an adhering substance having a lower melting point or vapor pressure temperature than the inorganic glass as a main component (that is, a substance which is more easily melted and / or vaporized (evaporated) than the inorganic glass under a predetermined pressure condition). (A) depositing the glass molded body having the adhered substance in the heating furnace, (b) depressurizing the heating furnace, and (c) depressurizing the glass molding in the heating furnace. Is heated to a predetermined temperature equal to or lower than the melting point of the inorganic glass (that is, a temperature at which the attached matter can be melted or vaporized under the reduced pressure) to melt or vaporize the attached matter.

[0007] In the separation method of the present invention having the above-described structure, after the glass molded article to be treated is accommodated in a heating furnace capable of reducing pressure, the inside of the heating furnace is first reduced in pressure. As a result, the melting point (that is, the temperature at which the solid melts under a predetermined pressure condition) and the vapor pressure temperature, that is, the evaporation temperature, of the substance constituting the deposit are set at atmospheric pressure. Can be significantly reduced than that of the case. Here, the vapor pressure is the pressure of the vapor phase in equilibrium with the liquid phase or solid phase at a constant temperature, and the vapor pressure temperature refers to the temperature at this time. That is, changing the pressure changes the vapor pressure temperature. For example, when the pressure is reduced, the vapor pressure temperature also decreases. In the separation method of the present invention, the predetermined deposit can be melted or vaporized at a lower temperature (that is, a supply of a smaller amount of heat) than when heating under atmospheric pressure conditions. As a result, according to the separation method of the present invention, it is possible to rapidly melt or vaporize a predetermined attached matter while reducing the time and energy required for heating as compared with the case where the treatment is performed under normal atmospheric pressure. For this reason, it is possible to easily and efficiently separate the predetermined attached matter from the glass molded body.

[0008] In one preferable separation method of the present invention, the depressurizing step is performed until the inside of the heating furnace becomes a substantially oxygen-free atmosphere. Here, the “substantially oxygen-free atmosphere” refers to a low vacuum state (typically 10 Pa or less) in which the pressure has been reduced to such a degree that an oxidation reaction does not substantially occur. In the separation method of the present invention having such a configuration, the glass molded body is subjected to heat treatment in a substantially oxygen-free state. For this reason, it is possible to melt or vaporize the target substance while suppressing a serious denaturation based on a thermal decomposition reaction or an oxidation reaction which usually occurs when a high heat treatment is performed in the presence of oxygen (typically in air). it can.

Because of these characteristics, another preferred method of the present invention is a separation method further including a step of recovering the substance derived from the melted or vaporized deposit, This is a separation method further including a step of recovering the main inorganic glass after melting or vaporizing. According to the separation method of the present invention, the substance derived from the deposit and / or the main inorganic glass can be separated and recovered in a state in which the modification based on the thermal decomposition reaction or the oxidation reaction has not occurred. For this reason, according to the separation method of the present configuration, each component of the separated and collected glass molded body can be recycled while maintaining its original properties.

[0010] Further, as another preferable separation method of the present invention, the glass molded body contains a plurality of deposits having different melting points and / or vapor pressure temperatures under reduced pressure. Then, the above (c) .Step, that is, the step of melting or vaporizing the deposits, the heating temperature is shifted stepwise from a low temperature side to a high temperature side so that the plurality of deposits are melted or vaporized at different times. It is characterized by being performed while.

In the separation method of the present invention, two or more heating temperatures are set in consideration of the difference in the melting point and / or the vapor pressure temperature of each of the plurality of deposits under the reduced pressure.
The heat treatment for a predetermined time at each heating temperature is performed stepwise in ascending order of the temperature (that is, while the heating temperature is gradually shifted to a higher temperature side). According to this method, first, by a heat treatment in a low-temperature region, one of the plurality of deposits having a relatively low melting point and / or vapor pressure temperature can be melted or vaporized. Next, by a heat treatment in a higher temperature range, a substance having a relatively high melting point and / or vapor pressure temperature among the plurality of deposits can be melted or vaporized. As described above, according to the separation method of this configuration, by appropriately changing the heating temperature, two or more attached substances can be melted or vaporized separately. Therefore, according to the separation method of the present invention having such a configuration, it is possible to selectively separate two or more deposits contained in the glass molded article to be treated, and to collect each deposit separately.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention can be typically implemented as follows. In the practice of the present invention, the setting of conditions other than the specific contents described below and the addition of auxiliary processing steps are those generally used in the field of disposal and recycling of conventional glass molded articles. No particular limitation is imposed.

