Fabrication of uranium nitride
View Patent ↗A method of producing uranium nitride (e.g., uranium mononitride) and/or uranium-containing intermediates that can be used to further produce uranium nitride includes reacting a reaction mixture comprising uranium carbide with a gas comprising hydrogen and nitrogen, cooling the reaction mixture to a temperature suitable to produce a phase comprising U 2 N 3 , and heating the reaction mixture to a temperature suitable to convert the phase comprising U 2 N 3 to a phase comprising UN. The method produces highly purified UN, is insensitive to excess carbon reactants, and can be readily integrated into existing uranium production facilities as part of a continuous process.
1. A method of producing uranium nitride (UN), the method comprising:
reacting a reaction mixture comprising uranium carbide with a gas comprising hydrogen and nitrogen;
cooling the reaction mixture to a temperature below a phase transition temperature between a phase comprising UN and a phase comprising U 2 N 3 , wherein such temperature ranging from 1352° C. to 1132° C., to thereby produce a phase comprising U 2 N 3 ; and
heating the reaction mixture to a temperature above the phase transition temperature between the phase comprising UN and the phase comprising U 2 N 3 , wherein such temperature is greater than 1352° C., to thereby convert the phase comprising U 2 N 3 to the phase comprising UN.
2. The method of claim 1 , the method further comprising:
reacting UO 2 with at least three molar equivalents of carbon to form the reaction mixture comprising uranium carbide.
3. The method of claim 2 , wherein the at least three molar equivalents of carbon comprises an excess of three molar equivalents of carbon.
4. The method of claim 2 , the method further comprising:
granulating the reaction mixture comprising uranium carbide prior to reaction with the gas comprising hydrogen and nitrogen.
5. The method of claim 1 , the method further comprising:
repeating the cooling the reaction mixture and heating the reaction mixture to purify the UN.
6. The method of claim 2 , wherein the reacting UO 2 with at least three molar equivalents of carbon is accomplished under an active vacuum.
7. The method of claim 2 , wherein the reacting UO 2 with at least three molar equivalents of carbon is accomplished under an inert atmosphere comprising N 2 , Ar, He, H 2 , or a mixture thereof.
8. The method of claim 1 , the method being a continuous process wherein the reaction mixture comprising uranium carbide is continuously moved through a series of at least first, second, and third reaction zones arranged in a sequence, wherein:
the first reaction zone has a temperature corresponding to the reacting the reaction mixture comprising uranium carbide with the gas comprising hydrogen and nitrogen;
the second reaction zone has a temperature corresponding to the cooling the reaction mixture to the temperature below the phase transition temperature between the phase comprising UN and the phase comprising U 2 N 3 , wherein such temperature ranging from 1352° C. to 1132° C., to produce the phase comprising U 2 N 3 ; and
the third reaction zone has a temperature corresponding to the heating the reaction mixture to the temperature above the phase transition temperature between the phase comprising UN and the phase comprising U 2 N 3 , wherein such temperature is greater than 1352° C., suitable to convert the phase comprising U 2 N 3 to the phase comprising UN.
9. The method of claim 1 , wherein the heating the reaction mixture to the temperature above the phase transition temperature between the phase comprising UN and the phase comprising U 2 N 3 to convert the phase comprising U 2 N 3 to the phase comprising UN comprises heating the reaction mixture to a temperature of 1375° C. to 2000° C.