Britannica Sources used in this answer

How does magnesium reduce uranium tetrafluoride to uranium metal?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Enrichment of uranium — uranium processing How uranium is enriched to make a nuclear weapon.

The conversion of uranium tetrafluoride ( $U F_{4}$ ) to uranium metal is achieved through the Ames process.1

In this procedure, granular $U F_{4}$ is mixed with an excess of finely divided magnesium ( $M g$ ) and placed inside a sealed, refractory-lined container known as a bomb. The bomb is heated to temperatures between 500 and 700 °C (930 to 1,300 °F), triggering an exothermic reaction.1

The heat generated by this reaction is sufficient to liquefy the contents, resulting in the production of metallic uranium and a slag of magnesium fluoride ( $M g F_{2}$ ). Because magnesium has a very high vapor pressure at the required reaction temperatures exceeding 1,300 °C (2,375 °F), the use of a sealed bomb is essential to contain the process. Once the bomb cools to ambient temperature, the resulting uranium metal is recovered as a high-quality product suitable for use in nuclear reactor fuel.1