DE2143505A1 - Procedure for the decontamination of radioactive liquids - Google Patents

Description

DIPL.-ING. BODO THIELKING

PATENT ADVOCATE

48OO BIELEFELD

ELSA-RRÄNDSTRÖM-STRASSE t-3

TELEPHONE (O521) 6O621 Λ ή / flFrtC

ADVOCATE REFERENCE ·. T_ Q 097 BIELEFELD, AUGUST 26, 1971

Patent application

Applicant: Belgonucleaire SA, Rue des Colonies 35, Brussels ("Belgium)

"Procedure for the decontamination of radioactive liquids"

The invention relates to a method for decontaminating radioactive substances Liquids with the help of mineral substances.

It is known to purify radioactive liquids with the help of ion exchangers. However _, ion exchangers are expensive because they have to be regenerated and the regeneration creates further radioactive liquids (regenerating liquids).

Another known method of treating radioactive liquids is to chemically precipitate radioactive liquids Ions. The precipitate obtained is filtered and mixed homogeneously with hot bitumen. The water present evaporates and the mass thus obtained is stored in steel tanks. Since the precipitation is not easy to filter, it is great Facilities required or the precipitation must after "Freeze-thaw process" (freeze-drying) to be dehydrated to make it easier to filter.

All of these methods also have the disadvantage that they are not designed specifically for radioactive ions, so that the ion exchangers tend to become largely saturated by ions which should not be extracted (for example Ka, Ca, or Mg). It is also possible that the

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Precipitation consists largely of ions that are not extracted v / should be grounded, with such ions always in the to be cleaned .vasser are present.

The invention proposes a new method which is specifically designed for radioactive ions and which it at the same time makes it possible to at least partially avoid the disadvantages of the known methods.

The invention relates to a method for extracting radioactive ions which are contained in small quantities or traces in a contaminated liquid, whereby the Liquid is brought into contact with a mineral substance which is selected from one or more of the following groups originates from: a barium salt, a metal sulfide and a copper ferrocyanide.

Ions like Na, Ca, Mg, Fe, Al are not extracted while however, the radioactive ions are extracted from the liquids to be cleaned.

In fact, experiments have shown that different inorganic substances have specific adsorption properties have when they are in with solutions which contain radioactive ions and especially those ions in trace amounts Be brought into contact.

The term "adsorption" includes as used in this specification is used any means and process by which an ion is transferred from a solution to a solid mineral Substance can be transferred that is in contact with the solution.

The adsorption can, for example, by single or multiple isotopic exchange, through the formation of mixed crystals and especially through precipitation, occurring simultaneously Failures and successive failures can be achieved.

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There is a problem of cojunction of radioactive liquids especially in the extraction of the following ions: strontium, Cesium, cerium, cobalt, ruthenium, radium and antimony,

According to the invention, these ions are preferably by certain Substances adsorbed:

Strontium with a barium salt, radium with a barium salt or a metal sulfide, Cerium by a barium salt or a metal sulfide,

Ruthenium by a barium salt, metal sulfide or copper ferrocyanide,

Antimony by a barium salt, metal sulfide or copper ferrocyanide,

Cobalt by a metal sulfide or copper ferrocyanide, Cesium by copper ferrocyanide.

These salts can be used as simple salts or mixed salts.

Various examples of the invention are described below.

BaSO. by mixing equal volumes of BaCl _? and well _? S0. manufactured; the precipitate formed here is filtered off and dried at 100 ° C. without being washed. The powder thus formed is used to determine the adsorption properties, which are expressed by the distribution coefficient "Kd". The distribution coefficient "Kd" is defined as the ratio of the concentration of the ion on α · 3Γί adsorbent (per gram) to the concentration of the ion iix ~ .e? löcimg (per ml). The experiments were carried out with demineralized water to which the radioactive ions to be determined and 40 ppm (milligrams / kg) Ca were added. The resulting distribution coefficients "Kd"

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for Sr = 7, for Ra = 27 and for Ce = 284.

