Question
Gold Bars Prior To Mel
Hello Dr I wonder if you could answer a question regarding the following. I recently melted together a bunch of 9ct gold scrap into a bar. I sent the drilling sample of the bar I melted to an assay office and was returned an assay of 37.5% which is what I expected. However I then took my very clean gold bars and sent it off for processing. They took both bars and melted them together however there was a 3% melt loss from the refining company. Is there a logical answer why I should loose nearly 55grams from this 9ct scrap gold bar that I melted? I trust the refining company implicitly but I need to know the scientific answer if there is one. Many thanks Tony
AnswerHello Tony,
the answer is perhaps the copper alloy..if you have 9ct gold it is less than 50% fine and as such sending in a bar of "pure 9ct gold " means you sent in an alloy- without dissolving off the copper in aqua regia
You sent them the alloy if I understand you correctly. If I am not , you sent in a bar of pure gold and the math does not work, however, the refinery usually does not give a 100% return on the gold content, so If I knew the refiners name I could look into their policies and do some figuring based on that info.
Since you are scrapping 9ct. I think this must be the UK, so Cooksons or any number of refineries should not have given a 37% loss on fine gold as settlement.
If you will send me some more facts I will certainly try and figure out what happened. If you like send it to me off this forum to protect your self and not name any corporations outright (vieuxcarrejewelers@gmail.com- will get the message to me confidentially).
Best regards, Ari
