CN-117127012-B - Method for extracting palladium from radioactive waste liquid

Abstract

The invention relates to a method for extracting palladium from radioactive waste liquid, which comprises the steps of mixing the radioactive waste liquid with an organic phase containing pyridine derivatives for extraction, wherein the pyridine derivatives are one or more than two of Ph-BTP, ph-BTBP or Ph-BTPhen, and the structures are respectively shown as follows: Compared with the prior art, the palladium extraction method is simple and feasible, is easy for industrial production, can enable the single-stage extraction rate of palladium to be more than 99% by adjusting the concentration, the phase ratio and the like of the extractant, has short extraction balance time, can meet the requirement of palladium recovery, and has wide application prospect in the fields of palladium recovery and high-level waste liquid disposal.

Inventors

• HU YUNPING
• GAO JIANMEI
• WANG JIAN
• LI LIANSHUN
• LI TIANFU
• HUA XIUFANG

Assignees

• 中核四0四有限公司
• 中核四0四成都核技术工程设计研究院有限公司

Dates

Publication Date

20260508

Application Date

20230726

Claims (9)

1. 1. A method for extracting palladium from radioactive waste liquid, which is characterized in that the radioactive waste liquid is mixed with an organic phase containing pyridine derivatives for extraction, wherein the pyridine derivatives are one or two of Ph-BTP or Ph-BTBP, and the structures are respectively shown as follows: ; the mixing time of the radioactive waste liquid and the organic phase is 2-120min; The concentration range of palladium in the radioactive waste liquid is 0.01-4.5 g/L.
2. 2. The method for extracting palladium from radioactive waste liquid according to claim 1, wherein the preparation method of the pyridine derivative comprises the steps of: s1, synthesizing amidrazone through nucleophilic addition reaction, namely adding hydrazine hydrate or anhydrous hydrazine into a dicyano solution, and carrying out solid-liquid separation after nucleophilic addition reaction to obtain the amidrazone; S2, synthesizing a pyridine derivative through condensation cyclization reaction, namely dispersing or dissolving the grinded amidrazone and diphenyl ethylene dione in a solvent, and carrying out solid-liquid separation after the condensation cyclization reaction to obtain the pyridine derivative; the dinitrile has the following structure: ; The amidrazone has the following structure: 。
3. 3. The method for extracting palladium from radioactive waste according to claim 1, wherein the concentration of the pyridine derivative in the organic phase is 0.1 to 500mmol/L.
4. 4. A method for extracting palladium from radioactive waste according to claim 3, wherein the concentration of the pyridine derivative in the organic phase is 2 to 100mmol/L.
5. 5. The method for extracting palladium from radioactive waste according to claim 1, wherein the diluent of the organic phase is one or more of dichloromethane, chloroform, dichloroethane, 1-difluoro-1, 2-dichloroethane, trichloroethane, tetrachloroethane, furan, dioxane, acetonitrile, DMSO, hydrogenated kerosene, sulfonated kerosene, petroleum ether, ethyl acetate, benzene, toluene, xylene, pentane, and n-dodecane.
6. 6. The method for extracting palladium from radioactive waste according to claim 1, wherein the ratio of the radioactive waste to the organic phase is 3:1 to 1:3.
7. 7. The method for extracting palladium from radioactive waste according to claim 1, wherein the extraction process temperature is 15 to 60 ℃.
8. 8. The method for extracting palladium from radioactive waste according to claim 1, wherein the organic phase is pre-equilibrated before extraction.
9. 9. The method for extracting palladium from radioactive waste according to claim 8, wherein the pre-equilibration is to prepare an aqueous phase having the same acidity as the radioactive waste, to fully contact the aqueous phase with the organic phase, and to separate the organic phase after mixing uniformly for extraction.

Description

Method for extracting palladium from radioactive waste liquid Technical Field The invention relates to the technical field of radioactive waste treatment, in particular to a method for extracting palladium from radioactive waste liquid. Background The high-level waste liquid contains noble metals of ruthenium, rhodium and palladium, wherein the content of the palladium is closely related to the type of a reactor, the burnup depth of fuel and the like. Taking a standard commercial pressurized water reactor with an average burnup depth of 33GWd/t as an example, its Pd content is >1Kg Pd/tU. The total amount of palladium resources stored in the high-level waste liquid is huge, and the generated palladium resources are continuously increased along with the vigorous development of the nuclear power industry. On the other hand, palladium (Pd) in the high-level waste liquid is recycled, so that the adverse effect on the glass solidification and melting process can be fundamentally eliminated. The solvent extraction method is the main stream method for separating and extracting palladium, and since the 60 th century, a great deal of research and development work is done on the extraction process of palladium and the research and development of extractant at home and abroad. The publication CN101020964 a discloses a method for extracting and separating palladium by solid phase extraction. The high molecular microsphere bonded with palladium extractant is used as stationary phase, hydrochloric acid solution containing noble base metal is used as mobile phase, and palladium can be extracted and separated from noble metal catalyst, platinum group metal concentrate or noble metal enrichment obtained from secondary resource through hydrochloric acid leaching, thiourea or ammonia water elution. The stationary phase has short service life and poor cycle performance in radioactive environment, can generate a large amount of radioactive solid waste, and is not suitable for treating a large amount of industrial waste liquid. The patent with publication number CN 105002359A discloses a method for extracting palladium from aqueous phase, which uses diazoamide pyridine derivative as extractant and adopts solvent extraction method to obtain extraction phase containing palladium. The partition ratio of the extractant to palladium reaches the maximum value (about 47) under the concentration of 2M HNO 3 nitric acid, the preferred extraction time in the extraction process is 120min, and the extraction equilibrium time is long. Patent publication No. CN 101713026A discloses a method for extracting palladium from high-level waste liquid, which uses triisobutyl phosphorus sulfide (TiBPS) as an extractant, adopts a solvent extraction method, and extracts palladium from simulated high-level waste liquid through steps of extraction, washing, back extraction and the like. TiBPS contains sulfur element and phosphorus element, and does not accord with the principle of green sustainable development. The reported palladium extraction method has the defects that the extraction distribution ratio of an extractant is low (such as tributyl phosphate and trialkyl phosphorus oxide, the distribution ratio is smaller than 10), the extraction balance time is long (such as dialkyl sulfide, the balance time is 8-10 hours), the method does not conform to the principle of green sustainable development, and the like, so that palladium cannot be efficiently separated and recovered, and extraction processes such as solid-phase extraction, ion exchange method and the like are not suitable for treating a large amount of industrial waste liquid. Disclosure of Invention The invention aims to provide a method for extracting palladium from radioactive waste liquid, which can efficiently separate and recycle palladium. The invention can be realized by the following technical scheme that the method for extracting palladium from the radioactive waste liquid is characterized in that the radioactive waste liquid is mixed with an organic phase O1 containing a pyridine derivative of a palladium extractant for extraction, and the pyridine derivative is one or more than two of Ph-BTP, ph-BTBP or Ph-BTPhen, and has the following structures: preferably, the preparation method of the pyridine derivative comprises the following steps: s1, synthesizing amidrazone through nucleophilic addition reaction, namely adding hydrazine hydrate or anhydrous hydrazine into a dicyano solution, and carrying out solid-liquid separation after nucleophilic addition reaction to obtain the amidrazone; S2, synthesizing a pyridine derivative through condensation cyclization reaction, namely dispersing or dissolving the ground amidrazone and diphenyl ethylene dione in a solvent, and carrying out solid-liquid separation after the condensation cyclization reaction to obtain the pyridine derivative; the dinitrile has the following structure: The amidrazone has the following structure: Still more preferab