Method for obtaining calcium aluminates from non-saline aluminum slags

Patent metadata

Field	Value
Publication number	US-2018222764-A1
Application number	US-201615748323-A
Country	US
Kind code	A1
Filing date	Jul 26, 2016
Priority date	Jul 28, 2015
Publication date	Aug 9, 2018
Grant date	—

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

1 . A method for obtaining calcium aluminates 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 , comprising the following steps:
a) carry out a reactive grinding of the non-saline aluminum slag from recovery by means of melting aluminum scrap metal or products of secondary smelting of this metal in the presence of calcium carbonate CaCO 3 ; b) thermally treating the product obtained in step a) at a temperature between 700° C. and 750° C.; c) thermally treating the product obtained in step b) at a temperature between 1300° C. and 1400° C.

2 . The method for obtaining according to the previous claim, 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 any of claim 1 or 2 , wherein the Al 2 O 3 :CaO molar ratio of the non-saline aluminum slag of step a) is 1:3.

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

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

6 . The method according to any of claim 3 , wherein the calcium aluminate content 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%.

7 . The method according to any of claim 3 or 6 , wherein the tricalcium aluminate content Ca 3 AlO 6 (C 3 A) is comprised between 71% and 85%.

Assignees

• Consejo Superior Investigacion
• Varmoxz

Inventors

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

Classifications

• C04B2235/661

  Multi-step sintering · CPC title

• C01F7/164 Primary

  Calcium aluminates · CPC title

• C21C7/0645

  Agents used for dephosphorising or desulfurising · CPC title

• C04B2235/322

  Transition aluminas, e.g. delta or gamma aluminas · CPC title

• C04B35/62615

  High energy or reactive ball milling · CPC title