A continuous stable operation ammonia evaporation and uranium precipitation device and ammonia evaporation and uranium precipitation method

Abstract

The application provides a continuously stable operation ammonia evaporation and uranium precipitation device and method, and relates to the technical field of uranium hydrometallurgy.The continuously stable operation ammonia evaporation and uranium precipitation device comprises ammonia evaporation equipment and multistage uranium precipitation equipment which are sequentially connected along the water flow direction.The continuously stable operation ammonia evaporation and uranium precipitation device can realize the continuous stable operation of the ammonia evaporation and uranium precipitation process, solves the problems, such as unavoidable overflow, discontinuous operation and the like, in the traditional ammonia evaporation and uranium precipitation process, and improves the stability and continuity of operation.

Description

Technical Field

[0001] This invention relates to the field of uranium hydrometallurgy, specifically to a continuously and stably operating ammonia stripping and uranium precipitation device and method. Background Technology

[0002] There are generally two methods for precipitating uranium from an ammonium carbonate solution: one is to add sodium hydroxide solution, causing the uranium to precipitate directly; the other is to heat the solution to boiling, causing the carbonates to decompose and the uranium to precipitate out of the solution. The sodium hydroxide precipitation method requires a large amount of sodium hydroxide reagent, and the resulting uranium-precipitated mother liquor cannot be directly returned to the upstream process. In contrast, the heating precipitation method not only requires no added reagents but also allows the NH3 and CO2 generated during decomposition to be recovered and returned to the preparation of the ammonium carbonate solution. Therefore, the heating precipitation method has significant advantages.

[0003] When the uranium carbonate solution is heated to boiling, the main component, uranyl tricarbonate (AUC), rapidly decomposes to produce UO₂CO₃. The reaction equation can be expressed as:

[0004] (NH4)4UO2(CO3)3→UO2CO3↓+4NH3↑+2CO2↑+2H2O

[0005] Because UO2CO3 is easily hydrolyzed, it is difficult for it to precipitate out in aqueous system as a solid. Instead, it readily reacts with ammonium carbonate in the system to form ammonium diuranate (ADU) precipitate. The reaction equation is as follows:

[0006] 2UO2CO3+(NH4)2CO3→(NH4)2U2O7↓+3CO2↑

[0007] In addition, ammonium carbonate in the system also decomposes upon heating. Therefore, the entire reaction process of ammonia stripping and uranium precipitation can be represented by the following general equation:

[0008] 2(NH4)4UO2(CO3)3→(NH4)2U2O7↓+6NH3↑+6CO2↑+3H2O(NH4)2CO3→2NH3↑+CO2↑+H2O

[0009] When the reaction system reaches a certain temperature, the violent decomposition of AUC and ammonium carbonate will generate a large number of bubbles in an instant. The bubble layer formed will accumulate rapidly, making it very easy for overflow to occur. At the same time, the generation of solids makes it more difficult for the reaction to proceed smoothly, and the reaction process is very violent. Summary of the Invention

[0010] The purpose of this invention is to provide a continuously and stably operating ammonia stripping and uranium precipitation device and method, which enables the continuous and stable operation of the ammonia stripping and uranium precipitation process.

[0011] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0012] This invention provides a continuously and stably operating ammonia stripping and uranium precipitation device, comprising an ammonia stripping unit and a multi-stage uranium precipitation unit connected sequentially along the water flow direction; the multi-stage uranium precipitation unit includes a first-stage uranium precipitation unit, a second-stage uranium precipitation unit, ..., n-1-stage uranium precipitation units and an n-stage uranium precipitation unit connected sequentially along the water flow direction; where n is 3 to 10.

[0013] Both the ammonia stripping equipment and the multi-stage uranium deposition equipment are independently equipped with heating and stirring devices.

[0014] Preferably, the ammonia stripping equipment and the multi-stage uranium deposition equipment are arranged in a stepped manner from high to low.