After adding H ₃ SO to the test water, for example to lower the pH value to 2, the Kd values increase to the following size: for Sr = 1950, for Ra = 3000 and for Ce = 6600.

The mechanism of adsorption can be deduced from these facts. If pure BaSO had adsorptive properties by itself, there would be no difference in the Kd values before and after the addition of H ₂ SO. However, this addition is necessary to achieve good adsorption. On the other hand, it can easily be demonstrated with the aid of the reference solution that the sulfate ions in the solution, which originate from the added sulfuric acid, are insufficient to reduce the solubility product of Sr and Ra to precipitate them as traces.

The reason why Sr and "-Ra _{are adsorbed more effectively after the addition of H 2} SO is perhaps the phenomenon of simultaneous precipitation on newly formed BaSO Barium ions together with the sulfate ions in the solution form an auxiliary BaSO.-deposit on the already existing solid BaSO-. During this formation process, strontium, radium and cerium are precipitated at the same time.

The Kd values can be increased significantly by preparing BaSO, with an abundance of barium ions. The Kd values achieved in this way are listed in Table 1. It is also possible to improve the adsorption properties of BaSO by activating it during the production of BaSO, for example by adding NaNO. The NaNO ^ concentration to be used is to be selected in such a way that a range from one sodium ion for one barium ion to one sodium ion for 24 barium ions is produced. Other concentrations of NaNO ₇ affect that

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Adsorptive capacity of BaSO _{4 is} not favorable.

Table 1
Adsorption of Sr, Ra and Ce on BaSO ₄

Test water = demineralized water with Sr, Ra and Ce and 40 ppm Ca, to which HpSO _{4 is} added until a pH value of 2 is reached.

Composition ",

BaSO ₄ ^Kd

Sr Ra Ce Ca

# Ba / S0 ₄ 1/1 7 27 284 0

Ba / S0 ₄ 1/1 1,950 3,000 6,600 120

2/1 14,000 28,000 ^ 45,000 160

3/1 27,400 39,000 70,000 160

Ba / SO ₄ 3/1. 45,300 73,000 194,000 180

• Kj test water without the addition of HpSO ₄

XxJBaSO. by adding 1 volume fraction of NaNO to 3 volumes

4 0

The percentage of BaCIp activated during the production of BaSO ₄ .

As can be seen from the table above, an abundance of barium ions in the BaSO ₄ adsorbent is necessary for good adsorption properties. While a ratio of 3 barium ions to 1 SO ₄ -IOn results in good adsorption, it should be noted that even higher proportions of barium ions do not improve the adsorption properties any further.

This simultaneous precipitation is very selective and there is practically no calcium precipitate like this can be seen from Table 1. Analogous experiments with demineralized water, the sodium ions and magnesium ions are added show that these ions are not

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isfV3SOS

be canceled early.

From the above considerations it can be seen that this is simultaneous failures occurring during the formation of newly emerging BaSO. he follows. It should be noted that fresh or new BaSO. could also be formed by someone soluble barium salt runs out and SO.-ions are added. Good results have been obtained with BaGO in a sulphate medium. In this way, fresh BaSO. formed and it becomes that together taking place, simultaneous precipitations of strontium, radium and 0er achieved.

The adsorption on BaCO was carried out with the same test water, first under the same acid conditions (pH = 2, HpSO.) As for BaSO., Then in a Na ₉ SO. Medium. The Kd values obtained are summarized in Table 2:

Table 2
Adsorption of Sr, Ra and Ce on BaCO-,

Test water = demineralized water with Sr, Ra and Ce and 40 ppm Ca, pH = 2 achieved by the one listed in column 2

BaCO ₅ = commercially available.

