METHOD OF PRODUCING MOLTEN CRUDE IRON OR MOLTEN CRUDE STEEL, AND PLANT FOR CARRYING OUT THE METHOD

摘要

PCT No. PCT/AT96/00191 Sec. 371 Date Jun. 10, 1997 Sec. 102(e) Date Jun. 10, 1997 PCT Filed Oct. 8, 1996 PCT Pub. No. WO97/13880 PCT Pub. Date Apr. 17, 1997In a process for producing molten pig iron or liquid steel pre-products, from particulate iron-oxide-containing material by fluidization, the iron-oxide-containing material is prereduced in at least one prereduction stage (7) by aid of a reducing gas and subsequently is reduced to sponge iron in a final reduction stage (8), the sponge iron is melted in a meltdown-gasifying zone (11) under the supply of carbon carriers and an oxygen-containing gas, and a CO- and H2-containing reducing gas is produced which is introduced into the final reduction stage (8), is reacted there, is drawn off, subsequently is introduced into a prereduction stage (7), is reacted there, is drawn off, subjected to scrubbing and subsequently is carried off as an export gas and wherein at least a portion of the reacted reducing gas is purified from CO2, is heated and is used as a recycle-reducing gas for the reduction of the iron-oxide-containing material. To ensure reduction while avoiding the occurrence of "sticking", while also minimizing the amount of carbon carriers charged, a portion of the reducing gas flowing from the final reduction stage (8) into the prereduction stage (7) is branched off, washed, purified from CO2 and heated and subsequently is recycled to the final reduction stage (8) (FIG. 1).