JPH10123291A - Method for solidifying organic solution and method for treating aqueous solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the solidification of an oil gelling agent by regulating a dielectric constant to a specified value with regard to an organic solution containing a least one polarity component and at least one non-polarity component. SOLUTION: In the case where 2% of stearic acid is added to an organic solution as a solidifier, solidarity is shown on a vertical axis, the dielectric constant of the solution is shown on a horizontal axis, and this relation shows that solidification can be performed in a region of the dielectric constant of 13 or lower. For instance, in the case where mutual separation of a rare each elements is performed by a solvent extraction method using an extraction solvent prepared by diluting di-2-ethyl hexyl phosphoric acid down to about 30% volume by n-heptane, an organic waste liquid of tool washing liquid such as ethanol mixed with the extraction solvent is produced. Ethanol and the like are removed from the organic waste liquid by extraction caused by simultaneously produced inorganic waste and liquid evaporation due to heating, the dielectric constant is made 13 or lower, and solidification of the organic waste liquid such as 12-hydroxy stearic acid can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a mixture of various organic solutions, in particular, a waste extraction organic solvent after being repeatedly used in a chemical separation process, and a sample for analysis taken out in a separation process for controlling the process. When storing an organic solution such as an organic solution mixture which is a waste liquid after being used as a waste liquid, it is easy to handle and enhances safety, and is used in an industrial field where an organic solution is used as an extraction solvent. You.

[0002]

2. Description of the Related Art As one of methods for treating organic waste liquid,
There is a method in which an oil gelling agent containing 12-hydroxystearic acid as a main component is dissolved while heating, and then cooled and solidified. This is applied to the solidification of waste oil discharged from households. Examples of these applications are PETROTECH, 7
(7), 573-577 (1984). l-Hydroxystearic acid has a hydroxyl group and a carboxylic acid group, and these functional groups are polymerized by hydrogen bonding and dimer formation in an organic solution to form a molecular arrangement, thereby forming a fibrous structure. Then, they are three-dimensionally entangled with each other to solidify the entire organic solution. 12-hydroxystearic acid can be satisfactorily solidified by adding only a small amount to various oils and nonpolar liquids. On the other hand, this oil gelling agent is not as effective for highly polar liquids as it is for nonpolar liquids.

[0003] The organic solution has a high polarity when a component having a high polarity is contained. In particular, an organic solution generated by a chemical separation process such as metal scouring has a high polarity. That is, in the chemical separation process, analysis of element concentration, deterioration of the separation reagent, etc. is performed in various steps for process management. When the solvent extraction method is used for chemical separation, from the analysis step, an inorganic waste liquid containing various inorganic components, and an organic solution containing alcohol, acetone, etc. used for washing the extraction solvent, analysis reagents and analysis instruments Occurs.
Among the organic solutions, alcohol and acetone are highly polar components. When these are mixed, the polarity becomes higher in the whole organic solution. Such organic solutions cannot be solidified well with an oil gelling agent such as 12-hydroxystearic acid.

[0004]

When extraction with an organic solvent is performed, the extraction solvent is usually reused through a recovery, separation and purification process, but is discharged in an aging extraction solvent and an analysis process after repeated use. Organic waste liquids containing various reagents and solutes are usually incinerated. However, storage in a liquid state before incineration requires strictly controlled facilities and facilities because of the risk of evaporation and leakage. If these organic solutions can be stored in a solid state, handling is easy and safety is greatly improved. As described above, the solidification by the use of the conventional oil gelling agent has only been reported individually for use in gelling a specific liquid oil. No applicable conditions were reported. The present invention relates to the application of a solidifying agent such as an oil gelling agent to various organic mixed solutions, for example, a complex organic mixed solution generated in a chemical extraction step, an analysis step for the management thereof, etc. By setting the conditions, it is possible to solidify the organic solution.

[0005]

According to the present invention, an organic solution containing at least one polar component and at least one non-polar component is used under the condition of a relative dielectric constant of 13 or less using a solidifying agent such as an oil gelling agent. The present invention relates to a method for solidifying an organic solution to be solidified.

