JP2010002378A - Method and device for treating boric acid containing waste liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel method and a device for treating a boric acid containing a waste liquid capable of restraining the viscosity of a boric acid containing the waste liquid from increasing, and stably treating the boric acid containing the waste liquid while preventing a pipe from being blocked. <P>SOLUTION: The method of treating a boric acid containing the waste liquid to be cemented and solidified includes steps of adding a compound of an alkali metal element to the boric acid containing the waste liquid, then heating the boric acid containing the waste liquid to a predetermined temperature higher than 85°C, then adding a compound of an alkali earth metal, and stirring the resulting solution. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and apparatus for treating boric acid-containing waste liquid generated in a pressurized water reactor (PWR) or the like.

  Since the boric acid-containing waste liquid generated in a pressurized water reactor (PWR) or the like contains boric acid containing a radionuclide, it must finally be solidified with cement or the like. However, since boric acid prevents the cement from solidifying, there is a limit to the amount of boric acid that can be added to the cement. For this reason, a calcium compound such as calcium hydroxide is added in advance to the boric acid-containing waste liquid to make boric acid insoluble and to precipitate calcium borate. The precipitate is dried and pulverized to solidify the cement. Thus, a method for avoiding the hindering effect of cement solidification by boric acid is known.

  However, the above-described method has a problem that the viscosity of the boric acid-containing waste liquid increases, and calcium borate settles and accumulates in a staying portion in the pipe and the pipe is blocked. For this reason, an alkali metal element compound and an alkaline earth metal compound are added to a boric acid-containing waste liquid heated to 80 ° C., and the waste liquid is allowed to flow through the piping while being kept at a temperature equal to or higher than the precipitation temperature, and supplied to the dryer. There has been proposed a method of suppressing sedimentation or the like to a staying portion in a pipe by performing a drying process (for example, see Patent Document 1).

  However, even in the improved background art described above, the viscosity of the waste liquid is increased by adding the alkali metal element compound and the alkaline earth metal compound to the boric acid-containing waste liquid, and sedimentation and deposition in the staying portion in the pipe As a result, there has been a problem that the piping is blocked.

  In view of such a situation, in Patent Document 2, paying attention to the temperature of the boric acid-containing waste liquid when adding the alkali metal element compound and the alkaline earth metal compound, the alkali metal element compound is added to the boric acid-containing waste liquid. After the addition, the temperature of the boric acid-containing waste liquid is raised to a temperature of 85 ° C. or higher, and then the alkaline earth metal compound is added and stirred to suppress an increase in the viscosity of the boric acid-containing waste liquid. Various problems such as the blockage of the piping as described above are solved.

According to such a method, an increase in the viscosity of the boric acid-containing waste liquid can be drastically suppressed as compared with the prior art, and the problem of blockage of the pipe due to sedimentation and accumulation of the waste liquid in the pipe is sufficiently improved. can do.
JP 2000-284092 A JP 2005-345440 A

  However, in recent years, it has been required to reduce the processing time and increase the efficiency of the waste liquid treatment of boric acid, and even with the above-described technology, when the concentration of boric acid in the waste liquid is high, the treatment of the waste liquid is efficient. Well, sometimes it could not be done in a short time.

  The present invention is a novel boric acid-containing waste liquid treatment that can suppress an increase in the viscosity of the boric acid-containing waste liquid and that can stably treat the boric acid-containing waste liquid without causing clogging of piping. It is an object to provide a method and a processing apparatus.

  In order to solve the above problems, one embodiment of the present invention is a method for treating a boric acid-containing waste liquid to be cement-solidified, the first step of adding an alkali metal element compound to the boric acid-containing waste liquid, and the boron The present invention relates to a method for treating a boric acid-containing waste liquid, comprising: a second step of heating the acid-containing waste liquid to a predetermined temperature higher than 85 ° C., adding an alkaline earth metal compound, and stirring.