[0015] Preferably, the outlet of the ammonia stripping device is higher than the inlet of the first-stage uranium deposition device, the outlet of the first-stage uranium deposition device is higher than the inlet of the second-stage uranium deposition device, and so on, with the outlet of the n-1 stage uranium deposition device being higher than the inlet of the nth stage uranium deposition device.

[0016] Preferably, both the ammonia stripping equipment and the multi-stage uranium deposition equipment are equipped with independent temperature sensors.

[0017] Preferably, it also includes a settling device connected to the n-stage uranium settling device.

[0018] This invention provides a method for the continuous and stable operation of the ammonia stripping and uranium precipitation device based on the above-described technical solution, comprising the following steps:

[0019] The ammonium carbonate system uranium solution is continuously fed into the ammonia stripping equipment for ammonia stripping treatment. The resulting reaction liquid overflows into a multi-stage uranium precipitation equipment for uranium precipitation treatment in each stage of the uranium precipitation equipment.

[0020] The temperature inside the Level 1 uranium precipitator, Level 2 uranium precipitator, ..., Level n-1 uranium precipitator and Level n uranium precipitator increases progressively.

[0021] Preferably, the residence time of the ammonia stripping treatment is more than 1 hour; the temperature of the ammonia stripping treatment is 85-92°C; and the ammonia stripping treatment is carried out under stirring conditions.

[0022] Preferably, the residence time for uranium deposition treatment in each stage of the uranium deposition equipment is independently more than 1 hour; the temperature in the stage 1, stage 2, ..., stage n-1 and stage n uranium deposition equipment increases progressively in the range of 92 to 100°C.

[0023] Preferably, the temperature difference between two adjacent uranium sinking devices is 1–3°C.

[0024] Preferably, the reaction liquid obtained after the last stage of uranium precipitation treatment is fed into a settling device for solid-liquid separation to obtain uranium precipitation mother liquor.

[0025] This invention provides a continuously and stably operating ammonia stripping and uranium precipitation device and method. This invention can achieve continuous and stable operation of the ammonia stripping and uranium precipitation process, solve the problems of overflow and discontinuous operation that are unavoidable in traditional ammonia stripping and uranium precipitation processes, and improve the stability and continuity of operation.

[0026] The present invention has the following beneficial effects:

[0027] (1) The ammonia stripping process and uranium deposition process were carried out in stages, avoiding the simultaneous generation of a large amount of gas and a large amount of solid in the same system, thus ensuring the stable operation of the entire process.

[0028] (2) The gas is mainly generated in the ammonia stripping equipment, mainly from the decomposition of ammonium carbonate. The generated bubbles are large and easy to break, and will not form a layer of accumulated bubbles, thus avoiding the occurrence of overflow. In addition, almost no uranium precipitation is generated in the equipment, and the operation process is relatively stable.

[0029] (3) The uranium precipitation process is mainly carried out in the uranium precipitation equipment. It is a decomposition process of AUC. A large amount of uranium precipitate is generated in the equipment. The generation of bubbles is very stable. A small amount of bubble layer will remain in the system but will not overflow the tank. The liquid level can be stably controlled. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of an ammonia stripping and uranium precipitation device, taking a 1-stage ammonia stripping and a 3-stage uranium precipitation device as an example in an embodiment of the present invention; 1 is an ammonia stripping tank, 2 is a 1-stage uranium precipitation tank, 3 is a 2-stage uranium precipitation tank, 4 is a 3-stage uranium precipitation tank, 5 is a metering feed device, 6 is a settling device, 7 is a tail gas absorption system, 8 is a heating device, 9 is a temperature sensor, and 10 is a stirring device.

[0031] Figure 2 This is a schematic diagram of the ammonia stripping and uranium precipitation method in an embodiment of the present invention. Detailed Implementation

[0032] This invention provides a continuously and stably operating ammonia stripping and uranium precipitation device, comprising an ammonia stripping unit and a multi-stage uranium precipitation unit connected sequentially along the water flow direction; the multi-stage uranium precipitation unit includes a first-stage uranium precipitation unit, a second-stage uranium precipitation unit, ..., n-1-stage uranium precipitation units and an n-stage uranium precipitation unit connected sequentially along the water flow direction; where n is 3 to 10.