Together
settlement
Adsorbent Sulfate-
medium Sr 300 Kd
Ra Ce 200 Approx BaCO ₅ H ₂ SO ₄ , 500 9,800 8th. 000 40 BaCO, 0.0IN Na ₂ SO ₄ 3. , 300 11,050 52. 000 100 BaCO ₅ 0, IN Na ₂ SO ₄ 30, 38,700 70. 230

This table shows that in a medium of 0.1 N Na ₃ SO _4, the results of the adsorption on BaCO- are comparable with those of Ba / S0 ₄ in a molar ratio Ba / SO ₄ equal to 3/1.

As it is not always economical, large amounts of wastewater in

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a medium of ί), 1 Ν Na ₂ SO. to "treat, according to the invention it is proposed to treat these amounts in an ion exchanger" and the later of this ion exchanger. holdon recovery fluids with BaCO.

It should be emphasized that ruthenium and antimony are also adsorbed on SaCO. It is therefore not necessary for these ions Metal sulfides as described later to be used when BaOO. Is used.

Such a simultaneous failure on a barium rals, however r> hr> n is useful with Sr, Ra and Ce, it can cannot be achieved with all ions which are to be extracted. This is the best way to knock down cobalt with the help of MnS, CuS or PeS as adsorbent “Ruthenium and antimony also precipitate with these sulfides.

According to the invention, the metal sulfides should in this case with one; Prepares an abundance of sulfides or sulfide ions and the adsorption should be carried out in an almost neutral medium (for example with a pH value = 5) because in a strongly acidic medium the sulfide ions would be released as hydrogen sulfide. The received Kd values are shown in Table 3 for

a) MnS produced by using the same volume

by MnSO. and well _? S;

b) MnS made with an abundance of sulfide ions

(2 volumes of Na ₃ S to 1 volume of MnSO.);

c) PeS made using 2 volumes

on 1 volume PeSo ..

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composition 1/1 2 Co sulfide 1/2 10 .000 1/2 30th .000 Mn / S .000 Mn / S Fe / S

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Table 3
Adsorption of Co, Ru and Sb on metal sulfides

Test water = demineralized water with Co, Ru and Sb and 40 ppm Ca

Kd

Ru Sb

2,000 1,600

50,000 26,000

7,000 9,500

It should be noted that cerium and radium are also adsorbed on sulfides; a metal sulfide can also be used for Extraction of these elements from the water can be used.

For the ratio of sulfide ions to metal ions in the adsorbent, an excess of sulfide ions "is necessary and a The ratio of 2/1 is preferably chosen. Larger amounts of sulfide ions do not improve the results.

When using sulfides, the adsorption mechanism is based on the formation of precipitates. Since the alkaline earth Sulphides are water soluble, calcium and magnesium, which are generally found in large quantities in the area to be cleaned Water are present, not precipitated. The adsorption mechanism so is very selective.

However, alkaline earth metal ions influence the adsorption of cobalt on metal sulfides. With the same test water as that 100 ppm Ka were added, experiments carried out give a Kd value for the PeS prepared as above Co = 7,800 instead of 30,000.

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The cobalt adsorption, however, can be critical by adding CaCIp can be improved during the production of FeS. The concentration of the CaClp to be used varies in the range from 1 Ca ion for 1 to 18 Fe ions. The effect such activation on co-adsorption is shown in Table 4.

Table 4

Adsorption of Co on metal sulfides.

Test water = demineralisie.zrtes water rait Go (Ru and Sb), 40 ppm Oa and 100 Na

composition
Sulphides 1/2 CaCl ₂ Aktivxerung Kd for Co Fe / S Ί / 2 CaCl ₂ no 7,800 Fe / S 1/2 CaCl ₀ Ca / Fe = 1/10 11,500 Fe / S 1/2 Ca / Fe = 1/3 24,700 Fe / S Ca / Fe * = 1/2 33,500

The adsorption of radioactive ions, which form insoluble sulphides from the regeneration fluids of Ion exchangers have also been tested with metal sulfides and have been given excellent results with natural iron sulfides such as troilite and pyrite. The adsorption of Ce, Ra, Co, Ru and Sb from the regeneration waters of ion exchangers on Troilit is shown in Table 5 below.

