The Bakal Mining Administration was asked to burn iron ores in a rotary furnace in the presence of solid fuel additives for more in-depth use of them. The kinetics studies of their characteristics of heat treatment in air at a heating rate of 10 grad./min made possible to identify seven process steps: drying, preheating dissociation of the carbonates, iron oxidation, formation of sparingly soluble silicate melt, accompanied by a change in their state, and the heat sealing conditions. The studies of changes of linear dimensions siderite samples during the isospeed heating made possible to establish the strengthening conditions for their structures in selected stages of heat treatment. The results of industrial test of firing of siderite of class (10 - 0) mm in a rotary furnace, heated with natural gas in the presence of additives coke are presented. The possibility of achieving the output burnt fraction to62.07 % is described for the thermal efficiency of the unit - 77,27 %.