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Recycling of scrap for high quality steel products
Author(s) -
Boom Rob,
Steffen Rolf
Publication year - 2001
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.200100090
Subject(s) - scrap , metallurgy , zinc , materials science , slag (welding) , raw material , waste management , tin , chemistry , organic chemistry , engineering
In an ECSC project several aspects of tramp element control in steel were studied by a group of steel producers and research institutes in the European Union. Upgrading of incinerator scrap and shredded automobile and consumer durable scrap was realised through size and density separation and by pre‐dismantling and sorting of goods before shredding. Removal of tin from tinplate by pre‐treatment with reactive gases was investigated. A dezincing process was developed by dissolution of the zinc‐alloy layer in caustic soda followed by electrochemical deposition of zinc. Results of laboratory scale trials showed that generation of high mass transfer between the phases metalslag‐gas as well as vacuum distillation of the solute elements influencing the evaporation rate can remove copper and zinc from steel melts. A mass balance for the distribution of zinc and lead between metal, slag and dust during scrap melting in an EAF was established. Additional sponge iron charging is a very efficient measure to lower zinc and lead content due to the CO boiling effect during melting.