| 摘要 |
FIELD: foundry industry. SUBSTANCE: iron ore 4 is reduced to sponge iron in direct metal reduction zone 2, sponge iron is smelt in smelting gasifying zone 15 whereto carbon-containing material is charged when being saturated with reducing gas to produce slag 17. Reducing gas is introduced into direct metal reduction zone 2 where it undergoes reaction and is withdrawn as blast-furnace gas. Reducing and/or blast-furnace gas is subjected to wet cleansing and separated sludge is combined with binder 30 and coal fines and then agglomerated. In order to sludge participating in direct iron ore reduction could be returned into direct reduction zone 4 in large amounts not affecting the overall process, (i) sludge is separated during the wet cleansing and dehydrated to have a certain residual moisture before further treatment; (ii) to sludge, coal fines and, as binding agent, rapidly hardening lime (30) are then admixed; (iii) sludge is granulated; and (iv) produced grains are loaded into smelting gasifying zone 15 when raising basicity of slag 17 to maximum 1.25, advantageously to maximum 1.20. EFFECT: improved process. |
