15 results about "Uranyl nitrate" patented technology

The invention discloses an application of a molybdenum disulfide-based piezoelectric catalytic material in a seawater uranium extraction material, and relates to the technical field of seawater uranium extraction, thiourea and sodium molybdate are used as precursors, and a MoS2 nanoflower with a specific 1T / 2H composite crystal structure is constructed through a hydrothermal synthesis technology. The method is placed in a uranyl nitrate solution, ultrasonic treatment is combined, efficient extraction of uranium can be achieved, and the method has potential application to extraction of uranium from seawater. The method is simple in process and environment-friendly, almost does not generate harmful waste in the synthesis process, does not need complex operation, and has good amplification preparation potential.

The invention provides a recovery treatment method of fluoride slag in uranium hexafluoride preparation, belongs to the technical field of nuclear industry waste slag treatment, and solves the technical problems that a product obtained by an existing fluoride slag treatment method is high in metal impurity content and low in uranium recovery rate, secondary fluoride slag is easily generated, and the product cannot be returned to a uranium purification and conversion production line for reuse. The method comprises the following steps: at the temperature of 400-600 DEG C, contacting the fluorinated slag with excessive water vapor to carry out high-temperature hydrolysis reaction, so that UF4 and uranium intermediate fluoride in the fluorinated slag generate uranium oxides U3O8 and UO3 with the fluorine ion content of less than 1mg / g, and filtering to obtain uranium oxides; mixing uranium oxide with a nitric acid solution, dissolving and reacting to obtain a uranyl nitrate solution; the pH of the uranyl nitrate solution is adjusted to 3-4, hydrogen peroxide is added for a precipitation reaction, solid-liquid separation is conducted, and uranium peroxide solid precipitates are obtained. The method is high in uranium recovery rate, low in product impurity content and capable of returning to a uranium purification and conversion production line for reuse.

This invention discloses a purification method for producing molybdenum-99 in a reactor using uranyl nitrate solution as nuclear fuel, relating to the field of radioisotope production technology. The method involves first adding an oxidant to the crude molybdenum-99 product solution produced by the solution reactor, oxidizing the crude molybdenum-99 product to MoO4. 2‑ The solution is then evaporated to dryness; a digestion solution is added to the evaporation residue to dissolve the impurities; a dissolving solution is added to the digested solid to dissolve the solid, which is then evaporated to dryness; finally, an alkaline solution is added to the evaporated solid to dissolve it, yielding a molybdenum-99 product solution that meets pharmacopoeia requirements. Compared to traditional methods for purifying molybdenum, this invention does not introduce new impurities, has a low heating temperature, low energy loss, is easy to operate in a hot chamber, and has a high impurity removal rate.

The invention belongs to the technical field of uranium compounds, and particularly relates to a preparation method of high-purity uranyl nitrate. According to the method, the high-purity uranyl nitrate hexahydrate and uranyl nitrate trihydrate are continuously prepared by taking a ternary system phase diagram as guidance and combining a pH controlled micro-disturbance impurity removal technology and a mother liquor closed-loop circulation technology. In-situ selective removal of amphoteric impurities is achieved through accurate pH oscillation impurity removal, the impurity removal effect is enhanced in cooperation with thermal-state filtration, a target crystal phase is directionally separated out through regulation and control of a phase diagram, mother liquor after centrifugation can be directly reused for a dissolution procedure through split-flow compounding, and therefore full utilization of materials is achieved; and environmental pressure and resource waste caused by discharge of high-acidity waste liquid are avoided. The method provided by the invention ensures high purity of the product and crystal phase stability, realizes flow simplification, high-efficiency utilization of materials and zero wastewater discharge, reduces the comprehensive production cost, has good industrial suitability, and can meet the preparation requirements of high-purity raw materials such as nuclear fuel grade and the like.

The method for uranium purification and removal from dissolving slag based on modification and acid leaching includes the following steps: 1. Modification treatment: The dissolving slag is mixed with an alkaline solution to form a mixed solution. The alkaline solution dissolves silicon oxides, fully exposing the uranium-containing phase. The mixed solution after reaction is subjected to solid-liquid separation, washing, and drying to obtain pretreated slag. 2. Acid leaching for uranium removal: The pretreated slag is mixed with nitric acid to form a slurry, which is then acid-leached. The uranium-containing phase in the pretreated slag reacts with the nitric acid to generate uranyl nitrate solution. The slurry after acid leaching is subjected to solid-liquid separation, washing, and drying to obtain acid-leached slag. The advantages of this invention are: the uranium content of the acid-leached slag obtained at the end of the process is reduced to below 0.05%, which can be disposed of as ordinary solid waste in landfills without the need for packaging in raw material containers, thus fundamentally solving the problem of high storage costs for dissolving slag.

