To add a comment, my experience of slag inclusion embedded in ferrous
artefacts coming from bloomery process indicate that low iron Slag Inclusion
coming from the reduction are in most of case in high carburised zone and
that is the only zone were it is possible to find it . This observation was
also made by other authors as Buchwald....
-----Message d'origine-----
De : Arch-Metals Group [mailto:[log in to unmask]] De la part de
David Killick
Envoyé : mercredi 18 mai 2005 01:06
À : [log in to unmask]
Objet : Re: Manganese in bloomery process
Hi Lee,
A very useful response - I wish that you had been at the British Museum
meeting earlier this week to hear at first hand the influence that your
experiments have had on Peter Crew's recent thinking!
In response to your observation that:
"In the hearth zone of a bloomery, carburised iron in contact with iron
rich slag will reduce iron from the slag, and decarburize the metal. In a
hot slag bath, decarburization and reduction are two sides of the same
coin."
This needs qualification. True enough if there is a lot of free iron oxide
in the slag, but not true is there isn't. In some of my own studies of slags
from African furnaces I've seen tap slags that contain essentially no free
iron oxide at all - all the iron that they contain is bound (once
solidified) up as silicates or as glass. These furnaces produced high carbon
steel blooms containing very little entrapped slag. So your coin has more
than two sides - it is possible in some cases (and the cases that I'm
referring to are big induced-draft furnaces) to have low-iron slags AND
high-carbon blooms that are clean enough to require little refining.
David Killick
Associate Professor
Department of Anthropology
University of Arizona
Tucson, AZ 85721-0030
U.S.A.
phone (520) 621-8685
fax (520) 621-2088
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