Turn Mercury into Gold Cheaply?

[7up]

Gold obtained by mining has copper and silver impurities. Gold of higher purity can be made through the photoneutron process:[citation needed]

Mercury 198 + 6.8MeV gamma ray --> 1 neutron + Mercury 197 (half-life 2.7 days --> Gold 197 + 1 positron)

Sorry I can’t post the link, I’m new. Google: wiki synthesis of precious metals

My question is what happens to Mercury 197 if it’s hit by a 6.8 MeV gamma ray? If nothing happens then it would complete the decay to Gold 197. If that’s the case couldn’t you just put a naturally occurring substance that emits 6.8 MeV gamma rays in a container filled with Mercury 198 and wait for it to turn to gold? BTW I’ve read the threshold for gold is 8.1 MeV before it becomes radioactive.

If gold can be made this cheaply then the current price of $1562/ounce (about $600 when the wikipedia article was written) is a tad high since oil companies turn out thousands of tons of Mercury as a by product every year.

Assuming it’s not that easy, then if you radiated a thin layer of Mercury 198 (6.8 MeV is about the same energy level food is irradiated with) then waited two days, couldn’t you just use something like this:

Google: Scientists synthesize gold to shed light on cells' inner workings

to lump the gold atoms together cheaply, or maybe single gold atoms melt together cheaply?

Who knows, gold may even still work as money, and what a lovely way to get rid of toxic mercury – unless there are other plentiful elements that can be transmuted cheaply to gold.

 

[Skeptical Greg]

I hear lead works pretty well..

 

[Andy_Ross]

Alchemy Lives!

 

[7up]

In a nuclear kind of way.

 

[geni]

If that’s the case couldn’t you just put a naturally occurring substance that emits 6.8 MeV gamma rays in a container filled with Mercury 198 and wait for it to turn to gold?

1)It's unlikely that there are any
2)Natural sources of radiation are pretty weak so the amount of gold you got out would be below the level of gold thats already in the Mercury as an impurity.

 

[AsleepAtTheKeyboard]

I'm guessing that a lot of the trouble will come from getting those gamma rays to be absorbed by the mercury. Even if you have a ton of mercury around the gamma emitter, the resulting gold atoms are just going to be that diffused. Then, even if you can get a significant percentage of the gamma rays absorbed, you need a source material that produces large numbers of gamma rays of sufficient strength. Per atom, I doubt you're going to find a source cheaper than gold.

I hold no nuclear science degree however. I'm just posting this in hopes one of the real physicists on the forum will swoop in to prove me wrong so I can learn something.

 

[WhatRoughBeast]

My question is what happens to Mercury 197 if it’s hit by a 6.8 MeV gamma ray? If nothing happens then it would complete the decay to Gold 197. If that’s the case couldn’t you just put a naturally occurring substance that emits 6.8 MeV gamma rays in a container filled with Mercury 198 and wait for it to turn to gold? BTW I’ve read the threshold for gold is 8.1 MeV before it becomes radioactive.

If gold can be made this cheaply then the current price of $1562/ounce (about $600 when the wikipedia article was written) is a tad high since oil companies turn out thousands of tons of Mercury as a by product every year.

First, please find a source of 6.8 MeV gamma radiation. Cobalt-60 and Caesium-137 (the standard food irradiators) both give off gammas less than 1.2 MeV.

Second, consider that for every atom of gold produced, you need a gamma source atom to decay. Assuming something with half the density of gold and about the same atomic number, for every pound of gold you need a half pound of donor material. And unless you're willing to wait a long time for all of the the donor atoms to decay, you need a really short lifetime. Producing kilogram lots of savagely radioactive material is not likely to be cheap. Then you add the price of handling and safety systems.

Assuming it’s not that easy, then if you radiated a thin layer of Mercury 198 (6.8 MeV is about the same energy level food is irradiated with)

Please read http://en.wikibooks.org/wiki/Basic_Physics_of_Nuclear_Medicine/Attenuation_of_Gamma-Rays

Now figure the half value layer for 6.8 MeV. You're probably talking meters. How much of this acutely penetrating radiation will be stopped by a thin layer of mercury? And how does this affect the donor/gold ratio? And how does this affect the economics?

Sorry, 7up. I'm afraid the universe is conspiring against you.

 

[7up]

2)Natural sources of radiation are pretty weak so the amount of gold you got out would be below the level of gold thats already in the Mercury as an impurity.

From Wikipedia

Gamma rays from radioactive decay commonly have energies of a few hundred keV, and almost always less than 10 MeV.

 

[Mister Earl]

In retrospect, considering the cost of gold, I'm kind of surprised there aren't alchemy scams galore going on.

 

[7up]

They also use:

(ii) Electrons (bremsstrahlung) generated by a machine at maximum energy of 10
million electron volts (MeV).
(iii) X-rays generated by a machine at a maximum energy of 5 MeV

to irradiate food.

I see what you mean about energy loss from the gamma rays missing their target. And I take it that you're saying "Producing kilogram lots of savagely radioactive material is not likely to be cheap. Then you add the price of handling and safety systems," means doing that is still far more expensive than the current price of gold.

Sorry, 7up. I'm afraid the universe is conspiring against you.

