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Information × Registration Number 0215U008301, 0114U002921 , R & D reports Title The studying of the transformation nature of weakly magnetic iron oxides/hydroxides into highly magnetic oxides under the influence of external factors to improve the processing technologies of natural and technogenic mineral raw materials. popup.stage_title Head Ponomarenko Oleksandr Mykolayovych, Registration Date 24-12-2015 Organization M.P. Semenenko Institute of Geochemistry, mineralogy and Ore Formation popup.description2 Collections of samples of iron ores from Krivyy Rig iron ore region were created. The phase transformation of hematite and goethite ores at temperatures up to 650°C in the presence biologically reducible raw materials, as well as mechanical activation were investigated. It was shown that under such influences weakly magnetic minerals transformed into magnetite. It was shown that isomorphic impurities in the structure of formed magnetite reduce its Curie temperature. The phase transformation of synthetic lepidocrocite by annealing up to 650°C in the presence of a reducing agent was investigated and it was shown that at such treatment lepidocrocite transforms to magnetite. The kinetics of transformation of the structure of iron oxides and hydroxides in aqueous medium (in the presence of iron salts and alkali) at 100° C and dry environment (by reducing with starch) were investigated. It is shown that such treatments leads to transformation of hematite and goethite into magnetite, while the saturation magnetization of formed samples increases considerably (up to 70 A * m2 / kg). The mechanisms of transformation of weakly magnetic iron oxides and hydroxides into highly magnetic iron oxides were proposed. Product Description popup.authors Брик Олександр Борисович Дудченко Наталія Олександрівна Юшин Олександр Олександрович popup.nrat_date 2020-04-02 Close