New uses of magnesium phosphate containing minerals

Patent metadata

Field	Value
Publication number	US-2022288555-A1
Application number	US-202017607966-A
Country	US
Kind code	A1
Filing date	May 4, 2020
Priority date	May 2, 2019
Publication date	Sep 15, 2022
Grant date	—

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

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 (e.g. bobierrite).

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

4 . The process of claim 3 , wherein the temperature of the aqueous solution is 5-120° C., preferably 30-95° 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 any preceding claim, wherein step a) comprises mixing the Mg 2+ ions with:
M′, wherein M′ is one or more trivalent or tetravalent cations,
X, wherein X one or more anions, and
optionally M, wherein M is a monovalent or divalent cation other than Mg 2+ , in an aqueous reaction medium (e.g. water) 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 or 7 , wherein the temperature of the aqueous reaction medium is 5-80° C.

9 . The process of any one of claims 6 to 8 , wherein the formed layered double hydroxide is aged in the aqueous reaction medium for 1-200 hours.

10 . The process of any one of claims 6 to 9 , 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 (such as 2-8 hours).

11 . The process of any one of claims 6 to 10 , 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+ .

12 . The process of any one of claims 6 to 11 , wherein M is selected from Li + , Ca 2+ , Zn 2+ , Fe 2+ , Ni 2+ , Co 2+ , Mn 2+ and Cu 2+ .

13 . The process of any one of claims 6 to 12 , wherein M′ is Al 3+ and M is absent or is Zn 2+ .

14 . The process of any one of claims 6 to 13 , wherein X is selected from a halide, an inorganic oxyanion, an anionic surfactant, an anionic chromophore and an anionic UV absorber.

15 . The process of any one of claims 6 to 14 , wherein X is one or more of carbonate, phosphate, sulfate and nitrate.

16 . The process of any one of claims 6 to 15 , wherein X is one or more of carbonate and phosphate.

17 . The process of any one of claims 6 to 15 , wherein X is carbonate.

18 . The process of any preceding claim, 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.

19 . A magnesium-containing layered double hydroxide obtainable by the process of any preceding claim.

20 . A magnesium-containing-layered double hydroxide having a specific surface area of 80 m 2 g -1 and a tap density of at least 0.25 g cm −3 .

21 . The magnesium-containing layered double hydroxide as claimed in claim 19 or 20 , wherein the layered double hydroxide has a specific surface area of ≥100 m 2 g −1 .

22 . The magnesium-containing layered double hydroxide as claimed in claim 19 , 20 or 21 , wherein the layered double hydroxide has a tap density of at least 0.30 g cm −3 .

23 . The magnesium-containing layered double hydroxide as claimed in any one of claims 19 to 22 , 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.

24 . The magnesium-containing layered double hydroxide as claimed in any one of claims 19 to 23 , wherein the layered double hydroxide is a magnesium aluminium carbonate layered double hydroxide.

25 . Use of the magnesium-containing layered double hydroxide as claimed in any one of claims 19 to 23 as a sorbent, a catalytic support or as a filler in a composite material.

26 . A thermally-treated (e.g. calcined) magnesium-containing layered double hydroxide as claimed in claims 19 to 23 .

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

• C01P2006/16

  Pore diameter · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• B01J20/3085

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

• C01P2004/03

  obtained by SEM · CPC title