[meteorite-list] EBAY Slag for sale

From: Randy Korotev <korotev_at_meteoritecentral.com>
Date: Mon, 09 Jul 2007 17:17:07 -0500
Message-ID: <200707092216.l69MGfr09274_at_levee.wustl.edu>

Sterling:

I didn't know about millerite, and I'm glad to
know more than I did. I talked to a colleague
who knows a lot about Missouri caves. He's seen
millerite, but he thinks it's volumetrically
rare. His reaction was the same as mine - it's a
mass-balance problem. In smelting iron ore a
given volume of metal would never be exposed to
enough limestone for the metal get pumped up to
600 ppm Ni. Geochemically, nickel is a
"siderophile" (iron-loving) element, so iron
metal would take all the nickel from the
limestone and the millerite it contained. But
the limestone would not likely contain more than
1 ppm Ni, perhaps all carried by millerite. So
the metal reduced from the ore would have to be
exposed to 600+ times its mass in limestone. I
don't think that happens. If the operation was
also deliberately roasting sulfides, however, it
probably wouldn't be a problem.

Another colleague asked, tongue in cheek, "How
much Ni would there be in the metal puddle left
if you melted a car?" His point (I think; this
was over Friday evening beer) was that even a
modern metal recycling operation would
occasionally get some nickel-rich metals.

Randy Korotev





At 14:07 06-07-07 Friday, you wrote:
>Hi, Randy, List,
>
> Starting out with a big disclaimer that this is
>all inexpert speculation, of course, I believe the
>source of nickel in Missouri slag meteor-wrongs
>could be the mineral millerite.
>
> Smelting is the reduction of iron ores with carbon
>as the reducing agent. Impurities in the ores are
>removed by the addition of a flux, usually limestone.
>In rural Missouri (and anywhere in the Midwest), it's
>pretty safe to say the flux is always limestone.
>
> The resulting slag will, of course, contain whatever
>was in the limestone, particularly if the material likes
>to combine with iron. Millerite is nickel sulfide, NiS.
>
> Quoting the Peterson's Rock and Mineral Guide:
>"Millerite is sometimes valued as an ore of nickel
>when present in minor quantities in association with
>other metallic sulfides in middle-temperature veins,
>as in Germany and the massive Sudbury, Ontario,
>sulfide complex. Locally it is sparsely distributed
>through limestones in central Mississippi Valley
>limestone quarries, particularly near St. Louis,
>Missouri, and Keokuk, Iowa. At these places
>long millerite hairs are found in cavities lined
>with crystals of calcite, dolomite, and fluorite. (An
>interesting, if improbable, speculation suggests the
>original source of this nickel might be a heavy
>Paleozoic meteor shower.) Coarser millerite needles
>have been found with hematite in Antwerp, New York,
>and in Alamos, Mexico."
>
> The use of limestone flux would likely concentrate
>all its nickel in the slag, and you would use more flux
>with poor ores, which are the ones likely to be used
>in a "backwoods" operation.
>
> Missouri has a lot of lead/zinc/copper/cobalt/iron
>sulfide ore belts, very extensive but low-grade localized
>deposits, called Olympic Dam deposits. The iron mine
>at Pea Ridge, Missouri, is a known Olympic Dam-type
>ore deposit. It would appear that rural Missouri would
>supply many low-grade local ores with mixed contents.
>(I found lots of references, all far too "geological" for
>me!)
>
> My half-cent's worth.
>
>
>Sterling K. Webb
>-------------------------------------------------------------------
>----- Original Message -----
>From: "Randy Korotev" <korotev at wustl.edu>
>To: <meteorite-list at meteoritecentral.com>
>Sent: Friday, July 06, 2007 9:52 AM
>Subject: Re: [meteorite-list] EBAY Slag for sale
>
>
>At 14:59 05-07-07 Thursday, STARSANDSCOPES at aol.com wrote:
> >I don't know why this slag tests positive for nickel, but it does!
>
>
>People have been making iron and disposing of the
>waste for several hundred years in this area and
>much of the US. The most common kinds of local
>meteorwrong I encounter are hematite nodules -
>iron ore - that weather out of the local
>limestone. This stuff has been used as feed
>stock for mom-and-pop iron smelting operations in
>the Ozarks since the 1800's. As Tom Phillips
>said, the processes were not as efficient as
>today, so a lot of iron metal was left
>behind. People have brought us all kinds of
>glassy stuff with metal in it, one of which even had the imprint of a bolt:
>
>http://meteorites.wustl.edu/meteorwrongs/m026.htm
>
>
>Two months ago a fellow came to my office with
>the ugliest 60-lb chunk of iron I've ever
>seen. He'd dug it up while "grub hoeing" in
>south St. Louis Co. There was no smooth surface,
>it was very rusty, and it was full of
>cavities. It didn't "look like" an iron
>meteorites to me, but I have no experience with
>iron meteorites that have been in the ground for
>100's to 1000's of years, so I really don't know
>what to expect. In a post 2 months ago, Eric
>Twelker said "Those of us who are lucky enough to
>have hundreds or thousands of meteorites pass
>through our hands possess a store of knowledge
>that has real value to academics that haven?t had
>this experience." I agree, and I wish I had that knowledge!
>
>I neglected to get a photo of the thing. I did a
>quick nickel test, though, with one of those
>nickel allergy test kits and got a positive
>result*. So, I cut a piece off and analyzed it
>for the Fe, Ni, Co, Au, and Ir. Strange results:
>
> >Fe 89%
> >Ni 600 ppm
> >Co 62 ppm
> >Ir 1 ppb
> >Au 12 ppb
>
>The object cannot be a meteorite because the
>concentrations of Ni and Co are 100x too low for
>metal in any kind of meteorite. Yet, the
>concentrations of Ni, Co, Ir, and Au are all
>higher that I would expect for iron smelted from
>iron ore. More weird is that the relative
>concentrations of those elements (ratios) are not
>out of line for an iron meteorite. It's as
>though the metal is 1% iron meteorite and 99%
>pure iron. I don't know what this thing is.
>
>Similarly, a fellow from Colorado sent this photo
>and a small sample a couple of years ago:
>
>http://meteorites.wustl.edu/meteorwrongs/m122.htm
>
>It is also a a man-made piece of iron, but one
>with far more Ni and Co than in any iron oxide ore I've ever analyzed.
>
> >Fe 90%
> >Ni 2590 ppm
> >Co 131 ppm
> >Ir <14 ppb
> >Au 85 ppb
>
>I don't get it.
>
>Randy Korotev
>
>
>* Note that the dimethyl glyoxime [DMG] test for
>Ni is very sensitive. If it gives a positive
>result for 600 ppm Ni, then it is too sensitive
>to really be of much use in distinguishing
>meteoritic metal from terrestrial metal. A
>negative result should be helpful, however, if the test is done correctly.)
>
>
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Received on Mon 09 Jul 2007 06:17:07 PM PDT