STEEL GRIPS online - Reduction of mill scale generated by steel processing

STEEL GRIPS online
ISSN 1866-8453

Last updated:
________________
Feb 3, 2012

Search STEEL GRIPS

from TOP

Raaft Farahat, Mamdouh Eissa, Gamal Megahed, and Amin Baraka:
Reduction of mill scale generated by steel processing

Reduction, sponge iron, recovery, mill scale, waste

Mill scale is one of the by-products produced during steel processing and its specific production is considerably high representing about 19-40 kg/t of hot rolled product, depending on the deformation technology used. The global production of steel during 2008 was 1125 million t and the corresponding mill scale produced is estimated to be 33 million t on average. On the other hand, mill scale is considered as a rich iron source (> 70 % Fe) with minimum impurities. Extensive research is being conducted for the recovery and utilization of the iron oxide that mill scale contains. Mill scale is used for magnetic storage, polishing, chemical manufacturing, pigment manufacturing, and biomedical application. The production of sponge iron from scale could be considered a highly profitable method of beneficiation.
In this study, the reduction of composite pellets produced from mill scale using anthracite coal was investigated. Laboratory scale trials have been conducted to study the effect of the amounts of reducing agent, reduction temperature and reduction time. The trial results show that it is possible to use mill scale as raw material in blast furnaces as well as in direct reduction plants producing sponge iron characterised by 84 % Fetotal, 82 % metallic Fe and metallization degrees of more than 97 %.