Mechanism and Kinetics of Thermal Decomposition of Uranyl Nitrate Hexahydrate under the Nonisothermal Conditions

摘要

Thermal decomposition of UO_(2)(NO_(3))_(2)(centre dot)6H_(2)O to U_(3)O_(8) was studied by thermogravimetric (TG),differential thermogravimetric (DTG), and differential thermal (DTA) analyses in combination with gas-chromatographic and chemical methods. The process is described by kinetic data recorded under the non-isothermal conditions. UO_(2)(NO_(3))_(2)(centre dot)6H_(2)O transforms into UO_(3) in eight main stages in the 40-300 deg C range, and UO_(3) into U_(3)O_(8), in three stages with the peaks of weight loss at 580, 620, and 645 deg C.