Spongy iron mfr. - in conveyor oxidising-reducing furnace for raw material which is wetted and heated in vertical magnetic field

摘要

Spongy iron of high quality is produced in the ferrous powder industry by agglomeration of raw material, followed by its redn. at a high temp. The agglomeration includes wetting of the raw material and heating it to a temp. above the Curie pt. The wetting and the heating, lasting 5-8 min. in an oxidising gas atmosphere at 1000-1050 deg.C are carried out in a furnace in a constant magnetic field with vertically oriented magnetic force lines. Keeping the particles in a flocculated state until they sinter to a microporous structure facilitates the access of the reducing gas to every particle, reduces the intra-diffusion resistance and intensifies the redn. process, requiring less reducing gas and improving the spongy iron quality.