METHOD OF HEAT TREATMENT OF PELLETS ON CONVEYER ROASTING MACHINE

摘要

FIELD: ferrous metallurgy; applicable in preparation of raw materials for blast-furnace production. SUBSTANCE: method includes successive laying of bottom bed and two layers of pellets onto carriages of conveyer roasting machine. Supplied to lower layer are pellets sizing 12-18 mm with porosity of 38-42%. Supplied to upper layer are pellets sizing 12-18 mm. Drying of pellets is carried out by heat carrier filtration. Height of lower layer amounts to 50-60% of total height of layers. Drying is effected by filtering of heat carrier from top to bottom in two stages. First, lower layer of pellets is dried at velocity rate of 1.0-1.5 m/s, and after laying of the second layer, velocity of heat carrier filtering is maintained within 0.55-1.3 velocity of heat carrier filtering through lower layer. EFFECT: intensified process of heat treatment and higher quality of roasted pellets. 1 ex