The organic solution to be solidified in the present invention includes:
There are various organic solution mixtures, especially waste organic solvents after repeated use in the chemical separation process and waste liquid after being used as an analytical sample which is taken out in the separation process to control the process Organic solution mixtures can be mentioned. In the chemical separation process, different organic solvents are used depending on the process.Non-polar components such as heptane, hexane, dodecane, toluene, and carbon tetrachloride, and polar components such as methyl isobutyl ketone, Acetone, ethanol and the like are examples of typical organic solvents used. Further, benzene, xylene, acetone, ethanol, methanol, acetic acid and the like used in the analysis process are also examples. Therefore, a mixture of these various organic solvents is an organic solution to be subjected to the solidification treatment method of the present invention.

These organic solutions vary widely depending on the type and amount of the organic solvent contained therein, and cannot be uniformly solidified simply by using a solidifying agent such as an oil gelling agent.

The present inventor has studied various conditions for solidifying these organic solutions and found that the relative permittivity of the organic solutions was 1
It has been found that the organic solution can be solidified by using a solidifying agent such as an oil gelling agent under the conditions of 3 or less, preferably 10 or less, particularly preferably 2.5 or less, and completed the present invention. is there.

Examples of the solidifying agent such as an oil gelling agent used in the present invention include known oil gelling agents such as 12-hydroxystearic acid.

[0012] The 12-hydroxystearic acid dissolved in an organic solution forms a dimer through its carboxylic acid group and forms a polymer by hydrogen bonding through a hydroxyl group to solidify the entire organic solution. It is considered.
From these functions, it can be assumed that a polymer is easily formed in a nonpolar solution in which a functional group is not dissociated. However, the polarity of the organic solution mixture varies depending on its composition, and it cannot be immediately assumed whether or not solidification by a solidifying agent such as a gelling agent is possible. Therefore, since the polarity of the organic solvent can be quantitatively evaluated using the relative dielectric constant, the relationship between the relative dielectric constant and the solidifying performance of the solidifying agent was examined variously. And the solidifying performance of the solidifying agent.

The relationship between the relative dielectric constant of the organic solution and the solidification by a solidifying agent such as an oil gelling agent will be described with reference to FIG.

This shows the solidification performance when 2% of 12-hydroxystearic acid is added to an organic solution. Ethanol having a relative dielectric constant of approximately 25 does not solidify, but has a relative dielectric constant of 13%. The methyl isobutyl ketone of 0.11 solidifies in the form of flakes, and paraffin having a relative dielectric constant of about 3 and toluene and pyridine of 10.6 completely solidify. Therefore, when the relative dielectric constant was 10, solidification was apparent, and when the relative dielectric constant was 2.5, more solidification was observed.

The above figure shows that an organic solution having a relative dielectric constant of 13 or less can be solidified with a solidifying agent such as an oil gelling agent.

The relative dielectric constant of an organic solution varies depending on its composition and is various. However, the value can be determined by measuring the relative permittivity, and can be solidified by adjusting the value to 13 or less. That is, the object of the present invention is achieved by adjusting the relative dielectric constant of an organic solution containing a polar component to 13 or less. Since the polarity of the organic solution can be quantitatively evaluated using the relative dielectric constant, when the relative dielectric constant is high, components having a high relative dielectric constant are separated or removed, or by dilution with a non-polar organic solvent having a low relative dielectric constant. It can be adjusted to the desired value.

In order to separate and remove the polar component, if the polar component is a water-soluble alcohol or acetone, it can be removed by extraction with water. Alternatively, a water-soluble organic solvent such as ethanol, methanol, acetone or the like may be added to an organic solution and then brought into contact with water to extract and separate with water together with a water-soluble organic solvent to which a polar component has been added. When the components other than the polar component have a higher boiling point than the polar component, it can be removed by evaporation. Further, for example, water which is a polar component is condensed by cooling, and can be removed by adsorbing water which is a polar component by using a molecular sieve.

The solidifying agent is added in a usual manner, for example, by adding an organic solution to the solution while heating, and then cooling and solidifying.
A high-concentration solution of the solidifying agent is added to the organic solution, for example, by adding the solution, stirring, and then allowing it to stand.

