JP2019051479A - Development waste liquid treating device and treating method - Google Patents

Abstract

To provide a development waste liquid treating device and treating method capable of obtaining high-purity recovery liquid which can be recycled as developing liquid by concentration/cooling crystallization processing as highly refining processing on a post stage.MEANS: A developing waste liquid treating device 1 is composed of a prior stage cooling crystallization unit 2a and a post stage cooling crystallization unit 2b for performing highly refining processing with respect to recovery liquid which is recovered and refined by the prior stage cooling crystallization unit 2a. Both of the prior stage cooling crystallization unit 2a and the post stage cooling crystallization unit 2b are configured so as to perform a series of processing [concentration → cooling crystallization → crystal separation → dissolution]. The prior stage cooling crystallization unit 2a includes a prior stage concentration device 3a, a prior stage cooling crystallization device 4a, a prior stage solid liquid separation device 5a, a dissolution device 6a and a prior stage filtrate tank 7a. The post stage cooling crystallization unit 2b includes a post stage concentration device 3b, a post stage cooling crystallization device 4b, a post stage solid liquid separation device 5b, a dissolution tank 6b and a post stage filtrate tank 7b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a developing waste liquid treatment apparatus and a processing method for removing impurities from a developing waste liquid in a semiconductor or liquid crystal factory and collecting a reusable developer.

  In order to recover a reusable developer (tetramethylammonium hydroxide, tetraalkylammonium hydroxide, etc.) from developer wastewater in a semiconductor or liquid crystal factory, it is necessary to remove impurities such as photoresist. As a recovery method, the waste liquid is neutralized as a pretreatment to remove the photoresist, and then purified by electrolysis (see Patent Document 1, hereinafter referred to as Conventional Example 1) or ion exchange resin. It is known to perform purification (refer to Patent Document 2, hereinafter referred to as Conventional Example 2).

  However, in such a method of removing the photoresist by the pretreatment, there is a problem that it is difficult to separate the photoresist when the photoresist concentration is high or the development waste liquid to be processed is large. It was. Therefore, in order to solve such a problem, a method of concentrating development waste liquid and further performing cooling crystallization has been proposed (refer to Patent Document 3, referred to as Conventional Example 3).

No. 2006-59760 Japanese Patent Laid-Open No. 4-228487 JP-A-10-53567

In the third conventional example using the above-described concentration / cooling crystallization, the removal of the photoresist is relatively easy as compared with the neutralization treatment or the like. In this case, the problems of the first conventional example and the second conventional example are solved. However, in the third conventional example, impurities are not sufficiently removed yet, and a high-purity recovered liquid that can be reused as a developer has not been obtained.
Therefore, in addition to the pre-stage concentration / cooling crystallization process, there has been a demand for a development waste liquid treatment apparatus and a treatment method capable of obtaining a high-purity recovered liquid that can be reused as a developer by performing a high-purification process in the latter stage. .

  The present invention has been conceived in view of the above problems, and its purpose is to obtain a high-purity recovered liquid that can be reused as a developer by performing a cooling crystallization process as a highly purified process in the subsequent stage. It is an object to provide a developing waste liquid processing apparatus and processing method that can be used.

  In order to achieve the above object, the invention according to claim 1 is a development waste liquid treatment apparatus, wherein a pre-stage concentration apparatus for concentrating the development waste liquid, and a cooling liquid crystallized from the concentrate supplied from the pre-stage concentration apparatus, A first-stage cooling and crystallization apparatus for producing a slurry in which crystals are precipitated, a first-stage solid-liquid separation apparatus for separating crystals from the slurry supplied from the first-stage cooling and crystallization apparatus, and a heating means, From the melting device for heating and dissolving the crystal supplied from the above, the subsequent cooling and crystallizing device for cooling and crystallizing the solution supplied from the melting device and generating the slurry in which the crystal is precipitated, and the latter cooling and crystallizing device It is characterized by comprising a latter-stage solid-liquid separation device for separating crystals from the supplied slurry, and a dissolution tank for dissolving the crystals supplied from the latter-stage solid-liquid separation device.

  As described above, by performing multiple cooling crystallization processes, a high-purity recovered liquid that can be reused as a developer can be obtained.

