process for refining natural gold?

[kmann1969]

Hello all! I have a question about raw/natural gold. Is there a different process for refining? I have searched the forum and have not found a answer. Any info will be greatly appreciated.Please share your experiences with natural Gold.

Thanks
Kevin

 

[goldsilverpro]

I assume you're talking about placer gold. I just treat it like karat gold. Inquart it.

 

[kmann1969]

Thanks for your response .how do you inquart it if you dont know the purity or karat?

 

[Harold_V]

Before you inquart, it won't hurt to incinerate, then give the gold a digest in dilute nitric. Then try to dissolve it without inquartation. If the silver conent is low enough, that works just fine. If you have very fine particles, all the better, as all of the gold will dissolve before an impervious layer of silver chloride can develop.

This process will generate a fair amount of silver chloride, but it is easily eliminated by filtration.

If you decide to give this a try, make certain to rinse the silver chloride quite well, so you don't leave much gold behind. You'll not lose any of it even if you do, if you immediately reduce the silver chloride with some scrap aluminum and HCl. The gold will be reduced as well, and will report in the resulting silver.

If you try this and the operation is stopped by the development of silver chloride, no problem. Simply melt the gold, along with some soda ash and borax, then weigh and inquart. You'd want to add about three times the weight of the gold in silver. A little less most likely wouldn't hurt, as the gold will contain at least 10% silver, otherwise it would have processed without issue.

Harold

 

[butcher]

I just process it with other Karat, or dental gold.
I in-quarter it with silver along with the other gold.
For figures of the placer gold, I just figure it at about 16/24 to 18/24 parts gold.

 

[MysticColby]

I remember reading somewhere that the purity of gold found in nature varies widely, but is pretty consistent for a given region.
"Nuggets are usually 20.5K to 22K purity (83% to 92%). Gold nuggets in Australia often are 23K or slightly higher, while Alaskan nuggets are usually at the lower end of the spectrum. " - http://en.wikipedia.org/wiki/Gold_nugget
So you can probably guess the purity of yours, check if it's right, then know the purity for future refinings.

 

[moose7802]

I remember reading somewhere that the purity of gold found in nature varies widely, but is pretty consistent for a given region.
"Nuggets are usually 20.5K to 22K purity (83% to 92%). Gold nuggets in Australia often are 23K or slightly higher, while Alaskan nuggets are usually at the lower end of the spectrum. " - http://en.wikipedia.org/wiki/Gold_nugget
So you can probably guess the purity of yours, check if it's right, then know the purity for future refinings.

I have read similar to this so I would say to just guess it at 18k. More silver inquarted is better than less as it won't form a crust like it would if your % of Ag is to low in the inquart.

Tyler