[0033] Both the ammonia stripping equipment and the multi-stage uranium deposition equipment are independently equipped with heating and stirring devices.

[0034] The ammonia stripping and uranium precipitation apparatus provided by this invention includes an ammonia stripping device. In this invention, the ammonia stripping device is equipped with a heating device and a stirring device.

[0035] As an embodiment of the present invention, the ammonia stripping equipment includes an ammonia stripping tank, a heating device disposed at the bottom of the ammonia stripping tank, and a stirring device disposed inside the ammonia stripping tank.

[0036] As an embodiment of the present invention, the ammonia stripping equipment is equipped with a temperature sensor; the temperature sensor is located inside the ammonia stripping tank.

[0037] The ammonia stripping and uranium precipitation apparatus provided by this invention includes a multi-stage uranium precipitation device. In this invention, the ammonia stripping device and the multi-stage uranium precipitation device are preferably arranged in a stepped manner from high to low.

[0038] In this invention, the multi-stage uranium deposition equipment includes a first-stage uranium deposition equipment, a second-stage uranium deposition equipment, ..., an n-1-stage uranium deposition equipment, and an n-stage uranium deposition equipment connected sequentially along the water flow direction; where n is 3 to 10, preferably 4 to 5. In a specific embodiment of this invention, when n is 3, the multi-stage uranium deposition equipment includes a first-stage uranium deposition equipment, a second-stage uranium deposition equipment, and a third-stage uranium deposition equipment connected sequentially along the water flow direction.

[0039] As one embodiment of the present invention, the outlet of the ammonia stripping device is higher than the inlet of the first-stage uranium deposition device, the outlet of the first-stage uranium deposition device is higher than the inlet of the second-stage uranium deposition device, and so on, with the outlet of the n-1 stage uranium deposition device being higher than the inlet of the nth stage uranium deposition device.

[0040] As an embodiment of the present invention, each stage of the uranium slagging equipment independently includes a uranium slagging container, a heating device disposed at the bottom of the uranium slagging container, and a stirring device disposed inside the uranium slagging container.

[0041] As an embodiment of the present invention, the uranium slagging device is equipped with a temperature sensor; the temperature sensor is located inside the uranium slagging container.

[0042] As an embodiment of the present invention, the ammonia stripping and uranium precipitation device further includes a settling device connected to the n-stage uranium precipitation equipment; the inlet of the settling device is lower than the outlet of the n-stage uranium precipitation equipment.

[0043] As an embodiment of the present invention, the ammonia stripping and uranium precipitation device further includes a tail gas absorption system; the tail gas absorption system is independently connected to the ammonia stripping equipment and the multi-stage uranium precipitation equipment.

[0044] As an embodiment of the present invention, the ammonia stripping and uranium precipitation device further includes a metering feed device 5; the outlet of the metering feed device 5 is located at the top of the ammonia stripping tank.

[0045] As an embodiment of the present invention, taking a 1-stage ammonia stripping + 3-stage uranium deposition as an example, the following is adopted: Figure 1 The ammonia stripping and uranium precipitation apparatus shown includes an ammonia stripping tank 1, a first-stage uranium precipitation tank 2, a second-stage uranium precipitation tank 3, a third-stage uranium precipitation tank 4, and a settling device 6, which are connected sequentially along the water flow direction. The outlet of the ammonia stripping tank 1 is higher than the inlet of the first-stage uranium precipitation tank 2; the outlet of the first-stage uranium precipitation tank 2 is higher than the inlet of the second-stage uranium precipitation tank 3; the outlet of the second-stage uranium precipitation tank 3 is higher than the inlet of the third-stage uranium precipitation tank 4; the outlet of the third-stage uranium precipitation tank 4 is higher than the inlet of the first-stage uranium precipitation tank 4; the outlet of the third-stage uranium precipitation tank 4 is higher than the inlet of the first-stage uranium precipitation tank 2; the outlet of the first-stage uranium precipitation tank 2 is higher than the inlet of the second-stage uranium precipitation tank 3; the outlet of the third-stage uranium precipitation tank 4 is higher than the inlet of the third-stage uranium precipitation tank 4; the outlet of the first-stage uranium precipitation tank 1 is higher than the inlet of the second-stage uranium precipitation tank 2 ... The liquid outlet is higher than the liquid inlet of the settling device 6; the ammonia stripping tank 1, the first-stage uranium settling tank 2, the second-stage uranium settling tank 3, and the third-stage uranium settling tank 4 are all connected to the tail gas absorption system 7; the bottom of the ammonia stripping tank 1, the first-stage uranium settling tank 2, the second-stage uranium settling tank 3, and the third-stage uranium settling tank 4 are all equipped with heating devices 8; the interior of the ammonia stripping tank 1, the first-stage uranium settling tank 2, the second-stage uranium settling tank 3, and the third-stage uranium settling tank 4 is equipped with temperature sensors 9 and stirring devices 10.

