Аннотация
The relevance of this work consists in treatment of complex brown iron ores. Large volumes of off-balance ores are an additional source of production raw materials, however, there is still a problem of their treatment by effective complex methods. This work shows a possibility of using liquid hydrocarbons as the reducers during thermochemical preparation of brown iron concentrates of the Lisakovsky field to metallurgical conversion and studies the features and main regularities of a roasting process of Lisakovsky gravitymagnetic concentrate in the presence of liquid hydrocarbons. The initial concentrate was treated by solution of a liquid hydrocarbon reducer (oil: phenyl hydride: water), which was subjected to heat treatment with the subsequent magnetic dressing. Research by the X-ray phase analysis of reducing products has shown that the main phases of magnetic fraction of a roasted product are presented by magnetite in a small amount hematite and quartz. Generally, only relative intensity of peaks is changed. The thermodynamic analysis of interaction between the hydrocarbons, which are a part of oil, and iron oxides was carried out. This analysis allowed us to suppose a reducing mechanism for the brown iron ores by liquid reducers. The data obtained by the thermodynamic analysis are confirmed by experimental results. It is proved that with increasing hydrogen-to-carbon ratio the probability of proceeding reactions of interaction between oxide of iron (III) and liquid hydrocarbon increases. The differential and thermal analysis allowed us to study a heat treatment process of the Lisakovsky gravity-magnetic concentrate, which is pre-treated by oil solutions, as well as to show a possibility for proceeding the process of interaction between liquid hydrocarbon and ferriferous products of Lisakovsky gravity-magnetic concentrate. It is found that with increasing temperature in the treated samples of LGMK the hydrogoethite dehydration product interacts with hydrocarbons, which product is strongly magnetic magnetite.