JPS6367595A - Method of processing waste organic phosphoric ester compound - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field) The present invention relates to a processing method for solidifying and reducing the volume of a waste organic solvent containing an organophosphorus α-ester compound as a main component generated in spent nuclear fuel reprocessing. More specifically, the present invention relates to the following methods: (a) The organic phosphate waste extraction solvent generated in the extraction process of uranium refining, nonferrous metal hydrometallurgical refining facilities, and nuclear fuel reprocessing facilities is treated with phosphoric acid. A method in which the waste organic solvent, which is mainly composed of organic phosphate esters, is treated by a chemical separation method, distillation method, etc., and then solidified to reduce its volume.

(υ Volume reduction and solidification treatment method for waste organic solvents mainly composed of organic phosphate esters generated from research facilities that handle nuclear fuels and radioactive isotopes, etc., (c) Extraction pretreatment for general analysis, etc. (separation tank M) The present invention also relates to a volume reduction and solidification treatment method for a waste organic solvent containing an organic phosphate ester as a main component used in the present invention.

(Prior art and its problems) The following methods are available as methods for treating the above waste solvent (organic phosphate ester + diluent).

(1) Solidification method This method is a method of solidifying by adding plastic (atactic polypropylene, thermosetting resin, thermoplastic PVC resin) or inorganic material (mica, Ca (OHt)) as a solidifying agent. is necessary compared to the organic phosphate ester, resulting in an increase in volume. Further, solidification of plastics is insufficient by ordinary methods, and it is not possible to obtain a solidified product with sufficient strength.

(2) Combustion method (at) The method of burning as is and the method involve corrosion of equipment due to P, so they are not implemented.

(b) PIJ constant combustion capacity method CCsC0H with salt addition)
*-Sodium carbonate, calcium, octoate, etc.) In this method, combustion decomposition and P fixation proceed simultaneously, so the total fP cannot be fixed. In other words, processing of 100% organic phosphate ester is difficult due to equipment corrosion etc. It is.

(3) Wet decomposition method (la) fi decomposition method (this method)! E(s P 04 * HIS 04
However, the reaction rate is slow.

(bl Hoot decomposition method ■ This method uses H! S 04 as a catalyst,
Although it is carried out at a temperature range of ~180°C, the reaction is violent and difficult to control.

(CI H!01 Decomposition Method ■ This method uses Hapo, copper sulfate, and phosphate steel as catalysts. A large amount of added H and O! is required per unit catalyst.

(d) 0□ decomposition method This method requires severe reaction conditions, such as requiring pressurization.

(Purpose of the Invention) The present inventors have solved the problems of the prior art described above, and have developed a process for solidifying and reducing the volume of waste organic solvents mainly composed of organic phosphate esters generated during spent nuclear fuel processing, etc. With the aim of providing a method, as a result of investigation, it was discovered that the purpose could be achieved by mixing organic phosphoric acid ester with hydrated aluminum chloride (hexahydrate) or polyaluminum chloride and heating, and the present invention was achieved. did.

(Structure of the Invention) That is, according to the present invention, hydrated aluminum chloride (hexahydrate) which is a waste organic solvent containing an organic heptaacid ester as a main component
Alternatively, a method for treating a waste organic phosphoric acid ester compound is obtained, which is characterized in that it is mixed with polyaluminum chloride and heated to form a solidified product containing phosphorus.

In the present invention, the solidified product containing the phosphorus content can be further calcined at a low temperature and decomposed into a stable inorganic phosphoric acid compound, thereby reducing the volume and stabilizing the product.

Furthermore, in the present invention, it is also possible to solidify the solidified material before and after the calcination with cement or plastic.

As described above, in the present invention, a waste organic solvent containing an organic phosphate ester as a main component is mixed with hydrated aluminum chloride (hexahydrate) or polyaluminum chloride, and heated at a temperature of 50 to 150°C. It becomes solid. At this time, the amount of hydrated aluminum chloride (hexahydrate) or polyaluminum chloride added is 0.3 or more based on the number of moles of the organic phosphate ester.