The amount of the solidifying agent used is usually 0.2 to 5% by weight, preferably about 2% by weight, based on the organic solution.

When the solidifying agent is added to the organic solution, the polar component is separated and removed or the non-polar component is diluted.
It can be performed at any time as long as the relative dielectric constant of the organic solution is 13 or less. For example, when the method of separating the polar component is extraction with water, the organic solution after the extraction operation may be before or after separation from water, may be during the separation operation, or may be after the separation. After the addition of the solidifying agent, the polar component may be separated and removed or the non-polar component may be diluted, and the organic solution may be solidified under the condition that the relative dielectric constant of the organic solution is 13 or less.

[0019]

Embodiments of the present invention will be described below.

(Embodiment 1) As a first embodiment of the present invention, an example in which the present invention is applied to process control of a chemical separation process by a solvent extraction method will be described. The aqueous solution and the extraction solvent are analyzed for process control, and inorganic and organic analyzed waste liquids are generated.

In the present embodiment, a case will be described in which the rare earth elements are mutually separated by a solvent extraction method using an aqueous hydrochloric acid solution and di-2-ethylhexyl phosphoric acid. Jee
When 2-ethylhexyl phosphoric acid is used as an extractant, it is used after being diluted to about 30% by volume with non-polar n-heptane. The solvent extraction operation is performed in multi-stage countercurrent, and the element concentration and acid concentration in each stage, or the degree of deterioration of the extractant are analyzed. In the analysis step, an aqueous solution containing various inorganic components such as hydrochloric acid, a rare earth element, and an analysis reagent is generated as an inorganic waste liquid 1. Organic solvent containing extraction solvent and washing solution for analytical instruments or instruments such as ethanol and various analytical reagents 2
Are generated as waste liquid. Of these, the organic solution 2 was l2
-Solidification is performed using hydroxystearic acid as a solidifying agent according to the procedure shown in FIG.

In the usual analysis, the inorganic waste liquid 1 and the organic solution 2 are collected separately. After performing mixing and shaking operation 3 in an appropriate container, the mixture is allowed to stand and phase separation operation 4 is performed. When the amount of waste liquid is small, the phase separation operation 4 can be performed by a centrifugal separation method. By mixing and shaking the inorganic waste liquid 1 and the organic solution 2, water-soluble ethanol is extracted from the organic solution 2 into the inorganic waste liquid 1. As a result, the main components in the organic solution after phase separation are di-2-ethylhexyl phosphoric acid and n-heptane. Since di-2-ethylhexyl phosphoric acid is as small as 30% by volume of n-heptane, the relative dielectric constant of the entire waste liquid is close to the value of n-heptane. n-
Since the relative dielectric constant of heptane is 1.9, which is lower than the value of 13 which can be solidified with l2-hydroxystearic acid, it can be solidified well using l2-hydroxystearic acid. on the other hand,
After the phase separation, the inorganic waste 5 is discarded by removing ethanol as necessary.

The operation for solidifying the organic solution will be described. Heating operation 6 of the organic solution is performed at 50 ° C. or more and 98 ° C. or less. A solidifying agent 7 containing l2-hydroxystearic acid is added thereto, and a dissolving operation 8 is performed with stirring, and a cooling operation 9 is allowed to cool or forcibly. As the temperature decreases, the l-hydroxystearic acid dissolved in the organic solution causes the solidifying components to initiate polymerization via hydrogen bonds, and becomes three-dimensionally entangled with each other to form the entire organic solution into a solid 10. it can.

The timing of adding the solidifying agent 7 is after the phase separation operation 4 in the above description, but may be before the phase separation operation 4 or during the phase separation operation 4.

As described above, according to the present embodiment, the organic solution can be solidified without additional equipment. Thereby, the handling of the waste can be facilitated and the danger such as outflow and volatilization of the waste liquid during storage can be avoided. Further, while removing ethanol from the organic solution reduces the volume of the waste liquid, the addition of the solidifying agent hardly affects the volume change, so that the volume of the organic waste can be reduced.

(Embodiment 2) In a second embodiment of the present invention, instead of removing ethanol from an organic solution by extraction with water as in the first embodiment, ethanol is removed by evaporation. Yes, and will be described with reference to FIG.