The invention according to claim 2 is the developing waste liquid treatment apparatus according to claim 1, wherein the filtrate after the crystals are separated and removed by the latter-stage solid-liquid separation apparatus is concentrated, and the concentrate is cooled in the latter-stage cooling. A latter-stage concentrator for supplying to the crystallizer, a latter-stage impurity measuring means for measuring the impurity concentration contained in the filtrate after the crystals have been separated and removed by the latter-stage solid-liquid separator, and the filtrate for the latter-stage concentrator A first return line that returns to the first concentration line, a second return line that returns the filtrate to the pre-concentrator,
When the concentration of impurities is less than a set value according to the measurement result of the latter control valve provided in the second return line and the latter impurity measuring means, the latter control valve is closed, and the filtrate is supplied to the latter concentration device. When the impurity concentration is equal to or higher than the set value, the latter control valve is opened, and the latter switching control is performed to switch the filtrate return passage so that at least a part of the filtrate is returned to the former concentrator. Means.

According to the said structure, there exists an effect of a recovery rate improvement and a purity improvement. Specifically, it is as follows.
(1) The recovery rate can be increased by returning the filtrate to the subsequent concentration apparatus.
(2) However, if the process of returning the filtrate to the subsequent concentration apparatus is continued, the impurity concentration on the subsequent cooling crystallization side gradually increases. When the concentration is higher than the set value, returning the filtrate to the pre-concentrator can lower the impurity concentration in the post-stage and improve the purity of the recovered liquid.
(3) When the impurity concentration is high, the filtrate may be discharged to the outside, but the recovery rate is lowered. By returning the filtrate to the pre-concentrator, the treatment can be performed without reducing the recovery rate. The filtrate returned to the pre-concentrator can be recovered again without greatly affecting the amount of impurities in the pre-concentrator because the impurities are greatly reduced on the pre-cooling crystallization side.

  The invention according to claim 3 is the development waste liquid treatment apparatus according to claim 1 or 2, wherein the first stage of measuring the concentration of impurities contained in the filtrate after the crystals have been separated and removed by the first-stage solid-liquid separation apparatus. Impurity measurement means, a third return line for returning filtrate to the pre-concentrator, a discharge line for discharging filtrate to the outside, a pre-stage control valve provided in the discharge line, and measurement of the pre-stage impurity measurement means As a result, when the concentration of impurities is less than a set value, the front-stage control valve is closed, and the filtrate is returned to the front-stage concentrator, and when the concentration of impurities is higher than the set value, the front-stage control valve is turned on. And a pre-stage switching control means for switching the filtrate return path so that at least a part of the filtrate is discharged to the outside.

According to the said structure, there exists an effect of a recovery rate improvement and a purity improvement. Specifically, it is as follows.
(1) The recovery rate can be increased by returning the filtrate to the pre-concentrator.
(2) However, if the process of returning the filtrate to the pre-concentration device is continued, the impurity concentration in the pre-cooling crystallization unit gradually increases, so if the concentration exceeds the set value, the filtrate is removed to the outside. By discharging, an increase in impurity concentration can be suppressed, and the purity of the recovered liquid can be improved.

  Invention of Claim 4 is a development waste liquid processing apparatus in any one of Claims 1-3, Comprising: At least any one of the said front | former stage concentration apparatus and the said back | latter stage concentration apparatus is an evaporative concentration apparatus, and evaporative concentration Condensate water is generated by condensing the steam generated at the time, and the condensed water generated in at least one of the pre-stage concentrator and the post-stage concentrator is used as dissolved water as at least the dissolution apparatus and the dissolution tank. It is characterized by being configured to supply to either one.

  According to the said structure, supplying condensed water separately can be suppressed by using condensed water as dissolved water. Moreover, since the condensed water temperature produced | generated becomes high by applying an evaporative concentration apparatus, melt | dissolution of a crystal | crystallization becomes easy. Furthermore, when the concentrating device is an evaporative concentrating device, if high-temperature condensed water is supplied to the dissolving device, energy to be heated in the dissolving device can be reduced. In addition, although the amount of condensed water produced | generated by a back | latter stage concentration apparatus is small, since it is a beautiful solution with very low content of impurities, it is preferable to supply it to a dissolution tank from the viewpoint of improving the purity of the recovered liquid.