Six liters of a regeneration liquid, which ₂ M NaCl and 0.05 M CaCl 2, to ~ -the Na ₂ SO. up to 0.1 N was added, were mixed with 10 grams of Troilit.

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Table 5

Regenerates "fluid with traces of

cerium

radium

cobalt

Ruthenium

antimony

Percent of adsorption on Troilit (FeS)

99.1 97.3 96.8

96.3 99.3

96

This table shows that Troilit is beneficial for such radioactive Waters can be used which contain no Gs or Sr. It is clear that when Cs or Sr is present Troilit could also be used, provided that that another adsorbent is also used for these ions.

The adsorption of cesium is preferably carried out using copper ferrocyanide, which is obtained by mixing two parts by volume of CuSO. with a volume part of K.Pe (CN) r is produced. This product retains practically 100% of all Cs ions. The specified volume ratio leads to the best results. If required, adsorption on copper ferrocyanide could be activated by adding CaClp to the CuSO during the manufacture of the CUpFe (CN) r.

The above considerations clearly show the selectivity of the products mentioned.

It is actually possible to make the radioactive ones by using a barium salt, a metal sulfide and copper ferrocyanide Extracting ions from contaminated water.

In order to facilitate industrial use of these products, they should have a structure that allows them to be used in industrial apparatus, for example in columns or

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Agitators made easier.

According to the invention, these substances are used during production self-generated sulphides such as PeS, CuS and MnS already have a granular structure, BaSO, and BaCO, are available as fine powders and in this form unsuitable for use in industrial columns. According to the BaSO. given a suitable porm, by preparing it as a mixed product. So BaSO- and CUpFe (GN) ^, which are prepared as a mixed substance, have a good one granular structure and can be used to simultaneously extract strontium, radium, cerium and cesium; Ruthenium and antimony are also extracted.

The following example indicates a preferred production process for this mixed substance: 300 parts by volume of 1 molar Ka _n SO ^ ₁ are added to 150 parts by volume of 0.1 molar CuSO *. While stirring, 945 parts by volume of 1 molar BaCl _{2 are} added to this mixture. 75 parts by volume of 0.1 molar K-Pe (CIfL (0) -g are then added to the resulting precipitate of BaSO. And vigorously stirred for 2 minutes. The precipitate can then form for 1 to 2 hours before it is filtered off. Without a washing process, the precipitate is then dry-dried at 100 ° C. The cake obtained in this way is then ground into grains of the desired size (in the present case sieve size more than 80 meshes). The theoretical composition of the grains is 97.7 $ BaSO. With a Ba / SO. Ratio of 3/1 and 2.3 $ Cu ₂ Fe (CN) ₆ with a Cu ₂ / Pe (CN) g molar ratio of 1 / 1. The granulate is divided into a Column used through which the test water flows.

The Kd values obtained are shown in Table 6.

In addition, the same example has been repeated with: -a.; O _v in a Vi
trains sets ζ wi r d.

:: a.; cu in a ratio of 3 barium ions to 1 sodium ion

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Finally, the same example is repeated, using the NaNO, by GaGIp in a Ve:
a calcium ion is replaced.

NaNO, by GaGIp in a ratio of 3 barium ions

Table 6
Adsorption of Sr, Ce and Cs on a mixed adsorbent

Kd 32 Cs Ce 55 .100 7,850 .000 45,000

Test water = demineralized water with Sr, Ra, Ce and Cs, 100 ppm Na and 30 ppm Ca, H ₃ SO ₄ added up to pH = 2

ÄST activation

Sr

none 2,560

97.7 10 BaSO ₄ / NaNO ₃ : Na / Ba = 1/3 1 "5,800 2.3 * Cu ₂ Fe (CN) _{6 OaG1} ^ . 0a / Ba = 1/3 9,150 31,500 63,750

Kd for Ra was not determined.

