Search / Korean Journal of Chemical Engineering
HWAHAK KONGHAK,
Vol.31, No.6, 767-775, 1993
암모니움 우라네이트의 열분해 및 환원반응
Thermal Decomposition and Reduction of Ammonium Uranate
UO2(NO3)2용액과 NH4OH용액으로부터 제조된 암모니움 우라네이트(AU)를 TG-DTA상에서 질소 및 수소 분위기 아래 열분해 및 환원시켰다. AU의 열분해 및 환원과정중 생성된 중간상들을 X-ray와 IR을 이용하여 조사하였다. 본 연구에서 제조한 AU는 Cordfunke[7]가 분류한 AU의 네가지 형태중 AU II와 AU III의 혼합물로 구성되어 있고, 질소와 수소 분위기에서 다음 메카니즘에 의해 열분해된다. AU III/II→AU II→AU I→A-UO3→β-UO3→α-U3O8. 또 열분해 생성된 α-U3O8는 수소 분위기에서 U4O9을 거쳐 UO2로 전환된다. 본 연구의 결과를 발표된 다른 결과들과 비교하였으며, 나이트레이트 이온이 AU의 열분해에 미치는 영향도 논의하였다.
Ammonium uranate(AU), prepared by the reaction of UO2(NO3)2 solution with NH4OH, was thermally decomposed and reduced in a TG-DTA unit in nitrogen and hydrogen atmospheres. Various inter-mediated phases produced during the thermal decomposition and reduction processes of AU have been investi-gated by X-ray analysis and infrared spectroscope. It was found that AU was a mixture of AU II and AU III classified by Cordfunke[7], and thermally decomposed in both nitrogen and hydrogen atmospheres as the follwing mechanism : AU III/II→AU II→AU I→A-UO3→β-UO3→αU3O8. In the hydrogen atmosphere, α-U3O8 was converted into UO2 via U4O9 phase. The obtained results were compared with the published data, and the effect of nitrate ion on the thermal decomposition AU was determined in the present study.
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