Uses of magnesium phosphate containing minerals

Patent metadata

Field	Value
Publication number	US-12208366-B2
Application number	US-202017607966-A
Country	US
Kind code	B2
Filing date	May 4, 2020
Priority date	May 2, 2019
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

Processes for making magnesium-containing layered double hydroxides from a magnesium phosphate-containing mineral are disclosed, as well as a magnesium-containing layered double hydroxides and their uses.

First claim

The invention claimed is:

1. A process for the preparation of a magnesium-containing layered double hydroxide, the process comprising the step of:
a) using a magnesium phosphate-containing mineral as a source of Mg 2+ ions in a process of preparing a layered double hydroxide.

2. The process of claim 1 , wherein the magnesium phosphate-containing mineral is struvite or a magnesium phosphate-containing mineral derived from struvite.

3. The process of claim 1 , wherein Mg 2+ ions are generated in step a) by contacting the magnesium phosphate-containing mineral with an aqueous solution.

4. The process of claim 3 , wherein the temperature of the aqueous solution is 5-120° C.

5. The process of claim 1 , wherein the magnesium phosphate-containing mineral is struvite or a magnesium phosphate-containing mineral derived from struvite, and the Mg 2+ ions are generated in step a) by contacting the magnesium phosphate-containing mineral with an aqueous solution for 30-75 minutes at a temperature of 55-90° C., and wherein the process of step a) is a coprecipitation process.

6. The process of claim 1 , wherein step a) comprises mixing the Mg 2+ ions with:
M′, wherein M′ is one or more trivalent or tetravalent cations,
X, wherein X is one or more anions, and
optionally M, wherein M is a monovalent or divalent cation other than Mg 2+ ,
in an aqueous reaction medium at a pH sufficient to form a layered double hydroxide.

7. The process of claim 6 , wherein the pH of the aqueous reaction medium is 9.5-13.0.

8. The process of claim 6 , wherein the temperature of the aqueous reaction medium is 65-85° C. and the formed layered double hydroxide is aged in the aqueous reaction medium for 1-24 hours.

9. The process of claim 6 , wherein M′ is selected from Al 3+ , Ga 3+ , Y 3+ , In 3+ , Fe 3+ , Co 3+ , Ni 3+ , Mn 3+ , Cr 3+ , Ti 3+ , V 3+ , La 3+ , Sn 4+ , Ti 4+ and Zr 4+ ; M is selected from Li + , Ca 2+ , Zn 2+ , Fe 2+ , Ni 2+ , Co 2+ , Mn 2+ and Cu 2+ ; and X is selected from a halide, an inorganic oxyanion, an anionic surfactant, an anionic chromophore and an anionic UV absorber.

10. The process of claim 9 , wherein X is one or more of carbonate, phosphate, sulfate and nitrate.

11. The process of claim 6 , wherein M′ is Al 3+ and M is absent or is Zn 2+ .

12. The process of claim 11 , wherein X is carbonate.

13. The process of claim 6 , wherein X is one or more of carbonate and phosphate.

14. The process of claim 1 , wherein the layered double hydroxide is a phosphate-containing layered double hydroxide and step a) further comprises using the magnesium phosphate-containing mineral as a source of phosphate ions in the process of preparing the layered double hydroxide.

15. A magnesium-containing layered double hydroxide produced by the process of claim 1 and having a specific surface area of ≥80 m 2 g −1 and a tap density of at least 0.35 g cm −3 .

16. The magnesium-containing layered double hydroxide as claimed in claim 15 , wherein the layered double hydroxide has a specific surface area of ≥100 m 2 g −1 .

17. The magnesium-containing layered double hydroxide as claimed in claim 15 , wherein the layered double hydroxide has a tap density of at least 0.45 g cm −3 .

18. The magnesium-containing layered double hydroxide as claimed in claim 15 , wherein the layered double hydroxide is a MgAl layered double hydroxide or a MgZnAl layered double hydroxide, optionally wherein carbonate accounts for >75 wt % of all interlayer anions present in the layered double hydroxide.

19. The magnesium-containing layered double hydroxide as claimed in claim 15 , wherein the layered double hydroxide is a magnesium aluminium carbonate layered double hydroxide.

20. A thermally-treated magnesium-containing layered double hydroxide as claimed in claim 15 .

Assignees

• Univ Oxford Innovation Ltd

Inventors

• O'Hare Dermot
• Suo Hongri

Classifications

• C01F7/784

  Layered double hydroxide, e.g. comprising nitrate, sulfate or carbonate ions as intercalating anions · CPC title

• C01B25/45

  containing plural metal, or metal and ammonium · CPC title

• B01J20/3085

  Chemical treatments not covered by groups B01J20/3007 - B01J20/3078 · CPC title

• B01J20/28057

  Surface area, e.g. B.E.T specific surface area · CPC title

• B01J20/28011

  Other properties, e.g. density, crush strength · CPC title