  One embodiment of the present invention includes a waste liquid supply tank that contains boric acid-containing waste liquid, a drying processing device that dries the boric acid-containing waste liquid, and the boric acid-containing waste liquid from the waste liquid supply tank to the drying processing device. A transfer mechanism for quantitative transfer, an apparatus for adding an alkali metal element compound in the waste liquid supply tank, an apparatus for adding an alkaline earth metal compound in the waste liquid supply tank, and the boric acid content in the waste liquid supply tank The present invention relates to an apparatus for treating boric acid-containing waste liquid, comprising: a heating mechanism that raises the waste liquid to a predetermined temperature; and a stirring mechanism that stirs the boric acid-containing waste liquid in the waste liquid tank.

  Moreover, in one aspect of the present invention, after the first step and the second step, by adding an acid to the boric acid-containing waste liquid, the boric acid-containing waste liquid has a pH of 9 or less. Can be set.

  As described above, the alkali metal element compound and the alkaline earth metal compound are added to the boric acid-containing waste liquid, and the temperature of the boric acid-containing waste liquid and the rate of temperature increase when the alkaline earth metal compound is further added. Is defined, the viscosity of the boric acid-containing waste liquid can be sufficiently reduced as described above. However, after such treatment, for example, if the waste liquid is held for a relatively long time in a treatment tank or the like, the viscosity of the waste liquid may increase again.

  Even when the holding time is short, the viscosity of the boric acid-containing waste liquid may not be sufficiently reduced only by the above-described treatment.

  In these cases, according to this embodiment, the viscosity of the waste liquid can be further reduced by adding an acid to the boric acid-containing waste liquid and adjusting its pH to 9 or less. Therefore, problems such as blockage of piping can be more effectively suppressed.

  The reason why the viscosity is lowered by adjusting the pH of the boric acid-containing waste liquid is not clear at this stage. Such a requirement has been found as a result of extensive experiments and tests by the inventors.

  In one embodiment of the present invention, a plurality of the waste liquid supply tanks can be provided. In this case, while the boric acid-containing waste liquid is being processed in one waste liquid supply tank, the treated boric acid-containing waste liquid can be supplied to a drying device or the like in another waste liquid supply tank. Therefore, the treatment time of the boric acid-containing waste liquid can be shortened.

  Furthermore, in one embodiment of the present invention, a pretreatment tank can be provided in addition to the waste liquid supply tank. In this case, in the pretreatment tank, treatment is performed by adding an alkali metal element compound and an alkaline earth metal compound, and the treated boric acid-containing waste liquid is supplied from the waste liquid supply tank to a drying device or the like. Therefore, the treatment time of the boric acid-containing waste liquid can be shortened.

  As described above, according to the present invention, it is possible to suppress an increase in the viscosity of the boric acid-containing waste liquid, and to stably treat the boric acid-containing waste liquid without causing piping clogging, A novel boric acid-containing waste liquid treatment method and treatment apparatus can be provided.

  Hereinafter, embodiments of the boric acid-containing waste liquid treatment method and treatment apparatus of the present invention will be described in detail with reference to the drawings.

(Method of treating boric acid-containing waste liquid)
First, a method for treating boric acid-containing waste liquid will be described. FIG. 1 is a flowchart showing an example of a method for treating a boric acid-containing waste liquid according to the present invention.

  As shown in FIG. 1, in the boric acid-containing waste liquid treatment method according to this example, boric acid generated from a nuclear power plant or the like is a main component, and a boric acid-containing waste liquid containing radioactive boric acid is obtained (step 1). Then, after neutralizing by adding an appropriate amount of an alkali metal element compound (step 2), heating to a temperature higher than 85 ° C. (preferably 88 ° C. to 95 ° C., more preferably about 90 ° C.) within 2 hours (step 3) Thereafter, an appropriate amount of an alkaline earth metal compound is added (step 4), and this temperature is preferably stirred for 8 hours or longer (step 5), and then the temperature is lowered to 50 ° C. or lower (step 6). Thereafter, a drying process (step 7) is performed, and cement solidification (step 8) is performed.