In the above, regarding the heating temperature of 50 to 150°C, heating to at least 50°C is required to complete the solidification reaction in several hours to 20 hours, so the lower limit is set to 50°C.
The upper limit is 150°C in relation to the boiling point of the organic phosphoric acid ester. That is, at temperatures above 150°C, the evaporation of the organic phosphate ester during the solidification reaction cannot be ignored.

Further, with regard to the amount of solidifying agent such as hydrous aluminum chloride added, no obvious solidifying effect is observed when the amount is less than 0.3 inch.

Furthermore, regarding the calcination temperature, the organic components such as butyl groups in the solidified product start to be decomposed (removed) as gas by calcination at 270°C, so the temperature should be 270°C or higher.
From the standpoint of equipment corrosion, it is desirable to calcinate at as low a temperature as possible, so the calcination temperature is set at 300°C. - The alkyl chloride compound and organic gas decomposed and produced by the above-mentioned low-temperature calcination can be disposed of by incineration or the like.

Next, the solidified product (lump) is calcined at a low temperature of 270°C or higher,
The alkyl group organic component remaining in the solidified product is completely removed as an organic combustible gas to form a stable inorganic phosphoric acid compound with reduced volume. The degree of stabilization of the thus obtained solidified material before and after calcination can be increased by solidifying it with plastic or cement.

In addition, by adding alkaline earth hydroxide or aluminum hydroxide to the above solidifying agent (hydrated aluminum chloride (hexahydrate) or polyaluminum chloride) to make it a solidifying agent, it can be used in the decomposition solidification reaction. It is also possible to facilitate trapping of excess chlorine (hydrochloric acid) into the assimilate.

The organic phosphate ester of the present invention is composed of one or more selected from tributyl phosphate, dibutyl phosphate, monobutyl phosphate, di-2-ethylhexyl phosphoric acid, and mono-2-ethylhexyl phosphoric acid.

In addition, in the case of a waste solvent in which the diluent concentration in the organic phosphate ester is relatively high (20 to 70% diluent + 7e ester), the solidification operation may be performed by adding calcium chloride. is possible. Calcium chloride at this time acts as an absorbent for the diluent. As the diluent, chain hydrocarbons (C 6 to 12) and aromatic hydrocarbons are usually used, but dodecane is mainly used.

Next, the present invention will be explained in more detail with reference to examples, but the following examples do not limit the scope of the present invention.

Example I TBP (tributyl phosphate) 100 cc (96,1
, 9) was added with aluminum chloride hexahydrate in an amount equivalent to the phosphorus content in TBP. li! When the mixture was added and mixed and heated to 100°C, it solidified in about 6 hours. Furthermore, when heating was continued, approximately 100% of the TBP molecules bonded with aluminum and became insoluble in about 15 hours.

Examples 2 to 14 The results of solidifying various simulated solvents (reagents) in the same manner as in Example 1 are also shown in Table 1 as Examples 2 to 14.

In all cases, the time required for each solvent molecule to bond with the 100-width aluminum and make it insoluble is 15 to 20 hours.

Example 15 A simulated waste solvent was prepared as follows. This is waste organic phosphate ester after diluent has been recovered by phosphoric acid extraction method.
This is a waste solvent that simulates

70tidecano-TBP solvent and a simulated high-level waste liquid containing cold F'P were brought into contact at a phase ratio of 1:1 for 5 hours,
F'P was extracted into a solvent. This solvent was
A simulated waste solvent that was irradiated with orllA and degraded by radiation to become unextractable was prepared.

This waste solvent is washed with an alkali and brought into contact with an approximately 70% phosphoric acid aqueous solution to separate dodeca/H and TBP/H as the third phase.
IPO4 solvent was obtained (simulated waste solvent 1).

In addition, this solvent was washed with water to obtain a solvent from which HsPO4 was separated (simulated waste solvent 2).

