Preparation of barium iron oxides by the oxidation of iron in the Fe-Ba(OH)2-NaOH-H2O-O2system

✍ Scribed by S. Uchida; H. Kashiwagi; T. Sato; A. Okuwaki

• Publisher: Springer
• Year: 1996
• Tongue: English
• Weight: 544 KB
• Volume: 31
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00366361

✦ Synopsis

Iron was oxidized in the Fe-Ba(OH)2-NaOH-H20-O2 system at elevated temperatures. Fe304 and 0~-FeOQH were formed in the absence of oxygen. On the other hand, hexagonal plate-like particles of BaFe~2019, 1.0-4.3 #m diameter, were formed as single phase by the oxidation of iron in Ba(OH)2 and NaOH mixed solutions at 250-300~ and above 1.0 MPa oxygen. The diameter of the particle significantly depended on the NaOH concentration. Additives such as CO~-, SO42-and CHaCOO-promoted the grain growth of BaFe~20~9.