Extraction processing of concentrated solutions of uranyl nitrate with high impurities content

Process flowsheet of recycling uranium concentrated solutions with its purification from insoluble impurities of iron, silicon, molybdenum, calcium oxides and hydroxides and soluble impurities with application of centrifugal extractors cascade has been developed and suggested for commercial introduction. The process was carried out at extractant saturation (30 % tributyl phosphate in hydrocarbon diluent) in extraction assembly lower than a limiting level (85...95 g/l) and in wash assembly - at limiting saturation (up to 120 g/l). As a result the waste uranium content in water-tail solutions 0,01...0,04 g/l and minimal content of impurities in re-extractors is provide

ELECTRONIC STRUCTURE OF FeSi

The full set of high-energy spectroscopy measurements including X-ray photoelectron valence band spectra and soft X-ray emission valence band spectra of both components of FeSi (Fe K_beta_5, Fe L_alpha, Si K_beta_1,3 and Si L_2,3) are performed and compared with the results of ab-initio band structure calculations using the linearized muffin-tin orbital method and linearized augmented plane wave method.Comment: 11 pages + 3 PostScript figures, RevTex3.0, to be published in J.Phys.:Cond.Matte

The research of uranium monoxide-oxide dissolution process in nitric acid

The kinetics of concentrates of uranium monoxide-oxide dissolution process by nitric acid solutions of 5...9 mole/l in the range of 11...90 °C has been studied. It is stated that initial nitric acid concentration increasing results in some uranium dissolution degree increasing only at the first process stage. Temperature increasing significantly raises uranium dissolution degree at the first stage as well. Uranium dissolution degree increases for all studied temperatures with increasing of the process period. The main feature of the studied process is that while dissolving uranium monoxide-oxide the behavior of iron, molybdenum, silicon additives is adequate to that of uranium. The equation of the reducing sphere describes the uranium leaching process from its nitric acid concentrate

Perspectives of Siberian chemical plant in increasing volumes of uranium concentrates recycling

The purification technology of uranium concentrate of natural isotopic composition developed at Siberian chemical enterprise is basically universal, allows recycling uranium concentrates with different content of impurities and obtaining uranium nitrate solutions corresponding by quality to the international standards requirements to uranium hexafluoride preparation for isotopes ASTM C 787-03 separation and to ceramic fuel ASTM C 788-02 preparation. Uranium reserves in Russia and abroad were appraise

Intensifying separating processes of high-concentration uranyl solutions and fine-dispersed suspended solids

The investigations on intensifying separation processes of highly concentrated uranylnitrate solutions and solid fine-dispersed suspended particles (ferric, silicon, molybdenum oxides and others) applying organic coagulants and flocculants have been carried out. It is shown that in the investigated regions of uranium concentrates of 300...450 g/l, nitric acid of 0,5...3,0 mole/l at optimal temperature 30...50 °С for effective phases separation the introduction of 100...200 mg/l of coagulant FLOQULATTM FL 45 С (or an analogue VPK-402) and 5...10 mg/l of flocculant FLOPAMTM FO 4140 PWG type is enoug