Thanks for the advice so far! We have a great local jeweller, very experienced, knowledgeable and up for the challenge. The thinking behind refining it back is that I’m more inclined to wear white gold and my soon to be wife wears gold. Trying to re-alloy unknown base metals into a white gold ring purely by remelting would seem problematic due to brittleness. I’m curious about the “too late to do anything now” commentary. If I can source the correct chemicals locally and have access to lab facilities at the local university why would a 2 week timeframe (to just refine the gold, not to make the rings) be considered too late?
I said that.
Thinking minimalistic:
You could do this outside, staying upwind and holding your breath every now and then, away from humans and animals, inquart the gold to 25% or 6K gold, the jeweler can do this for you, dissolve in nitric acid to get all silver out, dissolve the gold in AR, the right way by dissolving small amounts of nitric and watching the reaction die out or consume the last gold, and not by premixing it at a 3:1 ratio, precipitate the gold with SMB, filter and wash with boiling HCl and boiling water a couple times according harold's or others procedure, completely dry it and give it a hot nitric wash and melt into a pure button of gold.
You'll need the safety gear like gloves, goggles, a catch basin, acids, beakers, hotplate, filters, funnels, SMB to precipitate the gold out and the jeweller can alloy the clean powder or button to get the right ratio for the gold type you want.
For white gold you need Pd or Pt i think. Not sure. If that is in your source material, be exrtemely carefull, even more than with the 'normal' toxic chemical salts you create.
And thats a very short simplified way of saying it. Actually i consider this a dangerous advice to a novice. There are points where you can get into problems or need some experience to get it right.
It took me 4 years before I had the confidence to give it a go.
This craft is not easy or to think lightly about.
Do we have experienced members living near you to help you out? Fast! Would be awesome.
It can be refined in days, with the right knowledge and equipment.
Congratulations with your engagement and i hope you succeed in this wonderfull idea.
Martijn.
Edited for spelling and to add the precipitation step.