[meteorite-list] "I've been a miner for a heart of ....

From: John Cabassi <john_at_meteoritecentral.com>
Date: Sun, 7 Apr 2013 17:10:40 -0700
Message-ID: <CAFBTX4xftoAGmEGW+S13phNRptMf2cOmruidNz0Yz3830NXrxQ_at_mail.gmail.com>

G'Day List
I think I'll just sit around and wait for visitors from other galaxies
to turn up and cut a deal with them. They already know how to zip
around this universe :-)

Cheers
John

On Sun, Apr 7, 2013 at 3:39 PM, Alan Rubin <aerubin at ucla.edu> wrote:
>
> As long as we're being serious, Jeff has zeroed in on the most valuable
> property of asteroids -- water. Until and unless manufacturing occurs off
> the Earth, it is unlikely that PGE mining of asteroids will be
> cost-effective. But as humans again start exploring space beyond low Earth
> orbit, water will be a highly valuable commodity. Capturing carbonaceous
> asteroids that contain 8-12 wt.% water will enable manned missions, where to
> some extent, astronauts could live off the land like old-time invading
> armies. If we could also learn to eat asteroids and use them for fuel, that
> would be a great energy savings -- much less mass would have to be lifted
> off the Earth.
> Alan
>
>
> Alan Rubin
> Institute of Geophysics and Planetary Physics
> University of California
> 3845 Slichter Hall
> 603 Charles Young Dr. E
> Los Angeles, CA 90095-1567
> phone: 310-825-3202
> e-mail: aerubin at ucla.edu
> website: http://cosmochemists.igpp.ucla.edu/Rubin.html
>
>
> ----- Original Message ----- From: "Kevin Kichinka" <marsrox at gmail.com>
> To: <meteorite-list at meteoritecentral.com>
> Sent: Sunday, April 07, 2013 2:35 PM
> Subject: [meteorite-list] "I've been a miner for a heart of ....
>
>
> ....platinum (with apologies to Neil Young).
>
> Team Meteorite:
>
> This 'string' regarding 'asteroid mining' has attracted the scholarly
> attention of the Rubin's and Grossman's and seems worth tying into a
> couple more knots.
>
> I'm all thumbs though when tying knots, so subject to peer review
> which I will cheerfully accept from my uber peers Rubin and Grossman
> (as well as my everyday peers on this forum).....
>
> ..... here's some more facts and data dug from two mining company
> websites, hopefully properly interpreted by me, the mini-peer :>)
>
> ************************************************************************
>
> On Earth, typically ten tons of ore must be crushed and refined to
> yield one oz of platinum or platinum group metals (pgm).
>
> ***********************************************************************
>
> That fact informs me that an unsupervised process in a harsh
> environment like found on an asteroid in space will have a lower
> yield.
>
> The main concept of all this discussion is that bulk rock has to be
> processed for shipping in a small package.
>
> Next up is an abridged description of the process of mining ore to
> acquire platinum group metals(pgm), compiled/copied from two websites
> of mining companies in Africa, probably the richest source of Earth's
> pgm.
>
>
> *Concentration
>
> The ore is ground to liberate mineral particles. These are then
> recovered in the form of a concentrate by froth flotation. The ore
> mineralogy dictates both the fineness of grind required for liberation
> and the ideal flotation conditions. Very fine particles are difficult
> to recover, so two or even three milling and flotation stages may be
> used to minimise losses caused by over-grinding.
>
> There are minor differences in the details of the equipment and
> operations employed.... processing a metallic concentrate rich in PGMs
> is sometimes produced in addition to the flotation concentrate. This
> concentrate can be sufficiently rich to by-pass the smelter and be
> sent straight to base metal removal.
>
> *Smelting
>
> The concentrate is melted in an electric furnace. Large units with six
> electrodes in line are used for smelting concentrates.Upon melting,
> the concentrate separates into two layers. The upper layer is a
> silicate/oxide slag which is tapped off and then either discarded or
> returned to concentration. The lower layer is a sulphide motto which
> is sent for converting.
>
> The flotation-concentrate composition must be suitable for smelting.
> Its rock mineral content should produce a fluid slag at the desired
> temperature. At the same time, it must contain enough sulphides to
> form a reasonable quantity of matter. To compensate for minor problems
> with chemical composition, various fluxes are added. Typically, the
> main addition is burnt lime or limestone but other materials such as
> carbonaceous reductants, sulphides, oxides or silicates are used as
> necessary.
>
> *Base metal removal
>
> Base metals are removed from the converter matte either by leaching or
> by a combination of magnetic separation and leaching processes.
> Problem elements such as selenium, arsenic and tellurium are also