These examples clearly show the importance of the activation of the adsorbents.

The mixed adsorbents of BaSO ₄ and MnS have a good granular structure, MnS being the structure of BaSO. forms.

Another adsorbent that can be used according to the invention consists of BaCO and Cu ₂ Fe (CN) ₆ . In contrast to the above-mentioned mixed _{product containing BaSO 4, the BaCO 4-} based mixed salt is still a fine powder, so that the contact between the mixed product and the waste waters to be treated will have to be carried out batchwise. The adsorbent can be prepared, for example, as follows:

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On the one hand, a part by volume of 1-molar BaGl _{2 is added to} a part by volume of 1-molar em Na ₀ OO., And homogeneous precipitation is allowed. On the other hand, one part by volume of 1-molar K-Pe (GN) _{6 is added to} two parts by volume of 0.1-molar CuSO-2 and homogeneous precipitation is permitted. Both precipitates are mixed, stirred and dried without a washing process. This preparation leads to a mixed adsorbent, the 91fo BaGO., With a molar ratio Ba / Co., Of 1/1 and 9 $ Gu ₂ Pe (CN) ₆ with a molar ratio Cu ₂ / Pe (GN) ₆ of 1/1 contains. The Kd values on these adsorbents are determined with the same test water as used in Table 6, and these values are shown in the table below.

Table 7

Sr Kd 12th Cs 120 Ge 30th .500 Io 630 17,720 .700 8th. 56,200

The pH value 2 was achieved in a medium according to "" Spl ^ ate 2 (5 g of adsorbent were mixed with 1 1 for 15 min and then centrifuged)

composition
Adsorbent medium

91 $ BaCO, and H ₃ SO ₄

9 % Cu ₂ Fe (CN) ₆ 0.0IN Na ₃ SO ₄

0, IN Na ₂ SO ₄ 20,460 59,600 77,000

Ruthenium, antimony and cobalt are also adsorbed on this adsorbent. Further examples will explain the result obtained. This table shows the excellent results in a medium of 0.1 N Na ₂ SO ₄₀ As already mentioned in the description, it is not always economical to use large amounts of waste water in a medium of 0.1 N Na ₀ SO- to be treated. According to the invention, it is therefore proposed to treat the waste water in ion exchangers and also to treat the regeneration liquids later obtained from the ion exchangers

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treat this adsorbent.

Since the adsorbent is effective in a concentrated saline solution, there is an answer to the problem of decontamination of regeneration fluids for ion exchangers.

Ion exchangers have often been proposed for decontaminating radioactive liquids. To date, however, they have not been practical due to the problems that have arisen from the decontamination of their regeneration fluids. This is actually waste water with radioactive ions in a concentrated saline solution. With the help of a mixed BaGO., - Cu ₂ Fe (CN) / - - adsorbent, these regenerating liquids can be treated easily and effectively without any further problems.

The adsorbent is used in a sulphate medium when strontium is present in the wastewater to be treated. In fact, it has been found that the sulfate concentration affects the adsorption of various radioactive ions. Table 8 shows the influence of the sulfate concentration when using the above-mentioned BaCO ^ -Cu ₂ Fe (CN) g adsorbent. The test water contains a concentration of 2 molar NaCl and 0.05 molar CaCl ₂ as well as traces of Cs, Sr, Ce, Ra, Co, Ru and Sb. 3 g of adsorbent were added to 1 l of test water and for one hour before filtering mixed.

