Stoichiometry of the U3O8 phase formed during calcination of ammonium uranate

Electrical Conductivity of Some Uranium Oxides in the Composition Range UO3—U3 O8 _2

“…Uranium oxides, which have O/U ratio below 3, were prepared by calcination of sample 2 at 500 (sample 4), 600 (sample 5), 700 (sample 6) and 900 °C (sample 7). The formation of these oxides was also confirmed by chemical, thermal and X-ray analyses [10][11][12]. The conductivity cell used was the same as that reported before [13].…”

“…Uranium oxide samples were prepared by the reaction of a nuclear-pure uranyl nitrate Solution, refined from crude uranium concentrate by counter-current extraction through tributyl phosphate, with Analar ammonia liquor (Sample 1), ammonia gas (Sample 2) and urea (Sample 3) to precipitate ammonium uranate, followed by calcination to UO3 at 350°C as described before [10]. Uranium oxides, which have O/U ratio below 3, were prepared by calcination of sample 2 at 500 (sample 4), 600 (sample 5), 700 (sample 6) and 900 °C (sample 7).…”

Effects of washing conditions on the thermal decomposition behaviour of gelled UO3 microspheres

“…this variation is due to the effect of the thickness of the sample. The thickness of the sample has been found to have a pronounced effect on the compound formed during decomposition [17,18]. Dharwadkar [16] mentioned that 3 g samples were used on the holder.…”

Some Aspects on Fluorination of UO2 Using Dichlorodifluoromethane

“…Ammonium uranate was precipitated by urea as described before [5], the following specifications dp = 1.89g·cm 3 , dt = 2.38 gem -3 and uranium content = 87.8%. Uranium dioxide layers, 0.3 -1.0 cm thick, were placed in pyrex dishes and heated at 300 °C for different durations, while passing dichlorodifluoromethane at different flow rates.…”