摘要 |
PCT No. PCT/EP93/01290 Sec. 371 Date Mar. 18, 1994 Sec. 102(e) Date Mar. 18, 1994 PCT Filed May 21, 1993 PCT Pub. No. WO93/23575 PCT Pub. Date Nov. 25, 1993.For heating sponge iron to temperatures of about 850 DEG C. without substantial oxidation losses, there are provided at least two separate preheating stages at different temperatures, to which the sponge iron is successively fed and in which the temperature and the gas atmosphere are respectively individually controlled in such a way that a chemically neutral gas atmosphere is set in the first preheating stage at the lowest temperature and a reducing gas atmosphere is set in the last preheating stage at the highest temperature. The hot gas for the preheater is obtained at least in part from the waste gas from the melting furnace, to which the preheated sponge iron is fed. |