> removed. The concentrate which results is sent for further processing
> into refined precious metals. Base metals are a valuable by-product of
> PGM extraction. Their further refining by the various producers is
> largely dictated by economies of scale.
>
> Refining
>
> Precious metals refining processes have developed considerably in
> recent years. The older or ?classical? process involved first roasting
> the PGM concentrate. This made the rhodium, iridium and ruthenium
> insoluble in aqua regia. The platinum, palladium and gold were then
> dissolved and separated by a series of sequential precipitations, The
> remaining residue was then upgraded by pyro-metallurgical and leaching
> processes before being separated into individual metals. Final
> purification of all metals was by repeated dissolution and
> precipitation.
>
> Improved separation and refining procedures have become available for
> all of the precious metals. These commonly involve operations such as
> solvent extraction or ion exchange. They are being introduced either
> to replace procedures in the classical process or as part of
> completely new refining processes. Advantages such as improved
> precious metals recovery, lower refining costs and shorter processing
> times are being claimed.
>
>
> ********************************************************************************************
>
> Additional notes:
>
> The first step in the mining process uses explosives to break the
> rock, then it is loaded onto conveyor belts and delivered to machines
> to be crushed into fine particles.
>
> The "froth flotation" mentioned during the concentration stage
> consists of 'flotation separation' where finely ground pgm particles
> adhere to air bubbles in an aeration tank where they float to the top
> and are skimmed off.
>
> "Ore from different areas of the same mine can have quite different
> characteristics" which I presume to mean varying pmg concentrations
> and varying ratios and types of associated base metals either of which
> would call for a variable processing regime.
>
> Today's Conclusion by this mini-peer - At this point in the
> discussion, I remain skeptical of the economic viability of this
> scheme. I have some expertise in 'mining' because I follow
> precious/base metals and mining companies daily while trading equities
> (my main 'job').
>
> While the price of gold might seem high this year, the miners are not
> enjoying higher share prices, in fact they are being crushed (that's a
> pun). Why? They borrow a lot and/or dilute shareholders with
> additional share offerings because it costs a lot to be a mining
> company even before political risks (acquiring permits,
> taxation/royalties/expropriations) are considered. It's a bad
> business.
>
> The 'low apples on the tree have been picked' and the remaining
> resource metals are now either deeper in the ground or of lesser
> concentrations. Coupled with higher energy, labor, and transport costs
> from ever more remote regions, this means 'owning a gold mine' ain't
> what it used to be.
>
> The processes described in those two websites work well with gravity
> and when power to create high temps, fuel to power machines, and water
> for everything else is readily available.
>
> Engineers like difficult problems so -
>
> - hauling machinery millions of miles away or -
>
> - setting up 3D fabricating machines (and you still need refined metal
> to duplicate the machine you want to manufacture),
>
> - then controlling rocks blown into small pieces in a weightless
> environment,
>
> - in an airless setting where O2 is needed for bubbles in a tank of
> (yep) water (need to make that, too)
>
> - so that your specific crushed rock particles float to the top when
> in a weightless environment there is no 'top',
>
> - to be concentrated, fluxed, separated, leached and refined,
>
> - THEN freight the finished product home as 'foam balls of concentrate' to
>
> - safely re-enter Earth's atmosphere 'somewhere' to be collected and
> shipped for further refinement and sale on an ongoing basis from a
> planetoid millions of miles away all without direct adult supervision,
>
> - while accountants on Earth calculate the revenues and sales and
> declare some risk-taker wise and wealthy....
>
> ...will make a lot of engineers ecstatic.
>
> Did this first appear on April One?
>
> Sure FOOLED me.
>
> "I want to live,
> I want to give
> I've been a miner
> for a heart of gold.
> It's these expressions
> I never give
> That keep me searching
> for a heart of gold
> And I'm getting old.
> Keeps me searching
> for a heart of gold
> And I'm getting old."
>
>
> Kevin Kichinka
> Rio del Oro, Santa Ana, Costa Rica
> www.theartofcollectingmeteorites.com
> 'The Global Meteorite Price Report - 2013'
> Marsrox at gmail.com
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Received on Sun 07 Apr 2013 08:10:40 PM PDT