[0046] This invention provides a method for the continuous and stable operation of the ammonia stripping and uranium precipitation device based on the above-described technical solution, comprising the following steps:

[0047] The ammonium carbonate system uranium solution is continuously fed into the ammonia stripping equipment for ammonia stripping treatment. The resulting reaction liquid overflows into a multi-stage uranium precipitation equipment for uranium precipitation treatment in each stage of the uranium precipitation equipment.

[0048] The temperature inside the Level 1 uranium precipitator, Level 2 uranium precipitator, ..., Level n-1 uranium precipitator and Level n uranium precipitator increases progressively.

[0049] In this invention, the ammonium carbonate system uranium solution preferably includes one or more of the following: qualified ammonium carbonate back-extraction solution for uranium, qualified ammonium carbonate elution solution, and AUC crystallization mother liquor. In this invention, the uranium concentration in the ammonium carbonate system uranium solution is preferably 1–50 g / L, and more specifically, 2–15 g / L.

[0050] In this invention, the residence time of the ammonia stripping treatment is preferably more than 1 hour, more preferably 1.5 to 2 hours; the temperature of the ammonia stripping treatment is preferably 85 to 92°C, more preferably 88 to 90°C. In this invention, the ammonia stripping treatment is preferably carried out under stirring conditions; the stirring rate is preferably 300 to 500 rpm.

[0051] In this invention, the residence time for uranium deposition treatment in each stage of the uranium deposition equipment is preferably more than 1 hour, more preferably 1.5 to 2 hours; the temperature in the stage 1, stage 2, ..., stage n-1 and stage n uranium deposition equipment increases progressively in the range of 92 to 100°C.

[0052] In this invention, the temperature in the first-stage uranium deposition equipment, the second-stage uranium deposition equipment, ..., the n-1-stage uranium deposition equipment, and the n-stage uranium deposition equipment increases progressively; the temperature difference between two adjacent stages of uranium deposition equipment is preferably 1 to 3°C, more preferably 2°C. In this invention, the uranium deposition treatment is preferably carried out under stirring conditions; the stirring rate is preferably 300 to 500 rpm.

[0053] In this invention, the reaction liquid obtained after the final stage of uranium precipitation treatment is fed into a settling device for solid-liquid separation to obtain uranium precipitate mother liquor. Preferably, the feeding method is overflow.

[0054] In this invention, it is preferable to analyze the uranium precipitation mother liquor. If the uranium concentration does not meet the standard, it is preferable to return to the first-stage uranium precipitation equipment for further uranium precipitation treatment, or increase the number of stages of the uranium precipitation equipment, or extend the residence time of the single-stage uranium precipitation treatment, so as to reduce the uranium concentration of the uranium precipitation mother liquor to the required range.

[0055] In this invention, the ammonia and carbon dioxide generated from the ammonia stripping and uranium deposition processes are preferably absorbed by the tail gas absorption system; preferably, they are returned to the preparation of the back-extraction agent.

