|Министерство науки и высшего образования РФ|
|Программа повышения конкурентоспособности|
|Наука и образование против террора|
|Оформление социальной студенческой карты|
|Study in Russia|
|Уникальная научная установка НЕВОД|
|Международная олимпиада для студентов|
|Олимпиада «Я - профи»|
От каф. 19 представлены стендовые доклады на Международную конференцию по физико-химическим процессам в атомных системах INTERNATIONAL WORKSHOP ON PHYSICAL AND CHEMICAL PROCESSES IN ATOMIC SYSTEMS, November 15-17, 2015, Moscow, Russia
08.12.2015 Доклады, представленные на Международную конференцию по физико-химическим процессам в атомных системах:
LITHIUM SALTS SOLVATION IN ORGANIC SOLVENTS
For understanding the behavior of lithium isotopes separation the state of its salts in different environments must be known. Currently, there are experimental data for solutions of various osmotic coefficients of lithium salts in alcohols and other organic solvents. The equations of the solutions cluster model relating osmotic coefficient with salt concentration are proved in the present study. The equations consider the contributions of solvation, ionic and molecular association to the nonideality solutions. They contain 2-3 adjustable parameters. It was found that the solvation defines nonideality solutions of lithium salts in methanol. The nonideality ssolutions in ethanol and other solvents are mainly due to ionic association. The anion effects on the lithium salts solvation discussed.
ANALYSES OF LIQUID - VAPOR EQUILIBRIA ON BASE THE CLUSTER MODEL OF SOLUTION
The distribution of substances between the liquid and vapor are widely used for the separation of mixtures. In this paper analysis of the equilibrium distribution of substances between the phases carried out by the example of systems, which exhibit positive deviations from Raoult's law because of the association of one of the components. It is assumed that the solution formed associates and solvent is the ideal associate. The equation relating the vapor pressure above the solution to its composition are founded. It contains two adjustable parameters: the association number and variance of the distribution of stoichiometric coefficients associates in the standard state. For example, certain mixtures of aliphatic alcohols with organic solvents (halides, ethers, esters of organic acids) found that the equation of the model describes the vapor pressure of the composition are better than the equations many models solutions. The regularities of association of a number of biologically active compounds in aqueous solutions are discussed.
EXTRACTION SEPARATION OF RARE EARTH ELEMENTS BY TRIALKYLMETHYL-AMMONIUM NITRATE AND ITS MIXTURES WITH OTHER SOLVENTS
Separation of rare earth elements (REE) is difficult even by liquid-liquid extraction. The report summarizes the results of studies of the extraction of REE ion-exchange extractant nitrate trialkyl(C7-C9)methylammonium (TAMAN) and its mixtures with different solvents. The optimal conditions for the extraction of REE: nitrate solutions with a concentration of REE in the aqueous phase of 200 - 300 g/dm3, of nitric acid of 0.001 - 0.1 mol/dm3. The degree of extraction increases with the introduction of nitrate salts in the aqueous phase (LiNO3, NH4NO3, Ca(NO3)2 etc.) and decreases in the series of lanthanides from lanthanum to lutetium. The mixture, containing 50 - 70% of tributylphosphate (TBP) and 10 - 20% TAMAN in an inert diluent, recommended for the separation of samarium and gadolinium. When using mixtures of TAMAN with a cation exchange extractants (di-2-ethylhexylphosphoric acid or branched fatty acids) possible to separate yttrium from other rare-earth elements in the single stage process.
SOME PECULIARITIES OF EXTRACTION OF RARE EARTH ELEMENTS FROM APATITE CONCENTRATE
Kola apatite contain up to 1% of the mass. rare earth elements (REE). Given the scale processing (about 10 mln. tons.), apatite could be a significant source of rare earth compounds in the Russian Federation. The most attractive is the extraction of REE from nitric-phosphoric acid solutions. For purification of REE from impurities of phosphorus and calcium previously investigated methods of extraction by tributylphosphate in the presence of nitrate salts. Due to the risk of explosion by evaporation of solutions of ammonium nitrate and to reduce costs, the authors investigated and recommended the extraction process using a melt of calcium nitrate – waste nitric-acid processing of apatite. The optimal conditions of the process: the concentration of the melt of calcium nitrate 400-500 g/dm3 , of nitric acid is 1.0 - 1.3 mol/dm3 , the extractant - 100% TBP. The extraction technology includes the stage of extraction, washing and reextraction.
WATER TREATMENT FOR NPP BY ION EXCHANGE
When using water-cooled RBMK reactors is necessary to prevent the formation of deposits on the heat exchanger tubes. The report summarizes the results of studies process water treatment by magnet and ion exchange. The filter elements based on the ion exchange resin with porosity 1,5-2.0 micron are used. The predominant crystallographic modification of calcium carbonate in which it is released by heating the water treated in this way is found to be aragonite. Crystal formation occurs primarily in the volume of cooling water rather than on the surface of the heat exchanger.