Coprecipitation of uranium and thorium with barium sulfate

Separation and Determination of Neptunium, Plutonium, and Americium Using Coprecipitation with Barium Sulfate

“…Coprecipitation was examined under various conditions: kinds of acid, acidity, and amounts of barium and potassium sulfate in the presence or absence of sodium sulfate. The results show that a smaller amount of barium than that in the previous work [5,6] is sufficient to coprecipitate these actinides quantitatively. If it is necessary, with the knowledge that actinides of only in tri-and quadrivalent states are coprecipitated with All of the chemicals used were of analytical reagent grade; aqueous solutions were prepared from distilled water after being passed through ion exchange resins.…”

“…Addition of sodium ion to the potassium sulfate solution further increased the yield by about 10% as a result of the so-called salting-out effect These results suggest that the presence of both potassium and sodium ions in proper amounts is essential for the quantitative coprecipitation of these elements and that the presence of potassium ion is a primary factor governing the coprecipitation of these actinides with barium sulfate. The pronounced effect of potassium ion may be explained by the formation of a double potassium sulfate of Np(IV), Pu(IV), and Am(III) in analogy with Th and U(IV) [5]. constant at about 110 keV.…”

“…In the previous report [5], the coprecipitation behaviour of uranium and thorium with barium sulfate was investigated with tracer amounts in the range of a few milligram. In the present report neptunium, plutonium, and americium in tracer amounts were chosen as target elements.…”

Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns

“…Literature shows there are different ways to co-precipitate uranium as well as plutonium and americium [21], such as using Ca 3 (PO 4 ) 2 [22,23], CaF 2 [24], Fe(OH) 3 [25] , HTiO [26,27], and BaSO 4 [28] as precipitant. The alkali-earth (typically calcium) phosphate precipitation is often used for actinides co-precipitation from urines and does not require adding chemical species not already present in urines, except ammonia for pH adjustment over 9.…”

Coprecipitation of europium with barium sulphate

“…This material is placed among the most important minerals of the group of sulphates, suitable for the treatment of the radiochemical impurities [6][7][8]. The precipitation of Ra 2+ for example with barite makes the barite scale a radioactive waste commonly called "Naturally Occurring Radioactive Material (NORM)".…”