Titanium Oxide-Containing Aluminum Oxide Particles Based on Corundum Melted in an Electric Arc Furnace from Calcined Alumina, and a Method for the Production Thereof

• US 20150175769A1
• Filed: 11/23/2012
• Published: 06/25/2015
• Est. Priority Date: 11/25/2011
• Status: Active Grant

• Current Assignee: ImerTech SAS
• Original Assignee: Center For Abrasives and Refractories Research & Development C.A.R.R.D. GmbH
• Inventors: Sachse, Sebastian, Brger, Andreas, Kral, Alexander
• Granted Patent: US 9,163,128 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B02C 23/08 Separating or sorting of material, associated with crushing or disintegrating B02C23/18 takes precedence ; beater mills combined with sifting devices B02C13/13, B02C13/14; for tumbling mills B02C17/1835
• CPC Class Codes: C01F 7/027 Treatment involving fusion or vaporisation
• CPC Class Codes: C01F 7/38 Preparation of aluminium oxide by thermal reduction of aluminous minerals
• CPC Class Codes: C01P 2002/85 by XPS, EDX or EDAX data
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C04B 2235/5296 with a defined aspect ratio, e.g. indicating sphericity spherical constituents C04B2235/528
• CPC Class Codes: C04B 2235/72 Products characterised by the absence or the low content of specific components, e.g. alkali metal free alumina ceramics
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 35/622 Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
• CPC Class Codes: C04B 35/653 Processes involving a melting step
• CPC Class Codes: C08K 2003/2227 of aluminium
• CPC Class Codes: C08K 2003/2241 Titanium dioxide
• CPC Class Codes: C08K 2003/2244 of zirconium
• CPC Class Codes: C08K 2003/2272 Ferric oxide (Fe2O3)
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C09K 3/1409 Abrasive particles per se preparation of diamond C01B32/25

Abstract

Titanium oxide-containing aluminum oxide particles are based on corundum melted in an electric arc furnace from calcined alumina. The particles may have an aluminum oxide content of less than 97.0% by weight, a titanium oxide content ranging from 1.3% by weight to 1.8% by weight, and a zirconium oxide content of ranging from 0.02% by weight to 0.1% by weight. The aluminum oxide particles may have an arithmetic mean compactness of less than 0.8.

Claims

1. Titanium oxide-containing aluminium oxide particles based on corundum melted in an electric arc furnace from calcined alumina comprising the chemical composition:

Al₂O₃ greater than 97.0% by weight,

Fe₂O₃ 0.05% by weight to 0.2% by weight,

SiO₂ 0.1% by weight to 0.5% by weight,

TiO₂ 1.3% by weight to 1.8% by weight,

ZrO₂ 0.02% by weight to 0.1% by weight,

Na₂O 0.05% by weight to 2.0% by weight, and

others less than 0.2% by weight,

in each case based on the total weight of the melted corundum, characterized in that the ratio of the sum of the percentages by weight of Fe₂O₃, SiO₂, and ZrO₂ to the percentage by weight of Na₂O is less than 10.

2. The aluminum oxide particles according to claim 1, characterized in that the aluminum oxide particles encompass an arithmetic mean compactness of less than 0.8, wherein the measure for the compactness is the solidity (S), which is determined with the help of a picture analysis and which is defined as the ratio of the actual particle surface (A) to the convex particle surface (B).

4. A use of the aluminum oxide particles according to claim 1 for the production of abrasives and/or fireproof materials.

5. A use of the aluminum oxide particles according to claim 2 for the production of abrasives and/or fireproof materials.

3. A method for producing titanium oxide-containing aluminum oxide particles based on corundum melted in an electric arc furnace from alumina, comprising:

melting a mixture of Al₂O₃, TiO₂, SiO₂, and Fe₂O₃ containing raw materials in the presence of iron filings and charcoal in the electric light arc furnace,

cooling the melted mixture to obtain a solid block, which consists substantially of corundum, and

comminuting and processing of the corundum block into defined particle size distributions, wherein raw materials, which contain small quantities of contaminations, are thereby used as raw materials, chosen from the group consisting of calcined alumina, rutile, ilmenite, and iron ore in such quantities that titanium oxide-containing aluminum oxide particles comprising the chemical composition

Al₂O₃ less than 97.0% by weight,

Fe₂O₃ 0.05% by weight to 0.2% by weight,

SiO₂ 0.1% by weight to 0.5% by weight,

TiO₂ 1.3% by weight to 1.8% by weight,

ZrO₂ 0.02% by weight to 0.1% by weight,

Na₂O 0.05% by weight 2.0% by weight, and

others less than 0.2% by weight,

and an arithmetic mean compactness of less than 0.8 are formed, wherein the measure for the compactness is the solidity (S), which is determined with the help of a picture analysis and which is defined as the ratio of the actual particle surface (A) to the convex particle surface (B).