Half a croissant, on a plate, with a sign in front of it saying '50c'
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Gold panning non-submersible arc welder

  [vote for,

Owing to the current employment climate, MaxCo. has been exploring as many methods as possible for gold extraction.

Plan 73 is based on two facts:

(a) Gold is highly conductive
(b) Gold has a fairly low melting temperature
(c) Molten gold wets (and therefore bonds with) several other metals, such as silver.

With these points in mind, we have been developing the MaxCo. Gold-separating Arc Welding Device (or GAWD).

The GAWD consists of a series of pairs of metal plates, each arranged in a V-shape with a gap between them at the base of the V. The gap between the topmost pair is a few millimetres wide. The gap between the next pair is smaller, and so on until the gap between the last pair of plates is only about a tenth of millimetre.

The V-pairs are also tilted (if you're looking at the "V" profile, the plates are higher "into the screen" than they are "out of the screen").

Finally, since everything is better with vibration, we vibrate the whole thing.

An alarming voltage is now applied between the left-hand plates and the right-hand plates.

Next, we take either sand containing placer gold (that is, small particles of gold) or crushed rock containing some small amount of gold, and we pour it slowly into the topmost V.

Normal sand and grit will fall through the gaps in successive V's until it reaches a gap too small to pass through. At that point, it will be stopped, but the vibrations plus the front- to- back slope will cause it to spill out of the open face of the V.

Any gold particles, however, will sooner or latter fall through a gap which is just _slightly_ wider than they are. At this point, an electrical arc will form from one metal plate, across the gold particle, and on to the other plate.

Because gold melts quite easily, this arc will cause the gold particle to become welded to one or other (or both) of the two plates making up that V. If the now-welded particle spans the plates, it will create a small short-circuit between them.

When enough gold particles have been captured in this way, their short-circuiting effect will make it difficult to sustain a high voltage across the plates. At this point, we pause. We ramp up the current, sufficient to melt all the little gold bridges that have formed, and fire a blast of compressed air through the system. Any gold will either form a mist of small droplets which are captured by a filter system, or will flow onto the plates as a thin layer for later recovery - in either case, the gold "bridges" are broken, and the process can resume.

MaxwellBuchanan, Mar 17 2015


       Will this be more or less successful than trained magpies?
hippo, Mar 17 2015

       Almost certainly.
MaxwellBuchanan, Mar 17 2015

       Can it make gold teeth? Croissant hovers in anticipation of answer....
xenzag, Mar 17 2015

       Yes. Yes, it certainly can.
MaxwellBuchanan, Mar 17 2015

       I am concerned that as described, capture of a single piece of gold would require deactivation and clearing of the entire system. For example: the V sized to capture 1 cm nuggets of gold. After capture of one such nugget and formation of the bridge, additional nuggets stopped by that V will not be captured but will be vibrated out laterally and lost. The horror. It is hard for me to even type out such a scenario.   

       My solution: rather than plates, each V is modular, with voltage fed down strips that are insulated from one another. If a gold bridge forms, shorting out one strip comprising the V, the power is cut to that strip but remains on for the rest. One can thus collect several nuggets of gleaming gold per V rather than just one.
bungston, Mar 17 2015

       And if you make a dental mold and use it for your framework, you'll get gold veneers in the process.   

       Fashions change though...
normzone, Mar 17 2015

       //capture of a single piece of gold would require deactivation and clearing of the entire system//   

       It depends. As long as enough current can be supplied, you could tolerate several melted particles bridging the plates.   

       Also, if a particle persists as a "bridge", it will be kept molten by the passing current; if the plates are made of a metal wetted by gold, then this bridge will soon break as the gold is wicked away. Therefore, the system ought to keep running until there's a heavy enough buildup of gold on the plates that it forms a "lip" which can span the gap even when molten.
MaxwellBuchanan, Mar 17 2015

       Did GAWD visit you in a dream?
popbottle, Mar 17 2015

       No, but we sometimes meet for coffee.
MaxwellBuchanan, Mar 17 2015

       Arc welding a chunky nugget into place is one thing. But wouldn't a nugget melted by ohmic heating just fall thru the crack? It seems like you would want to turn off the juice to prevent that.   

       Ohmic heating. Ohmic heating. So rare that I get to use that term. I hope I have used it correctly.
bungston, Mar 17 2015

       Yes, a big melty nugget would drip through. But then it would drop onto the next pair of plates, and so on. And at each stage it will melt and tend to wick onto the surfaces.   

       A *really* big nugget might not wick onto the plates completely. But you're unlikely to find a really big nugget. I'm thinking more of placer deposits, where small particles of eroded gold are found in sand.
MaxwellBuchanan, Mar 17 2015

       If my dentist tells me this is no good, then you owe me a croissant AND a new gold crown.
xenzag, Mar 17 2015

       Silver corrodes.
MaxwellBuchanan, Mar 17 2015

       A corrode is the third electrode in a system. There's the anode (where anions migrate to); the cathode (where cations migrate to); and the corrode (where onions migrate to).
MaxwellBuchanan, Mar 17 2015

       Thanks, [bigs]. I have to admit I was a little worried for a while, having worked in the same lab for 23 years. Fortunately, I have landed a job as Product Evaluator for Smirnoff. I haven't actually told Smirnoff this, but I plan on working freelance.   

       If you look on the Smirnoff website, they have plenty of cocktail recipes. Inexplicably, though, none of them seem to include antidepressants or beta-blockers. This is a gap in the market and I'm expecting I can help them out there. And I wasn't planning on operating heavy machinery anyway, which means that I'm basically made for the job.   

       And, while we're on the subject (which is of course wildly off-topic; but it's my topic so what the heck), my condolences on your own. Life, in general, is at significantly less than 760mm Hg.
MaxwellBuchanan, Mar 17 2015

       /But you're unlikely to find a really big nugget/   

       I can see that big one now, when I close my eyes. But I've been looking at the sun so maybe that's it. I know those gold marbles are out there, on the alluvial flume, winking in the shadows of the sturgeon. Beckoning. Go ahead, call me mad. Mad, they called me. Mad! But I'll show them. I'll show them all!
bungston, Mar 18 2015

       //But I'll show them. I'll show them all!// Wouldn't you be better off not showing anyone?
MaxwellBuchanan, Mar 18 2015

       (+) For welding.
cudgel, Mar 18 2015


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