METHOD FOR PRODUCING DIRECT-PROCESS IRON IN MULTIPLE-HEARTH FURNACE Russian patent published in 2003 - IPC

FIELD: metallurgy. SUBSTANCE: method involves using multiple-hearth furnace provided with several hearths arranged one above another with higher temperatures in lower hearths; continuously charging ore on highest hearth of multiple- hearth furnace, from which ore is gradually moved to lower hearths; feeding reducer to highest and/or to one of hearths positioned below highest hearth to provide for reaction between reducer and ore, which results in obtaining direct- process iron; supplying through lower half of side wall oxygen-containing gas, which reacts with part of reducer to produce reducing gas reacting with ore with formation of direct-process iron; discharging direct-process iron together with remaining reducers from furnace lower hearth. Method allows cheap reducer with comparatively high ash content to be used and /or process to be carried out with excessive amounts of reducer. EFFECT: increased efficiency and reduced production costs. 12 cl, 2 dwg