Plutonium oxychloride

Although the reduction of plutonium from its trichloride using calcium proceeds fairly quickly, a small portion of plutonium chloride still reacts with calcium oxide—a component of the crucible lining—to produce plutonium oxychloride.

Although the reduction of plutonium from its trichloride using calcium proceeds fairly quickly, a small portion of plutonium chloride still reacts with calcium oxide—a component of the crucible lining—to produce plutonium oxychloride.

This reaction is thermodynamically favorable due to calcium's stronger affinity for chlorine compared to oxygen. Additionally, a measurable quantity of calcium oxide dissolves into the slag from the lining, as its solubility in the chloride melt can reach up to 15%. During laboratory testing of plutonium metal production techniques, significant thinning of the crucible lining was observed, caused by calcium oxide dissolving into the slag. As a result, plutonium chloride may also react with this dissolved calcium oxide to form plutonium oxychloride.

This reaction is thermodynamically favorable due to calcium's stronger affinity for chlorine compared to oxygen. Additionally, a measurable quantity of calcium oxide dissolves into the slag from the lining, as its solubility in the chloride melt can reach up to 15%. During laboratory testing of plutonium metal production techniques, significant thinning of the crucible lining was observed, caused by calcium oxide dissolving into the slag. As a result, plutonium chloride may also react with this dissolved calcium oxide to form plutonium oxychloride.<ref name="MC"/>

Furthermore, calcium metal — which is added in large excess during the reduction smelting process — is itself soluble in calcium chloride. This means that the plutonium oxychloride dissolved in the slag can further react with the metallic calcium present in the melt, leading to the formation of [[plutonium monoxide]].<ref name="MC"/>

::{{chem2|PuCl3 + CaO -> PuOCl + CaCl}}

::{{chem2|PuCl3 + CaO -> PuOCl + CaCl}}