Method embodiments for extracting elements from coal combustion products

Patent metadata

Field	Value
Publication number	US-12084743-B1
Application number	US-202117201729-A
Country	US
Kind code	B1
Filing date	Mar 15, 2021
Priority date	Mar 13, 2020
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

Abstract

Disclosed herein are embodiments of methods for isolating rare earth elements (REEs) and radioisotopes from coal combustion products, such as fly ash. In particular embodiments, lanthanides, Al, Sc, Y, or compounds comprising lanthanides, AI, Sc, Y, or any combination thereof; or actinides can be isolated using the methods disclosed herein.

First claim

We claim:

1. A method, comprising:
contacting a coal combustion product comprising at least one target element or a compound thereof and an aluminosilicate or silicate with:
(i) a first treatment of ammonium bifluoride and water to extract an actinide from the coal combustion product; and
(ii) a second treatment of ammonium bifluoride and an aqueous solution comprising an acid to extract a lanthanide, Al, Sc, Y, or a combination thereof from the coal combustion product; provided that the method does not comprise exposing the coal combustion product, the ammonium bifluoride, or the at least one aqueous solution to microwaves or sonication.

2. The method of claim 1 , wherein the aqueous solution further comprises water.

3. The method of claim 1 , wherein the actinide is selected from actinium, thorium, uranium, protactinium, or a combination thereof.

4. The method of claim 1 , wherein the actinide is U.

5. The method of claim 1 , further comprising recovering, concentrating, and/or separating the (i) actinide and/or (ii) the lanthanide, Al, Sc, Y, or the combination thereof using ion exchange and/or solvent extraction.

6. The method of claim 1 , wherein the acid is an inorganic acid or an organic acid.

7. The method of claim 6 , wherein the inorganic acid is selected from sulfuric acid, hydrochloric acid, nitric acid, or a combination thereof; and wherein the organic acid is selected from oxalic acid, acetic acid, or citric acid.

8. The method of claim 6 , wherein the acid has a concentration ranging from 0.5 M to 2 M.

9. The method of claim 6 , wherein the acid has a concentration ranging from 1 M or 2 M.

10. The method of claim 1 , wherein the first treatment and/or the second treatment occurs at a temperature ranging from 18° C. to 100° C.

11. The method of claim 1 , wherein the first treatment and/or the second treatment occurs at a temperature below 80° C.

12. The method of claim 1 , wherein the coal combustion product is contacted with the water for a time period ranging from 30 minutes to 24 hours and is contacted with the aqueous solution for a time period ranging from 30 minutes to 24 hours.

13. The method of claim 1 , wherein the coal combustion product comprises fly ash, bottom ash, or boiler slag.

14. The method of claim 1 , wherein the coal combustion product comprises fly ash.

15. A method, comprising: contacting, at room temperature, fly ash with (i) a first treatment of ammonium bifluoride and water to extract, an actinide present in the fly ash, and (ii) a second treatment of ammonium bifluoride and an aqueous solution comprising an acid to extract a lanthanide, Al, Sc, Y, or a combination thereof present in the fly ash.

16. The method of claim 15 , wherein the actinide is selected from actinium, thorium, uranium, protactinium, or a combination thereof.

17. The method of claim 15 , wherein the acid is selected from sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, acetic acid, or citric acid.

Assignees

• Triad Nat Security Llc

Inventors

• Leibman Christopher
• Droessler Janelle
• May Iain
• Hubley Nicholas

Classifications

• C22B3/26

  by liquid-liquid extraction using organic compounds · CPC title

• C22B3/42

  by ion-exchange extraction · CPC title

• C22B7/007

  by acid leaching · CPC title

• C22B3/06

  in inorganic acid solutions {, e.g. with acids generated in situ; in inorganic salt solutions other than ammonium salt solutions} · CPC title

• C22B7/02

  Working-up flue dust · CPC title