Ammonium uranyl carbonateとは 意味・読み方・使い方

Ammonium uranyl carbonate(UO₂CO₃·2(NH₄)₂CO₃) is known in the uranium processing industry as AUC and is also called uranyl ammonium carbonate. This compound is important as a component in the conversion process of uranium hexafluoride (UF₆) to uranium dioxide (UO₂). The ammonium uranyl carbonate is combined with steam and hydrogen at 500-600°C to yield UO2. In another process aqueous uranyl nitrate, known as uranyl nitrate liquor (UNL) is treated with ammonium bicarbonate to form ammonium uranyl carbonate as a solid precipitate. This is separated from the solution, dried with methanol and then calcinated with hydrogen directly to UO₂ to obtain a sinterable grade powder. The ex-AUC uranium dioxide powder is free-flowing, relatively coarse (10 µ) and porous with specific surface area in the range of 5m²/g and suitable for direct pelletisation, avoiding the granulation step. Conversion to UO₂ is often performed as the first stage of nuclear fuel fabrication.