[0056] In this invention, the ammonium carbonate system uranium solution undergoes the above-mentioned ammonia stripping and uranium precipitation method, and the evaporation rate of the solution is preferably ≥75%, more preferably 78-85%; the uranium precipitation rate is preferably ≥90%, more preferably 92-95%.

[0057] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0058] Example 1

[0059] A process involving one-stage ammonia stripping followed by five-stage uranium precipitation is used to process ammonium carbonate back-extracted uranium-qualified solution with a uranium concentration of 15 g / L.

[0060] The ammonia stripping and uranium precipitation device used in this embodiment includes an ammonia stripping tank, a first-stage uranium precipitation tank, a second-stage uranium precipitation tank, a third-stage uranium precipitation tank, a fourth-stage uranium precipitation tank, a fifth-stage uranium precipitation tank, and a sedimentation device, all connected sequentially along the water flow direction. The outlet of the ammonia stripping tank is higher than the inlet of the first-stage uranium precipitation tank; the outlet of the first-stage uranium precipitation tank is higher than the inlet of the second-stage uranium precipitation tank; the outlet of the second-stage uranium precipitation tank is higher than the inlet of the third-stage uranium precipitation tank; the outlet of the third-stage uranium precipitation tank is higher than the inlet of the fourth-stage uranium precipitation tank; and the outlet of the fourth-stage uranium precipitation tank is higher than the inlet of the fifth-stage uranium precipitation tank. The inlet of the uranium precipitator; the outlet of the 5th stage uranium precipitator is higher than the inlet of the settling device; the ammonia stripping tank, the 1st stage uranium precipitator, the 2nd stage uranium precipitator, the 3rd stage uranium precipitator, the 4th stage uranium precipitator, and the 5th stage uranium precipitator are all connected to the tail gas absorption system; the bottom of the ammonia stripping tank, the 1st stage uranium precipitator, the 2nd stage uranium precipitator, the 3rd stage uranium precipitator, the 4th stage uranium precipitator, and the 5th stage uranium precipitator are all equipped with heating devices; the interior of the ammonia stripping tank, the 1st stage uranium precipitator, the 2nd stage uranium precipitator, the 3rd stage uranium precipitator, the 4th stage uranium precipitator, and the 5th stage uranium precipitator is equipped with temperature sensors and stirring devices.

[0061] The qualified uranium carbonate back-extraction solution was added to the ammonia stripping tank via a metering feed device. The residence time of the qualified uranium carbonate back-extraction solution in the ammonia stripping tank was 1.5 hours. The temperature of the system in the ammonia stripping tank was 85°C. Heating and stirring were performed simultaneously. The reaction solution sequentially overflowed into the first-stage uranium deposition tank, the second-stage uranium deposition tank, the third-stage uranium deposition tank, the fourth-stage uranium deposition tank, and the fifth-stage uranium deposition tank. The residence time of the reaction solution in each of the five stages of the uranium deposition tank was [not specified]. The reaction time was 1.5 hours. The temperatures of the system in the first, second, third, fourth, and fifth uranium precipitation tanks were 92°C, 94°C, 96°C, 98°C, and 100°C, respectively, while the system was heated and stirred. The reaction liquid eventually overflowed into the sedimentation equipment for solid-liquid separation. The uranium concentration in the obtained uranium precipitation mother liquor was 5 g / L, the solution evaporation rate was 85%, and the uranium precipitation rate was 95%. The ammonia and carbon dioxide emitted from the entire system were absorbed by water and returned to prepare the back-extraction agent.

[0062] In this embodiment, the entire operation process is continuous, stable, and controllable. The interface height and bubble layer thickness are basically stable, and no violent reactions such as bubbling occur.

[0063] Example 2

[0064] A process involving a 1-stage ammonia stripping followed by a 3-stage uranium precipitation device was used to treat AUC crystallization mother liquor with a uranium concentration of 6 g / L.

