铀与氧气和二氧化碳的程序升温反应行为研究

Study on Uranium Temperature Programmed Reaction With O_2 and CO_2

利用程序升温分析方法研究了铀与氧气和二氧化碳的反应行为(TPO)。结果表明:在两种气氛中的反应过程均存在诱导期;当氧气分压处在16%～45%范围内时,铀的着火点温度为581～606K,中间产物为UO2,最终产物为U3O8;铀在CO2气氛中的着火点温度相对较高,在反应过程中,CO2解离产生CO气体;反应的表观活化能随气体浓度的升高而降低。

The reaction of U(UO_2) with O_2 and CO_2 was studied by temperature programmed analytical technology. The experimental results show that there is an inducement-term in the reaction of U(UO_2) with O_2 and CO_2. The ignition temperature(T_0) varies between 581 and 606 K at different concentrations of oxygen(16%～45%), the major intermediate product is UO_2 and the final product is U_3O_8. The T_0 of carbon dioxide is higher than that of O_2 and the CO_2 dissociates into CO during the reaction. The results also indicate that the apparent activation energy reduces with increase of gas concentration.