Sorbent for mutual separation of MA/RE in high-level waste and preparation thereof

Abstract

The invention discloses a sorbent for MA / RE mutual separation in high-level waste and a preparation method thereof. The sorbent is prepared from 2, 6-di-(5, 6-di-n-butyl-1, 2, 4-triazine-3-radical)-pyridine loaded on macropore SiO2 of a coated polymer, and the mass ratio of the macropore SiO2 to R-BTP is (1-20):1. The sorbent has good identification capability on MA, high adsorption capacity and high recovering rate; when the sorbent is used in an adsorptive separation process, the sorbent does not need to be diluted or dissolved by with diluent of special performance, and can avoid introducing large amount of toxic solvent substances or generating secondary radioactive waste; and the ion diffusion, adsorption and desorption rate of the sorbent are remarkably improved, and the sorbent can run safely under the condition of high flow rate and is a safe and economic sorbent for efficiently mutually separating MA / RE in the high-level waste.

Description

technical field [0001] The invention relates to the field of high-level radioactive waste treatment and disposal produced in the spent fuel reprocessing process of the nuclear industry, in particular to an adsorbent used for mutual separation of MA / RE in high-level radioactive waste and a preparation method thereof. Background technique [0002] Spent fuel contains long-lived (millions of years) minor actinides (MA) and fragmentation products (FP) such as exothermic elements. The current status of reprocessing is: in addition to separating and recovering useful metals U and Pu, a part of Np and almost all FP elements went into the acidic HLLW. MA in HLLW is a long-lived fragment product, represented by trivalent Am and Cm, with a half-life of millions of years, and is considered to be the most dangerous potentially harmful element that causes long-term burdens on environmental safety and affects the earth's ecological environment One, it needs to be effectively separated an...

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Problems solved by technology

[0006] However, the extraction agent used has limited solubility in common hydrocarbon diluents such as n-dodecane and kerosene, so diethylbenzene, tert-butylbenzene, or highly branched 1,1,2,2, Some toxic diluents such as 3,3,4,4,-octamethylbutane-based hydrogenated tetrapropylene mixture (TPH); or in order to suppress the third phase, 30% tributyl phosphate (TBP) must be added ) or 30% n-octanol and other organic phase regulators; and the acid resistance and radiation resistance are not high, the chemical stability is poor, and there are many degradation products, so that the separation process must use large-capacity multi-stage extraction equipment, and a large amount of Liquid waste and toxic refractory secondary radioactive organic waste, the resulting solvent chemical instability leads to concerns about the safety of the reprocessing cycle

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