Simulated waste solvent 1 Add aluminum chloride hexahydrate in an amount equivalent to the phosphorus content in the solvent to 100 cc (106,99),
? When the mixture was added and mixed and heated at 100°C, it solidified in about 6 hours. Furthermore, when heating was continued, approximately 1001 TBP molecules bonded with aluminum and became insoluble in about 15 hours.

The results of solidifying the above simulated waste solvents 1 and 2 using the same method are Sj! These are shown in Table 2 as Examples 16-1B.

Example 19 A simulated waste solvent was subjected to vR cleavage as follows. This is a waste solvent that simulates waste organic phosphate ester after the diluent is recovered by vacuum distillation.

After washing the irradiated f8 soot of Example 15 with an alkali, dodecane was recovered by vacuum distillation to create a high-boiling pot residue containing TBP and DBP 1 (simulated waste solvent 3).

In addition, TBP constituting this simulated waste solvent 3 is 90 cm, D
BP was 10%.

Simulated abandoned construction 3 91p of aluminum chloride hexahydrate, which is equivalent to the phosphorus content in the solvent, was added to 100cc (98,!i') and mixed, and when heated at 100℃, it solidified in about 6 hours. did. If heating is continued further, approximately 1
000 TBP molecules combined with aluminum and became non-MM.

Example 20 To 3,100 cc of the solvent (98Jin), the phosphorus content in the solvent and the t81si polyaluminum chloride 8011 were added and mixed, and when heated to 100°C, it solidified in about 8 hours.Furthermore, When heating was continued, approximately 100% of the TBP molecules bonded with aluminum and became insoluble in about 17 hours.

Example 21 91! The solidified materials obtained in Examples 15, 16, and 19 were pulverized, mixed with 7 Il each, and 20.9 was mixed with about 3 liters of 9-element gas in a tubular electric furnace while feeding about 100 cc/- of 9-element gas.
When calcined at 00℃ for 4 hours, the organic components in the solid were
It was mainly decomposed and removed as butene gas, and an inorganic phosphoric acid compound of 11.5.9 was obtained. The volume reduction ratio (#/i) after calcination to the powder before calcination was about 110.7.

In order to confirm the phosphorus content volatilized during calcination, a water trap (100 cc) was provided at the silicon gas outlet, and the phosphorus concentration in the liquid was measured by spectrophotometry, and the result was 12 ppm.

According to this result, the amount of phosphorus volatilized from solid flowers is only about 0.41 or less compared to the amount of phosphorus in the solidified materials, which is approximately 10% per second.
It was confirmed that 0% phosphorus content was fixed in the calcined product. 100 phosphoric acid ester solvent (phosphoric acid ester/I
/ concentrated solvent) was possible.

In addition, during calcination, a water trap (100%
cc), Ru, Zr, MotPd in the liquid
The concentration of tNct,Y was measured by emission spectrometry.

As a result, both original purples were below the detection limit (ippm or below)
It was confirmed that the entire amount of FP in the waste solvent was fixed in the solidified product.

The solidified products obtained in Examples 17, 18, and 20 were pulverized, 7II of each was mixed, and a calcination test was conducted in exactly the same manner as above, and 1011 inorganic phosphoric acid compounds were obtained. The volume reduction ratio after calcination to the powder before calcination (before/after) is approximately 1
10.7, and the concentration of glue in the trap is 10 ppm.
The amount of phosphorus volatilized from the solidified product was only about 0.4 seconds or less than 7 minutes in the solidified product, and the amount of F'P volatilized was below the detection limit.

Example 22 Example 1. 2. The solidified material obtained in step 3 was crushed, mixed with 7I each, and calcined at about 300°C for 4 hours at about 20F in a tubular electric furnace while feeding nitrogen gas at about 10 Occ/gourd. The organic components were mainly decomposed and removed as bran gas, and 12 g of inorganic phosphoric acid compound powder was obtained. The volume reduction ratio after calcination to the powder before calcination was (#/after) about 170.7.