[0065] The ammonia stripping and uranium precipitation device used in this embodiment includes an ammonia stripping tank, a first-stage uranium precipitation tank, a second-stage uranium precipitation tank, a third-stage uranium precipitation tank, and a settling device, which are connected sequentially along the water flow direction. The outlet of the ammonia stripping tank is higher than the inlet of the first-stage uranium precipitation tank; the outlet of the first-stage uranium precipitation tank is higher than the inlet of the second-stage uranium precipitation tank; the outlet of the second-stage uranium precipitation tank is higher than the inlet of the third-stage uranium precipitation tank; and the outlet of the third-stage uranium precipitation tank is higher than the inlet of the settling device. The ammonia stripping tank, the first-stage uranium precipitation tank, the second-stage uranium precipitation tank, and the third-stage uranium precipitation tank are all connected to the tail gas absorption system. Heating devices are installed at the bottom of the ammonia stripping tank, the first-stage uranium precipitation tank, the second-stage uranium precipitation tank, and the third-stage uranium precipitation tank. Temperature sensors and stirring devices are installed inside the ammonia stripping tank, the first-stage uranium precipitation tank, the second-stage uranium precipitation tank, and the third-stage uranium precipitation tank.

[0066] The AUC crystallization mother liquor was added to the ammonia stripping tank via a metering feeder. The residence time of the AUC crystallization mother liquor in the ammonia stripping tank was 1 hour, and the temperature of the system in the ammonia stripping tank was 88°C. Heating and stirring were performed simultaneously. The reaction solution was sequentially overflowed into the first-stage uranium precipitation tank, the second-stage uranium precipitation tank, and the third-stage uranium precipitation tank. The residence time of the reaction solution in each of the three tanks was 1 hour. The temperatures of the system in the first-stage, second-stage, and third-stage uranium precipitation tanks were 93°C, 95°C, and 97°C, respectively, while heating and stirring were performed simultaneously. The reaction solution finally overflowed into a settling device for solid-liquid separation. The uranium concentration in the obtained uranium precipitation mother liquor was 2.2 g / L, the solution evaporation rate was 78%, and the uranium precipitation rate was 92%. The ammonia and carbon dioxide emitted from the entire system were absorbed by water and returned to prepare the back-extraction agent.

[0067] In this embodiment, the entire operation process is continuous, stable, and controllable. The interface height and bubble layer thickness are basically stable, and no violent reactions such as bubbling occur.

[0068] Example 3

[0069] A process involving one stage of ammonia stripping followed by four stages of uranium precipitation is used to treat a qualified ammonium carbonate leaching solution with a uranium concentration of 2 g / L.

[0070] The ammonia stripping and uranium precipitation device used in this embodiment includes an ammonia stripping tank, a first-stage uranium precipitation tank, a second-stage uranium precipitation tank, a third-stage uranium precipitation tank, a fourth-stage uranium precipitation tank, and a sedimentation device, all connected sequentially along the water flow direction. The outlet of the ammonia stripping tank is higher than the inlet of the first-stage uranium precipitation tank; the outlet of the first-stage uranium precipitation tank is higher than the inlet of the second-stage uranium precipitation tank; the outlet of the second-stage uranium precipitation tank is higher than the inlet of the third-stage uranium precipitation tank; and the outlet of the third-stage uranium precipitation tank is higher than the inlet of the fourth-stage uranium precipitation tank. The outlet of the fourth-stage uranium deposition tank is higher than the inlet of the sedimentation equipment; the ammonia stripping tank, the first-stage uranium deposition tank, the second-stage uranium deposition tank, the third-stage uranium deposition tank, and the fourth-stage uranium deposition tank are all connected to the tail gas absorption system; the bottom of the ammonia stripping tank, the first-stage uranium deposition tank, the second-stage uranium deposition tank, the third-stage uranium deposition tank, and the fourth-stage uranium deposition tank are all equipped with heating devices; the interior of the ammonia stripping tank, the first-stage uranium deposition tank, the second-stage uranium deposition tank, the third-stage uranium deposition tank, and the fourth-stage uranium deposition tank is equipped with temperature sensors and stirring devices.