The invention belongs to the technical field of nuclear fuel development, and particularly relates to a preparation method of a large-grain UO2 fuel pellet. The preparation method comprises the following steps: (1) uniformly mixing a grain growth substance and an acid-deficient uranyl nitrate solution, adding saturated ammonium carbonate or introducing reaction gas for precipitation reaction to generate an AUC precipitate; the reaction gas is a mixture of NH3 and CO2; (2) filtering the AUC precipitate to obtain a filter cake, and washing, filtering, drying and calcining to obtain powder; (3) granulating the powder, and forming to obtain a green fuel pellet; and (4) sintering the green fuel pellet to obtain the large-grain UO2 fuel pellet. The average grain size of the prepared large-grain UO2 fuel pellet is larger than or equal to 40 micrometers, and the large-grain UO2 fuel pellet has the high melting point, good water corrosion performance and irradiation stability of traditional UO2 fuel and further has the low fission gas release rate and the high heat conductivity.

The present application relates to the technical field of uranium waste treatment, and particularly relates to a method for recovering uranium from sodium lime adsorbed with uranium. The method for recovering uranium from sodium lime adsorbed with uranium comprises the following steps: S1, adding a nitric acid solution to the sodium lime adsorbed with uranium to perform uranium elution, and obtaining a uranyl nitrate solution; S2, separating the eluted sodium lime from the uranyl nitrate solution; and S3, adjusting the pH value of the uranyl nitrate solution, so that the uranium is recovered in the form of sodium diuranate precipitate. The present application is simple in operation, high in uranium recovery rate, and can recycle the uranium in a recyclable form while reducing the solid waste treatment cost.

The invention provides a gas compounding system and method for catalytic dehydrogenation of a uranyl nitrate solution reactor, and belongs to the technical field of medical isotope reactors, the system comprises a hydrogen-oxygen recombiner communicated with a uranyl nitrate solution reactor container, and an injection pump communicated with the hydrogen-oxygen recombiner; a cooling water tank in which a gas-liquid separator and a heat exchanger are arranged is arranged below the injection pump; the gas-liquid separator is connected with the injection pump through a pipeline; the heat exchanger is connected with an equipment cooling water system pipeline; the top of the cooling water tank is communicated with the uranyl nitrate solution pile through an exhaust pipeline; the side part of the cooling water tank is communicated with the uranyl nitrate solution pile through an overflow pipe; the bottom of the cooling water tank is communicated with the injection pump through a pipeline, and a circulating pump is arranged on the pipeline where the cooling water tank is communicated with the injection pump. According to the gas compounding system for catalytic dehydrogenation of the uranyl nitrate solution reactor and the gas compounding method of the gas compounding system, the number of equipment is small, the structure is simple, safety is high, the integration level is high, and the operation mode is simple.

The application discloses a purification method for producing iodine-131 by a reactor with a uranyl nitrate solution as nuclear fuel, and comprises the following steps: adding a reducing agent into a crude iodine-131 product solution to reduce sodium iodine-131 into iodine-131 element; distilling the iodine-131 element to obtain iodine-131 element vapor; and absorbing the iodine-131 element vapor by using an alkaline solution to obtain a sodium iodine-131 solution product. The purification method can effectively remove radioactive impurities in the iodine-131 extracted from the reactor with the uranyl nitrate solution as the nuclear fuel, and can obtain the sodium iodine-131 solution product meeting the medical requirements. The purification method for the iodine-131 isotope is simple, and can effectively remove the impurities in the iodine-131 isotope, so that the iodine-131 isotope meets the medical requirements, and the average recovery rate of iodine can reach more than 90%.

This invention discloses a purification apparatus and method for iodine-131 produced by a nuclear reactor using uranyl nitrate aqueous solution as fuel, relating to the field of radioactive isotope production technology. The apparatus includes a carrier gas cylinder, an evaporator, a waste liquid tank, a primary absorption tank, a secondary absorption tank, a tertiary absorption tank, and a product tank. The carrier gas cylinder is connected to the evaporator via an inlet pipe. A liquid inlet is located at the top of the evaporator. An outlet pipe is connected to the top of the evaporator, connecting to the primary absorption tank. The primary absorption tank is connected to the secondary absorption tank via a pipe, and the secondary absorption tank is connected to the tertiary absorption tank via a pipe. Discharge pipes are connected to the bottom of the primary, secondary, and tertiary absorption tanks, and these pipes are all connected to the product tank. The bottom of the evaporator is connected to the waste liquid tank via a drain pipe. This apparatus and method achieve high product recovery and high product purity after iodine-131 purification. 131 The sodium hydroxide solution product meets the requirements of medical technical specifications.