  As the alkali metal element compound in step 2, for example, sodium or potassium hydroxide can be used. The addition amount of the alkali metal element compound is such that the ratio of the alkali metal element compound to the boric acid-containing waste liquid is a molar ratio of the alkali metal in the alkali metal element compound to the boron in the boric acid-containing waste liquid. 0.25 to 0.35, preferably 0.3.

  For example, in the case of NaOH, Na / B (molar ratio) = 0.25 to 0.35 (preferably 0.3), and in the case of KOH, K / B (molar ratio) = 0.25 to 0.35 ( Preferably 0.3).

  According to the present invention, the rate of temperature increase up to a temperature of 85 ° C. or higher in Step 3 needs to be within 2 hours, and preferably within 30 minutes. The experimental data as the basis for this will be shown below.

  FIG. 2 is a graph showing the relationship between the viscosity (mPa · s) of the boron-containing waste liquid and the retention time (h) using the heating temperature and the temperature rising time as parameters.

  Curve A shows that the waste liquid containing boric acid at 70 ° C. was neutralized with an alkali metal element compound in Step 2 and then heated to 85 ° C. in 2 hours. After 17 hours, an alkaline earth metal compound was added in Step 4. It is a graph at the time of processing and holding at 74 degreeC. Curve B shows that the waste liquid containing boric acid at 70 ° C. was neutralized with an alkali metal element compound in Step 2 and then heated to 85 ° C. in 30 minutes. After 17 hours, the alkaline earth metal compound was added in Step 4 It is a graph at the time of adding and processing and hold | maintaining at 74 degreeC. Further, curve C is a graph in the case where the waste liquid containing boric acid at 70 ° C. is neutralized with an alkali metal element compound in step 2 and then treated with an alkaline earth metal compound added in step 4 after 17 hours. .

  In addition, the holding time 0 in FIG. 2 means the time when the alkaline earth metal compound is added in Step 4 and the treatment is started, and the holding time is set based on the treatment start time. It is what.

  As apparent from FIG. 2, in curve A, the viscosity drops to about 3 (mPa · s) after the elapse of 8 hours in the case where the temperature is held at 74 ° C. after the start of the process in step 4, and thereafter 100 hours or more. It was found that no increase in viscosity was observed after the passage. Also, in curve B, when the temperature is kept at 74 ° C. after the start of the process in step 4, the viscosity decreases to about 1.5 (mPa · s) after 8 hours, and the viscosity does not exceed 100 after that. It was found that no increase was confirmed.

  On the other hand, in curve C, it was found that the viscosity of the boric acid-containing waste liquid after the treatment was significantly increased to 100 (mPa · s) or more. Therefore, when such a high-viscosity boric acid-containing waste liquid is subjected to a subsequent drying process (step 7), the piping of the processing apparatus is blocked.

  From the above results, when the treatment with the alkali metal element compound and the alkaline earth compound (steps 2 and 4), the heating in step 3 during that time is raised to 85 ° C. or more within 2 hours, after the treatment Thus, the viscosity of the boric acid-containing waste liquid can be kept low for a long period of time, and blockage of the pipes can be prevented and stable treatment can be performed for a long period of time.

  In addition, the heating temperature in the process 3 becomes like this. Preferably it is 88-95 degreeC, More preferably, it is about 90 degreeC. In this case, the viscosity of the boric acid-containing waste liquid can be reduced in a shorter time.

