[meteorite-list] EBAY Slag for sale

Mon Jul 9 18:17:07 EDT 2007

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 haven¹t 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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