Abstract
The synthesis of ferrite under hydrothermal conditions for electromagnetic wave absorption materials was investigated using the exhaust alloy sludge from the aircraft manufacturing. The alkaline suspension of precipitates containing Ni, Cr and Co in sludge and Fe(II) was oxidized by the air bubbling at 25 °C and treated under hydrothermal conditions at 170 °C for 8 h. In the product at pH 12, all the metal ions were incorporated excepting Mo into the spinel ferrite structure.
The formation of spinel ferrite structure was also attained easily by the Schikorr reaction at the comparatively low temperature. This method has the effective possibility for the synthesis of higher crystalline and large particle ferrite as compared with the traditional method, and also has the possibility for the production of higher saturation magnetization. This matter may be useful for the electromagnetic wave absorption materials.
The spinel type ferrite could be easily formed from the waste by using the mild hydrothermal conditions.