As the alkaline earth metal compound in step 4, for example, calcium or magnesium can be used. In this case, the ratio of the alkaline earth metal compound to the boric acid-containing waste liquid is set at a molar ratio of 0.1 to the boron in the boric acid-containing waste liquid of the alkaline earth metal in the alkaline earth metal compound. 4 to 0.5, preferably 0.45 wave. Specifically, when the alkaline earth metal compound is Ca (OH) ₂ , Ca / B (molar ratio) = 0.4 to 0.5 (preferably 0.45), and Mg (OH) ₂ In this case, Mg / B (molar ratio) = 0.4 to 0.5 (preferably 0.45).

  The stirring time in step 5 is 8 hours or longer. Even in this case, although the reason is not clear, the viscosity of the boric acid-containing waste liquid after treatment can be sufficiently reduced and can be held for a long time. In addition, the upper limit of stirring time is not specifically limited.

  Step 6 is a step of storing the waste liquid after the treatment is completed by substantially adding the alkali metal element-containing compound and the alkaline earth metal compound to the boric acid-containing waste liquid through the steps 1 to 5. It is. In this example, the temperature in step 6 is set to 50 ° C. or lower.

  The waste liquid after treatment is preferably stored at a low temperature from the viewpoint of energy saving due to reduction in power consumption unless it is used to clog the inside of the pipe when it is subjected to subsequent drying treatment accompanied by an increase in viscosity or the like. . In this example, even if the boric acid-containing waste liquid after treatment is kept at a low temperature of 50 ° C. or lower in the treatments from Step 1 to Step 5, problems such as an increase in viscosity do not occur. In step 6 of this example, the boric acid-containing waste liquid that has passed through steps 1 to 5 is cooled to 50 ° C. or lower and stored.

  The boric acid-containing waste liquid stored in step 6 at a temperature of 50 ° C. or lower is then subjected to a drying treatment in step 7 and further cemented in step 8.

  FIG. 3 is a flowchart showing another example of the method for treating a boric acid-containing waste liquid according to the present invention. This example is the same as the example related to FIG. 1 except that step 9 is added between steps 5 and 6. Therefore, below, it demonstrates centering on the process 9. FIG.

  Even after passing through steps 1 to 5 as described above, for example, if the retention time of the boric acid-containing waste liquid is prolonged, the viscosity of the waste liquid may increase again. Even when the holding time is short, the viscosity of the boric acid-containing waste liquid may not be sufficiently reduced only by the above-described treatment. In such a case, it is preferable to add an acid to the boric acid-containing waste liquid in Step 9 so that the pH value is 9 or less, more preferably 8 or less. This makes it possible to reduce the viscosity of the boric acid-containing waste liquid. The experimental data as the basis for this will be shown below.

  FIG. 4 is a graph showing the relationship between the viscosity (mPa · s) of the boric acid-containing waste liquid and the ratio of addition of sulfuric acid (ml / 1000 ml of waste liquid), and FIG. It is a graph which shows the relationship between a viscosity (mPa * s) and pH value. In FIGS. 4 and 5, the stirring time is a parameter.

  As shown in FIG. 4, it can be seen that the viscosity of the boric acid-containing waste liquid decreases by increasing the ratio of sulfuric acid added to the boric acid-containing waste liquid. Specifically, in the case where sulfuric acid is not added to the boric acid-containing waste liquid, the viscosity is 330 (mPa · s), whereas by adding sulfuric acid, although depending on the stirring time, the viscosity is 100 It turns out that it can reduce to (mPa * s) or less.

  On the other hand, as shown in FIG. 5, when the viscosity of the boric acid-containing waste liquid decreases due to the addition of sulfuric acid, the pH value also decreases. When the viscosity is 100 (mPa · s) or less as described above, the pH value is 9 or less. It turns out that it is.

  Therefore, it turns out that the viscosity of the said boric acid containing waste liquid can fully be reduced by adding an acid with respect to a boric acid containing waste liquid, and making the pH value into 9 or less.

  As is clear from FIGS. 4 and 5, the reduction in viscosity in the case of 4 hours is more remarkable than in the case where the stirring time is 110 minutes. That is, even in this case, it can be seen that the viscosity of the waste liquid is effectively reduced by performing the stirring time for a long time, for example, 4 hours or more.

