Manufacture of acicular .gamma.-iron(III) oxide

US4061726A · kind A · utility

Assignee

• BASF SE

Inventors

• Manfred Ohlinger · Bischofswerda, DE
• Eduard Schoenafinger
• Guenter Vaeth · Schifferstadt, DE
• Heinz Stritzinger · Ludwigshafen, DE
• Eberhard Koester · Bischofswerda, DE
• Hans H. Schneehage · Bad Dürkheim, DE
• Werner Steck · Ludwigshafen, DE

Key dates

• Filing date: Oct 15, 1976
• Grant date: Dec 6, 1977
• Expiry date: Oct 15, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Goethite is obtained by reacting an aqueous solution of an iron (II) salt with an aqueous solution of an alkali metal hydroxide and oxidizing the resulting iron(II) hydroxide. The oxidation is carried out in three stages. In the first stage, from 4 to 15% by weight are oxidized in the course of from 0.4 to 5 hours, in the second stage from 60 to 85% by weight are oxidized in the course of from 1.5 to 6 hours and in a third stage the remaining amount of iron is oxidized.