19 Oct
2002
19 Oct
'02
9:43 a.m.
Still... Oxygen produced after 1945 could also contain
trace radioactive contaminants. I dunno of a process
that produces bulk amounts of oxygen without contamination,
not even electrolysis of water. Remember even the seas & oceans
got radioactively contaminated since 1945.
I can imagine CERN wanting to use the cleanest steel
possible for their Large Hadron Collider. You don't want
to be swamped by various (avoidable) background events
in search for the "Higgs Boson". Their steel contamination levels
should be way down, even compared to the levels for use
in medical radiological equipment and the like.
I wonder if you could also use cast-iron for the steel making
proces?. In that case cast-iron from old bridges and building
reinforcements from before 1945 could be used.
Sipke de Wal
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----- Original Message -----
From: "Stan Pietkiewicz" <pietstan(a)rogers.com>
To: <cctalk(a)classiccmp.org>
Sent: Saturday, October 19, 2002 12:19 AM
Subject: Re: OT: Clean steel?
Sellam Ismail wrote:
<<snip>>
process,
and therefore contains no radiation. Apparently,
air since the first
atomic bomb test is now filled with background radiation, and because so
much air is used in the smelting process, a lot of the radiation gets into
modern steel making it unsuitable for some applications (such as medical
test equipment where radioactive isotopes are used as part of the
operation).
Unless the steel is refined using either the open hearth or the Bessemer
there is no "air" used at all. Both of these processes were notorious for air
pollution problems. More commonly, in the last 40 years or so, steel refining
is
done
using the basic oxygen steel process. Pure oxygen is blown into a
brick-lined vessel charged with liquid iron and scrap steel and the
impurities burn off at. Alloying elements are added as needed, and the
steel is poured off into ladles, and further processed. Electric arc
furnaces are also used for specialty steels (stainless comes to
mind....) and probably other applications as well.
The bottom line is, there are more efficient ways to make steel than to
use air to burn off the impurities...
Stan