CN-117534186-B - Method for enhancing commercial iron powder uranium separation efficiency by using external field

Abstract

The invention discloses a method for enhancing the uranium separation efficiency of commercial iron powder by using an external field, which comprises the following steps: commercial iron powder is added into a reactor filled with the uranium-containing wastewater containing fluorine, and the uranium separation treatment is carried out on the uranium-containing wastewater containing fluorine under the continuous stirring of an external weak magnetic field or magneto-optical coupling. According to the invention, commercial iron powder is magnetized by introducing a weak magnetic field, fe 2+ is pulled to migrate, so that a passivation layer on the surface of the iron powder is damaged, the redox reaction of U (VI) and Fe 0 is promoted, meanwhile, the affinity between magnetized iron powder particles and paramagnetic molecules O 2 is enhanced, so that gamma-FeOOH nano-sheets with high specific surface area are generated on the surface of the iron powder, and the gamma-FeOOH surface has rich oxygen-containing functional groups, and the separation of U (VI) is realized through the bonding of-OH and U (VI). On the basis of a weak magnetic field, the separation efficiency of commercial iron powder on U (VI) in the uranium-containing wastewater is further improved through coupling the light field.

Inventors

• ZHU WENKUN
• HE RONG
• CHEN TAO
• ZHU BOMING

Assignees

• 西南科大四川天府新区创新研究院
• 西南科技大学

Dates

Publication Date

20260505

Application Date

20231113

Claims (5)

1. 1. A method for enhancing uranium separation efficiency of commercial iron powder by using an external field is characterized by comprising the steps of adding commercial iron powder into a reactor filled with uranium-containing wastewater containing fluorine, and carrying out uranium separation treatment on the uranium-containing wastewater containing fluorine under the action of the external field and continuous stirring, wherein the external field is magneto-optical coupling, the concentration of U (VI) in the uranium-containing wastewater containing fluorine is 20-500 mg/L, the molar ratio of F - to U (VI) is 0-130:1, and the pH value is 3-10; the specific method of the external field effect is as follows: (1) Externally arranging a weak magnetic field around or at the bottom of the reactor, wherein the strength of the weak magnetic field is 3-10 mT; (2) On the basis of the step (1), an external light source is added, and the reactor is irradiated to form magneto-optical coupling; the commercial iron powder is magnetized by a weak magnetic field, fe 2+ is pulled to migrate, a passivation layer on the surface of the iron powder is damaged, oxidation-reduction reaction of U (VI) and Fe 0 is promoted, affinity between magnetized iron powder particles and paramagnetic molecules O 2 is enhanced, gamma-FeOOH nano-sheets with high specific surface area are generated on the surface of the iron powder, and the gamma-FeOOH surface has rich oxygen-containing functional groups, so that the separation of U (VI) is realized through bonding of-OH and U (VI).
2. 2. The method for enhancing uranium separation efficiency of commercial iron powder through an external field according to claim 1, wherein the commercial iron powder is in a micron level, and the adding amount of the commercial iron powder is 0.5-2.5 g/L.
3. 3. The method for enhancing uranium separation efficiency of commercial iron powder in an external field according to claim 1, wherein the stirring speed is 300-500 r/min.
4. 4. The method for enhancing uranium separation efficiency of commercial iron powder of claim 1, wherein the weak magnetic field is any one of a uniform magnetic field and a non-uniform magnetic field.
5. 5. The method for enhancing uranium separation efficiency of commercial iron powder according to claim 1, wherein the external light source is a 200-400 w xenon lamp provided with an AM1.5G filter.

Description

Method for enhancing commercial iron powder uranium separation efficiency by using external field Technical Field The invention belongs to the technical field of uranium separation, and particularly relates to a method for enhancing commercial iron powder uranium separation efficiency by using an external field. Background UF 6 is an important compound in the production of nuclear fuels, which results in the production of fluorine-containing uranium-containing wastewater during operation of uranium enrichment plants and nuclear fuel (component) manufacturers. F-U bonding in the uranium-containing wastewater forms UO 2F+、UO2F2、UO2F3- and other complexes which cause obstruction to the extraction and separation of U (VI), and the traditional process route (chemical precipitation, ion exchange, adsorption method) gradually loses advantages due to the problems of complex process, high cost and the like in application. Therefore, new technologies for treating the uranium-containing fluoride wastewater, which are lower in development cost, higher in efficiency and more friendly to the environment, are needed. At present, nano zero-valent iron (nZVI) is considered as a new method which is most expected to replace the traditional process of the uranium-containing wastewater containing fluorine. The nano zero-valent iron has advantages in uranium separation in the uranium-containing waste liquid because it has better ability to be injected into the aqueous layer system, higher reaction surface area, faster and more complete reaction. However, nano zero-valent iron has great limitations in practical application, such as extremely easy oxidation, difficult long-term storage and the like. The nano zero-valent iron is easy to oxidize on the surface in a solution system to form a passivation layer, which can obviously reduce the uranium removal performance in the solution. Meanwhile, aggregation of nano zero-valent iron can reduce fluidity of nano zero-valent iron on a subsurface, and further influence reactivity of nano zero-valent iron. In order to solve the above problems, researchers have carried out a great deal of modification studies on nano zero-valent iron. Researchers can greatly reduce the aggregation phenomenon of nano zero-valent iron and the size distribution of synthesized nZVI is narrower by using carriers (attapulgite, illite, montmorillonite, bentonite, silicon dioxide-based mesoporous or nano-material, magnesium hydroxide nanocrystalline, carbon-based material and other porous carriers) in the preparation process of the nano zero-valent iron. Although researchers solve the problem of complicated preparation procedures, high cost and the like through the surface carrier, the large-scale utilization of the nZVI is limited. From the cost point of view, commercial iron powder with lower price is an ideal substitute for nano zero-valent iron. However, although the two components are the same, commercial iron powder has a large particle size, and has problems such as extremely weak reducing power and extremely low specific surface area of the produced oxide. Therefore, the reduction capacity of commercial iron powder is enhanced, the structure of an oxidation product is regulated and controlled, the size gap between the commercial iron powder and nano zero-valent iron is overcome, and the method is a key for realizing the efficient separation of uranium in the uranium-containing waste liquid. Disclosure of Invention It is an object of the present invention to address at least the above problems and/or disadvantages and to provide at least the advantages described below. To achieve these objects and other advantages and in accordance with the purpose of the invention, a method for enhancing uranium separation efficiency of commercial iron powder by an external field is provided, which comprises the steps of adding commercial iron powder into a reactor containing uranium-containing wastewater containing fluorine, and performing uranium separation treatment on the uranium-containing wastewater containing fluorine under continuous stirring under the action of the external field. Preferably, the external field comprises a weak magnetic field or magneto-optical coupling. Preferably, the specific method of the external field effect is that a weak magnetic field is externally arranged at the periphery or the bottom of the reactor; preferably, the specific method of the external field effect is as follows: (1) Externally arranging a weak magnetic field around or at the bottom of the reactor; (2) And (3) adding an external light source on the basis of the step (1), and irradiating the reactor to form magneto-optical coupling. Preferably, the commercial iron powder is of micron order, more preferably 1 μm, and the addition amount of the commercial iron powder is 0.5-2.5 g/L, more preferably 0.5g/L Preferably, the stirring speed is 300-500 r/min. Preferably, the weak magnetic field is any one of a uniform magnetic field