Help needed with Extracting Au from PGM Concentrate

[Zee365]

Hi guys,

Hoping someone can assist me with the following - extracting the Gold from the PGM concentrate.

I have a couple of grams of PGM concentrate - I had it assayed and here is the results:
Total weight - 189gr
AU - 376ppm
Pt - 8.86ppm
Pd - 17.4ppm

Before sending it for Assay, I had someone mess around with it...
He took approx 10gr and made a nugget weighing 1.7gr. See pics of the nugget and the xrf result of the nugget. Upon seeing the xrf result it looks a tad promising.

So now, I'm really hoping someone can assist me with the process to do the rest
(unfortunately, his gone travelling)

Thanks

 

[snoman701]

I'm not really following the assay results.

Your 12k nugget, from 10 grams of material, is more along the lines of 85,000 PPM Au...whereas your assay of 376 PPM Au would only give about $3 of gold out of your 189 gram sample.

What is the source of the concentrate?

 

[Geo]

Melt the metals and add enough silver to bring the gold and Pt content to 25% of the total. Pour the metaled metal into shot or cornflake. Process the metal in a nitric acid leach consisting of 40% tech nitric acid and 60% distilled water. This will remove Ag and Pd along with the Pb, Cu and Fe. The remaining metal will be Au and Pt. Add a few ml's of sulfuric acid to the leach to drop the Pb, Filter and add HCl to drop the silver as silver chloride. Cement the Pd from solution with solid copper metal.

 

[Zee365]

Melt the metals and add enough silver to bring the gold and Pt content to 25% of the total. Pour the metaled metal into shot or cornflake. Process the metal in a nitric acid leach consisting of 40% tech nitric acid and 60% distilled water. This will remove Ag and Pd along with the Pb, Cu and Fe. The remaining metal will be Au and Pt. Add a few ml's of sulfuric acid to the leach to drop the Pb, Filter and add HCl to drop the silver as silver chloride. Cement the Pd from solution with solid copper metal.

Geo - thanks very much for this, will be giving it a try . I'll revert back and let you know how it went.

 

[nickvc]

Using that method will remove a lot of platinum with the silver which is why using silver is the norm for inquarting, you may well have some left in the powder remaining so refining would be advisable.