RU2074017C1 - Method of photochemical separation of mercury isotopes - Google Patents

Abstract

FIELD: isotope separation. SUBSTANCE: mixture of mercury isotopes is irradiated in presence of oxygen and butadiene with mercury lamp light having wavelength corresponding to Hg-198 isotope emission to produce dump depleted in Hg-198 and Hg-201 isotopes and a mixture enriched with them. The latter is separated by the same technique with wavelength corresponding to Hg-196 isotope emission. The dump is irradiated with wavelength corresponding to emission of isotope Hg-196 and/or Hg-200 and/or Hg-202 to produce mixture of Hg-199 and 204 isotopes. This mixture is separated with wavelength correspond to Hg-196 isotope emission. Enrichment degree is 96.0-97.2% and output 1.32-1.62 mg/h. EFFECT: improved procedure. 3 cl, 4 dwg, 5 tbl

Description

 The invention relates to optical methods for the separation of isotopes and can be used in the separation industry.

 A known method for the photochemical separation of mercury isotopes [1] This method consists in the fact that mercury vapor with an oxidizing substance is irradiated with a mercury lamp and a photochemical mercury oxidation reaction is carried out. Methyl fluoride is used as an oxidizing agent.

 This method does not allow to separate all isotopes of mercury, cannot provide high productivity and degree of enrichment of isotopes.

Closest to the invention is a method for the photochemical separation of mercury isotopes, including irradiation and excitation of mercury atoms with light with a wavelength of 253.7 nm and the implementation of a photochemical reaction with excited mercury atoms [2]
This method cannot ensure the separation of all isotopes of mercury, high productivity and the degree of enrichment of isotopes.

 The purpose of the invention is the possibility of separation of all isotopes of mercury while maintaining high productivity and the degree of enrichment of isotopes; Isotope Hg-198, Hg-201, Hg-199, and Hg-204 isotopes whose components overlap in the hyperfine structure of the 253.7 nm line. The separation of these isotopes with the preservation of their degree of enrichment became possible due to an increase in the distance between the components of the target isotope and impurity isotopes.

 The goal is achieved by the fact that mercury atoms are irradiated with a mercury lamp in the presence of oxygen and butadiene and the target isotopes are extracted, and mercury atoms are irradiated with mercury lamp with a wavelength corresponding to the radiation of the Hg-109 isotope to produce a mixture of isotopes depleted in Hg-198 and Hg-201 and enriched in these isotopes, from which a mixture of Hg-198 and Hg-201 isotopes is extracted, which are separated by irradiating light with a wavelength corresponding to the emission of Hg-199 and / or Hg-204 isotopes.

 A mixture depleted in the Hg-198 and Hg-201 isotopes is irradiated with light with a wavelength corresponding to the emission of the Hg-199 and / or Hg-204 isotope to obtain a mixture of isotopes depleted in and enriched in the Hg-199 and Hg-204 isotopes isotopes from which the Hg-199 and Hg-204 isotopes are extracted, irradiating it with light with a wavelength corresponding to the radiation of the Hg-196 isotope.

 The mixture depleted in the Hg-198 and Hg-201 isotopes is irradiated with light with a wavelength corresponding to the emission of the Hg-196 and / or Hg-200 and / or Hg-202 isotopes to produce a mixture of the Hg-199 and Hg-204 isotopes.

The scientific and technical literature describes the reactions of excited mercury atoms with HCl, CH ₃ Cl, HJ, HBr, etc. However, the greatest application in practice has been the reaction of excited mercury atoms with oxygen in the presence of butadiene 1,3.

 In FIG. Figure 1 shows the hyperfine structure of the resonance mercury line of 253.7 nm taking into account real broadening factors under separation conditions.

Figure 2 presents:
a) the emission line of a lamp filled with the Hg-198 isotope,
b) the absorption line of the blade,
c) absorption line of a mixture of isotopes Hg-198, Hg-201.

Figure 3 presents:
a) the emission line of a lamp filled with the Hg-199 isotope,
b) the emission line of a lamp filled with the Hg-204 isotope,
c) the absorption line of the blade,
d) absorption line of a mixture of isotopes Hg-199 and Hg-204.

 Figure 4 shows the absorption line of a mixture of Hg-199 and Hg-204 isotopes and the emission line of a lamp filled with the Hg-196 isotope with different contour widths.

 In FIG. Figure 1 shows that by irradiating mercury atoms even with a sufficiently narrow emission line, only Hg-196, Hg-200, and Hg-202 isotopes can be selectively excited. The isotopes Hg-198, Hg-199, Hg-201 and Hg-204 can only be excited by the groups: (Hg-199, Hg-204 and Hg-201), (Hg-198 and Hg-201), (Hg-199 and Hg-201).

 At the first stage, mercury vapor possesses a lamp filled with the Hg-198 isotope (Fig. 2a) and a mixture of the Hg-198 and Hg-201 isotopes is extracted (Fig. 2c). At this stage, it is important to achieve maximum extraction from the dump (fig.2b) of the indicated mixture of isotopes, since the components of the absorption line of the Hg-201 isotope practically coincide with the absorption lines of the Hg-199 and Hg-204 isotopes.

