Production of low carbon footprint magnesia

Patent metadata

Field	Value
Publication number	US-12448298-B2
Application number	US-202217849862-A
Country	US
Kind code	B2
Filing date	Jun 27, 2022
Priority date	Jul 27, 2016
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A process for producing magnesia can include contacting CO 2 -containing emissions with a magnesium-containing material to produce magnesium carbonate; subjecting the magnesium carbonate to calcination to produce a CO 2 by-product and magnesia; and recycling at least a portion of the CO 2 by-product for contacting the magnesium-containing material to produce the magnesium carbonate. The magnesium-containing material can include mining residues, such as phyllosilicate or chrysotile mining residue, and the magnesium carbonate produced can include precipitated nesquehonite that is subjected to calcination to produce the magnesia.

First claim

The invention claimed is:

1. A process for producing magnesia, comprising:
producing magnesium carbonate from a magnesium silicate material, including:
subjecting the magnesium silicate material to dehydroxylation to produce a magnesium-containing material, and
contacting a CO 2 -containing gas with the magnesium-containing material; and

subjecting the magnesium carbonate to calcination to produce magnesia;
wherein producing the magnesium carbonate further includes:
recycling at least a portion of the CO 2 by-product as a recycled CO 2 by-product;
recycling CO 2 derived from the dehydroxylation as at least part of the CO 2 -containing gas; and
contacting the magnesium-containing material with the recycled CO 2 by-product and the CO 2 -containing gas.

2. The process of claim 1 , wherein producing the magnesium carbonate further comprises providing the magnesium-containing material in an aqueous slurry and contacting the CO 2 -containing gas and the recycled CO 2 by-product with the aqueous slurry.

3. The process of claim 2 , further comprising:
in the contacting step, producing a carbonate loaded slurry comprising precipitable carbonates and substantially free of precipitated alkaline earth metal carbonates;
separating the carbonate loaded slurry into an aqueous phase comprising the precipitable carbonates and a solid phase;
precipitating the magnesium carbonates from the aqueous phase; and
separating the magnesium carbonates from the aqueous phase.

4. The process of claim 1 , wherein the CO 2 -containing gas further comprises CO 2 -containing emissions that are directly used as they are produced from a plant.

5. The process of claim 4 , wherein the CO 2 -containing emissions comprise emissions from a separate emission source.

6. The process of claim 1 , wherein the CO 2 containing gas further comprises CO 2 derived from an additional magnesia production train.

7. The process of claim 1 , wherein the magnesium silicate material comprises at least one of basalt, peridotite, serpentinized peridotite, ophiolitic rock, mafic rock, ultramafic rocks, peridot, pyroxene, olivine, serpentine, and serpentinite.

8. The process of claim 1 , wherein the magnesium-containing material is pre-treated to produce magnesium-containing particulate material prior to carbonation, and the magnesium-containing particulate material has a magnesium content between about 1 wt % and about 35 wt %.

9. The process of claim 8 , wherein the magnesium content is between about 10 wt % and about 30 wt %.

10. The process of claim 1 , wherein the magnesium-containing material is derived from a mining residue comprising phyllosilicate mining residue and/or chrysotile mining residue.

11. The process of claim 1 , further comprising:
subjecting the magnesium-containing material to size reduction and removal of a magnetic fraction prior to carbonation.

12. The process of claim 1 , further comprising:
grinding a starting material to provide a particle size between about 200 microns and about 1000 microns to produce a sized material;
removing the magnetic fraction from the sized material to produce a non-magnetic fraction; and
grinding the non-magnetic fraction to produce the magnesium-containing material having a particle size of at most 75 microns.

13. The process of claim 1 , wherein the CO 2 content of the recycled CO 2 by-product is at least 10% greater than that of the CO 2 -containing gas.

14. The process of claim 13 , wherein the CO 2 content of the recycled CO 2 by-product is at least 20% greater than that of the CO 2 -containing gas.

15. The process of claim 14 , wherein the CO 2 content of the recycled CO 2 by-product is at least 50% greater than that of the CO 2 -containing gas.

16. The process of claim 1 , wherein the dehydroxylation is performed at a temperature from 600 to 700 degrees Celsius.

17. The process of claim 1 , wherein the dehydroxylation is performed for a duration of approximately 20 to 60 minutes.

18. The process of claim 1 , wherein the magnesium silicate material is a phyllosilicate.

19. The process of claim 18 , wherein the magnesium silicate material comprises serpentine.

Assignees

• Inst Nat Rech Scient

Inventors

• Mercier Guy
• Pasquier Louis-César
• Kemache Nassima
• Cecchi Emmanuelle
• Blais Jean-François

Classifications

• C01F5/02 Primary

  Magnesia · CPC title

• C01F5/24

  Magnesium carbonates · CPC title

• C01B32/50

  Carbon dioxide · CPC title

• C01F5/06 Primary

  by thermal decomposition of magnesium compounds (calcining magnesite or dolomite C04B2/10) · CPC title