In order to confirm the amount of phosphorus volatilized during calcination, a trap (100 cc) was installed at the nitrogen gas outlet, and the phosphorus concentration in the liquid was measured by spectrophotometry, and the result was 16 ppm.

According to this result, the phosphorus content volatilized from the solidified product is only about 0.4'j or less than the phosphorus content in the solidified product, and about 10
It was confirmed that 0% phosphorus was fixed in the calcined product.

The assimilates obtained in Examples 6 and 7.8 were crushed, and 7 g each
When a calcination test was conducted in exactly the same manner as above, the volume reduction ratio after calcination to the powder before calcination was (before/after).
110.7, the phosphorus concentration in the trap is 13 ppm, and the phosphorus content volatilized from the solidified material is only about 0.
．． The amount of F'P volatilized was 4% or less, which was below the detection limit.

Example 23 The solidified bodies obtained in Examples 4, 5, and 9.10 were pulverized, 59 pieces of each were mixed, and about 211 was heated at about 300°C for 4 hours while feeding about 100 cc/- of nitrogen gas in a tubular electric furnace. When calcined for an hour, the organic component in the solid had a carbon number of 2.
Decomposed and removed as organic combustible gas of ~6, 10.5J
A powder of an inorganic phosphoric acid compound of F was obtained. The volume reduction ratio after calcination to the powder before calcination (before/after) was about 170.7.

In order to confirm the phosphorus content volatilized during calcination, a water trap (100cc) was installed at the nitrogen gas outlet, and the phosphorus concentration in the liquid was measured by spectrophotometry.

There were 12 pp-. According to this result, the phosphorus content volatilized from the solidified product was only about 0.4 times less than the phosphorus content in the solid, and it was confirmed that almost 100% of the phosphorus content was fixed in the calcined product. Ta.

Example 24 The solidified products obtained in Examples 11, 12, 13. Then, butene gas and C were decomposed and removed as hydrocarbons having 5 or less, and 79 inorganic phosphoric acid compound powders were obtained. The volume reduction ratio after calcination to the powder before calcination is Cm/after) approximately 1
/ 0.7.

In order to confirm the phosphorus content volatilized during calcination, a water trap (100 cc) was installed at the nitrogen gas outlet, and the phosphorus concentration in the liquid was measured by spectrophotometry, and the result was 15 ppm. According to this result, the phosphorus content volatilized from the solidified product was only about 0.4% less than the phosphorus content in the solidified product, and about 10%
It was confirmed that 0% phosphorus content was fixed in the calcined product.

Example 25 Examples 1 to 5'! The solids obtained in Steps 15 and 16.
was solidified with epoxy resin and cement under the following conditions. In addition, Examples 6 to 1O and 17°1B, 20. In addition, the solids obtained in Examples 11, 12, 13, and 14 were also pulverized and mixed, each yielding approximately 300 cc.

Approximately 150 cc was assimilated in the same manner.

Bispheno-A/A epoxy resin + curing agent + (reactive diluent) Curing time: Approximately 1 day, Temperature: Room temperature Mixing ratio (solidified product/above compounded resin): 3/2 cement 10 water (2:1) Curing and curing time: about 1 week, temperature: room temperature mixing ratio (
Solidified product/water in cement): 1/3 First, 3F with epoxy resin! The compressive strength of each solidified product of No. 1 is approximately 500 to 9/c! I was able to obtain a solidified product with sufficient strength compared to the conventional solidified product of liquid TBP with epoxy (compressive strength of 20 to 1ooky/cri) K.

Next, the 8E shrinkage strength of cement solidified bodies is about 2oo) II/cil, which is equivalent to that of ordinary cement solidified bodies, and it is WIK that waste solvent can be assimilated by cement. :! did it.

Example 26 The calcined solids obtained in Examples 21 to 24 were pulverized and mixed, and about 300 cc was solidified with cement and epoxy resin under the following conditions.