The boiling points of n-heptane and ethanol as the main components in the organic solution 2 described in the first embodiment are 98 ° C. and 78.3 ° C., respectively. From this, the ethanol can be removed by the evaporation operation 11 by heating the organic solution to 78.3 ° C. or more and 98 ° C. or less. In this case, the ethanol is in a boiling state. On the other hand, below 78.3 ° C., the evaporation operation 11 can be performed gently.

The organic solution 2 is heated in a suitable container. At this time, when evaporating and removing ethanol in a boiling state,
Install a device to collect splashes from boiling as needed. Taking the case of small-scale processing as an example, the waste liquid can be safely heated by putting the waste liquid into a flask and connecting a demister. On the other hand, when ethanol is gently evaporated and removed, the demister becomes unnecessary. By these methods, all or a part of the ethanol is removed by evaporation so that the relative dielectric constant of the organic solution becomes equal to or less than the target value of 13.
After the evaporation is completed, a solidifying agent 7 containing l-hydroxystearic acid is added, and a dissolving operation 8 is performed with stirring. After the relative dielectric constant of the organic solution has reached the target value of 13 or less and the added solidifying agent has completely dissolved, cooling operation 9 is performed. As the temperature decreases, the organic solution becomes a solid 10 by the polymerization of 12-hydroxystearic acid. The solidifying agent 7
Although the timing of the addition was after the end of evaporation in the above,
It may be before the evaporation operation or during the evaporation operation. Also,
In the above, the evaporation operation was performed as the separation means, but condensation, precipitation, or adsorption may be used as an alternative means. Also in this case, the timing of addition of the solidifying agent can be set before the separation operation.
It does not matter during the separation operation or after the separation operation.

According to this embodiment, as in the case of the first embodiment, simplification of waste liquid treatment, reduction of the amount of waste, and improvement of safety can be achieved. Further, in this embodiment, since the organic solution is not brought into contact with the inorganic waste liquid, there is an advantage that the organic component is not extracted into the inorganic waste liquid, and the inorganic waste liquid can be discarded directly or after passing through a conventional treatment method. (Embodiment 3) As a third embodiment of the present invention, a method according to claim 7 will be described. Here, the first
The treatment of the inorganic waste liquid from which ethanol or the like generated by the organic solution solidification treatment method according to the embodiment is extracted will be described.

When the concentration of ethanol contained in the first organic solution is high, when ethanol is extracted into the inorganic waste liquid by the method of the first embodiment, other organic components are extracted together with ethanol. As a result, since the inorganic waste liquid 12 contains an organic component, it is difficult to dispose it directly or by a conventional method. In this embodiment, the inorganic waste liquid 1
The waste liquid is mineralized by utilizing the fact that other organic components are liberated by removing ethanol from 2. Hereinafter, the method will be described.

The inorganic waste liquid 12 containing ethanol and other organic components is heated to 98 ° C. or lower by heating operation 6 to evaporate and remove ethanol. By this operation, the extractant and the diluent are released from the aqueous solution. After separating this, the solidifying agent 7 is added and dissolved while maintaining the temperature at 50 ° C. or higher, and then cooled to solidify. The remaining inorganic waste liquid can be directly discarded.

The inorganic waste liquid can be treated by another procedure. This will be described with reference to FIG. The solidifying agent 7 is added to the inorganic waste liquid 12 containing ethanol or the like while performing the heating operation 6. Upon heating, the ethanol evaporates, releasing other organic components. Along with this, the solidifying agent 7 already added is dissolved in the released organic components. After the dissolving operation 8, if cooled, the organic components liberated above the inorganic waste liquid are solidified. This is subjected to a solid-liquid separation operation 13 such as filtration to recover the solidified organic material 10. On the other hand, the filtered inorganic waste 5 can be directly discarded.

In the above, evaporation is performed as the separation means, but condensation, precipitation or adsorption can be used as an alternative means.

As described above, according to the present embodiment, the waste liquid containing an organic component can be mineralized and can be safely disposed. In addition, since the organic component is solid, the separation from the inorganic waste liquid can be performed by solid-liquid separation easier than liquid-liquid separation.

