Roasting is the main stage of production technology of electrode products. Heat exchange processes in burning furnaces for coal-graphite blocks are detailed investigated taking into account that heat exchange through a layer of fill is the limiting process of its moving over from a generation zone to a technological process zone at all stages of roasting. The developed mathematical model allows to count and predict thermobalance of the burning furnace in dynamics. It allows to use this model for optimization of burning curves for the purpose of the fullest use of heat from reburning of volatile product and low of fuel flow.