  The invention according to claim 5 is a processing method for developing waste liquid, and a pre-concentration step for concentrating the developing waste liquid, and cooling and crystallizing the concentrated liquid obtained in the pre-concentration step to produce a slurry in which crystals are deposited. A pre-cooling crystallization step, a pre-solid-liquid separation step of separating crystals from the slurry obtained in the pre-cooling crystallization step, a heating dissolution step of heating and dissolving the crystals obtained in the pre-solid-liquid separation step, The solution obtained in the heating and dissolving step is cooled and crystallized to produce a slurry in which crystals are precipitated. The latter cooling and crystallizing step for separating the crystals from the slurry obtained in the latter cooling and crystallizing step. It is characterized by comprising a separation step and a dissolution step for dissolving the crystals obtained in the latter solid-liquid separation step.

  According to the above configuration, a high-purity recovered liquid that can be reused as a developer can be obtained.

  According to the present invention, by performing multiple cooling crystallization processes, a high-purity recovered liquid that can be reused as a developer can be obtained.

1 is an overall configuration diagram of a development waste liquid treatment apparatus according to an embodiment. The partial block diagram which shows the structure of a part of the developing waste liquid processing apparatus which concerns on other embodiment.

  Hereinafter, the present invention will be described in detail based on embodiments. Note that the present invention is not limited to the following embodiments.

FIG. 1 is an overall configuration diagram of a development waste liquid treatment apparatus according to an embodiment. The development waste liquid treatment apparatus 1 is an apparatus that removes impurities from the development waste liquid and collects a reusable developer (tetramethylammonium hydroxide (TMAH)). Here, the impurities include a photoresist component and metals such as copper and aluminum generated in each step of development processing. The main impurity is a photoresist component.
The developing waste liquid treatment apparatus 1 is provided for the first-stage cooling and crystallization unit 2a and the recovered liquid recovered and purified by the first-stage cooling and crystallization unit 2a (corresponding to a solution generated by the dissolving apparatus 6a of FIG. 1 described later). It is comprised from the back | latter stage cooling crystallization unit 2b which performs a highly purified process. Hereinafter, the structure of the front | former stage cooling crystallization unit 2a and the back | latter stage cooling crystallization unit 2b is demonstrated concretely.

[Configuration of Pre-cooling Crystallization Unit 2a]
The pre-cooling crystallization unit 2a includes a pre-concentration device 3a for concentrating the developing waste liquid, and a slurry in which crystals are precipitated by cooling the concentrated liquid concentrated by the pre-concentration device 3a to lower the solubility and crystallizing the solute in the concentrate. The first-stage cooling and crystallization apparatus 4a for generating the first and second stages, the first-stage solid / liquid separation apparatus 5a for separating the crystals from the slurry supplied from the first-stage cooling and crystallization apparatus 4a, and the heating means 80 are supplied from the first-stage solid / liquid separation apparatus 5a. A melting device 6a for heating and dissolving the crystals, a first filtrate tank 7a for storing the filtrate after the crystals are separated and removed by the first solid-liquid separation device 5a, and the condensed water obtained by the first concentration device 3a. It has a condensed water tank 8a to be stored.

  The pre-stage concentrator 3a is not particularly limited as long as it is a concentrator that concentrates the developing waste liquid to near saturation. An example of the pre-stage concentrator 3a is an evaporative concentrator. Examples of evaporative concentrators include a low-pressure evaporative concentrator equipped with an evaporator that evaporates the supplied processing solution (development waste liquid) with a heat source, and a vacuum pump that lowers the inside of the evaporator, and further, the generated steam is insulated. A vapor compression type low-pressure evaporative concentration apparatus comprising a compressor for compressing and configured to return the vapor whose temperature and pressure have been increased by the compressor to the evaporator and to serve as a heat source for evaporating the processing liquid. it can.

