Low temperature synthesis of monazite-type materials

Patent metadata

Field	Value
Publication number	US-2025270090-A1
Application number	US-202519063432-A
Country	US
Kind code	A1
Filing date	Feb 26, 2025
Priority date	Feb 27, 2024
Publication date	Aug 28, 2025
Grant date	—

Abstract

The present disclosure is generally directed to methods for forming anhydrous rare earth and actinide phosphate minerals. In some embodiments of the present disclosure, the method generally comprises subjecting rare earth or actinide phosphates or salts thereof to microwave radiation.

First claim

What is claimed is:

1 . A method for converting starting reactants comprising a non-hydration-resistant phosphate mineral to a hydration-resistant phosphate mineral, the method comprising:
microwave heating the starting reactants in the presence of water.

2 . The method of claim 1 , wherein the microwave heating lasts for 1 to 40 hours.

3 . The method of claim 1 , wherein the microwave heating is performed at a temperature of from 210° C. to 300° C.

4 . The method of claim 1 , wherein the starting reactants further comprise an acid.

5 . The method of claim 1 , wherein the starting reactants have a pH of less than 5.

6 . The method of claim 1 , wherein the formula of the non-hydration-resistant phosphate mineral is LnPO 4 ·nH 2 O, wherein Ln is selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd and Y and n is from 0 to 1.

7 . The method of claim 1 , wherein the formula of the non-hydration-resistant phosphate mineral is AB(PO 4 ) 2 ·nH 2 O, wherein A represents an alkaline earth, B represents an actinide, and n is from 0 to 1.

8 . The method of claim 1 , wherein the formula of the non-hydration-resistant phosphate mineral is M(PO 4 ) 2 ·nH 2 O, wherein M is selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and n is from 0 to 1.

9 . The method of claim 1 , wherein the starting reactants further comprise a radionuclide.

10 . A method for direct synthesis of hydration-resistant phosphate minerals comprising:
combining starting reactants comprising a rare earth or actinide salt, a source of phosphate and water; and microwave heating the starting reactants.

11 . The method of claim 10 , wherein the starting reactants are microwave heated for a period of time of from 1 hour to 4 hours.

12 . The method of claim 10 , wherein the step of microwaving the starting reactants is performed at a temperature of from 210° C. to 300° C.

13 . The method of claim 10 , wherein the starting reactants have a pH less than or equal to 4.

14 . The method of claim 10 , wherein the starting reactants further comprise a radionuclide.

15 . The method of claim 10 , wherein the starting reactants further comprise flux.

16 . The method of claim 10 , wherein the source of phosphate is phosphoric acid.

17 . The method of claim 10 , wherein the starting reactants further comprise NH 4 H 2 PO 4 and an acid.

18 . The method of claim 10 , wherein the starting reactants further comprise an alkaline earth salt.

Assignees

• Univ South Carolina

Inventors

• Zur Loye Hans-Conrad

Classifications

• C01B25/327

  After-treatment · CPC title

• C01B25/32

  Phosphates of magnesium, calcium, strontium, or barium · CPC title

• C01B25/45

  containing plural metal, or metal and ammonium · CPC title

• C01B25/26 Primary

  Phosphates (perphosphates C01B15/16) · CPC title

• C01B25/265 Primary

  General methods for obtaining phosphates · CPC title