Bespoyasko E. Technological mineralogy of hypergeneously changed iron ores of Kryvyi Ryh basin Inguletske deposit

Features of geological structure of hypergene changes zone of banded iron formation of the deposit are examined. The layer of the fifth and sixth iron horizons was determined as main raw material base for poor hematite ores after the crust of weathering thickness. Vertical and horizontal mineralogical zonality of these stratigraphical horizons crust of weathering was described. It was shown that hypergene zonality succeeds to authigenous-metamorphogenetic mineralogical zonality of iron and schist horizons after main mineralogical characteristics. Data on mineral composition, structure and texture of hematite quartzites as characteristics determining their physical, technical indexes and their dressability as poor iron ores are shown. It was shown that noticeable increase of mean values of ore porosity and feeding productivity of mill as per newly created class as well as gradual decrease of actual and volumetric density and hardness of rocks are observed with the increase of intensiveness of hypergenechanges. After the results of poor iron ores dressability study it was determined that their mineralogical indexes condition bigger effectiveness of gravity technology of concentration (the concentrate grade is 67 mass %) comparing to magnetic one (60-62%).