  As the pre-cooling crystallization apparatus 4a, a cooling crystallization apparatus using a jacket or an internal coil, an external circulation cooling crystallization apparatus, and the like are known, and there is no particular limitation. The jacket type crystallizer is a type in which a jacket is provided around a container for crystallization, and cold water (or a refrigerant) from a chiller is passed through the jacket and cooled through the wall of the container. The internal coil crystallizer is a type in which a cooling coil is disposed in a container for crystallization, and cold water (or refrigerant) from a chiller is passed through the cooling coil to cool the solution in the container. The external circulation cooling type crystallizer is formed by a circulation path composed of piping, valves, etc., between the crystallization tank and a cooler arranged outside thereof, and a multi-tube type cooler is suitable as the cooler. used. A container equipped with a stirring blade and a baffle in which the internal solution can be satisfactorily stirred is preferable. Moreover, it is preferable that any type has a draft tube inside for the improvement of a mixing property.

  Examples of the first-stage solid-liquid separation device 5a include a centrifuge and a rotary vacuum filter. The pre-stage solid / liquid separation device 5a is supplied with cold pure water for washing, and as a result, the separated crystals are washed with cold pure water, and are converted into crystals without dissolving excessive crystals. The adhering impurities can be removed by washing.

  Examples of the heating means 80 provided in the melting apparatus 6a include a configuration for supplying heated steam, an electric heater, and the like.

  In addition, a third return line 9a for returning the filtrate in the tank 7 to the previous stage concentration unit 3a is connected to the previous stage filtrate tank 7a. A filtrate pump 10a is provided in the third return line 9a. The third return line 9a is provided with a branch line 11a, and a part of the third return line 9a and the branch line 11a constitute a circulation line for circulating the filtrate in the preceding filtrate tank 7a. ing. The return line 9a is provided with a discharge line 12a branched in the middle, and the filtrate is discharged to the outside through the discharge line 12a. The third return line 9a is provided with an absorptiometer (corresponding to the previous stage impurity measuring means) 14a for measuring the concentration of impurities (photoresist components and metals such as copper and aluminum) contained in the filtrate. A pre-stage control valve 13a is provided in the discharge line 12a. The measurement result of the absorptiometer 14a is given to a control device (equivalent to the front-stage switching control means and the rear-stage switching control means) 40, and the opening / closing of the front-stage control valve 13a is controlled according to the measurement result. Specifically, when the measured impurity concentration is lower than the set value, all the filtrate is returned to the pre-concentration unit 3a, and when the impurity concentration is higher than the set value, a part of the filtrate is discharged to the outside from the discharge line 12a. Is done.

The condensed water tank 8a is connected to a dissolving device 6a and a dissolving tank 6b described later, and condensed water is used as the dissolving water in the dissolving device 6a and the dissolving tank 6b.
Here, in this specification, “dissolved water” means water for dissolving crystals, and “dissolved liquid” means a liquid in a state after the crystals are dissolved. In other words, the liquid supplied to the dissolution apparatus 6a and the dissolution tank 6b for dissolution is defined as “dissolution water”, and the liquid after the dissolution treatment in the dissolution apparatus 6a and the dissolution tank 6b is referred to as “dissolution liquid”. Define.
In addition, the solution supplied from the dissolving device 6a is supplied to the later-stage cooling and crystallizing device 4b described later.

[Configuration of the latter cooling crystallization unit 2b]
The post-cooling crystallization unit 2b basically has the same configuration as that of the pre-cooling crystallization unit 2a, and each component of the pre-cooling crystallization unit 2b is appended with a suffix b. Show. Specifically, the latter cooling crystallization unit 2b includes a latter concentration apparatus 3b, a latter cooling crystallization apparatus 4b, a latter solid-liquid separation apparatus 5b, a dissolution tank 6b, a latter filtrate tank 7b, and a first return line. 9b, a filtrate pump 10b, a branch line 11b, and an absorptiometer (corresponding to a subsequent impurity measuring means) 14b. As an example of the latter stage concentration apparatus 3b, the same evaporation concentration apparatus as the previous stage can be mentioned. The dissolution tank 6b and the dissolution apparatus 6a are common in that the dissolution process is performed, but the dissolution tank 6b does not have the heating means 80 provided in the dissolution apparatus 6a, and is the same as a general dissolution tank. Further, the measurement result of the absorbance meter 14b is given to the control device 40, and the opening and closing of the rear control valve 13b is controlled according to the measurement result. In the latter stage cooling crystallization unit 2b, a second return line 20 for returning the filtrate to the former stage concentration device 3a is provided instead of the discharge line 12a for discharging the filtrate to the outside. Therefore, according to the measurement result of the impurity concentration by the absorptiometer 14b, all of the filtrate in the latter-stage filtrate tank 7b is returned to the latter-stage concentrator 3b, or a part of the filtrate is returned to the former-stage concentrator 3a. Thus, the filtrate passage is configured to be switched.

