Process for producing liquid pig iron comprising recirculating agglomerated sludges

In a method of producing molten pig iron (13) or molten steel pre-products from charging substances formed of iron ore (4), preferably in the shape of lumps and/or pellets, and optionally of fluxes (5), the charging substances are directly reduced to sponge iron in a reduction zone (2), the sponge iron is charged into a melt-down gasifying zone (12) and, there, is melted under the supply of carbon carriers (10) and an oxygen-containing gas, wherein a CO-H2-containing reducing gas is generated that is withdrawn from the melt-down gasifying zone (12) and introduced into the reduction zone (2), is reacted there and is withdrawn as a topgas, wherein the topgas is subjected to scrubbing and the sludges thus separated are at least partially agglomerated. To utilize the agglomerates thus formed while expending as little energy as possible, the agglomerates are recirculated into the reduction zone (2).