yellowcake

Yellowcake is a uranium oxide concentrate, primarily composed of the compound triuranium octoxide (U3O8). It is produced from uranium ore during the milling phase of the nuclear fuel cycle and serves as the principal feedstock for uranium enrichment and fuel fabrication. The material is typically shipped as a dry powder or cake with a yellow to brownish color; in some contexts the earlier deposit is referred to as orange cake.

Production involves mining, crushing, and milling of ore; uranium is leached from the ore by acidic or alkaline solutions; the resulting pregnant solution is processed to recover uranium as a precipitate, most commonly ammonium diuranate (ADU) or ammonium uranyl carbonate; the precipitate is filtered, dried, and calcined at high temperature to obtain U3O8 yellowcake. Purity varies; typical U3O8 content ranges about 70–90% with impurities such as thorium and rare earth elements.

Yellowcake is not a fuel by itself; it is converted to uranium hexafluoride (UF6) or other forms for enrichment and fuel fabrication. It is a radiological material subject to strict national and international controls on mining, processing, transport, and possession; handling occurs in secure facilities under licensing and safety regimes.

Global production concentrates in a few countries, with major operations in Kazakhstan, Canada, Australia, Namibia, Niger, and Uzbekistan, among others.