Table 8

In traces in percent of the adsorption m: j.t a sulfate concentrate- ' Regeneration of

liquid

Included 0.01 N 0.025 N 0.05 N 0.1 N 0.125 N 0.15 N

QEsium 99.0 % 99.3 1 " 99.5 # 99.5 # 99.2 # 99.5 #

Strontium 36.5 ⁰ A 80.0 % 94.1 "/> 97.0 fo 97.7 i> . 98.0 f

Cer 98.5 $ 98.9 % 99.3 # 99.5 1 ° 99.2. % 99.3 %

Radium 97.0 <fa 97.2 # 97.6 $> 97.4 # 97.6 $ 97.3 %

Cobalt 94.2 <f ° 93.4 # 93.1 # 95.3 $ 95.1 $ 94.7 #

Ruthenium 96.4 % 97.1 £ 97.5 % 97.0 £ 97.1 % 96.8 %

Antimony $ 97.2> 97.9 # 97.8 % 97.9 1 » 97.8 <? <> 98.0%

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liior.c Ta-hp] l (? shows clearly that the adsorption of Sr is particularly a puncture of the ujfat concentration. A concentration of 0.1N IJa ₂ SO. is preferable, since higher concentrations lead to the Bi 1: 1 us; von OaSO .. It should also be noted that carbonates are generally soluble in an acidic medium, so that a pH of more than 3.5 is indicated, especially the experiments described above with a mixed adsorbent were carried out which 91 $> BaOO- and 9 contained io CUpFe (ON) _6, other ratios of these salts.

Table 9 shows the adsorption of radioactive ions on Cu ₀ Fe (CN ) _r on one side, on BaCO., On the other side and on a mixture of 91 ° BaCO, and 9 ° / ° Cu ₂ Fe (CN) ₆ . The test water contained 2 molar NaCl and 0.2 molar CaClp in addition to Cs, Sr, Ce, Ra, Co, Ru and Sb. Na _? S0. was added up to 0.1 N and the adsorbent was added in a ratio of 7 g of adsorbent per liter of water.

Table 9

Decontamination? in percent

Isotopes CUpFe ( 96.07 fesium 12.00 strontium 63.10 Ger 75.30 radium 23.20 cobalt 98.08 Ruthenium 98.33 antimony

) r BaCO, 91% BaCO, & 9% Cu ₀ F

26.11 io 99.77 io

86.79 io 95.05%

99.42 io 99.76%

97.57% 99.64%

47.49% 94.60%

96.81% 98.90%

■ 98.69 ⁰ Jo 98.90%

This table shows that Ru and Sb are adsorbed by both components, while Gs is mainly adsorbed by Cu ₂ Fe (CN) ₆ . Ce and Ra, on the other hand, are mainly adsorbed by NaCü ^. The ratio of the mixed adsorber-TI-TiS should be specific with regard to the adsorption of

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Sr and Oo are seen. It has been found that for good adsorption of Sr least 90 fo BaCO, mixed adsorbent must be present.

The same ratio leads to good results for Co; it could also be increased to a ratio of 85 % BaCO and 15 ^c p CUpFe (CN) g. In view of the radiological toxicity, however, a mixed adsorbent containing at least 90 fo BaCO., Is preferable in order to ensure the adsorption of a maximum amount of Sr.

Further examples for the adsorption of radioactive ions, which in the regeneration fluids of ion exchangers used to decontaminate radioactive wastewater are described below.

A wastewater with the metal ions B 2 pp "m, Mn 0.16 ppm, Fe 0.2 ppm, Mg 1.15 ppm, Si 2.55 ppm, Ca 41 ppm, generally 112 ppm, Sr 0.06 ODm and K 6 , 4 ppm, which is in addition to the isotopes Ce ¹⁴⁴ 'Ru ¹⁰⁶ ' Os ¹⁵⁷ , Zr ⁹⁵ , Nb ⁹⁵ 'Co5 ⁸ , Co ⁶⁰ , Mn ^ _{and S} r ⁹ °

was passed through a column at pH 3 which contained a synthetic ion exchanger in sodium form (amberlite IR-120). After 350 volumes of waste water were gone, the water was up to the following values W decontaminated:

Sr ⁹⁰ = 99.7 io
Ru ¹⁰⁶ = 95.6 io
Cs ¹³⁷ = 94.1

⁵⁸ = 100 % and Co ⁶⁰ = 98.3 ¹⁴⁴

Co

Ce ¹⁴⁴ = 100 %

Zr ⁹⁵ + Nb ⁹⁵ = 100 io

Mn ⁵⁴ = 100 io

The ion exchanger was regenerated with seven parts by volume of 4 molar j \ iaül. The pH value of the regenerant fluid is raised to 3.5 and ₀ Na SO. becomes up to 0.1N to- ·: Γ.ηΐ; _t.

