Process for producing sponge iron by direct reduction of iron-oxide-containing material

摘要

PCT No. PCT/AT97/00236 Sec. 371 Date Sep. 30, 1998 Sec. 102(e) Date Sep. 30, 1998 PCT Filed Nov. 5, 1997 PCT Pub. No. WO98/20171 PCT Pub. Date May 14, 1998In a process for producing sponge iron by direct reduction of iron-oxide-containing material, synthesis gas is mixed with top gas forming in the direct reduction of the iron-oxide-containing material and is utilized as a CO- and H2-containing reducing gas for direct reduction and for heating the iron-oxide-containing material to a reduction temperature. To be able to save energy in an economically efficient manner when producing steel, especially in the refining process, direct reduction is carried out as follows: (1) in addition to the reducing gas, a carbon-containing gas, such as natural gas, or a gas having higher hydrocarbons is utilized for reduction; (2) the iron-oxide-containing material for a predetermined period of time exceeding the period necessary for complete reduction is exposed to the reducing gas and to the additionally supplied carbon-containing gas, and (3) a CO/CO2 ratio ranging between 2 and 5, preferably a ratio in excess of 2.5, is adjusted in the reducing gas.