salt water nitric acid solution how do i recover platinum

[dezoray]

I have just began the process and im new to leaching i dont have a problem desolving the gold or platinum its when i precipitate them out they are mixing together is there any way to precipitate the gold and platinum seperatly

 

[Oz]

It is near impossible to advise you with so few details as to the process you followed, let alone not knowing your source material.

 

[Anonymous]

SSN is primarily used for dissolving base metals,not platinum.
Added:I was not thinking when I wrote the above statement.SSN will in fact dissolve almost any metal,and very fast.The PDF I have states that you are not to use a orp meter with a platinum end because it WILL dissolve it.Sorry about the confusion.

 

[Gratilla]

SSN will dissolve a wide range of metals including gold, platinum and unfortunately whatever junk (base) metals you have in your mix. I think though SSN users are primarily interested in the PGMs.

Selective precipitation is tricky and usually needs a second leach and precipitation (with say AR) to get fairly pure metals.

I'd suggest you consider solvent extraction. There are a number of organic solvents that target (and can produce high-purity) gold. The best known is probably butyl diglyme (BDG), but there are many others including ethyl acetate, diethyl malonate, dichloromethane, etc. I'm currently using BDG, but will probably move to one of the others when my current stock runs out.

I know there are organic solvents that target just platinum, but I have no relevant experience; a google should turn up an example or two.

Would welcome any practical experiences of SSN and Solvent eXtraction (SeX <G>).

 

[freechemist]

Hello dezoray,

Yes, there are methods to precipitate gold and/or platinum selectively from mixed acicic chloride solutions.

1) If Pt-concentration is high enough and all Pt is Pt(IV) (is in it's four-valent oxidation state), yellow ammonium- or potassium-hexachloroplatinate can be precipitated by slow addition of ammonium- or potassium-chloride solution. After thourough mixing of the resulting suspension let stand overnight in a cool place to complete cristallization. The overnatant liquid contains the gold and still some small quantity of platinum. The platinum salt on the filter has to be washed with small portions of ice-cold water and may still contain traces of gold.

2) Gold can be precipitated selectively and quantitatively with oxalic acid. The Au/Pt- solution is treated with a slight excess (about 10%) of oxalic acid, dissolved in water. The resulting mixture is digested on a nearly boiling water-bath for 12-24 hours to make gold-precipitation complete. The resulting gold usually is pure and contains no platinum.

Regards, freechemist

 

[wade brenckle]

I have a mix of AR that I want to try the oxalic acid on. Are you saying that the mix should be near boiling to use ? Or will it react to near boiling ? Or can it simply be put in the mix. I see in some post here that it is to be mixed with water Pryor to adding it to the AR mix. Silly Q? here but does it have to be mixed with the water first ? I just let it sit 3 days after adding 4 parts water to it. Cant refference hoke at the moment. I had to rebuild my computer, and I'm having a problem getting hoke back. Some pages are not responding when I try to download, or even view. Not just hoke many things.

 

[Palladium]

You can read it on the Scribd site in the link below in my sig line without downloading it with their pdf viewer.