  Although not particularly illustrated, the viscosity reduction of the waste liquid could be confirmed by performing the stirring for a long time up to about 10 hours, but the viscosity reduction could not be confirmed even after stirring for a longer time. Therefore, the upper limit of the stirring time is about 10 hours.

  In addition, any acid can be used as long as it satisfies the above-described requirements, not limited to sulfuric acid. For example, the same effect can be obtained by blowing carbon dioxide.

  Since Steps 1 to 8 are the same as the above-described example, description thereof is omitted.

(Boric acid-containing waste liquid treatment equipment)
Next, a treatment apparatus for boric acid-containing waste liquid will be described. FIG. 6 is a schematic configuration diagram illustrating an example of a boric acid-containing waste liquid treatment apparatus.

  As shown in FIG. 6, the boric acid-containing waste liquid treatment apparatus according to this embodiment includes a concentrated waste liquid supply tank 11, a transfer mechanism including a concentrated waste liquid supply pump 12, a head tank 13, and the like, and a drying treatment apparatus (saddle type). Thin film dryer) 14.

  Further, the concentrated waste liquid supply tank 11 includes an alkali metal element compound adding device 15 for adding an alkali metal element compound as a neutralizing agent, and an additive measuring device 16a for adding an alkaline earth metal compound. An alkaline earth metal compound addition device 16 for controlling the amount of addition is provided.

  Furthermore, the concentrated waste liquid supply tank 11 measures the electric heater 17 for keeping the liquid temperature in the tank constant, the cooling device 18 for lowering the liquid temperature, the vent cooler 19, and the liquid level in the tank. A liquid level meter 20 for measuring the temperature, a thermometer 21 for measuring the temperature of the liquid in the tank, and a mechanical stirrer 22 for stirring the waste liquid in the tank are provided. In the figure, 23 and 24 are flow meters, 25 is a level meter, 26 is a regulating valve, and 27 is a cleaning line.

  Although not particularly shown, an addition device for adding an acid to the concentrated waste liquid supply tank 11 can be provided.

In the boric acid-containing waste liquid treatment apparatus having the above-described configuration, the boric acid-containing concentrated waste liquid is stored in the concentrated waste liquid supply tank 11 according to the above-described treatment method, and an alkali metal element compound such as NaOH is supplied from the alkali metal element compound addition apparatus 15. After neutralization by adding a predetermined amount, the boric acid-containing concentrated waste liquid is heated to a temperature higher than 85 ° C. (for example, 90 ° C.) by the electric warmer 17. Then, a predetermined amount of an alkaline earth metal compound such as Ca (OH) ₂ is added from the alkaline earth metal compound addition device 16 and stirred by the mechanical stirrer 23 for a predetermined time (8 hours or more). Thereafter, the boric acid-containing concentrated waste liquid is cooled to a predetermined temperature (for example, approximately 50 ° C.) by the cooling device 18.

  By performing the treatment as described above, the waste liquid properties of the boric acid-containing waste liquid can be stabilized, and an increase in viscosity can be suppressed. Then, since the concentrated waste liquid containing boric acid having a low viscosity increase width is supplied to the drying processing device 14 by the concentrated waste liquid supply pump 12 and the head tank 13 or the like, there is a situation in which the piping is blocked. Can be prevented, and reliability can be improved. Moreover, since the boric acid-containing concentrated waste liquid described above can be processed in the concentrated waste liquid supply tank 11, the number of constituent devices is relatively small, and the occupied space can be reduced.