A useful metal may be recovered from a solution of a nitrate salt of a metal cation or a metal oxycation, by adding the solution of the nitrate salt to a formation column having an inlet and an outlet nozzle, the solution of the nitrate salt being added in a dropwise fashion through the inlet. The formation column contains a recirculating solution containing a base selected from the group consisting of ammonia, ammonium hydroxide, an alkali metal hydroxide, and an alkaline earth metal hydroxide. The nitrate salt reacts with the base in the recirculating solution to produce a metal oxide salt or a metal hydroxide salt as a precipitate. The precipitate and the recirculating solution exit the formation column through the outlet nozzle and are captured the precipitate in a basket beneath the formation column while recovering the recirculating solution in a catch tank under the basket. The recovered recirculating solution is pumped from the catch tank to the formation column. The nitrate salt of the metal cation may be a nitrate salt of a radioactive metal cation, e.g., uranium or a uranyl cation.

The invention relates to the technical field of UN nuclear fuel, and particularly discloses a high-density single-phase UN fuel microsphere and a preparation method thereof in order to solve the problem that existing uranium nitride fuel microsphere crystal structure phase composition is relatively complex, the preparation method comprises the following steps: S1, taking a uranyl nitrate solution, adding urea, urotropine and a carbon source, and mixing to prepare carbon-containing sol; s2, dispersing the carbon-containing sol into an organic solvent through a dispersion pore plate to form carbon-containing gel balls, and then washing, drying and calcining to obtain UO3-C dry calcined balls; s3, the UO3-C dry calcined pellets are sequentially subjected to carbon thermal reduction and nitriding sintering treatment, and the single-phase UN fuel microspheres are obtained. In the stage of preparing the uranyl nitrate solution, a special carbon source is added, so that the distribution uniformity of the carbon source in the UO3-C dry calcined ball is ensured; and in the later conversion processes of carbon thermal reduction, nitridation and the like, reducing gases with different proportions are introduced, and finally, the UN fuel microspheres composed of high-density and single-phase UN components are prepared.

The invention discloses an aqueous solution type reactor capable of improving the fuel utilization rate and an operation method of the aqueous solution type reactor. The nuclear fuel reactor takes a thorium-uranium mixture as nuclear fuel and takes a mixed solution formed by mixing a uranyl nitrate aqueous solution, a thorium nitrate aqueous solution and a nitric acid solution as the nuclear fuel. The thorium-uranium mixture is used as the nuclear fuel of the water solution type reactor, nuclear fuel conversion from thorium-232 to uranium-233 is achieved in the reactor, the purpose of self-sustaining of the nuclear fuel is achieved, the fuel economy of the reactor is improved, the operation cost of the reactor can be reduced, effective utilization of thorium resources is achieved, and the method is suitable for industrial production. The economical efficiency and the large-scale application of the aqueous solution type reactor are favorably improved.

The invention provides a uranyl nitrate solution reactor passive hydrogen-oxygen recombiner, and belongs to the technical field of medical isotope reactors. The device comprises a device shell with one closed end. A gas inlet is formed in the open end of the device shell; an inlet heater communicated with the gas inlet is arranged in the device shell, and the other end of the inlet heater is sequentially connected with a front honeycomb catalyst and a rear honeycomb catalyst; a certain space is reserved between the side walls of the inlet heater, the front honeycomb catalyst and the rear honeycomb catalyst and the inner wall of the device shell to serve as a gas channel; a flow guide plate is arranged on the side wall of the tail part of the rear honeycomb catalyst, and a certain distance is reserved between the flow guide plate and the inner wall of the device shell; and a gas outlet communicated with the space is formed in one side of the end part of the device shell. The uranyl nitrate solution reactor passive hydrogen-oxygen recombiner provided by the invention can ensure safe and stable operation of the reactor, and is high in integration degree, simple in system structure and convenient to overhaul and maintain.

The invention relates to the technical field of gel materials for nuclear fuels, and particularly discloses a carbon-doped gel ball with hydro-thermally treated organic sugar as a carbon source and a preparation method of the carbon-doped gel ball aiming at the problem that carbon is easy to lose in the subsequent production and processing process when the organic sugar is used as the carbon source in the existing gel ball for the nuclear fuels. Comprising the following steps: taking an organic sugar aqueous solution, carrying out hydrothermal treatment, carrying out solid-liquid separation, taking a solid phase, washing and drying to obtain a carbon source; taking the acid-deficient uranyl nitrate solution, sequentially adding a carbon source, urea and urotropine step by step, mixing and standing to obtain sol; dispersing the sol into heated silicone oil, carrying out aging treatment, and then washing with kerosene, absolute ethyl alcohol and an absolute ethyl alcohol-ammonia water mixed solution in sequence to obtain the carbon-doped gel balls. According to the method, organic sugar is subjected to hydro-thermal treatment, the hydrophilic property of the organic sugar is improved, the carbon yield is increased, a carbon source which has the nanoscale particle size and is easily dispersed in a water phase is obtained, and then the carbon-doped gel balls which are free of carbon loss and uniform in carbon distribution can be prepared.