[Development waste liquid treatment device 1]
Next, the processing operation of the development waste liquid processing apparatus 1 will be described.
First, the developing waste liquid is supplied to the pre-stage concentrator 3a. In the pre-stage concentrator 3a, a concentrated liquid concentrated to near saturation is generated. When a low-pressure evaporative concentrator is used in the pre-stage concentrator 3a, the temperature of the concentrate is lowered by the low-pressure evaporation, so that the energy required for the next cooling crystallization can be reduced. In addition, when a vapor compression type evaporation concentrator is used, the vapor generated in the evaporator can be adiabatically compressed by the compressor and raised to a high temperature, so that energy efficiency is better than in the case of vapor heating and further energy saving is achieved. In addition, the condensed water produced | generated with the pre-stage concentrator 3a is supplied to the condensed water tank 8a.

  Next, the concentrated liquid is supplied to the pre-cooling crystallizer 4a. The pre-cooling crystallizer 4a cools the concentrate to lower the solubility, and crystallizes and precipitates the solute (TMAH) in the concentrate. Then, the slurry containing TMAH crystallized from the pre-cooling crystallizer 4a is discharged to the pre-solid-liquid separator 5a.

Next, in the former solid-liquid separator 5a, the TMAH crystal solid (TMAH · 5H ₂ O) is taken out by being separated from the liquid. The TMAH crystal solid is washed with cold pure water and discharged to the dissolving device 6a. In the dissolving device 6a, a small amount of water (dissolved water) is added to the crystalline solid (TMAH · 5H ₂ O) and dissolved by heating to generate a high-temperature solution close to the saturation concentration. And the melt | dissolution solution produced | generated by this melt | dissolution apparatus 6a is given to the back | latter stage cooling crystallization apparatus 4b.

In this way, the melting by the melting apparatus 6a is performed for the following reason. That is, prior to the subsequent cooling crystallization in the subsequent cooling crystallization unit 2b, it is necessary to obtain a high-temperature solution close to the saturation concentration. In this regard, TMAH becomes TMAH · 5H ₂ O crystals by the process of concentration → cooling crystallization → solid-liquid separation in the previous stage, and TMAH · 5H ₂ O becomes a solution by self-water by heating at 63 ° C. or higher. Therefore, if it heats at 63 degreeC or more, only the addition of a small amount of water can produce | generate the high-temperature solution near saturation concentration. Therefore, it is not necessary to dissolve the crystals with a large amount of water and evaporate and concentrate again to obtain a solution close to saturation. By such treatment, impurities can be reduced by dissolving the crystals and recrystallization.

On the other hand, the filtrate after the crystalline solid is separated and removed is discharged to the pre-stage filtrate tank 7a.
In the dissolution apparatus 6a, the condensed water supplied from the condensed water tank 8a is used as the dissolved water. At this time, since the condensed water is at a high temperature, the energy to be heated in the melting device 6a can be reduced.

  On the other hand, the filtrate in the first-stage filtrate tank 7a is measured for the impurity concentration by the absorbance meter 14a. When the impurity concentration is less than the set value, the first-stage control valve 13a is maintained in the closed state, and the filtrate tank 7a All the filtrate is returned to the pre-concentrator 3a. When the impurity concentration is equal to or higher than the set value, the upstream control valve 13a is opened, and a part of the filtrate in the filtrate tank 7a is discharged to the outside. Thereby, it is possible to suppress an increase in the impurity concentration in the pre-cooling crystallization unit 2a and to improve the purity of the solution from the dissolving device 6a (corresponding to the recovered liquid of the pre-cooling crystallization unit 2a).

  Next, the following processing is performed in the rear cooling crystallization unit 2b. Specifically, the solution supplied from the dissolving device 6a is supplied to the subsequent cooling and crystallizing device 4b, cooled and crystallized in the subsequent cooling and crystallizing device 4b, and crystal separation (TMAH) in the subsequent solid-liquid separating device 5b. The crystal solids are washed with cold pure water), and the dissolution process is performed by adding water (dissolution water) to the crystals in the dissolution tank 6b, and the recovered TMAH liquid is recovered from the dissolution tank 6b as the final product. The Thus, by setting it as the structure which performs the multiple cooling crystallization process of a front | former stage cooling crystallization and a back | latter stage cooling crystallization, the collection | recovery TMAH liquid provided with the high purity which can be reused as a developing solution is obtained.