  FIG. 7 shows a configuration of a boric acid-containing waste liquid treatment apparatus according to another embodiment, and portions corresponding to the above-described embodiments are denoted by the same reference numerals. In the embodiment shown in the figure, two concentrated waste liquid supply tanks 11 are provided. While one of the concentrated waste liquid supply tanks 11 performs the process of making the boric acid-containing concentrated waste liquid insoluble, the other concentrated waste liquid supply is performed. In the tank 11, it is possible to perform a boric acid-containing concentrated waste liquid supplying process that has already been subjected to a slightly solubilizing process, and thus the overall processing time can be shortened. In addition, processing using only one concentrated waste liquid supply tank 11 can be performed, which is effective when the other concentrated waste liquid supply tank 11 is maintained.

  FIG. 8 shows a configuration of a boric acid-containing waste liquid treatment apparatus according to another embodiment, and portions corresponding to the above-described embodiments are denoted by the same reference numerals. In the embodiment shown in the drawing, the boric acid-containing concentrated waste liquid that has been hardly solubilized is supplied directly from the concentrated waste liquid supply tank 11 to the drying treatment apparatus 14 by the concentrated waste liquid supply pump 12 without using the head tank. It has become. For this reason, the drying process in the drying processing apparatus 14 can be performed before the viscosity increases.

  In this case, a dryer cleaning water tank 30 and a dryer cleaning water pump 31 for receiving dryer cleaning water for cleaning the drying processing device 14 are provided. The dryer washing water tank 30 is provided with a heater 32, a thermometer 33, a liquid level gauge 34, a mechanical stirrer 35, and the like.

  FIG. 9 shows a configuration of a boric acid-containing waste liquid treatment apparatus according to another embodiment, and parts corresponding to the above-described embodiments are denoted by the same reference numerals. In the embodiment shown in the figure, a pretreatment tank 40 is provided in the concentrated waste liquid supply tank 11, and further, an alkali metal element compound addition device 15, an alkaline earth metal compound addition device 16, an electric type are provided in the pretreatment tank 40. A heater 17, a cooling device 18, a thermometer 42, a mechanical stirrer 43, a liquid level meter 44, and the like are provided. In this case, the concentrated waste liquid supply tank 11 is provided with a heat retaining device 41.

  Since the boric acid-containing waste liquid treatment apparatus having the above-described configuration includes the pretreatment tank 40 and the concentrated waste liquid supply tank 11, the pretreatment (slightly soluble treatment) step and the liquid supply step can be simultaneously performed by these, The overall processing time can be shortened.

  Although not particularly shown, an addition device for adding an acid to the pretreatment tank 40 may be provided.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

It is a flowchart which shows an example of the processing method of the boric acid containing waste liquid of this invention. It is a graph which shows the relationship between the viscosity (mPa * s) and retention time (h) of a boron containing waste liquid, using heating temperature and temperature rising time as a parameter. It is a flowchart which shows the other example of the processing method of the boric acid containing waste liquid of this invention. It is a graph which shows the relationship between the viscosity (mPa * s) of a boric-acid containing waste liquid, and the addition ratio (ml / waste liquid 1000ml) of a sulfuric acid. It is a graph which shows the relationship between the said viscosity (mPa * s) and pH value of a boric-acid containing waste liquid. It is a schematic block diagram which shows an example of the processing apparatus of the boric acid containing waste liquid of this invention. It is a schematic block diagram which shows the other example of the processing apparatus of the boric acid containing waste liquid of this invention. It is a schematic block diagram which shows the others of the processing apparatus of the boric acid containing waste liquid of this invention. It is a schematic block diagram which shows further others of the processing apparatus of the boric acid containing waste liquid of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Concentrated waste liquid supply tank 12 Concentrated waste liquid supply pump 13 Head tank 14 Drying processing device 15 Alkali metal element compound addition device 16 Alkaline earth metal element compound addition device 17 Electric warmer 18 Cooling device 19 Vent cooler 20 Liquid level meter 21 Thermometer 22 Mechanical agitator

Claims (12)