In the separation method of the present invention, there is no limitation on the type of the glass molded article to be treated, as long as the above steps can be performed. The deposit separated by the separation method of the present invention is composed of a main inorganic glass (typically, 1400 at normal pressure (atmospheric pressure)).
(Soda-lime glass or other silicate glass having a high melting point close to 100 ° C) is a material whose melting point or vapor pressure temperature (or boiling point) is lower under a predetermined pressure (reduced pressure) condition. Kimonos include molded articles, films and paint products made of various synthetic resin materials. Further, the present invention also relates to a fixed substance (such as an enamel) formed by baking a glass surface with a glaze or a sealing material containing a lead-based or non-lead-based low-melting glass composition, ceramic, metal powder, pigment, or the like. It is a typical example included in the attachment. Therefore, an automobile window glass made of laminated glass having an intermediate film made of PVB or the like as an attachment, a grid made of a thick-film-shaped silver conductor (a fired product of fine silver particles and glass frit), or a black ceramic as an attachment. Defogger function automotive window glass, quarter glass, etc.
It is a typical example of a glass molded body that can be suitably treated by the separation method of the present invention.

Next, a preferred embodiment of the separation method of the present invention will be described. In the present invention, as a premise for melting or vaporizing and separating the deposits, first, the above-mentioned (a). Process, that is, treatment in a heating furnace capable of reducing pressure (typically a heating furnace connected to a vacuum pump) A step of accommodating the target glass molded body is performed. At this time, the glass molded body may be housed in a predetermined heating furnace while maintaining its shape. In this case, the main inorganic glass can be recovered in its original shape and reused after predetermined attachments are separated and removed. Alternatively, before the step (a) (accommodating step), a step of appropriately crushing (including crack formation) or crushing the glass molded article to be treated may be performed. According to the separation method of the present invention further including such a step, the surface area of the glass molded article to be treated, that is, the exposed area of the deposit can be increased. For this reason, heating efficiency (heat penetration efficiency) and melting or vaporization efficiency can be improved.

Next, the steps (b). (Pressure reduction step) and (c). Step (separation step) will be described. The separation method of the present invention separates a predetermined adhered substance and a main inorganic glass part by subjecting a glass molded body that is no longer needed to be discarded to a vacuum heat treatment. Or vaporization. First, when the attached matter is melted and separated (b).
(c). The process will be described. Melt separation is employed when separating deposits having a lower melting point than the main inorganic glass under a predetermined reduced pressure condition. In carrying out such a method, the pressure is preferably reduced to a substantially oxygen-free atmosphere, that is, to such an extent that an oxidation reaction does not substantially occur. Under such reduced pressure conditions, it is possible to prevent the oxidation reaction and the combustion decomposition reaction (combustion reaction) of the melt during heating and melting. Note that the degree of the pressure reduction can be appropriately changed depending on the material of the attached matter and the heatable temperature. For example, in the case of treating a glass with a defogger function used for an automobile window glass or the like to melt and separate a baked solid such as a black ceramic or a thick-film silver conductor layer from the surface of a main inorganic glass (glass substrate). The pressure is preferably reduced to about 10 Pa or less, more preferably 1 Pa or less. By setting such suitable pressure-reducing conditions, the melting point of the calcined product can be significantly reduced as compared with the atmospheric pressure conditions.

After performing the above-described reduced pressure treatment, the glass molded body in the heating furnace can be melted at a predetermined temperature, that is, at a temperature equal to or lower than the melting point of the main inorganic glass under the reduced pressure. Heat to temperature. By such a heat treatment, the target deposit can be quickly melted and separated and removed from the main inorganic glass. The means for heating the glass molded body in the heating furnace is determined according to the type of heating furnace to be used (gas furnace, heavy oil furnace, coal furnace, etc.), and is not limited to a specific means. Absent. From the viewpoint of easy temperature control and the like, an electric heating means using Joule heat by current or heat generated by high-frequency induction current is preferable. Therefore, as a heating furnace suitable for carrying out the present invention, an electric furnace (particularly, a high-frequency induction electric furnace) which can be connected to a vacuum pump and can be depressurized can be mentioned.

