Method for obtaining calcium aluminates from non-saline aluminum slags

Patent metadata

Field	Value
Publication number	US-10858261-B2
Application number	US-201615748323-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Jul 28, 2015
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

The present invention relates to a method for obtaining calcium aluminates for metallurgical use from non-saline aluminum slags by means of reactive grinding and thermal treatment.

First claim

The invention claimed is:

1. A method for obtaining a mixture of the following calcium aluminates suitable for the manufacturing of steel: CaAl 2 O 4 (CA), CaAl 4 O 7 (CA 2 ), Ca 12 Al 14 O 33 (C 12 A 7 ), Ca 3 AlO 6 (C 3 A) and CaAl 12 O 19 (CA 6 ), where C═CaO and A=Al 2 O 3 , from a non-saline aluminum slag comprising the following steps:
a) carrying out a reactive grinding of the non-saline aluminum slag from recovery by melting aluminum scrap metal or products of secondary melting of aluminum in the presence of calcium carbonate CaCO 3 , wherein the non-saline aluminum slag is generated from scrap metal and the reactive grinding of the non-saline aluminum slag with CaCO 3 is carried out at a molar ratio of 1:3 Al 2 O 3 :CaO;
b) thermally treating the product obtained in step a) at a temperature between 700° C. and 750° C. for one hour; and
c) thermally treating the product obtained in step b) at a temperature between 1300° C. and 1400° C.

2. The method according to claim 1 , wherein the non-saline aluminum slag of step a) has a percentage of hydrated aluminum oxides between 5% and 65%.

3. The method according to claim 1 , wherein the grinding of step a) is carried out by means of a ball mill.

4. The method according to claim 1 , wherein the product obtained in step a) has an average particle size of less than 40 μm.

5. The method according to claim 1 , wherein the content of the mixture of the following calcium aluminate CaAl 2 O 4 (CA), CaAl 4 O 7 (CA 2 ), Ca 12 Al 14 O 33 (C 12 A 7 ), Ca 3 AlO 6 (C 3 A) and CaAl 12 O 19 (CA 6 ), where C═CaO and A=Al 2 O 3 , of step c) is comprised between 70% and 92%.

6. The method according to claim 1 , wherein between 71% and 85% of the calcium aluminates produced by the method are tricalcium aluminate Ca 3 AlO 6 (C 3 A).

Assignees

• Consejo Superior Investigacion
• Varmoxz
• Arzyz S A De C V

Inventors

• Lopez Gomez Felix Antonio
• Alguacil Priego Francisco Jose
• Gonzalez Gracia Jose Ramon
• Ramirez Zablah Mario Sergio

Classifications

• Y02P10/20

  Recycling · CPC title

• C04B2235/3454

  Calcium silicates, e.g. wollastonite · CPC title

• C04B2235/3865

  Aluminium nitrides · CPC title

• C04B2235/3222

  Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4) · CPC title

• C04B2235/3279

  Nickel oxides, nickalates, or oxide-forming salts thereof · CPC title