Thermally treated briquettes containing a “quick” calcium-magnesium compound and calcium ferrites, and method of manufacture thereof

Patent metadata

Field	Value
Publication number	US-10851017-B2
Application number	US-201716308293-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 8, 2016
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

Composition in the form of green or thermally treated briquettes comprising at least one “quick” calcium-magnesium compound and an iron-based compound, the method of production thereof and uses thereof.

First claim

The invention claimed is:

1. Composition in the form of thermally treated briquettes comprising a “quick” calcium-magnesium compound selected from the group consisting of quicklime, magnesian quicklime, dolomitic quicklime and quick calcined dolomite, and an iron-based compound in the form of calcium ferrite, characterized in that said calcium ferrite forms a matrix, the matrix being a continuous phase of calcium ferrite in which particles of said “quick” calcium-magnesium compound are dispersed.

2. Composition in the form of thermally treated briquettes according to claim 1 , characterized in that, said particles of “quick” calcium-magnesium compound have a two-dimensional size under 63 μm, observable by scanning electron microscopy coupled to energy dispersive analysis, in a section of said thermally treated briquette.

3. Composition in the form of thermally treated briquettes according to claim 1 , characterized in that it further comprises particles of “quick” calcium-magnesium compound of two-dimensional size above 63 μm and under 5 mm, observable by scanning electron microscopy coupled to energy dispersive analysis, in a section of said thermally treated briquette.

4. Composition in the form of thermally treated briquettes according to claim 3 , in which said particles of “quick” calcium-magnesium compound of two-dimensional size above 63 μm and under 5 mm, observable by scanning electron microscopy coupled to energy dispersive analysis, in a section of said thermally treated briquette cover at least 20% of the area of said section.

5. Composition in the form of thermally treated briquettes according to claim 3 , in which said particles of “quick” calcium-magnesium compound of two-dimensional size above 63 μm and under 5 mm, observable by scanning electron microscopy coupled to energy dispersive analysis, in a section of said thermally treated briquette cover at most 60% of the surface area of said section.

6. Composition in the form of thermally treated briquettes according to claim 1 , in which at least 70 wt % of said iron-based compound is in the form of calcium ferrites.

7. Composition in the form of thermally treated briquettes according to claim 1 , characterized in that at least 40 wt % of said calcium ferrites are in the form of monocalcium ferrite Ca 2 Fe 2 O 4 .

8. Composition in the form of thermally treated briquettes according to claim 1 , characterized in that at least 40 wt % of said calcium ferrites are in the form of dicalcium ferrite Ca 2 Fe 2 O 5 .

9. Composition in the form of thermally treated briquettes according to claim 1 , characterized in that it has a BET specific surface area greater than or equal to 0.4 m 2 /g.

10. Composition in the form of thermally treated briquettes according to claim 1 , characterized in that it has porosity greater than or equal to 20%.

11. Composition in the form of thermally treated briquettes according to claim 1 , characterized in this said thermally treated briquettes have a shatter test index below 10%, said shatter test index being the percentage by weight of fines wider 10 mm generated after 4 drops from 2 m starting from 10 kg of product, the fines being quantified by sieving through a screen with square mesh of 10 mm after 4 drops from 2 m.

12. Composition in the form of thermally treated briquettes according to claim 1 , wherein said quick calcium-magnesium compound is quicklime.

13. Composition in the form of thermally treated briquettes made by baking green briquettes at a temperature between 1050° C. and 1200° C. for a time between 5 and 25 minutes, comprising a “quick” calcium-magnesium compound selected from the group consisting of quicklime, magnesian quicklime, dolomitic quicklime and quick calcined dolomite, and an iron-based compound in the form of calcium ferrite, characterized in that said calcium ferrite forms a matrix, the matrix being a continuous phase of calcium ferrite in which particles of “quick” calcium-magnesium compound are dispersed.

Assignees

• Lhoist Rech Et Developpement Sa

Inventors

• Criniere Guillaume
• Nispel Michael

Classifications

• C04B22/066

  Magnesia; Magnesium hydroxide · CPC title

• C22B1/245

  with carbonaceous material for the production of coked agglomerates · CPC title

• C22B1/243

  inorganic · CPC title

• C04B2111/0087

  for metallurgical applications · CPC title

• C04B2111/00732

  for soil stabilisation · CPC title