In addition, in the above-described separation method based on melting, components derived from deposits are typically melted from the glass molded product and flow out from the surface or the inner space of the main inorganic glass. Therefore, after the melting and separating step, the melting component and the main inorganic glass can be separately collected. Typically,
As schematically shown in FIG. 1, a crushed glass molded product S (for example, a crushed window glass with a defogger function) to be treated is vacuum-heated (preferably an electric furnace) 1.
, And subjected to the above-described decompression treatment and heat treatment to melt the constituent M of the attached matter to be separated from the crushed material S (for example, a baked solid material such as a black ceramic or a silver conductor).
Let out. At this time, by providing a container 2 for collecting the outflowing component M at the bottom of the vacuum heating furnace 1 and a guiding path (not shown) for guiding the component M in the container 2, the component M can be obtained. Can be recovered. In this case, the main inorganic glass G after the component M has flowed out can be taken out of the vacuum heating furnace 1 after returning the inside of the vacuum heating furnace 1 to the atmospheric pressure. At this time, when the component M in the molten state remains on the surface of the recovered glass G, before or after taking out from the heating furnace 1, a predetermined recovered glass washing step (for example, a predetermined A step of spraying a fluid to remove the residual components, more preferably a step of further performing ultrasonic cleaning treatment to remove the residual components) may be performed.

Alternatively, as another preferred method of the recovery method, hot water or another solvent is poured into the heating furnace 1 after the melting treatment, and the two are separated based on a difference in specific gravity between the main inorganic glass G and the component M. Good. For example, based on the difference in specific gravity, while suspending or suspending the component M in the solvent injected into the furnace, the glass G is allowed to settle, whereby both can be separated and separately collected.

If there are two or more kinds of deposits to be melted and separated and further recovered and they have different melting points under a predetermined reduced pressure, the heating temperature is changed from a low temperature to a high temperature. It is preferable to perform the step (c) while shifting stepwise to the side. Thus, the components of each attached substance can be separately separated and collected. For example, a baked and fixed product made of a low-melting glass composition having a glass softening point of 400 ° C. to 500 ° C. (hereinafter referred to as a “low-melting fixed material”) and a glass softening point higher than that (750 ° C. to 8 ° C.)
In the case where both the fired fixed matter (hereinafter, referred to as “high melting point fixed matter”) made of the glass composition at 50 ° C.) are melted and separated from the glass substrate, first, after the predetermined decompression treatment, the low melting point fixed matter is melted. The inside of the furnace is heated to the obtained temperature (for example, 700 ° C.). Thus, only the low-melting-point fixed matter can be melted and discharged in a state where the high-melting-point fixed matter cannot be melted. Then, after collecting the low-melting-point fixed matter in the predetermined container 2 (FIG. 1) as described above, the temperature in the furnace is shifted to a temperature at which the high-melting-point fixed matter can be melted (for example, 1100 ° C.). . Thereby, the high-melting-point fixed matter can be melted and flown out, and can be collected in the predetermined container 2.

Next, in the case where the deposit is vaporized and separated,
Steps (b) and (c) will be described. Such separation by vaporization is employed when separating deposits having a vapor pressure temperature (evaporation temperature) lower than the melting point of the main inorganic glass under a predetermined reduced pressure condition. In carrying out such a method, the pressure is preferably reduced to a substantially oxygen-free atmosphere, that is, to such an extent that an oxidation reaction does not substantially occur. It is particularly preferable to reduce the pressure until a substantial vacuum state is reached (that is, a highly reduced pressure state that can be reached using a vacuum pump or the like in the field of substance separation / purification technology). By adopting such reduced pressure conditions, it is possible to prevent oxidation reaction and combustion decomposition reaction (combustion reaction) of the melt during heating and melting, and furthermore, it is possible to improve the efficiency without denaturing the components of the target deposit. Can be well vaporized. The degree of the pressure reduction can be appropriately changed depending on the properties of the components (chemical substances) constituting the deposit to be vaporized and the heatable temperature. For example, when the laminated glass used for an automobile window glass or the like is processed to vaporize and separate an intermediate film made of a thermoplastic resin such as PVB from a main inorganic glass (glass substrate), a low vacuum state of approximately 10 Pa or less is required. Preferably, the pressure is reduced until the pressure is reduced to a high vacuum of 1 Pa or less or 0.1 Pa or less. By setting such suitable pressure reduction conditions, the evaporation temperature of the intermediate film can be remarkably lowered as compared with the atmospheric pressure conditions.