On the other hand, the filtrate after the crystal solids are separated and removed by the latter-stage solid-liquid separation device 5b is discharged to the latter-stage filtrate tank 7b, and further returned to the latter-stage concentration apparatus 3b for concentration treatment. Next, in the latter cooling crystallization apparatus 4b, the reconcentrated liquid from the latter concentration apparatus 3b and the dissolution liquid from the dissolving apparatus 6a are mixed and supplied to the latter cooling crystallization apparatus 4b. Analyzed. With such a configuration, the recovery rate is improved.
In addition, the condensed water produced | generated by the back | latter stage concentration apparatus 3b is supplied to the condensed water tank 8a similarly to the condensed water produced | generated by the front | former stage concentration apparatus 3a.

  The difference between the processing of the rear cooling crystallization unit 2b and the processing of the previous cooling crystallization unit 2a is as follows. That is, when the impurity concentration in the filtrate returned from the latter filtrate tank 7b is less than the set value, the latter control valve 13b is kept closed, and all the filtrate in the latter filtrate tank 7b is sent to the latter concentration device 3b. Will be returned. When the impurity concentration becomes equal to or higher than the set value, the rear control valve 13b is opened, and a part of the filtrate in the rear filtrate tank 7b is returned to the front concentration device 3a. Thereby, the purity of the recovered liquid as the final product can be improved.

(Other matters)
(1) In the above embodiment, all the condensed water generated in the pre-concentrator 3a is supplied to the condensed water tank 8a, but as shown in FIG. 2, in the middle of the condensed water supply line L10. A branch line L11 that branches may be provided, and the preheater 50 and the cooler 51 may be provided in the branch line L11. With such a configuration of FIG. 2, a part of the condensed water passes through the preheater 50 and is heat-exchanged with the developing waste liquid, so that the developing waste liquid is preheated. Further, the condensed water is cooled by passing through the preheater 50 and the cooler 51, and this cooled condensed water is supplied to at least one of the front-stage solid / liquid separation device 5a and the rear-stage solid / liquid separation device 5b, and the crystal washing water is supplied. It becomes possible to use as.

  (2) In the above embodiment, the condensed water generated in the former-stage concentrating device 3a is configured to be supplied to both the dissolving device 6a and the dissolving tank 6b as dissolved water, and the concentrated water generated in the latter-stage concentrating device 3b. The water was configured to be supplied to both the dissolution apparatus tank 6a and the dissolution tank 6b as dissolved water. However, the concentrated water generated by the former-stage concentrator 3a is configured to be supplied only to one of the dissolving apparatus 6a and the dissolving tank 6b, and the concentrated water generated by the latter-stage concentrator 3b is used as the dissolving apparatus 6a. Alternatively, it may be configured to supply only to either one of the dissolution tank 6b.

  Furthermore, the configuration using the condensed water as dissolved water may be only the pre-stage concentrator 3a or the post-stage concentrator 3b.

  In addition, although the amount of the condensed water produced in the latter-stage concentrating device 3b is small, it is clean water containing very low impurities, so that it is preferably supplied to the dissolution tank 6b from the viewpoint of improving the purity of the recovered liquid.

  (3) In the above embodiment, the measurement of the impurity concentration of the filtrate is configured to measure the absorbance with an absorptiometer, but the present invention is not limited to this and may be measured by other methods.

  (4) Instead of the heating device 6a in the above embodiment, a dissolution tank (without the heating means 80) is used, and the solution generated in the dissolution tank is supplied to the subsequent concentration device 3b. May be.

  The present invention can be applied to a development waste liquid treatment apparatus and a treatment method that can perform a concentration and cooling crystallization treatment as a highly purified treatment in the subsequent stage to obtain a high-purity recovered liquid that can be reused as a developer. is there.

