Study on the Preparation of Uranium Carbides

Abstract

(1) Single phase uranium monocarbide was prepared by the solid-solid reaction uranium hydride and carbon above 900°C. At 1, 100°C the reaction completes in 2 hr. The sample form and the graphitization degree of carbon have little effects on the reaction rate. The activation energy of the reaction is estimated to be in the range of 2545 kcal/mol. The rate of the reaction is supposed to depend upon the diffusion of carbon rather than that of uranium.
(2) Uranium sesquicarbide can be prepared by the solid-solid reaction between uranium monocarbide and carbon at 1, 500°1, 700°C. No stress is necessary for its formation. In the preparation of uranium dicarbide, it was found that the temperature highar than 1, 800°C was necessary to prepare it in a pure single phase.
The authors wish to thank Messrs. Toshio Uchijima, Kazuya Takano, Yukio Kawarazaki, Kinji Ouchi and Kunihiro Goto for their assistance in the experiment.
They are grateful to Dr. Masayuki Kawasaki for providing uranium metal, to Tokai Electrode Mfg. Co. for providing carbon sample and to Nippon Electrode Co. for graphitization service. They are also indebted to Drs. Keichi Oshima, Toshio Nakai and Kenjiro Kimura for their continuous encouragement.