After the pressure reduction treatment as described above, the adhered material is vaporized (typically at a predetermined temperature, that is, at a temperature equal to or lower than the melting point of the main inorganic glass under the reduced pressure. Is heated to a temperature at which evaporation can occur.
By such a heat treatment under reduced pressure, the target deposit can be efficiently vaporized and separated and removed from the main inorganic glass. Note that there is no particular limitation on the means for heating the glass molded body in the heating furnace. For the above reasons, an electric furnace equipped with electric heating means (particularly a high-frequency induction electric furnace) is preferred.

In the above-mentioned separation method based on vaporization, typically, components derived from deposits are vaporized from the glass molded body and released from voids on the surface or the inner surface of the main inorganic glass. For this reason, after the vaporization separation step, the vaporized component and the main inorganic glass can be separately recovered. For example, the vaporized component M and the main inorganic glass G can be recovered by treating the glass compact S by a separation and recovery system 10 as schematically shown in FIG. That is, the system 10 typically includes a heating furnace 11 having appropriate heating means (here, a high-frequency heating device 12 having a high-frequency generator 13) and a vacuum pump 16.
And a distiller (distillation tower) 15. Thus, the distillation unit (distillation column) 15 is preferably connected and arranged between the heating furnace 11 and the vacuum pump 16 together with the condenser 14. With this configuration, the component M vaporized in the heating furnace 11 is introduced into the still 15 via the condenser 14 according to the suction of the vacuum pump 16. Thus, the introduced component M is cooled and held at a predetermined temperature or lower (that is, at a condensation temperature or lower) in the still 15 and can be recovered in the predetermined recovery tank 17 as a liquid. On the other hand, the main inorganic glass G from which the component M has been vaporized and removed can be easily recovered by returning the inside of the vacuum heating furnace 1 to the atmospheric pressure and then taking it out of the furnace.

If there are two or more kinds of deposits to be separated by vaporization and further to be recovered and they have different vapor pressure temperatures (evaporation temperatures) under a predetermined reduced pressure, heating is performed. It is preferable to perform the step (c) while shifting the temperature stepwise from a low temperature side to a high temperature side. This allows the components of each deposit to be separately vaporized and recovered. For example, a resin molded product having a vapor pressure temperature of about 300 ° C. under a pressure condition of 10 Pa (hereinafter referred to as “low-boiling resin molded product”) and a resin having a higher vapor pressure temperature (eg, about 400 ° C.) When a molded product (hereinafter, referred to as a “high-boiling resin molded product”) is vaporized from the main inorganic glass, the inside of the furnace is first heated to a temperature (for example, 350 ° C.) at which a low-boiling resin molded product can be vaporized after a predetermined pressure reduction treatment. Heat. Accordingly, it is possible to vaporize only the low-boiling-point resin molded product in a state where the high-boiling-point resin molded product cannot be vaporized, and it is possible to collect the vaporized component by using the above-described distillation device 15 or the like. After recovering the low-boiling resin molded product, the temperature in the furnace is shifted to a temperature at which the high-boiling resin molded product can be vaporized (for example, 450 ° C.). Thereby, the high-boiling-point resin molded product can be vaporized and collected.

[0024]

EXAMPLES Hereinafter, preferred examples of the separation method of the present invention will be described. <Example 1> Laminated glass used as a windshield of an automobile was treated by the separation method of the present invention. The laminated glass is a glass molded body in which an intermediate film made of PVB is sandwiched between two silicate glass plates. That is, the laminated glass was crushed and cracked, and the glass portion was broken into pieces while being bonded to the interlayer film. Thereafter, the glass molded body after the crushing treatment was accommodated in a vacuum heating furnace (high-frequency electric furnace). Next, a vacuum pump connected to the vacuum heating furnace was operated to reduce the pressure in the furnace to about 10 Pa. After the completion of the pressure reduction, an induction current was generated by a high-frequency current, and the laminated glass (crushed product) in the furnace was heated to 400 ° C.

