Improving Thermal Compaction of Siderite Fine Fraction

To effectively process siderite fine fraction, it is proposed to carry out its heat treatment in rotary kilns with the addition of carbon-containing components (high-moor peat). Using the patterns of the siderite compaction kinetics in an oxidizing environment in an isospeed heating mode, seven regime periods are identified: drying, heating, carbonate decomposition, oxidation of ferrous oxide, solid-phase reactions, re-oxidation of magnetite and melting. It is experimentally shown that an increase in the addition of peat in the composition of the initial siderite samples leads to a shift of the heating zone in the rotary kiln to the region of lower temperatures, obtaining a minimum value of expansion phenomena with a peat content of about 3.0%, a decrease in the required dissociation siderite temperature with an increase in shrinkage phenomena, a shift in the oxidation conditions of ferrous oxide to the region of lower temperatures. Solid-phase and liquid-phase reactions begin to occur at temperatures 30–35°C lower than without peat. This helps to almost double the shrinkage phenomena with an increase in the strength properties of the final materials, an increase in the yield of the roasted product by 5–15% and a reduction in the required energy consumption from an external source by 10–15%.