[0071] The qualified ammonium carbonate leaching solution was added to the ammonia stripping tank through a metering feed device. The residence time of the qualified ammonium carbonate leaching solution in the ammonia stripping tank was 2 hours, and the temperature of the system in the ammonia stripping tank was 90°C. The reaction solution was heated and stirred simultaneously, and then sequentially overflowed into the first-stage uranium precipitation tank, the second-stage uranium precipitation tank, the third-stage uranium precipitation tank, and the fourth-stage uranium precipitation tank. The residence time of the reaction solution in each of these four tanks was 2 hours. The temperatures of the system in the first-stage uranium precipitation tank, the second-stage uranium precipitation tank, the third-stage uranium precipitation tank, and the fourth-stage uranium precipitation tank were 92°C, 94°C, 96°C, and 98°C, respectively. The reaction solution was heated and stirred simultaneously, and finally overflowed into the sedimentation device for solid-liquid separation. The uranium concentration in the obtained uranium precipitation mother liquor was 0.7 g / L, the solution evaporation rate was 80%, and the uranium precipitation rate was 93%. The ammonia and carbon dioxide emitted from the entire system were absorbed by water and returned to prepare the back-extraction agent.

[0072] In this embodiment, the entire operation process is continuous, stable, and controllable. The interface height and bubble layer thickness are basically stable, and no violent reactions such as bubbling occur.

[0073] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for continuous and stable operation of ammonia stripping and uranium precipitation based on an ammonia stripping and uranium precipitation device, comprising the following steps: The ammonium carbonate system uranium solution is continuously fed into the ammonia stripping equipment for ammonia stripping treatment. The resulting reaction liquid overflows into a multi-stage uranium precipitation equipment for uranium precipitation treatment in each stage of the uranium precipitation equipment. The ammonia stripping and uranium precipitation device includes an ammonia stripping device and a multi-stage uranium precipitation device connected sequentially along the water flow direction; the multi-stage uranium precipitation device includes a first-stage uranium precipitation device, a second-stage uranium precipitation device, ..., n-1-stage uranium precipitation devices and an n-stage uranium precipitation device connected sequentially along the water flow direction; where n is 3 to 10; Both the ammonia stripping equipment and the multi-stage uranium precipitation equipment are independently equipped with heating and stirring equipment. The residence time for the ammonia stripping treatment is more than 1 hour; the temperature for the ammonia stripping treatment is 85~92℃; the ammonia stripping treatment is carried out under stirring conditions; The temperature inside the Level 1 uranium precipitation device, Level 2 uranium precipitation device, ..., Level n-1 uranium precipitation device and Level n uranium precipitation device increases progressively. The residence time for uranium precipitation in each stage of the uranium precipitation equipment is independently more than 1 hour; the temperature in the stage 1, stage 2, ..., stage n-1 and stage n uranium precipitation equipment increases progressively in the range of 92~100℃.

2. The ammonia stripping and uranium precipitation method according to claim 1, characterized in that, The ammonia stripping equipment and the multi-stage uranium deposition equipment are arranged in a stepped manner from high to low.

3. The ammonia stripping and uranium precipitation method according to claim 1 or 2, characterized in that, The outlet of the ammonia stripping device is higher than the inlet of the first-stage uranium deposition device, the outlet of the first-stage uranium deposition device is higher than the inlet of the second-stage uranium deposition device, and so on, with the outlet of the n-1 stage uranium deposition device being higher than the inlet of the nth stage uranium deposition device.

4. The ammonia stripping and uranium precipitation method according to claim 1, characterized in that, Both the ammonia stripping equipment and the multi-stage uranium deposition equipment are equipped with independent temperature sensors.

5. The ammonia stripping and uranium precipitation method according to claim 1, characterized in that, It also includes a settling device connected to the n-stage uranium settling device.

6. The ammonia stripping and uranium precipitation method according to claim 1, characterized in that, The temperature difference between two adjacent uranium sinking devices is 1~3℃.

7. The ammonia stripping and uranium precipitation method according to claim 1, characterized in that, The reaction liquid obtained after the final stage of uranium precipitation treatment is fed into a settling device for solid-liquid separation to obtain uranium precipitate mother liquor.

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