Elaboration of an advanced ceramic made of recycled industrial steel waste

Patent metadata

Field	Value
Publication number	US-11787745-B2
Application number	US-201816487308-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Feb 22, 2017
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

A ceramic and a method of forming a ceramic including milling steel slag exhibiting a diameter of 5 mm of less to form powder, sieving the powder to retain the powder having a particle size in the range of 20 to 400 removing free iron from the powder with a magnet, heat treating the powder at a temperature in the range of 700° C. to 1200° C. for a time period in the range of 1 hour to 10 hours and oxidizing retained iron in the powder, compacting the powder at a compression pressure in the range of 20 MPa to 300 MPA, and sintering the powder at a temperature in the range of 700° C. to 1400° C. for a time period in the range of 0.5 hours to 4 hours to provide a ceramic.

First claim

The invention claimed is:

1. A method of forming a ceramic from steel slag for use as a thermal energy storage material, comprising:
milling steel slag to form powder;
removing free iron from said powder with a magnet;
heat treating said powder at a temperature in the range of 700° C. to 1200° C. for a time period in the range of 1 hour to 10 hours and oxidizing retained iron in said powder;
compacting said powder at a compression pressure in the range of 30 MPa to 300 MPa; and
sintering said powder at a temperature in the range of 700° C. to 1400° C. to provide a ceramic.

2. The method of claim 1 , further comprising preheating said powder prior to sintering wherein said green compact is preheated at a rate of 1 K/min to 10 K/min.

3. The method of claim 1 , wherein said sintering is performed after compacting, wherein said compression pressure is in the range of 120 MPa to 300 MPa, and said sintering temperature is in the range of 1200° C. to 1400° C.

4. The method of claim 3 , wherein said compression pressure is in the range of 120 MPa to 180 MPa.

5. The method of claim 1 , wherein sintering is performed concurrently with said compacting.

6. The method of claim 5 , wherein said compression pressure in the range of 120 MPa to 180 MPa.

7. The method of claim 1 , wherein said sintering is performed for a time period of 4 hours.

8. The method of claim 1 , further comprising mixing additives into said powder after heat treating said powder.

9. The method of claim 8 , wherein said additives include a binder and a carrier.

10. The method of claim 9 , wherein said binder includes at least one polymer selected from the following: poly(vinyl alcohol), poly(alkylene carbonate), starch, carboxymethylcellulose, dextrin, and waxes.

11. The method of claim 8 , wherein said additives include a dry lubricant.

12. The method of claim 8 , wherein said additives are present in the range of 0 wt % to 60 wt %.

13. The method of claim 1 , wherein said steel slag is EAF slag.

14. A method of forming a ceramic from steel slag for use as a thermal energy storage material, comprising:
milling steel slag to form powder;
removing free iron from said powder with a magnet;
heat treating said powder at a temperature in the range of 700° C. to 1200° C. for a time period in the range of 1 hour to 10 hours and oxidizing retained iron in said powder;
compacting said powder at a compression pressure in the range of 20 MPa to 300 MPa; and
sintering said powder for four hours at a temperature in the range of 700° C. to 1400° C. to provide a ceramic.

15. The method of claim 14 , wherein said sintering is performed after compacting, and said sintering temperature is in the range of 1200° C. to 1400° C.

16. The method of claim 14 , wherein said sintering is performed concurrently with said compacting, and said compression pressure is in the range of 120 MPa to 180 MPa.

17. A method of forming a ceramic from steel slag for use as a thermal energy storage material, comprising:
milling steel slag to form powder;
removing free iron from said powder with a magnet;
heat treating said powder at a temperature in the range of 700° C. to 1200° C. for a time period in the range of 1 hour to 10 hours and oxidizing retained iron in said powder;
mixing additives into said powder;
compacting said powder at a compression pressure in the range of 20 MPa to 300 MPa; and
sintering said powder at a temperature in the range of 700° C. to 1400° C. to provide a ceramic.

18. The method of claim 17 , wherein said additives include a binder and a carrier.

19. The method of claim 18 , wherein said binder includes at least one polymer selected from the following: poly(vinyl alcohol), poly(alkylene carbonate), starch, carboxymethylcellulose, dextrin, and waxes.

20. The method of claim 17 , wherein said additives include a dry lubricant.

Assignees

• Univ Khalifa Science & Technology

Inventors

• Calvet Nicolas Jean-Michel
• Cardozo Uver Dario Villalobos
• Al Na'Imi Khaloud Mohammed
• Hoffmann Jean Francois

Classifications

• C04B35/62204 Primary

  using waste materials or refuse (clay-wares containing waste materials C04B33/132) · CPC title

• C04B35/057

  based on calcium oxide · CPC title

• C04B35/2683

  Other ferrites containing alkaline earth metals or lead · CPC title

• C04B35/6261

  Milling · CPC title

• C04B35/6265

  involving reduction or oxidation · CPC title