Organic-inorganic hybrid material of use for extracting uranium (VI) from aqueous media containing phosphoric acid, processes for preparing same and uses thereof

1. An organic-inorganic hybrid material, which comprises an inorganic solid support on which is covalently grafted a plurality of organic molecules of formula (I):

wherein:

x, y and z are equal to 0 or 1, with the proviso that at least one of x, y and z is equal to 1;

m is an integer ranging from 1 to 6;

v and w are equal to 0 or 1, with the proviso that v is equal to 1 when w is equal to 0 and v is equal to 0 when w is equal to 1;

if x is equal to 0, R 1 represents a hydrogen atom or a linear or branched, saturated or unsaturated hydrocarbon group comprising from 1 to 12 carbon atoms, and, if x is equal to 1, R 1 represents a group bound to the inorganic solid support through at least one covalent bond represented by the dotted line;

if y is equal to 0, R 2 represents a hydrogen atom or a linear or branched, saturated or unsaturated hydrocarbon group comprising from 1 to 12 carbon atoms, and, if y is equal to 1, R 2 represents a group bound to the inorganic solid support through at least one covalent bond represented by the dotted line;

if z is equal to 0, R 3 represents a hydrogen atom or a linear or branched, saturated or unsaturated hydrocarbon group comprising from 1 to 12 carbon atoms, and, if z is equal to 1, R 3 represents a group bound to the inorganic solid support through at least one covalent bond represented by the dotted line;

R 4 and R 5 represent, independently of each other, a hydrogen atom, a linear or branched, saturated or unsaturated hydrocarbon group comprising from 2 to 8 carbon atoms, or a monocyclic aromatic group.

2. The organic-inorganic hybrid material of claim 1 , wherein the inorganic solid support comprises a metal oxide, a mixed metal oxide, a mixture of metal oxides, or carbon.

3. The organic-inorganic hybrid material of claim 1 , wherein the inorganic solid support is a porous material.

4. The organic-inorganic hybrid material of claim 3 , wherein the porous material is a mesoporous or macroporous material.

5. The organic-inorganic hybrid material of claim 4 , wherein the porous material is a mesoporous silica, a mesoporous titanium oxide, a mesoporous zirconia or a mesoporous carbon.

6. The organic-inorganic hybrid material of claim 5 , wherein the inorganic solid support is a SBA mesoporous silica or a CMK mesoporous carbon.

7. The organic-inorganic hybrid material of claim 1 , wherein R 3 represents —(CH 2 ) q —X 1 — wherein q is an integer ranging from 0 to 12, and X 1 represents a group selected from the group consisting of:

and —CH═CH—.

8. The organic-inorganic hybrid material of claim 1 , wherein at least one of R 1 and R 2 represents a group of formula (a), (b), (c), (d), (e), (f) or (g):

—(CH 2 ) p —C(O)—NH—(CH 2 ) q —X 2 —  (a)

—(CH 2 ) p —NH—C(O)—(CH 2 ) q —X 2 —  (b)

—(CH 2 ) p —C(O)—O—(CH 2 ) q —X 2 —  (c)

—(CH 2 ) p —O—C(O)—(CH 2 ) q —X 2 —  (d)

—(CH 2 ) p —O—(CH 2 ) q —X 2 —  (e)

—(CH 2 ) p -triazole-(CH 2 ) q —X 2 —  (f)

—(CH 2 ) q —X 2 —  (g)

wherein p is an integer ranging from 1 to 6, q is an integer ranging from 0 to 12, and X 2 represents a group selected from the group consisting of:

and —CH═CH—.

9. The organic-inorganic hybrid material of claim 8 , wherein R 3 represents —(CH 2 ) q —X 1 — wherein q is an integer ranging from 0 to 12 and X 1 is identical with X 2 .

10. The organic-inorganic hybrid material of claim 1 , wherein the organic molecules have the formula (Ia):

11. The organic-inorganic hybrid material of claim 10 , wherein x and y are 0, R 1 and R 2 represent, independently of each other, a linear or branched alkyl group comprising from 1 to 12 carbon atoms; z is 1 and R 3 represents a group bound to the inorganic solid support through at least one covalent bond, and R 4 and R 5 represent, independently of each other, a hydrogen atom or a linear or branched alkyl group comprising from 2 to 8 carbon atoms.

12. The organic-inorganic hybrid material of claim 11 , wherein R 1 and R 2 are identical with each other and represent a branched alkyl group comprising from 6 to 12 carbon atoms.

13. The organic-inorganic hybrid material of claim 11 , wherein R 4 and R 5 represent, independently of each other, a hydrogen atom or a linear or branched alkyl group comprising from 2 to 4 carbon atoms.

14. The organic-inorganic hybrid material of claim 10 , wherein the inorganic solid support is based on a metal oxide, a mixed metal oxide or on a mixture of metal oxides and R 3 represents:

wherein q is 1 to 5.

15. The organic-inorganic hybrid material of claim 10 , wherein the inorganic solid support is based on carbon and R 3 represents:

wherein q is 1 to 5.

16. A method for extracting uranium(VI) from an aqueous medium comprising phosphoric acid comprising contacting the aqueous medium with the organic-inorganic hybrid material of claim 1 and then separating the aqueous medium and the organic-inorganic hybrid material.

17. The method of claim 16 , wherein the aqueous medium comprises from 0.012 mol/L to 9 mol/L of phosphoric acid.

18. The method of claim 17 , wherein the aqueous medium results from the attack of a phosphate ore with sulfuric acid.

19. A method for recovering uranium(VI) from an aqueous medium comprising phosphoric acid, comprising:

extraction of uranium(VI) from the aqueous medium, the extraction comprising contacting the aqueous medium with the organic-inorganic hybrid material of claim 1 , and then separating the aqueous medium and the organic-inorganic hybrid material; and

stripping of uranium(VI) from the organic-inorganic hybrid material obtained at the end of the extraction, the stripping comprising contacting the organic-inorganic hybrid material with a basic aqueous solution, and then separating the organic-inorganic hybrid material and the basic aqueous solution.

20. The method of claim 19 , wherein the aqueous medium results from the attack of a phosphate ore with sulfuric acid.