Tc-ru alloy dissolution method

FIELD: hydrometallurgy.

SUBSTANCE: method involves use of alkali solutions containing excess of oxidant, namely alkali metal metaperiodates, at temperature 70-80є.

EFFECT: enabled dissolution of alloy.

2 ex

 

The invention relates to the field of radiochemistry and can be used in radiochemistry, analytical and preparative chemistry.

Long-lived isotope-99 accumulate in significant quantities in spent fuel of nuclear power plants. Technetium is one of the most problematic components of radioactive waste, with dangerously high migracionnymi abilities in the atmosphere and natural waters. The most promising method for processing technetium is transmutation (burning in nuclear reactors), resulting in obtaining a valuable product - stable platinoid ruthenium. The main consumers of ruthenium are the electronic and electrical industry. Large-scale transmutation of TC in combination with the industrial purification of the resulting ruthenium faded from TC could fully satisfy the requests to this platinoid.

For transmutation of technetium are the target of metallic Cu, which is in the process of irradiation becomes alloy Tc-EN. To separate these items must be pre-dissolution of the alloy Tc-EN. In analytical chemistry for dissolution of metallic technetium used mineral acid (HNO3N2SO4HCl+HNO3), alkaline and neutral solutions of N2About2, bromine water (Analiticheskie the chemistry of technetium, PM, astatine and France. Acclaris, Ash, M.: Nauka, 1966, 307 S.). Known methods of dissolution of metallic ruthenium: fusion with alkalis and oxidizing agents (oxidants are applied KNO3, Na2O2, VAO2, KlO3, KMPO4), oxidation in alkaline medium by hypochlorites, hypobromites, persulfate sodium or potassium, oxidation at neutral and acidic environment periodate potassium [Chemistry of ruthenium. Annabel, Tudapetrol, Age, Oesphageal, Nigalin, M.: Nauka, 1965, 300 S.]. Proposed methods of electrolytic dissolution of metallic ruthenium - anodic dissolution in an alkaline environment [New way of dissolution of ruthenium. Ago, Annabel //inch, 1965, volume 10, issue. 12, s-2601], dissolution of alternating current in a hydrochloric acid medium (by analogy with the dissolution of metallic iridium or rhodium) [Manual on chemical analysis of platinum metals and gold. Swinsburg and other M.: Nauka, 1965, 313 S.]. At the same time, in the literature there are no data about how the dissolution of alloys Tc-Ru.

In the present invention proposes a method of chemical dissolution of alloys Tc-EN in alkaline solutions in the presence of excess oxidant-metaperiodate alkali metal at a temperature of 70-80°C.

The choice of temperature is due to the fact that at temperatures below 70°C process restorereplica low speed, and if the temperature is above 80°begins With thermal decomposition of metaperiodate alkali metals, which leads to a large waste. Excess metaperiodate alkali metals (within the limits of solubility) accelerates the process of dissolution of the alloys of the Cu-Ru.

Example 1

The alloy specimen Tc-34% Ru was dissolved in 2 mol/l KOH in the presence KIO4. Concentration KIO40.4 mol/l, the mass of the dissolved sample of 80 mg, the total solution volume of 25 ml, the solution temperature 80°C, the duration of the process of dissolution 6 hours.

Example 2.

The alloy specimen Tc-34% Ru was dissolved in 2 mol/l NaOH in the presence of NaIO4. The number of NaIO40.3 g, the mass of the dissolved sample 1.1 mg, total solution volume of 10 ml, the solution temperature 80°C, the duration of the process of dissolution 6 hours

The method of dissolution of alloys Tc-EN, namely, that for the dissolution of the alloy used alkaline solutions containing an excess of oxidant - metaperiodate alkali metal, at a temperature of 70-80°C.



 

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1 ex, 1 tbl

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