阅读说明：本技术 将六氟化铀转化为二氧化铀的方法和设施 (Method and installation for converting uranium hexafluoride into uranium dioxide ) 是由 安德烈·弗吉耶 布鲁诺·梅索纳 于 2018-10-09 设计创作，主要内容包括：转化方法包括以下步骤：在水解反应器(4)中通过注入到该反应器(4)中的气态UF-6与干水蒸气之间的反应将UF-6水解为氟氧化铀(UO-2F-2)；和在热水解炉(6)中通过UO-2F-2与注入到该炉(6)中的干水蒸气和氢气(H-2)之间的反应将UO-2F-2热水解为UO-2。供给至反应器(4)的气态UF-6的每小时质量流量为75kg/h至130kg/h,供给至反应器(4)用于水解的干水蒸气的每小时质量流量为15kg/h至30kg/h,并且反应器(4)内部的温度为150℃至250℃。(The transformation method comprises the following steps: in the hydrolysis reactor (4) by gaseous UF injected into the reactor (4) 6 Reaction with dry steam will UF 6 Hydrolysis to Uranium Oxyfluoride (UO) 2 F 2 ) (ii) a And in the thermal hydrolysis furnace (6) by UO 2 F 2 With dry steam and hydrogen (H) injected into the furnace (6) 2 ) Reaction between (A) and (B) is to react UO 2 F 2 Pyrohydrolysis to UO 2 . Gaseous UF supplied to reactor (4) 6 Is 75 to 130kg/h, the dry steam supplied to the reactor (4) for hydrolysis has a mass flow per hour of 15 to 30kg/h, and the temperature inside the reactor (4) is 150 to 250 ℃.)

1. A method for preparing uranium hexafluoride (UF)₆) Conversion to uranium dioxide (UO)₂) The method of (3), said method comprising the steps of:

-in hydrolysis reactor (4) by gaseous UF injected into said reactor (4)₆Reaction with dry steam will UF₆Hydrolysis to Uranium Oxyfluoride (UO)₂F₂) (ii) a And

-passing UO in a thermal hydrolysis furnace (6)₂F₂With dry steam and hydrogen (H) injected into the furnace (6)₂) Reaction between (A) and (B) is to react UO₂F₂Pyrohydrolysis to UO₂，

Wherein is supplied to the reactor (4)) Gaseous UF of₆Is from 75kg/h to 130kg/h, the dry steam fed to the reactor (4) for hydrolysis has a mass flow per hour of from 15kg/h to 30kg/h, and the temperature inside the reactor (4) is from 150 ℃ to 250 ℃.

2. The conversion process according to claim 1, comprising injecting a neutral purge gas into the reactor (4).

3. The transformation method of claim 1 or 2, wherein the UO is₂The specific surface area of the particles is 1m²G to 4m²A/g, preferably of 1.9m²G to 2.9m²UO in g₂Obtained in the form of a powder.

4. The transformation method of any of the preceding claims, wherein the UO is₂Has a residual fluorine (F) content of less than 50ppm, preferably less than 35 ppm.

5. Conversion process according to any one of the preceding claims, wherein UF fed to the reactor (4)₆The temperature of (A) is from 75 ℃ to 130 ℃, preferably from 90 ℃ to 120 ℃.

6. The conversion process according to any one of the preceding claims, wherein the temperature of the dry steam for hydrolysis fed to the reactor (4) is comprised between 175 ℃ and 300 ℃, preferably between 200 ℃ and 270 ℃.

7. Conversion process according to any one of the preceding claims, wherein the dry steam for thermal hydrolysis is fed to the furnace (6) at a mass flow rate per hour of from 25 to 40kg/h, preferably from 30 to 35 kg/h.

8. The reforming process according to any one of the preceding claims, wherein the temperature of the dry steam for thermal hydrolysis fed to the furnace (6) is from 250 ℃ to 450 ℃, preferably from 300 ℃ to 400 ℃.

9. Conversion process according to any one of the preceding claims, wherein the H fed to the furnace (6)₂The volume flow rate of (2) is 10Nm³H to 25Nm³H, in particular 15Nm³H to 20Nm³/h。

10. Conversion process according to any one of the preceding claims, wherein the flow rate of neutral purge gas fed to the reactor (4) is 1.5Nm³H to 5Nm³-h, the temperature of the neutral purge gas fed to the reactor (4) is between 80 ℃ and 130 ℃, and the relative pressure of the neutral purge gas fed to the reactor (4) is higher than the relative pressure inside the reactor (4), and preferably lower than 1 bar.

11. The conversion process according to any one of the preceding claims comprising passing gaseous UF₆Is fed to the reactor (4) from a discharge device (82), the discharge device (82) comprising: at least one heating chamber (86), the or each heating chamber (86) containing solid UF₆And heating said storage tank (84) to generate gaseous UF₆(ii) a And a feed circuit (87) configured to feed from the or each heating chamber (86) to the reactor (4).

12. Conversion process according to claim 11, wherein the discharge device (82) comprises at least two heating chambers (86), the supply circuit (87) being configured to supply the reactors (4) in sequence from the heating chambers (86), passing from a current heating chamber (86) to a subsequent heating chamber (86) when the tank (84) contained in the current heating chamber (86) is no longer sufficiently full.

13. The conversion process according to claim 12, wherein the supply from the subsequent heating chamber (86) to the reactor (4) is started before the supply from the current heating chamber (86) to the reactor (4) is stopped, so that the simultaneous supply from both heating chambers (86) to the reactor (4) continues for a period of time.

14. Conversion method according to any one of claims 11 to 13, wherein said supply circuit (87) comprises a pump (90) associated with the or each heating chamber (86) to force UF₆From the tank (84) housed in the heating chamber (86) to the reactor (4), the or each pump (90) preferably being a positive displacement pump, and more preferably a positive displacement pump with bellows.

15. Conversion process according to claim 14, wherein the supply circuit (87) comprises a flow regulating valve (88) associated with the or each heating chamber (86) and bypassing a pump (90) associated with the heating chamber (86).

16. A method for preparing uranium hexafluoride (UF)₆) Conversion to uranium dioxide (UO)₂) The reforming apparatus of (1), said reforming apparatus comprising:

-a reactor (4) for the passage of gaseous UF injected into said reactor (4)₆Reaction with dry steam will UF₆Hydrolysis to Uranium Oxyfluoride (UO)₂F₂) Powder;

-a furnace (6) for passing UO₂F₂Powder with dry steam and hydrogen (H) injected into the furnace (6)₂) Reaction between (A) and (B) is to react UO₂F₂Thermal hydrolysis of powder to UO₂Powder; and

-means (8) for feeding reactive gases and neutral purge gases to said reactor (4) and to said furnace (6),

the conversion apparatus is configured to carry out the method according to any one of the preceding claims.

17. The reforming apparatus according to claim 16, comprising feeding UF to the reactor (4)₆The discharge device (82), the discharge device (82) comprising: at leastA heating chamber (86), the or each heating chamber (86) being configured to contain solid UF₆And heating the reservoir (84) to generate gaseous UF₆(ii) a And a feed circuit (87) configured to feed from the or each heating chamber (86) to the reactor (4).