Cement water (2:1) Hardening and curing time: about 1 week, r! Degree A: Room temperature mixing ratio (solidified product/water in cement): 2/1 bisphenol A epoxy resin + curing agent + (reactive diluent) Curing time: about 1 day, Temperature 2 room temperature mixing ratio (solidified product/water in cement) The above blended resin'): 3/2 First,
The solidified cement thus obtained has a compressive strength of approximately 2
00 klI/d, which is the same value as that of a normal cement solidified body, and by using an inorganic waste solvent as the waste solvent, stable solidification of the waste solvent by cement became possible.

Next, the solidified body of epoxy resin has a compressive strength of about 500 yu/cil, and the conventional solidified body of liquid TBP made of epoxy (compressive strength of 20 to 100 kIi/cIl)
We were able to obtain a solidified material with sufficient strength compared to the previous method.

(Effects of the Invention) By adopting the above configuration, the present invention can exhibit the following effects.

(1) The entire amount of phosphorus in the solvent is fixed in the solidified product,
A calcining operation can be performed afterwards, and by removing organic components, a volume reduction effect can be obtained, and at the same time, a more stable inorganic phosphoric acid compound can be obtained.

In addition, since it can be mineralized, it can be solidified and stabilized with cement (organic liquids cannot normally be solidified with cement).

(2) Organic phosphate esters can be solidified as powder or bulk phosphoric acid compounds. When liquid solvents are applied to plastic solidification, there remain problems such as insufficient solidification. However, by solidifying,
This problem is resolved. Therefore, it can be used as a pretreatment operation for these solidification methods.

(3) Aluminum chloride hydrate or basic (PAC
) Compounds are easier to handle than anhydrides, and reactions can be easily controlled.

Claims (7)

[Claims] (1) Solidify waste organic solvent containing phosphorus by mixing waste organic solvent mainly composed of organic phosphate ester with solidifying agent mainly composed of hydrated aluminum chloride (hexahydrate) or polyaluminum chloride and heating. 1. A method for processing waste organic phosphate ester compounds, characterized in that the waste organic phosphoric acid ester compounds are converted into products. (2) By mixing the waste organic solvent mainly composed of organic phosphate ester with a solidifying agent mainly composed of hydrated aluminum chloride (hexahydrate) or polyaluminum chloride and heating it, it is solidified to contain phosphorus. 1. A method for treating waste organic phosphoric acid ester compounds, which comprises converting the solidified material into a stable inorganic phosphoric acid compound by calcining the solidified material. (3) Solidify waste organic solvent containing phosphorus by mixing the waste organic solvent mainly composed of organic phosphate ester with a solidifying agent mainly composed of hydrated aluminum chloride (hexahydrate) or polyaluminum chloride and heating. 1. A method for treating waste organic phosphate ester compounds, which comprises solidifying the solidified product with cement or plastic. (4) A solidified product containing phosphorus is produced by mixing waste organic solvent mainly composed of organic phosphate ester with a solidifying agent mainly composed of hydrated aluminum chloride (hexahydrate) or polyaluminum chloride and heating the mixture. A method for treating waste organic phosphate ester compounds, which comprises: calcining the solidified product to decompose it into a stable inorganic phosphate compound; and further solidifying the inorganic phosphate compound with cement or plastic. (5) The method for treating a waste organic phosphate compound according to any one of claims (1) to (4), wherein the organic phosphate compound is tributyl phosphate, dibutyl phosphate, monobutyl phosphate, 1. A treatment method characterized by using one or more selected from the group consisting of di-2-ethylhexyl phosphoric acid and mono-2-ethylhexyl phosphoric acid. (6) A method for treating a waste organic phosphate compound according to any one of claims (1) to (4), characterized in that the waste organic solvent contains inorganic phosphoric acid. processing method. (7) The method for treating waste organic phosphate compounds according to any one of claims (1) to (4), wherein the solidifying agent is alkaline earth metal hydroxide or hydroxide. A treatment method characterized by containing aluminum.