You mean you think I'm interested in making it? No, I'm not, but if it can't be made cheaply, it's a good investment. Unless there's a cheap energy source that makes fusioning it cheaply?

 

[Dr. Trintignant]

The idea isn't utterly ridiculous.

I'm assuming that we'll have to produce the gamma rays ourselves, since no one has named a suitable natural decay source. This leaves synchrotrons and such. Most of these seem to be in the keV range, but perhaps a more powerful one could be built.

So, some math:
E = 6.8 MeV/atom = 1.089e-12 J/atom
L = 6.022e23 atoms/mol
A = 196.97 g/mol
EL/A = 3.329e9 J/g

1 kW-h = 3.6e6 J
924.7 kW-h/g

1 kW-h =~ $0.05 (wholesale electricity prices)
1 g Au =~ $46

This is slightly less than the current price of gold (~$50). Of course, those are pretty slim margins given the capital costs and waste (which is probably going to be quite high). You would likely want to send the beam through a long column of mercury, and then extract the small amount of gold produced.

If electricity goes down in price by a factor of 10 compared to gold, it might just be worth it, though...

- Dr. Trintignant

 

[DC]

[citation needed]

 

[Skeptic Ginger]

[citation needed]

I take it you are quoting the Wiki entry. Other sites I found merely copied the Wiki entry.

Then I found a reference on the Ron Paul free for all blog? (or whatever it is), saying to Google "Phil Schneider how to make gold"

And from that I found this ludicrous claim: Philip Schneider's Formula for making Gold !!!,

Apparently people just suck up the nonsense.

7up: Just type out the link with a few extra spaces in it and we can figure out the link you can't post.

 

[Ziggurat]

Mercury 198 + 6.8MeV gamma ray --> 1 neutron + Mercury 197 (half-life 2.7 days --> Gold 197 + 1 positron)

Assuming 100% efficiency in photon capture and transmutation, for 1 mol of gold, we need about 6.5x10¹¹ Joules, or 1.8x10⁵ kW hr. At (say) 10 cents per kw hr, that would cost around $18,000 dollars. 1 mol of gold is about 197 grams/mol. At a current price of about $50/gram, that mol of gold would be worth about $9,850 dollars.

So at perfect conversion efficiency, transmutation is a waste of money, even at today's elevated gold prices. You'd need gold to roughly double before a perfectly efficient conversion process would be worthwhile. But of course, conversion efficiencies won't be perfect. They won't even be close to 100%, which means even a doubling of gold prices (and assuming energy prices don't rise too) wouldn't make this anywhere close to profitable.

The energy needed to convert mercury to gold is more valuable than gold is. This is a losing proposition.

 

[Ziggurat]

If electricity goes down in price by a factor of 10 compared to gold, it might just be worth it, though...

That's roughly the break-even point if you ignore capital costs and other overhead, assuming a 10% efficiency. I think that high an efficiency is far too high. I doubt the conversion efficiency is even 1%.

 

[Skeptic]

If it is possible, the sole result would be to make gold as cheap as lead, since its value is (practically) all due to scarcity.

 

[Dr. Trintignant]

That's roughly the break-even point if you ignore capital costs and other overhead, assuming a 10% efficiency. I think that high an efficiency is far too high. I doubt the conversion efficiency is even 1%.

Yup. I pulled the 10x out of my ass, of course. Thoughts on where the major efficiency losses would be? It seems that the synchrotron could be made to be fairly efficient. I'm not sure about the gamma ray capture. Would most of it turn to heat, even with a finely-tuned energy level?

I was actually surprised that the cost of energy was even within an order of magnitude of the price of gold, even assuming perfect efficiency...

- Dr. Trintignant

 

[Ziggurat]

If it is possible, the sole result would be to make gold as cheap as lead, since its value is (practically) all due to scarcity.

Current lead price: $1.15/lb
Current copper price: $4.25/lb

Gold will never drop below the price of copper, no matter how common it becomes, because it's superior to copper for most of copper's uses (a thermal and an electrical conductor). Lead, on the other hand, has fewer uses and more problems (ie, toxicity), so it is likely to remain cheaper regardless of supply. So copper makes a much better source of comparison for theoretical low-scarcity pricing of gold than lead does.

 

[Ziggurat]

Yup. I pulled the 10x out of my ass, of course. Thoughts on where the major efficiency losses would be?

The biggest source of inefficiency is simply that most photons hitting a mercury atom aren't going to eject a neutron. Most of them will scatter off the electrons surrounding the nucleus.

It seems that the synchrotron could be made to be fairly efficient.

In the generation of photons, yes. But the transmutation process cannot be made efficient.

I'm not sure about the gamma ray capture. Would most of it turn to heat, even with a finely-tuned energy level?

Exactly. That's energetic enough to ionize mercury, so it doesn't matter what exact energy you use, you've got a continuum of states the ejected electron can scatter into. And the electrons, being much lighter than the nucleus, will have a much larger scattering cross section that the nucleus.

 

[Dr. Trintignant]

Gold will never drop below the price of copper, no matter how common it becomes, because it's superior to copper for most of copper's uses (a thermal and an electrical conductor).

Copper is a better electrical conductor than gold (by a perhaps surprising margin). Silver is better yet, though not by as much. The corrosion resistance of gold obviously has some uses, though.

- Dr. Trintignant