(Embodiment 4) As a fourth embodiment according to the present invention, a case where adjustment of the relative dielectric constant of an organic solution is performed by dilution using a non-polar solvent will be described with reference to claims 1 and 2.

The solvent extraction method using methyl isobutyl ketone (MIBK) as an extraction solvent has been applied to the separation of nickel-cobalt, zirconium-hafnium or niobium-tantalum. Methyl isobutyl ketone is usually used neat, and is a solvent having a relatively high relative dielectric constant of 13.11. Therefore, when considering the solidification treatment of waste methyl isobutyl ketone, solidification is difficult with 12-hydroxystearic acid. Actually, as shown in FIG. 1, when 2% of the solidifying agent 12-hydroxystearic acid is added, it cannot be solidified. In this embodiment, the waste methyl isobutyl ketone is diluted with a non-polar solvent to
About the method of solidifying with 2-hydroxystearic acid,
This will be described with reference to FIG.

A dilution operation 16 is performed by adding a non-polar solvent such as n-hexane 15 (dielectric constant: 1.88) to the waste methyl isobutyl ketone 14. This is subjected to a heating operation 6 at 50 ° C. or higher and 98 ° C. or lower, a solidifying agent 7 containing l2-hydroxystearic acid is added, and a dissolving operation 8 is performed with stirring. After the solidifying agent is dissolved, a cooling operation 9 is allowed to cool or forcibly. As the temperature decreases, the waste liquid becomes solidified 10
Becomes

The timing of adding the solidifying agent 7 is after the dilution operation 16 in the above, but before the dilution operation 16,
Alternatively, it may be during the dilution operation 16.

As described above, according to the present embodiment, if a relatively high-polarity organic solution is diluted to a relative dielectric constant of 13 or less, it can be solidified using a known solidifying agent, thereby simplifying waste treatment. And safety are improved.

(Embodiment 5) As a fifth embodiment according to the present invention, a case where a radioactive organic solution containing a polar solvent as a main component is solidified will be described.

Spent nuclear fuel generated from a nuclear power plant is separated and recovered from uranium and plutonium by a solvent extraction method using tributyl phosphoric acid dissolved in nitric acid and then diluted with n-dodecane. In the solvent extraction step, there is an analysis step for analyzing the recovery rate, radiation deterioration of the solvent, and the like, and a waste liquid containing a radioactive substance is generated. Of these, inorganic waste liquid 18
Is mainly composed of a nitric acid aqueous solution in which a radioactive substance is dissolved.
The organic solution 17 is mainly composed of a waste extractant mainly composed of tributylphosphoric acid and n-dodecane combined with a radioactive substance, and a washing waste liquid such as ethanol. The method of solidifying the waste liquid will be described with reference to FIG.

The radioactive organic solution 17 is mixed and shaken with the radioactive inorganic waste liquid 18 to extract ethanol from the organic solution into the inorganic waste liquid. Thereafter, a phase separation operation 4 for both waste liquids is performed. Operation of heating the separated organic solution to 50 ° C. or higher 6
Then, a solidifying agent 7 containing 12-hydroxystearic acid is added, and a dissolving operation 8 is performed. Thereafter, a cooling operation 9 is performed to obtain a solidified body 10.

The inorganic waste liquid is treated by the method described in the third embodiment or is treated as radioactive inorganic waste 5 after removing the organic components by evaporation.

As described above, according to the present embodiment, since the organic solution containing a radioactive substance can be solidified, the treatment of the radioactive waste liquid is simplified and the safety is improved. Furthermore, a part of the radioactive substance combined with the extractant component in the organic solution is transferred to the inorganic waste liquid side where the solidification method is established by contact with the inorganic waste liquid, so that the radioactive material contained in the solidified organic solution is There is an advantage that the amount of the substance can be reduced and the exposure associated with handling can be reduced.

[0045]

According to the present invention, an organic solution containing a polar solvent can be solidified without using equipment by using an inexpensive oil gelling agent such as 12-hydroxystearic acid. Can be simplified, and danger such as outflow and volatilization of waste liquid during storage can be avoided. Furthermore, since a part of the radioactive substance combined with the extractant component in the organic solution is transferred to the inorganic waste liquid side by contacting with the inorganic waste liquid, the amount of the radioactive substance contained in the solidified organic solution is reduced by that much. It reduces the exposure associated with handling.