 At the second stage, either Hg-198 and Hg-201 isotopes are separated, or a mixture of Hg-199 and Hg-204 isotopes is extracted from the dump obtained at the first stage. At this stage, a lamp filled with the isotope Hg-199 (figa) or Hg-204 (fig.3b) is taken as a light source.

 From the dump of the second stage (Fig.3c), Hg-200, Hg-202 and Hg-196 isotopes can be distinguished, taking lamps filled with these isotopes, respectively, as a light source.

 It should be noted that the isolation of a mixture of Hg-199 and Hg-204 isotopes (Fig. 3d) can be accomplished by depleting the first stage mercury by isotopes of Hg-196, Hg-200 and Hg-202 by exposing them to light from lamps filled with Hg- isotopes 196, Hg-200 and Hg-202, respectively, or a mixture thereof.

 Using a lamp filled with the Hg-196 isotope to extract the Hg-199 isotope from a mixture of isotopes (Fig. 4), it is necessary to select its operating mode, for example, temperature, so that the Hg-199 isotope is excited as efficiently as possible.

 It is easy to see that at the first stage, mercury depleted in the Hg-196-Hg-200 and Hg-202 isotopes or their mixtures can be used.

 PRI me R 1. The selection of the isotopes Hg-198 and Hg-201 is carried out in several enrichment cycles, using as a light source a low pressure lamp filled with the isotope Hg-198. In each subsequent enrichment cycle, the enriched mercury obtained in the previous enrichment cycle is taken as raw material. The resulting mixture of isotopes is separated using a lamp filled with Hg-199 isotopes to irradiate it. The results are summarized in table. one.

 Using a lamp filled with the Hg-204 isotope to separate a mixture of isotopes Hg-198 and Hg-201, it is easy to replace a certain decrease in the productivity of the separation process. The data are summarized in table. 2.

 PRI me R 2. The selection of the isotopes Hg-199 and Hg-204 begin with a deep, to a fraction of a percent, depletion of raw materials isotopes Hg-198 and Hg-201. At this stage, the feed is irradiated with a lamp filled with the Hg-198 isotope, and the Hg-198 and Hg-201 isotopes are recovered. At the second stage, using a lamp filled with the Hg-199 isotope to excite the Hg-199 and Hg-204 isotopes, a mixture of the Hg-199, Hg-204 isotopes is extracted from the dump of the first stage.

 At the third stage, the mixture of Hg-199 and Hg-204 isotopes is separated using a lamp filled with the Hg-196 isotope with an artificially broadened emission line contour as a light source. The radiation from the lamp was passed through an isotope filter containing a mixture of the isotopes Hg-198, Hg-200 and Hg-202.

 The results are summarized in table. 3.

 When using a lamp filled with the Hg-204 isotope in the second stage, a slight decrease in productivity was observed (Table 4).

 A more significant decrease in productivity was observed when using a lamp at the second stage filled with a mixture of Hg-196, Hg-200 and Hg-202 isotopes, with the help of which a deep depletion of the dump of the first stage was carried out using the Hg-196, Hg-200 and Hg-202 isotope ( table 5).

 Comparison in all cases was carried out with the results obtained in the production of the Hg-202 isotope. Until now, photochemical technology has been used to produce the Hg-202 and Hg-196 isotopes.

 As was shown, it is possible to increase the efficiency of the separation process when using at different stages of filtration the radiation of a light source through mercury vapor with a selected isotopic composition. So, for example, at the first stage of radiation, a lamp filled with the Hg-198 isotope can be passed through an isotope filter filled with mercury vapor, from which the Hg-198 and Hg-201 isotopes are extracted.

 The implementation of the invention will allow to obtain all mercury isotopes of high enrichment.

Claims (3)

 1. The method of photochemical separation of mercury isotopes, comprising irradiating the initial mixture of mercury isotopes with the light of a mercury lamp in the presence of oxygen and butadiene and extracting the target isotopes, characterized in that the initial mixture of isotopes is irradiated with light of a mercury lamp with a wavelength corresponding to the radiation of the Hg-198 isotope, s obtaining a dump depleted in the Hg-198 and Hg-201 isotopes and a mixture enriched with the indicated isotopes, and the resulting mixture of isotopes is separated by irradiating it with the light of a mercury lamp with a wavelength corresponding to the radiation of the isotope H g-199 and / or Hg-204.  2. The method according to p. 1, characterized in that the dump depleted in the Hg-198 and Hg-201 isotopes is irradiated with the light of a mercury lamp with a wavelength corresponding to the radiation of the Hg-199 and / or Hg-204 isotope, to obtain a dump depleted Hg-199 and Hg-204 isotopes, and a mixture enriched with the indicated isotopes, and the resulting mixture is separated by irradiating with a mercury lamp with a wavelength corresponding to the radiation of the Hg-196 isotope.  3. The method according to p. 1, characterized in that the dump depleted in the Hg-198 and Hg-201 isotopes is irradiated with the light of a mercury lamp with a wavelength corresponding to the radiation of the Hg-196 isotope and / or Hg-200 and / or Hg -202, to obtain a mixture of isotopes Hg-199 and Hg-204, which is separated by irradiating the light of a mercury lamp with a wavelength corresponding to the radiation of the isotope Hg-196.

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