Continuous production of iron oxide hydroxide

US4112063A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Gunter Buxbaum · Krefeld, DE
• Franz Hund · Krefeld, DE

Key dates

• Filing date: Dec 3, 1976
• Grant date: Sep 5, 1978
• Expiry date: Dec 3, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01G49/06
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

In the production of an FeOOH seed suspension, comprising contacting an iron(II) salt solution with a basic precipitant to form a basic iron(II) salt or hydroxide suspension, oxidizing the salt or hydroxide, the precipitation and oxidation steps being carried out locally separate from one another and recovering a suspension of FeOOH, the improvement which comprises PA1 (a) effecting the precipitation by mixing an about 1 to 20% by weight iron(II) salt solution with sufficient basic precipitant to precipitate about 25 to 95 atom % of the iron(II), PA1 (b) at another location oxidizing 10 to 50% of the iron(II) precipitated in (a) over a period of from about 0.5 to 5 hours at a temperature in the range from about 20.degree. C to 65.degree. C, PA1 (c) at another location oxidizing the suspension obtained in (b) with intensive mixing over a period of from about 0.01 to 1 hour to oxidize at least about 10% more iron until up to at most about 60% of the iron(II) precipitated in stage (a) is oxidized, and PA1 (d) at another location substantially completely oxidizing the precipitated iron(II) still present over a period of from about 1 to 10 hours. Advantageously the temperature rises pro…