[Brief description of the drawings]

FIG. 1: Solidification performance of 12-hydroxystearic acid for solvents of various dielectric constants

FIG. 2 is a flow chart of a method for solidifying an organic solution in which polar components in the organic solution are extracted and removed with water and then solidified.

FIG. 3 is a flow chart of a method for solidifying an organic solution in which polar components in the organic solution are evaporated and solidified.

FIG. 4 is a flowchart of a method for treating an inorganic waste liquid from which an organic component has been extracted.

FIG. 5 is a flowchart of an organic solution solidification treatment method in which the relative dielectric constant of an organic solution is adjusted by adding a non-polar solvent to solidify the solution.

FIG. 6 is a flowchart of a method for solidifying a radioactive organic solution in which polar components in an organic solution are extracted and removed with an inorganic waste liquid and then solidified.

[Explanation of symbols]

1: Inorganic waste liquid 2: Organic solution 3: Mixing and shaking operation
4: Phase separation operation 5: Inorganic waste 6: Heating operation 7: Solidifying agent 8: Dissolution operation 9: Cooling operation 10: Solidified body 11: Evaporation operation 12: Inorganic waste liquid 1
3: Solid-liquid separation operation 14: Waste methyl isobutyl ketone 15: n-hexane 16: Dilution operation 17: Organic solution (radioactive) 18: Inorganic waste liquid (radioactive)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriko Yazawa 3-1-1 Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (72) Inventor Toshihiko Hasegawa 3-2-2 Sachimachi, Hitachi-shi, Ibaraki No. 1 Inside Hitachi Engineering Co., Ltd.

Claims (10)

[Claims] An organic solution containing at least one polar component and at least one non-polar component is solidified using a solidifying agent under the condition that the relative dielectric constant of the organic solution is 13 or less. Method for solidifying an organic solution. 2. The method for solidifying an organic solution according to claim 1, wherein the method of adjusting the relative dielectric constant of the organic solution includes separating at least a part of a polar component or diluting the organic component with a nonpolar solvent. A method of solidifying an organic solution. 3. The method for solidifying an organic solution according to claim 1 or 2, wherein at least a part of a polar component having a relative dielectric constant of 13 or more by itself is separated to increase the relative dielectric constant. A method for solidifying an organic solution, wherein the method is adjusted to 13 or less. 4. The method for solidifying an organic solution according to claim 2 or 3, wherein the method for separating a polar component is at least one of extraction, evaporation, condensation, precipitation and adsorption with water. A method for solidifying an organic solution, the method comprising: 5. The method for solidifying an organic solution according to claim 4, wherein when the method for separating the polar component is extraction with water, any of before, during and after separation of the organic solution and water after the extraction operation. A method for solidifying an organic solution, comprising adding a solidifying agent at some point. 6. The method for solidifying an organic solution according to claim 3, wherein the polar component is separated by adding a water-soluble organic liquid to the organic solution and then contacting the organic component with water to convert the polar component into a water-soluble organic solution. A method for solidifying an organic solution, which is a separation method for extracting into water together with a liquid. 7. A water-soluble organic liquid is removed from an aqueous solution in which a part of the organic component generated by the method according to claim 5 is dissolved by evaporation, condensation, precipitation or adsorption to remove other organic components. A method for treating an aqueous solution, wherein the aqueous solution is released from the solution and solidified using a solidifying agent. 8. The method for solidifying an organic solution according to claim 1 or 3, wherein the addition of the solidifying agent is performed before, during, or after adjusting the relative dielectric constant of the organic solution or separating the polar component. A method for solidifying an organic solution. 9. A solidifying agent used in the method for solidifying an organic solution according to claim 1 or 3, wherein the solidifying agent components dissolved in the organic solution are polymerized via hydrogen bonding to solidify the entire solution. A solidifying agent comprising at least one of the following: 10. A method for solidifying an organic solution, wherein the solidifying agent used in the method for solidifying an organic solution according to claim 1 or 3 is 12-hydroxystearic acid.