mel jacobson on sun 22 oct 00
>Date: Sat, 21 Oct 2000 23:33:59 -0400 (EDT)
>From: Tom Buck
>To: Mel Jacobson
>Subject: manganese dioxide vapours (fwd)
>
>mel,
> at 11+ pm Saturday, I checked my inbox and the post below didn't
>show up. So I am uncertain whether you oked it, and sent it to the list.
>Because sometimes that happens. the server doesn't send it to the
>originator.
> Please post. til later. love. tom.
>
>Tom Buck ) tel: 905-389-2339
>(westend Lake Ontario, province of Ontario, Canada).
>mailing address: 373 East 43rd Street,
> Hamilton ON L8T 3E1 Canada
>
>---------- Forwarded message ----------
>Date: Fri, 20 Oct 2000 14:28:11 -0400 (EDT)
>From: Tom Buck
>To: clayart forum
>Subject: manganese dioxide vapours
>
>Ron Roy's post (below) jogged my memory of a visit long ago (October 1973)
>to International Nickel's then new nickel refinery in Ontario. This plant,
>still in operation as far as I know, is quite unique in the world...it
>uses Carbon Monoxide gas as a reactant, that is, as the means of refining
>nickel/copper mattes (smelted ore).
> Using some exotic chemistry the plant's process converts metal
>oxides to "Carbonyls" which are GASES at low temperatures, the kind of low
>temperatures that Ron mentions below. These gases, Iron carbonyl, Nickel
>carbonyl, Copper carbonyl, other carbonyls, can then be cooled and
>liquefied, and the liquids subsequently "distilled" into different
>fractions of high-purity "streams". As separate "fractions" these
>hugh-purity carbonyls are then heat-treated to produce pure nickel
>granules, pure iron powder, and some copper metal. There is also a
>byproduct of other mixed metallics.
> The metallic Carbonyls are extremely toxic at very low doses (the
>INCO refinery has extreme safety measures underway at all times; in some
>sections, workers conduct themselves as if they were working in Outer
>Space). In an operating electric kiln, metallic carbonyls may be involved
>in the fumes coming off during firing. Recall that many claybodies have
>carbonaceous components, and Carbon Monoxide could be generated in place,
>and may react with metals like Manganese to form a volatile carbonyl at
>quite low temperatures.
> Take Ron's advice to heart, make sure your electric kiln is well
>vented to the outside, especially if you must work nearby in the studio
>while the kiln is active.
> keep well. Peace. Tom B.
>
>Tom Buck ) tel: 905-389-2339
>(westend Lake Ontario, province of Ontario, Canada).
>mailing address: 373 East 43rd Street,
> Hamilton ON L8T 3E1 Canada
>
>---------- Forwarded message ----------
>Date: Thu, 19 Oct 2000 23:09:11 -0500
>From: Ron Roy
>Reply-To: Ceramic Arts Discussion List
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: boiling point of manganese dioxide --
>
>It is worth noting that boiling points and melting points are not reliable
>indicators to vaporization. Copper and Chrome both fume at our
>temperatures - chrome in very refractory and yet it is fuming even at
>lower temperatures.
>
>RR
>
> >have appreciable vapor pressure well below its decomposition point; I
> >just don't know.
>
>Ron Roy
>93 Pegasus Trail
>Scarborough
>Ontario, Canada
>M1G 3N8
>Evenings 416-439-2621
>Fax 416-438-7849
>
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>melpots@pclink.com.
FROM MINNETONKA, MINNESOTA, USA
http://www.pclink.com/melpots (website)
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