Method for cleaning of aluminum oxide powders

US5914024A · kind A · utility

Assignee

• ABB Flaekt AB · SE

Inventors

• Lothar Schuh · Plankstadt, DE
• Helge Jansen · Friedland, DE

Key dates

• Filing date: Jun 24, 1997
• Grant date: Jun 22, 1999
• Expiry date: Jun 24, 2017

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B03B1/00
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A method and a cleaning device for the mechanical cleaning of a powder, in particular of primary aluminum oxide, direct the powder against a surface in order to strip particulate impurities adhering to the surface of the powder. The aluminum oxide to be cleaned is introduced into a stripping device having a striking mechanism directing the powder with a speed of 20 to 30 m/s several tens of times per second for a time period of <1 to 10 seconds against impact blades rotating in a direction opposite to the striking mechanism The particles of the cleaned, powder-form aluminum oxide having a size of >10 .mu.m are separated from the cleaned, powder-form aluminum oxide having a size <10 .mu.m and the impurities by an air sifter and/or a cyclone and are fed for smelting electrolysis. The powder-form aluminum oxide having a size <10 .mu.m and the impurities are fed to a waste dump or are further processed as raw material.