Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: L. Fucugauchi x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

An effective modification of the chemical processes has been obtained to dissolve uranium(IV) and extract it as uranium triperoxocomplex, which facilitates its manipulation and final conversion into uranium nitrate as a high purity concentrate.

Restricted access

Abstract  

In order to determine the best conditions for removing95Zr from uranium/hydrogen carbonate solutions, the adsorption behavior of fission product95Zr on hydrated MnO2 as a function of HCO 3 ion molarity has been studied both in the presence and absence of uranium. Batch experiments showed that the maximum95Zr uptake occurred at low HCO 3 concentration, both in uranium-free and uranium (at a constant molarity of 0.02) containing solutions, the relative95Zr uptake being lower when uranium was present in the solution. Conversely, when the HCO 3 concentration augmented beyond 0.10M, the95Zr uptake was higher for the uranium containing solution. Concerning this last case, the maximum95Zr uptake was found at a 0.06M HCO 3 concentration. However at this HCO 3 concentration, uranium was observed to precipitate and thus, a HCO 3 concentration of 0.12M was chosen to perform the dynamic95Zr removal by MnO2 from uranium/hydrogen carbonate solutions. Under these conditions, the95Zr removal reached 99%.

Restricted access

Abstract  

It has been established that the coexistence of chemical species structurally different from cerium, is a direct consequence of the time taken for its preparation. Its practical applications, within the scope of purifying uranium, may constitute the most important technological aspect in the process of ionic exchange, to separate141Ce from uranium.

Restricted access

Abstract  

The Na4UO2(O2)3·8H2O complex was prepared from aqueous systems and its crystallographic and chemical structural conformation characterized. IR spectroscopy and X-ray diffraction were used for analyzing the solid crystal extracted with ethanol to determine the anionic compositon. Composition of the solid phase did not depend on the molar ratio of the reactants or on the pH of the medium, but only upon the absolute concentrations of uranium and alkali. It was observed that the temperature significantly influenced the crystal structure of the product and that a limit to the UO2 concentration existed for inducing the production of a mixture of soluble and insoluble species.

Restricted access

Abstract  

A number of ammonium uranates have been obtained, all of them different in their X-ray diffraction patterns. This contribution attempts to demonstrate that different series of compounds can be produced depending on the preparation method. The ammonium uranates were precipitated from solutions of uranyl nitrate using gaseous ammonium to determine the effect of precipitation pH on their composition and morphology.

Restricted access

Abstract  

The chemical effects of98Mo(n, )99 Mo reaction on molybdenum(II) chloride [(Mo6Cl8)Cl4] have been studied. Retention, thermal and radiolytical annealing were determined. It was found that this molybdenum compound has low retention, a negligible tendency to thermal annealing and a virtual insensitivity to hydrolysis. For practical application in the enrichment of99Mo by the Shilard-Chalmers method, molybdenum(II) chloride [(Mo6Cl8)Cl4] appears to offer good prospects.

Restricted access

Abstract  

An effective method to minimize the presence of141Ce in the final hexahydrated uranyl nitrate recovery product has been obtained. This condition is considered as one prepurification stage in the recovery process of residual nonfissioned uranium in the production of99Mo of fission.

Restricted access