Preparation of Magnetite Particles from Hematite and Goethite in Aqueous Medium

Phase transformations of hematite and goethite iron ore by heating to temperature of 95 degrees C in aqueous Fe+2-containing water medium were investigated. The saturation magnetization of all initial samples was similar to 1 A.m(2)/kg, while the saturation magnetization of the samples after phase transformations increases greatly (up to 14 A.m(2)/kg for hematite iron ore sample). It was shown by X-Ray diffraction method that some phases transformed into magnetite. Results of this study can be used for solving of fundamental and practical mineralogical problems connected with transformation of weakly magnetic minerals into strongly magnetic magnetite.