Re-utilising iron rich wastes from integrated iron and steel plants is currently a problem, especially due to their unattractively low (yet still harmful) levels of zinc and lead. In the present project extensive investigations with various dusts and sludges from integrated European steel plants were carried out. This work has confirmed the particular suitability of the INMETCO process for the re-utilisation of such residues. As these residues are charged in the form of green (i.e. unfired) pellets, the process allows the utilisation of the wastes' own carbon as a reductant. A very close contact between oxides and reductants in the green pellet, as well as the problem-free use of temperatures up to 1350 C without sticking, enable both a virtually full metallisation and a complete volatilisation of the heavy metals within about 15 minutes. As the packed bed rests motionless on the rotary hearth during reduction, a rich secondary dust is produced simultaneously, which is almost free of pellet and coal fines, and has a zinc plus lead level of more than 50%. This secondary dust can be converted directly into zinc and lead without further enrichment.
Bibliographic Reference: EUR 13420 DE (1991) 210 pp., FS, ECU 18.75
ISBN: ISBN 92-826-2642-3
Record Number: 199111150 / Last updated on: 1994-12-02
Original language: de
Available languages: de