Extraction of uranium from wet-process phosphoric acid
A process for extracting uranium compounds from wet-process phosphoric acid (WPA) includes lowering iron content of WPA to produce a lowered iron WPA, reducing valency of any remaining iron in the lowered iron WPA to produce a reduced iron valency WPA. Uranium compounds are extracted from the reduced iron valency WPA via a solvent extraction process.
1. A process for extracting uranium compounds from wet-process phosphoric acid (WPA), the process comprising:
lowering iron content of WPA by precipitating iron to produce a lowered iron WPA;
reducing valency of any remaining iron in the lowered iron WPA to produce a reduced iron valency WPA; and
extracting uranium compounds from the reduced iron valency WPA via a solvent extraction process.
2. The process of claim 1 , wherein the solvent extraction process includes a step of oxidizing the WPA.
3. The process of claim 1 , wherein lowering iron content of WPA comprises precipitating iron.
4. The process of claim 1 , wherein reducing valency of any remaining iron in the lowered iron WPA to produce a reduced iron valency WPA comprises adding a reducing agent to the lowered iron WPA.
5. The process of claim 1 , wherein lowering iron content of WPA comprises precipitating iron as an iron ammonium phosphate compound.
6. The process of claim 1 , wherein the solvent extraction process comprises:
contacting uranium-containing WPA with an oxidant to form oxidized WPA;
removing uranium from the oxidized WPA by blending the oxidized WPA with an organic solvent to form a uranium depleted WPA and a pregnant organic phase containing uranium;
forming a uranium concentrated WPA by stripping uranium from the pregnant organic phase with reduced or oxidized WPA; and
producing a uranyl solution from the uranium concentrated WPA.
7. A process for extracting uranium compounds from wet-process phosphoric acid (WPA), the process comprising:
lowering iron content of WPA by precipitating iron to produce a uranium-containing lowered iron WPA;
contacting the uranium-containing lowered iron WPA with an oxidant to form oxidized WPA;
removing uranium from the oxidized WPA by blending the oxidized WPA with a first organic solvent to form uranium depleted WPA and a first pregnant organic phase containing uranium;
forming a uranium concentrated WPA by stripping uranium from the first pregnant organic phase with reduced WPA;
oxidizing the uranium concentrated WPA;
making a second pregnant organic phase by blending the oxidized uranium concentrated WPA with a second organic solvent; and
producing a uranyl solution from the second pregnant organic phase.
8. The process of claim 7 , wherein the first and second organic solvents are the same.
9. The process of claim 7 , wherein the reduced WPA is formed by treating WPA with a reducing agent that reduces valency of iron in the WPA.
10. The process of claim 7 , wherein the first and second organic solvents comprise kerosene, DEHPA, and TOPO.
11. The process of claim 7 , wherein producing a uranyl solution from the second pregnant organic phase comprises reacting the second pregnant organic phase with ammonium carbonate to form uranyl carbonate.
12. A process for extracting uranium compounds from wet-process phosphoric acid (WPA), the process comprising:
lowering iron content of WPA by precipitating iron to produce a uranium-containing lowered iron WPA;
contacting the uranium-containing lowered iron WPA with an oxidant to form oxidized WPA;
removing uranium from the oxidized WPA by blending the oxidized WPA with a first organic solvent to form uranium depleted WPA and a first pregnant organic phase containing uranium;
forming a uranium concentrated WPA by stripping uranium from the first pregnant organic phase with oxidized WPA;
oxidizing the uranium concentrated WPA;
making a second pregnant organic phase by blending the oxidized uranium concentrated WPA with a second organic solvent; and
producing a uranyl solution from the second pregnant organic phase.
13. The process of claim 12 , wherein the first and second organic solvents are different.
14. The process of claim 12 , wherein the reduced WPA is formed by treating WPA with a reducing agent that reduces valency of iron in the WPA.
15. The process of claim 12 , wherein the first organic solvent comprises kerosene, mono-octylphenyl phosphoric acid, and di-octylphenyl phosphoric acid and the second organic solvent comprise kerosene, DEHPA, and TOPO.
16. The process of claim 12 , wherein producing a uranyl solution from the second pregnant organic phase comprises reacting the second pregnant organic phase with ammonium carbonate to form uranyl carbonate.
17. The process of claim 1 , wherein the solvent extraction process comprises stripping uranium compounds from an organic solvent.