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Kataev E.A.,TU Chemnitz | Pantos P.,University of Texas at Austin | Karnas E.,University of Texas at Austin | Kolesnikov G.V.,Moscow State University | And 3 more authors.
Supramolecular Chemistry

Cyclo[8]pyrrole, an octapyrrolic expanded porphyrin with no meso-linking atoms, was found to interact with a series of anions in the solid state and in a chloroform solution. The anion selectivities have been determined relative to a structurally characterised salt, H2cyclo[8]pyrrole2+·I-·I3-, via counter anion exchange. Although cyclo[8]pyrrole demonstrates a general selectivity for sulfate, it interacts well with both the pertechnetate and perrhenate anions. Moreover, it has been shown to act as a phase-transfer catalyst facilitating the extraction of pertechnetate from an aqueous to an organic phase in the presence of sulfate. © 2014 © 2014 Taylor & Francis. Source

Ermakov A.V.,Ural Innovation Technologies JSC | Panfilov A.M.,Ural Federal University | Batorshin G.Sh.,Production Association Mayak | Ryabov B.I.,Production Association Mayak | Bugrov K.V.,Production Association Mayak
Tsvetnye Metally

Purification of processed platinum group metals from a small content of radioactive elements (plutonium, thorium, uranium etc.) is often complex because of extremely low content of radioactive elements and their fairly equal distribution across the whole matrix of the base metal. In this case, traditional methods of purification and deactivation, used by Rosatom enterprises, become ineffective. Capability of effective purification of secondary platinum from radioactive pollution by methods of fire purification is shown. There were considered two methods of platinum purification from plutonium by the plutonium conversion into gas or slag phases. There was established, that conversion of plutonium in oxide form into the slag phase is more preferable. According to this, minimum loss of platinum is an apparent advantage of this method. For a score of reasons, both methods of platinum purification were used in practical application. The method of plutonium removal through its conversion into the slag phase has proved its efficiency and economic reasonability. Technology of fire purification of radioactively polluted platinum was developed on the basis of experiments, carried out at the Production Association "Mayak" ("Rosatom" Corporation). This technology was realized, using the inclusion of preliminary hydrometallurgical purification of platinum scrap surface from impurities of non-ferrous metals (Cu, Ni) into the technical plan. Source

Stefanovsky S.V.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Stefanovskaya O.I.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Kadyko M.I.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Remizov M.B.,Production Association Mayak | And 3 more authors.
Doklady Physical Chemistry

The effect of the method of synthesis on the structure of aluminophosphate glasses intended for immobilization of high level waste from uranium–graphite channel reactor spent nuclear fuel reprocessing has been studied by X-ray powder diffraction and Fourier transform IR spectroscopy. Slow cooling in a furnace, both spontaneous cooling in a switched-off furnace and cooling simulating the conditions of glass cooling in their disposal canisters, or additional heat treatment (annealing) led to partial crystallization of glasses with segregation of different modifications of aluminum orthophosphate. For orthoand pyrophosphate based glasses with similar anionic motifs, their phase composition and degree of crystallization depend not so much on the chemical composition of a sample as on its heat treatment history. © 2016, Pleiades Publishing, Ltd. Source

Zilberman B.Ya.,Khlopin Radium Institute | Makarychev-Mikhailov M.N.,Khlopin Radium Institute | Ryabkov D.V.,Khlopin Radium Institute | Shadrin A.Yu.,Khlopin Radium Institute | And 5 more authors.
Theoretical Foundations of Chemical Engineering

We present the results of the computer simulation of a method for better purification of nitric acid from HF and CH3COOH admixtures by creating a stripping section in the fractionation column with HNO3 scrubbing and by the feeding of a parasitic water flow to the bottom section. The production column in the evaporator section of the RT-1 plant at the PA "Mayak" was upgraded using the calculation results and test trials on real process high-level waste were performed, which made it possible to improve the purification of regenerated 12 mol/L HNO3 from HF and simultaneously from HCl by a factor of 3-5. The specification figures for three flowsheet of nitric acid regeneration that were used at different times since 1979 for commer- cial purification from halogens and radioactive contaminants were compared. © Pleiades Publishing, Ltd., 2012. Source

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