By this series of treatments, the constituents of the intermediate film, which are the deposits, were vaporized and could be separated and removed from the silicate glass (main inorganic glass portion). At this time, as a result of reducing the pressure in the furnace to about 10 Pa to make the inside of the furnace substantially oxygen-free, no phenomenon (pyrolysis) in which the intermediate film was carbonized by heating was observed. Depending on the degree of vacuum in the furnace, there is a case where the intermediate film is carbonized,
In that case, the carbonized component can be removed by performing ultrasonic cleaning or the like. Then, the vaporized intermediate film component, that is, PVB, was liquefied and recovered by a predetermined vacuum distillation apparatus. After the separation treatment, the inside of the furnace was returned to the atmospheric pressure, and the glass fragments were collected. As is clear from the above examples, according to the separation method of the present invention, a desired deposit (here, a PVB intermediate film) and a main inorganic glass are separated and separately collected while avoiding an oxidation reaction of the substance. be able to.

Example 2 Glass having a defogger function used as a rear window glass of an automobile was treated by the separation method of the present invention. This glass is 1
A glass molded article having a thick-film silver conductor (ie, a baked and fixed silver paste composed of 80% silver powder, 1% glass frit and 19% organic binder in an approximate weight ratio) on the surface of one silicate glass substrate It is. That is, the glass with the defogger function was crushed to be crushed, and then housed in a vacuum heating furnace (high-frequency electric furnace). Then
The pressure inside the furnace was reduced to about 10 Pa by operating a vacuum pump connected to the vacuum heating furnace. After the completion of the depressurization, an induction current was generated by a high-frequency current, and the glass (fragment) in the furnace was heated to about 1400 ° C. As a result, the baked solids in the crushed pieces were melted. The silicate glass substrate (fragment) was not melted by the heat treatment under reduced pressure.

Through this series of treatments, the fired product (thick film-shaped silver conductor) could be melted and separated from the silicate glass substrate. Then, the inside of the heating furnace was returned to the atmospheric pressure and cooled down to a furnace temperature of 100 ° C. or lower. Then, hot water was injected into the furnace to wash and remove the substance derived from the fired product. Thereafter, the hot water was discharged (recovered) from the furnace, and crushed pieces of the silicate glass substrate were recovered. As is clear from the above examples, according to the separation method of the present invention, the attached matter (here, the thick-film silver conductor baked and fixed on the glass surface) and the main inorganic glass are separated and separately collected. be able to.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing one embodiment of a separation method of the present invention.

FIG. 2 is a block diagram schematically illustrating one embodiment of a separation and recovery system for performing the separation method of the present invention.

[Explanation of symbols]

 1,11 Heating furnace 10 Separation and recovery system 12 Heating device 15 Distiller 16 Vacuum pump

Claims (5)

[Claims] 1. A step of housing a glass molded body in which a substance having a lower melting point or a lower vapor pressure temperature adheres to a main inorganic glass in a heating furnace, a step of depressurizing the heating furnace, and Heating the glass molded body in the depressurized heating furnace to a predetermined temperature equal to or lower than the melting point of the inorganic glass to melt or vaporize the adhered substance; How to separate. 2. The separation method according to claim 1, wherein the depressurizing step is performed until the inside of the heating furnace becomes a substantially oxygen-free atmosphere. 3. The separation method according to claim 1, further comprising a step of recovering the substance derived from the melted or vaporized deposit. 4. The method according to claim 1, further comprising a step of recovering the inorganic glass after the deposit is melted or vaporized.
4. The separation method according to any one of claims 1 to 3. 5. The glass molded body contains a plurality of deposits having different melting points and / or vapor pressure temperatures under reduced pressure, and the step of melting or vaporizing the deposits comprises the plurality of deposits. The heating is performed while shifting the heating temperature stepwise from a low temperature side to a high temperature side so that the deposits are melted or vaporized at different times.
The separation method according to claim 1.