[mxmlnkn]

Even if you could separate mercury-198 for zero cost, it would only be 10% of the mercury production, and the yearly mercury production is 4500 t/yr, i.e., at most a maximum of 450 t/yr mercury-198. Compare this to gold production, which is 3100 t/yr, or silver production of 27000 t/yr. One might argue that mercury production could be ramped up if it is needed more, but its Earth's crust abundance is only slightly higher than silver, and again, mercury-198 would be 10x rarer than silver, i.e., only twice as abundant as gold.

https://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth...

[floxy]

Seems like you are interested in section 5.2.4 of the paper:

https://www.marathonfusion.com/alchemy.pdf

> Since the process described here permanently transmutes mercury into a valuable material, it is possible that fusion transmutation could be considered as a form of waste disposal. While early plants will be highly incentivized to specifically transmute 198Hg, we note that the isotopes with higher neutron number can also in the long term be transmuted to 197Au...

>The EU also has 6000 tons of mercury currently and expects to need to dispose of 11,000 tons over the next 40 years [95, 96]. As such, even with no change in existing processes, 14,000 metric tons of mercury could be made available for processing and isotope removal in the next ten years of fusion development, corresponding to 1400 tons of 198Hg and about the same mass of 197Au, with a current market value of ∼ $140B.

[mxmlnkn]

Yes, that section is fitting and interesting. It is the production-side view. I think I was more motivated by the comments envisioning an abundance of cheap gold, which seems not in any way near or even possible, even with this approach as cool and baffling as it is.

I don't think that it is of much use as waste disposal because again, it can only remove 10%, i.e., an insignificant amount. If it were even mined because of this, then more mercury waste would be produced than before, but increased mining would probably be many decades or centuries in the future, as long as there is still waste to reuse.

So, how long would the current midterm stockpile of 1400 t for 198Hg for the next 10 years last? At 5 t per 1 GW per year, i.e., 5 t per 8.76 TWh, and a current global electricity generation of ~30 PWh, replacing all energy production with fusion would be able to transmute 3400 t 198Hg per year, over twice the stockpile. Of course, there would be a myriad of other bottlenecks long before that, but consuming all the existing stockpile seems feasible in human time spans.

I am honestly impressed by the amount of transmutation that is possible with fusion. And it is a lucky coincidence that the half-life is only dozens of hours for the middle product. I never thought of that process or would have guessed grams of production instead of tons, probably because of the association with existing particle accelerators. It is quite amazing, but also presumably still decades off into the future.

[floxy]

This seems more like a way to help kick-start commercially viable fusion plants, rather than a way to mass produce gold.

[dr_dshiv]

Man, this is definitely a 2025 hacker news comment. Amazing.