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10 g of the mixed adsorbent 91 1 ° BaCO, - 9 1 ° , 1 1/2 l of the waste water are added, the mixture is stirred for one hour and centrifuged for 10 minutes. The water was tested and found a G-amma decontamination of $ 95.1, a Beta decontamin

taminated.

98.7 % decontamination and 98.6 % decontamination for Sr

Another wastewater, which contains the metal ions Bl ppm, Mh 0.09 ppm, Pe 1.3 ppm, Mg 0.9 ppm, Si 2 ppm, Al 1.95 ppm, Ca 61.5 ppm, Na 38 ppm, Sr 0, 1 ppm and K 6.5 ppm, additionally containing the isotopes Ce ¹⁴⁴ , Ru ¹⁰⁶ , Cs ¹⁵⁷ , Zr ⁹⁵ , Nb ⁹⁵ , Co ⁵⁸ , Co ⁶⁰ , Mn ⁵⁴ and Sr, rooted through a column containing the same ion exchanger as in the previous example. After 625 parts by volume of the wastewater had run through, the water was purified with 94.8 $ gamma-beta decontamination and 97.8 Jo Sr - decontamination.

The ion exchanger was then regenerated with 12.5 parts by volume of 2-irolar NaCl. The pH of the regeneration liquid was raised to 6.5 by adding NaOH and Na _? SO. was added to 0.1N. 10 g of the mixed adsorbent 91 $> BaCO, - 9 $> Cu ₂ Pe (CN) ₆ were added to 2 liters of the waste water, stirred for one hour and then filtered. In the subsequent test, a gamma

90 iieta decontamination of 97.7 % and one Sr - decontamination

90 renation of 99.8 <fo. The last example shows that Sr decontamination was more effective with a pH of 6.5.

The above-mentioned adsorbents can also be used for the extraction of other radioactive ions contained in some Types of radioactive water may be included, such as TJ, Pu and I. Experiments have shown that II and Pu are mixed with the help of a Adsorbent made from BaSO. and a metal sulfide, can be extracted. On the other hand, iodine on CuSp and CuJ /, being knocked down. In this pail, CuS must have a

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Abundance of Gu ions can be produced. When iodine in radioactive It contains liquids from which ruthenium, cobalt and antimony could also be extracted CuS first with an abundance of Cu ions and then with one Abundance of sulfide ions can be produced.

Both copper sulfide grains can be mixed and hold back iodine as well as ruthenium, cobalt and antimony.

It will be understood that the invention can be used by one skilled in the art in many different ways and for many different applications can be used.

As an example of such a special application, radium could be extracted from solutions with a high concentration of Na ions. Such solutions appear in the waste liquids resulting from the separation carried out after the production of actinium starting from radium. Such solutions have a 6 molar Na concentration and contain amounts of radium that are worth recovering. For this purpose a mixed adsorbent, the 50 i <> BaSO. with a ratio of Ba / SO, of 2/1 and 50 % MnS with a ratio of Hn / S of 1 / l. The cake obtained was dried at a temperature of about 300 ° 0 to obtain a hard precipitate. It was then ground into a grain size suitable for use in columns. From the highly concentrated sodium solution which ran through the columns were more> radium ions separated than 99 "/.

Table 10 summarizes the preferred "activated adsorbents" for removing radioactive ions from contaminated ones Liquids.