1: Development waste liquid treatment device 2a: Pre-cooling crystallization unit 2b: Post-cooling crystallization unit 3a: Pre-concentration device
3b: latter stage concentrator 4a: former stage cooling crystallizer
4b: Subsequent cooling crystallizer 5a: Pre-stage solid-liquid separator 5b: Sub-stage solid-liquid separator 6a: Dissolver 6b: Dissolving tank 8a: Condensed water tank 9a: Third return line 9b: First return line 12a: Discharge line 13a: front stage control valve 13b: rear stage control valve 14a: Absorbance meter (front stage impurity measuring means)
14b: Absorbance meter (second-stage impurity measuring means)
20: Second return line 40: Control device (front stage switching control means, rear stage switching control means)
80: Heating means

Claims (5)

A pre-concentrator for concentrating developer waste,
Cooling and crystallizing the concentrated liquid supplied from the preceding-stage concentrating device, and generating a slurry from which crystals have precipitated,
A pre-solid-liquid separation device for separating crystals from the slurry supplied from the pre-cooling crystallizer;
A melting device that has heating means and heat-dissolves crystals supplied from the preceding solid-liquid separation device;
A cooling crystallization apparatus for cooling and crystallizing the solution supplied from the dissolution apparatus to produce a slurry in which crystals are deposited; and
A latter-stage solid-liquid separation device for separating crystals from the slurry supplied from the latter-stage cooling crystallizer;
A dissolution tank for dissolving crystals supplied from the latter-stage solid-liquid separator;
A developing waste liquid treatment apparatus comprising: A post-concentration device for concentrating the filtrate after the crystals are separated and removed by the post-stage solid-liquid separation device, and supplying the concentrate to the post-cooling crystallizer;
A post-stage impurity measuring means for measuring the impurity concentration contained in the filtrate after the crystals are separated and removed by the post-stage solid-liquid separation device;
A first return line for returning the filtrate to the latter concentration device;
A second return line for returning the filtrate to the pre-concentrator,
A rear control valve provided in the second return line;
When the concentration of impurities is less than a set value, the latter control valve is closed when the result of measurement by the latter impurity measuring means is less than the set value, and the filtrate is returned to the latter concentration device. The latter-stage control valve for switching the return path of the filtrate so that the latter-stage control valve is opened and at least a part of the filtrate is returned to the former-stage concentrator;
The development waste liquid processing apparatus of Claim 1 provided with. Pre-stage impurity measuring means for measuring the impurity concentration contained in the filtrate after the crystals are separated and removed by the pre-stage solid-liquid separation device,
A third return line for returning the filtrate to the pre-concentrator,
A discharge line for discharging the filtrate to the outside;
A pre-stage control valve provided in the discharge line;
When the concentration of impurities is less than a set value, the previous control valve is closed when the result of measurement by the previous impurity measuring means is returned, the filtrate is returned to the previous concentration device, and the concentration of impurities is higher than the set value. A first-stage switching control means for switching the return passage of the filtrate so that the first-stage control valve is opened and at least a part of the filtrate is discharged to the outside;
The developing waste liquid treatment apparatus according to claim 1 or 2, further comprising:   At least one of the pre-stage concentrator and the post-stage concentrator is an evaporative concentrator, and condensate is generated by condensing the vapor generated when evaporating and concentrating. At least one of the pre-stage concentrator and the post-stage concentrator is used. The development waste liquid processing apparatus according to any one of claims 1 to 3, wherein the condensed water generated in any one of the above is supplied as dissolved water to at least one of the dissolution apparatus and the dissolution tank. A pre-concentration step for concentrating developer waste,
Cooling and crystallization of the concentrated liquid obtained in the preceding concentration step, and the preceding cooling and crystallization step for producing a slurry in which crystals are precipitated,
A pre-solid-liquid separation step of separating crystals from the slurry obtained in the pre-cooling crystallization step;
A heating and dissolving step for heating and dissolving the crystals obtained in the previous solid-liquid separation step;
Cooling and crystallization of the solution obtained in the heating and dissolving step, and a subsequent cooling and crystallization step for producing a slurry in which crystals are precipitated,
A subsequent solid-liquid separation process for separating crystals from the slurry obtained in the latter cooling crystallization process;
A dissolving step for dissolving the crystals obtained in the latter solid-liquid separation step;
A processing method for developing waste liquid, comprising:

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