Fundamental Studies on Uranium Oxides. I : Equilibria among UO_2, U_4O_9 and U_3O_8 at 360〜580℃
スポンサーリンク
概要
- 論文の詳細を見る
Oxidation and reduction equilibria of the composition range of UO_2-U_3O_8 were measured with a flow method at 360〜580℃ and the results are summarized as follows : In the composition range of UO_2-U_4O_9 there are two regions : homogeneous region in which oxygen dissolves in UO_2, and heterogeneous region containing UO_2 saturated with oxygen and U_4O_9. The former was found to exist also at lower temperature as Willardson et al. had suggested. In this region Henry's law can be adapted between oxygen potential and solubility of oxygen in solid. The temperature dependence of equilibrium constant is as follows : O[UO_2]=1/2O_2(g), logK=-10, 387/T+19.95logT+0.0391T-86.31. The empirical formula expressing the solubility limit of oxygen in UO_2 phase is given as a function of temperature, [O]= 0.11176 ・ 10^<-4>T^2-1.9465・10^<-2>T+8.479, and the temperature dependence of oxygen potential is given by the following equation 2U_4O_9=8UO_2 (saturated with O)+O_2, logPo_2=-26, 814/ T+19.51 logT+0.02151T-61.18. The composition range of U_4O_9-U_3O_8 can be regarded as a homogeneous solid solution. By using the activities of U_3O_8 and U_4O_9 in solid phase, the temperature function of equilibrium constant is calculated as follows : 8/5U_3O_8 (in solid solution)=6/5U_4O_9 (in solid solution)+O_2, logK=-12, 581/T-6.592logT+0.0627T-35.69. Furthermore, an equilibrium diagram of the uranium oxide-oxygen system was given in this temperature range.
- 東北大学の論文
著者
-
KIGOSHI Akiichi
The Research Institute of Mineral Dressing and Metallurgy
-
SUDO Kingo
The Research Institute of Mineral Dressing and Metallurgy
関連論文
- Fluidized-Bed Roasting of Pyrite
- Fundamental Researches on Smelting of Sulphide Ores. XI : On the Equilibria in the Reductions of Solid Nickel Sulphides by Hydrogen Gas
- On the Dissociation Pressures of Germanium Sulfides
- Fundamental Researches on Smelting of Sulphide Ores. I : Experimental Apparatus and Method of Measurement
- Fundamental Studies on Uranium Oxides. I : Equilibria among UO_2, U_4O_9 and U_3O_8 at 360〜580℃
- Studies on Treatment of Uranium Ores. I : Leaching of Uranium Ore from the Matsuiwa Mine
- Studies on Treatment of Uranium Ores. II : Recovery of Uranium from Leach Liquors of a Uranium Ore from the Matsuiwa Mine
- The Behavior of Silicon and Aluminum in the Nitrofluor Process
- Fundamental Studies on Uranium Oxides. II : Equilibria among UO_2, U_4O_9 and U_3O_8 at 500〜1, 200℃
- The Extraction of Niobium and Tantalum from Columbite by the Nitrofluor Process
- The Recovery of Beryllium from Beryl by a Nonaqueous HF-NO_2 Solution
- The Recovery of Titanium from Ilmenite by the Nitrofluor Process
- Fundamental Researches on Metallurgical Treatment of Manganese Ores. I : On the Equilibrium in the Reduction of Mn_3O_4 with CO.
- On the Dissociation Pressure of Pyrite
- Fundamental Researches on Smelting of Sulphide Ores. IV : On the Equilibrium in the Reduction of Solid Lead Sulphide by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. IX : On the Equilibrium in the Reduction of Sulphur in Molten Tin by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. VIII : On the Equilibrium in the Reduction of Solid Stannous Sulphide by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. VI : On the Equilibrium in the Reduction of Solid Cuprous Sulphide by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. X : On the Equilibrium in the Reduction of Sulphur in Molten Lead by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. V : On the Equilibrium in the Reduction of Solid Cobaltous Sulphide by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. VII : On the Equilibrium in the Reduction of Copper Sulphide in Molten Copper by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. III : On the Equilibrium in the Reduction of Solid Silver Sulphide by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. II : On the Equilibrium in the Reduction of Solid Ferrous Sulphide by Hydrogen Gas
- Fundamental Researches on Smelting of Sulphide Ores. XIV : On Molten Copper Sulphide