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Adsorbent

BaGO ₅
Metal sulfides

Cations Sr Ra Ce Ru Sb Go Gs

X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X

• ■: p: 'O ₄ / metal sulfides χ

Also other ions, for example U, Pu, I, Zr, Wb and Mn can be adsorbed with the inventive method,

- patent claims -

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Claims (1)

ID 097-20-26 August 1971 Claims 1. Method of extracting radioactive ions, particularly in "trace amounts of ions contained in a contaminated Liquid, characterized that the liquid is brought into contact with a mineral substance, which consists of one or more consists of the following group; a barium salt, a metal sulfide and copper ferrocyanide. 2, The method of claim 1 for extracting strontium, radium and / or cerium, contained in particular in trace amounts in a liquid, characterized in that the liquid with ^~:: ariumsulfat is brought into contact, the one an excess of barium in contains medium containing sulphate. 5. The method according to claim 2, characterized in that that the barium sulfate has a ratio of 3 barium ions to 1 sulfate ion on v / e. 4. The method according to claim 2 or 3, characterized characterized in that the sodium nitrate is added to the barium sulfate in such an amount that the mix result contains 1 sodium ion for 1 to 24 barium ions. 5. The method according to claim 1 for extracting one or more of the substances strontium, radium, 0er, ruthenium and Antimony, which is contained in a liquid in particular in traces, characterized in that that the liquid is brought into contact with a barium carbonate in a Juüfatnodium. 2 09810/1362
BAD ORiGINAL ffstT 097-21-26 Aug 6. The method of claim 1 for extracting one or more of the: "'. Toffe cobalt, ruthenium, antimony, cerium and Radium, which is contained in liquids in particular in trace amounts, characterized in that that the liquids are brought into contact with a metal sulphide which contains an abundance of sulphide ions. 7. The method according to claim 6, characterized in that the metal sulfide is a manganese sulfide with a ratio of 1 manganese ion to 2 sulfide ions. 8. The method according to claim 6, characterized in that the metal sulfide is an iron sulfide with a ratio of 1 iron ion to 2 sulfide ions. 9. The method according to claim 8, characterized in that that calcium chloride is added in an amount such that in the resulting mixture one calcium ion for every 1 to 18 iron ions. 10. The method according to claim 1 for adsorbing ions of one or more of the substances cesium, ruthenium and antimony, which are contained in liquid in particular in trace amounts, characterized in that the liquids come into contact with copper ferrocyanide brings v / earth. 11. The method according to claim 10, characterized in that that calcium chloride is added to the copper ferrocyanide. " 12. The method according to claim 1 for extracting one or more of the substances strontium, radium, cerium, cesium, Ruthenium and antimony, especially in trace amounts are contained in liquids, characterized that the liquids with a - 22 - 209810/1362 BATHROOM ^ 2H3505 097-22-26 August 1971 mixed adsorbent, which from barium sulphate with a ratio of 3 barium ions to 1 sulphate ion and from copper ferroeyanide with a ratio consist of 3 cupping ions to 1 ferrocyanide ion in a sulphate-containing medium. 13. The method according to claim 12, characterized. draws that sodium nitrate is added, so that the resulting mixture contains from 1 sodium ion to 1 to 24 barium ions. 14. The method according to claim 12, characterized in that calcium chloride is added, so that in the resulting mixture there are 1 calcium ion for 1 to 20 barium ions. 15. The method according to claim 1 for extracting one or more of the substances cesium, strontium, cerium, radium, Cobalt, ruthenium and antimony, which are particularly contained in trace amounts in liquids, thereby characterized that the liquids with ■ brought into contact with a mixed adsorbent, the BaCO, and CUpFe (ON), - in a sulphate-containing medium contains. 16. The method according to claim 15, characterized in that at least 90 "/ ο of the mixed adsorbent 3a00. Is. 17. The method according to claim 1, characterized in that the contaminated liquids the regeneration fluids of an ion exchanger previously used to decontaminate radioactive waste water are. 209810/1362 BAD ORfGf!