Separation Possible via Acids and Centrifuges?

Hello, I wasn't exactly sure where to post this kind of question but I
figured this was a logical choice (among a few others)...
Suppose you have a solid mixture of tungsten, gold, and other metals
that can be dissolved with aqua regia acid. Assume also that the
mixture contains only those metals and very, very tiny trace amounts
(less than 100 ppm) of anything else. Now imagine placing them, as
shavings, into a suitable container, like a pyrex beaker, into a
centrifuge. Also assume that the beaker can be heated as it spins to
help increase the speed of the acid action on the metals.
Assuming a relatively equal amount of each metal, would it be possible
to separate the metals into stratas or layers? It might be possible to
boil the acid off as it spins too. This way, a more dry particulate
may be left and separated, at least partially. The density near room
temperature (and not too far from aqua regia boiling point) for
tungsten and gold are quite close, 19.25 and 19.3 g/cm^3
respectively.
Does such a practice exist? How good of separation is possible? Could
it work in general for any metals dissovable, if given enough time
(maybe even with additional acid added after boil-off).
Thanks in Advance!
parlous
Reply to
parlous2112
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Modifications of these do exist - "Centrifugal Fast Sacn Analyzer" and "ore floatation" as an examples. Nature separates metals and their ores using gravitation and flowing water (best example: the gold found at Sutters mill CA that started to gold rush).
However, when metals are dissolved in acids they are at a lower thermodynamic state than when they were alloyed and cannot be separated as free elements (only as ions) by graviation or centrifugal forces alone - electron transfere must occur to free the metal ion into free metals - electroplating is the most direct but not necessarly the most energy efficent.
Boiling away the acid will leave the dissolved metals as chlorides and oxides (essentially ores). This is the main problem addressed in the field of extractive metallurgy.
Ed
Reply to
Ed
In my particular ore, I'm quite interested in extracting the gold first and worry about other particulates later. Here is a breakdown of the elements in my "ore":
Main contributors:
W Re Os Ir Pt Au
10-300ppm (estimated):
Te Hf Tm Er Yb
I've noticed the melting points of all the elements mentioned for the main contributors are quite high but gold is basically the lowest of them. Te and Yb are much lower than gold's but I was thinking if I pulvurized the ore as much as possible and then heated it to slightly above the melting point of gold, I could "leach" out the gold? From there, I could focus on separating the Au from Yb and Te directly for some profit. There is a significant portion of gold, as it can be seen due to the yellow tint and various SEM microphoto scans show.
Does anyone suppose this would be a viable approach? It is unfortunate that all the elements are fused together in the "ore" (which is not natural by the way). It is possible Au particles are literally wrapped inside other elements deposited. Therefore, milling or whatever to pulvarize the material would be crucial step. The predominant element will must certainly be W.
Thanks for all your help, it has been quite informative!
Reply to
parlous2112
the only thing that i can think of is the ability of W to form tungstates (WO4)-2, under oxidizing conditions.
i dunno....
dissolve it all in aqua regia, oxidize the heck out of it, precip the tungstate, then send the residue to a Au/PGM recycler?
not very elegant.
Reply to
beavith
How about zonal refining. RF loop. Think semiconductor refining. Many foundries have gone to larger and larger. You might be able to find a small unit for sale.
Martin Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net TSRA, Life; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal. NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member.
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snipped-for-privacy@gmail.com wrote:
Reply to
Martin H. Eastburn
It all comes down to economics - Gold metal can be extracted from any ore as long as the cost to extract does not exceed the market value of the extracted gold plus any market value of the tailings.
ED
Reply to
Ed

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