JPS63134520A - Continuous hydrolysis of uranium hexafluoride - Google Patents

Abstract

PURPOSE:To make it possible to obtain both effects of packings, e.g. conventional Rasching rings, etc., and cooling means, by providing an ice-packed bed in a hydrolyzing column in continuously hydrolyzing the residual UF6 fed from an UF6 cylinder. CONSTITUTION:The internal space of a hydrolyzing column 8 with cold insulation [cold-insulating layer (8a)] is bisected by a perforated plate 12 and an ice-packed bad 13 connected to an ice hopper (13a) is formed in the upper space thereof. A nozzle 10 connected to an UF6 cylinder is simultaneously provided in the lower space. A vacuum pump 7 mounted on a pipe connecting the top of the hydrolyzing column 8 to an alkali scrubber 16 is operated to provide a state of negative pressure in the hydrolyzing column 8 to continuously feed the residual UF6 9 in the UF6 cylinder through the nozzle 10 to the lower space. Thereby the hydrolytic reaction of the residual UF6 with pieces of ice in the ice-packed bed 13 is carried out to drip the formed aqueous solution (9a) of UO2F2 into an UO2F2 storage tank 11 and HF gas (9b) is removed and recovered in the alkali scrubber 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field) The present invention is directed to the residual UF6 supplied from the UF6 cylinder.
The present invention relates to a method for continuous hydrolysis of uranium hexafufluoride.

(Prior art and its problems) The residual Ur6 supplied from the conventional UF6 cylinder is hydrolyzed by a scrubber bandai, but in that case, in order to improve the contact effect with water, a Raschig ring etc. is filled and the hydrolysis reaction There were problems such as the need for cooling means to suppress the temperature rise due to heat.

(Objective of the invention) The present inventors have solved the problems of the above-mentioned prior art, and
As a result of our study to provide a method for continuously supplying the residual 'II U Fa in the cylinder and hydrolyzing it, we found that
We discovered that by using an ice packed bed, it can serve both as a filling material in conventional Raschig rings and as a cooling means,
We have arrived at the present invention.

(Structure of the Invention) That is, according to the present invention, the internal space of a refrigerated hydrolysis column is divided into two by a perforated plate, an ice packed layer connected to an ice hopper is formed in the upper space, and an ice packed layer is connected to the UF/cylinder in the lower space. A vacuum nozzle attached to the pipe 9 connecting the top of the hydrolysis column and the alkaline scrubber was activated, and the hydrolysis column was placed under negative pressure to remove the residue in the #UF'@7 scrubber. Continuously supplies UF into the lower space through the nozzle, and! j! UFs
Due to the hydrolysis reaction between the gas and the ice chips in the ice-filled #A layer, U
O,F'.

Continuous hydrolysis method of uranium hexafluoride, characterized in that an aqueous solution and HF gas are generated, the generated UOIF'l aqueous solution is dropped into a UOmF'm liquid storage tank, and the HF gas is removed and recovered with an alkali stopper. , is obtained.

Next, the present invention will be explained with reference to the drawings.

Drawings are part of the invention! FIG. 2 is a system diagram of an apparatus used in an example. The operation F in this equipment system diagram will be described.

(1) Close the valve 1.2.3.6, open the valve S, and operate the vacuum pump 7 to maintain a negative pressure inside the hydrolysis column 8. Next, the pulp 5 is closed and the pulp 2 is opened, and a UF cylinder (not shown) is installed.
The residual UF59 in the column is suctioned and continuously supplied to the lower space of the hydrolysis column 8 from the nozzle IO. At this time, the UF6 gas pipe 9c is kept at a temperature of 80 to 100°C to prevent the UF@gas from solidifying.

The sucked UP6 gas 9 passes through the perforated plate 12 and enters the packed bed 1.
It reacts with the ice piece in step 3 and UOIF'! It is hydrolyzed into an aqueous solution 9a and an HF' gas 9b. As mentioned above, the hydrolysis reaction of UF'. produces about 100 kcal per UFel.
Because heat is generated, the surface of the ice piece melts when it reacts with ice. υO produced by the hydrolysis reaction of UF6 gas
9 m of tFg aqueous solution passes through the perforated plate 12 and accumulates at the bottom of the hydrolysis column 8.

When the negative pressure of the hydrolysis force 2m8 becomes the same as the pressure inside the UFs cylinder, the pulp 2 closes, and then the valve 6
is opened, and the pressure of the hydrolysis column 8 and the ゛UO*F'* liquid storage tank 11 is equalized (same pressure).Then, the pulp 3 is opened and the UOyF'* aqueous solution is connected to the hydrolysis column 8 with piping. The liquid is dropped into the UO*F'* liquid storage tank 11.

(2) The hydrolysis column 8 is kept cool by the cold insulation layer 8a,
If the ice packed layer 13 decreases due to melting of ice, pulp l will be added as appropriate.
Open the ice hopper and refill with ice from the 13m ice hopper.

(3) If you repeat the operation in (1) above, the UF
Residual UF from the cylinder can be recovered and simultaneously hydrolyzed.

(4) When the liquid level of the UOtF'* aqueous solution in the UO*F'm liquid storage tank 11 reaches a predetermined height, the valve 4 is opened and at the same time the vacuum pump 7 is operated, and the UOmFm aqueous solution is sent to the precipitation step 9d. Send liquid.

(5) UO! F! Aqueous solution is 50-300#U/J
It becomes an aqueous solution and does not freeze in the range of -1O to 0°C due to the freezing point depression.

(6) The F gas generated during hydrolysis of UFs is removed and recovered by the alkaline scrubber 16, and the remaining gas is discharged to the exhaust equipment 18.

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

(1) UF without repeating cooling and heating operations
Enables continuous recovery of residual UF/gas from 6 cylinders.

(2) Hydrolysis can be performed simultaneously with recovery of Ur.

[Brief explanation of the drawing]

The drawing is a system diagram of equipment used in the -W embodiment of the present invention. In the figure, 1, 2.3.4.5.6---Pulp γ---Vacuum pump 8---1 Hydrolysis column 8g-1---Cold layer 9---1-U t'・Gas 9 fields---UOt F6 aqueous solution 9 b---HF gas 9cm-m-U F''-Supply pipe 9d---1 Precipitation process 1G------ Nose 〃 11- ---1-UOI F'l liquid storage tank 12--1-perforated plate 13--1 ice packed layer 13a--1 ice hoverer 14---11 ice making machine 15-- - Pure water 16 ---- Alkali scraper 17 ---- Pump 1B - Exhaust equipment

Claims (1)

[Claims] (1) The cooled internal space of the hydrolysis column is divided into two by a perforated plate, an ice packed layer connected to an ice hopper is formed in the upper space, and a nozzle connected to a UF_6 cylinder is installed in the lower space, and the top of the hydrolysis column is Activate a vacuum pump attached to the piping connecting the and the alkaline scrubber, bring the hydrolysis column into a negative pressure state, and continuously supply the residual UF_6 in the UF_6 cylinder into the lower space through the nozzle; Due to the hydrolysis reaction between the UF_6 gas and the ice chips in the ice packed bed, the UO_2F_2 aqueous solution and HF
Gas is generated and the generated UO_2F_2 aqueous solution is UO_
A continuous hydrolysis method for uranium hexafluoride, which is characterized by dropping the uranium hexafluoride into a 2F_2 liquid storage tank and removing and recovering HF gas with an alkaline scrubber.