A method for treating boric acid-containing waste liquid that solidifies into cement,
A first step of adding an alkali metal element compound to the boric acid-containing waste liquid;
After the first step, the second step of raising the temperature of the boric acid-containing waste liquid to a predetermined temperature higher than 85 ° C., adding an alkaline earth metal compound, and stirring,
A method for treating boric acid-containing waste liquid, comprising:   The said predetermined temperature is 88-95 degreeC, The processing method of the boric acid containing waste liquid of Claim 1 characterized by the above-mentioned.   The ratio of the alkali metal element compound to the boric acid-containing waste liquid is 0.25 to 0.35 in a molar ratio of the alkali metal in the alkali metal element compound to boron in the boric acid-containing waste liquid. The processing method of the boric acid containing waste liquid of Claim 1 or 2 characterized by the above-mentioned.   The ratio of the alkaline earth metal compound to the boric acid-containing waste liquid is 0.4 to 0 by molar ratio of the alkaline earth metal in the alkaline earth metal compound to boron in the boric acid-containing waste liquid. The processing method of the boric acid containing waste liquid as described in any one of Claims 1-3 characterized by the above-mentioned.   After the first step and the second step, comprising a third step of lowering the temperature of the boric acid-containing waste liquid heated to the predetermined temperature to 50 ° C. or less, The processing method of the boric acid containing waste liquid as described in any one of Claims 1-4.   After the first step and the second step, including a fourth step of setting the pH of the boric acid-containing waste liquid to 9 or less by adding an acid to the boric acid-containing waste liquid. The processing method of the boric acid containing waste liquid as described in any one of Claims 1-4 characterized by these. A waste liquid supply tank for storing boric acid-containing waste liquid;
A drying apparatus for drying the boric acid-containing waste liquid;
A transfer mechanism for quantitatively transferring the boric acid-containing waste liquid from the waste liquid supply tank to the drying treatment apparatus;
An apparatus for adding an alkali metal element compound into the waste liquid supply tank;
An apparatus for adding an alkaline earth metal compound to the waste liquid supply tank;
A heating mechanism that raises the boric acid-containing waste liquid in the waste liquid supply tank to a predetermined temperature;
An agitation mechanism for agitating the boric acid-containing waste liquid in the waste liquid tank;
An apparatus for treating waste liquid containing boric acid, comprising:   The apparatus for treating boric acid-containing waste liquid according to claim 7, further comprising a cooling device that lowers the temperature of the boric acid-containing waste liquid in the waste liquid supply tank to 50 ° C or lower.   The apparatus for treating a boric acid-containing waste liquid according to claim 7 or 8, further comprising an apparatus for adding an acid to the waste liquid supply tank. A waste liquid supply tank for storing boric acid-containing waste liquid;
A drying apparatus for drying the boric acid-containing waste liquid;
A transfer mechanism for quantitatively transferring the boric acid-containing waste liquid from the waste liquid supply tank to the drying treatment apparatus;
A pretreatment tank for pretreating the boric acid-containing waste liquid supplied to the waste liquid supply tank;
An apparatus for adding an alkali metal element compound into the pretreatment tank;
An apparatus for adding an alkaline earth metal compound into the pretreatment tank;
A heating mechanism that raises the boric acid-containing waste liquid in the pretreatment tank to a predetermined temperature;
A stirring mechanism for stirring the boric acid-containing waste liquid in the pretreatment tank;
An apparatus for treating waste liquid containing boric acid, comprising: A cooling device for lowering the temperature of the boric acid-containing waste liquid in the pretreatment tank to 50 ° C. or lower, and a heat retaining device for maintaining the temperature of the boric acid-containing waste liquid in the waste liquid supply tank at 50 ° C. or lower;
The processing apparatus of the boric acid containing waste liquid of Claim 10 characterized by the above-mentioned.   The apparatus for treating boric acid-containing waste liquid according to claim 10 or 11, further comprising an apparatus for adding an acid to the pretreatment tank.

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