# Platinum Refining Practice with a Pure Pt Coin Pt2 - VIDEO



## kadriver (Nov 15, 2017)

Here is the second half, part 2, of the platinum refining video:

https://youtu.be/HbDwaccp50c

kadriver


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## Shark (Nov 15, 2017)

Thanks, I enjoy your video's and as usual I picked up a few pointers. Is there a reason that you didn't use a vacuum filter instead of a regular funnel and filter?


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## anachronism (Nov 15, 2017)

Great video mate.

One thing though- given the choice between cyanide and Platinum I'm choosing cyanide. Platinum is so darned toxic it's unreal and the danger is that you don't see it coming. Even if I had a completely "pro" setup I'd drop the metal as metal impure and let someone else purify it, and if you ask any of the pros on here (apart from Lou who specialises in it and has spend a HUGE amount of money on safety) they'll say the same. 

A great trial but do yourself a favour and leave it there ok?

With kind wishes.

Jon


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## gcdrummer02 (Nov 19, 2017)

is there any reason you chose the calcination route over the formic acid route?


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## Lou (Nov 19, 2017)

Nice video, Kevin! I am typing this as I watch. Very barren filtrate--stannous it to make a point.

Handle the salt _damp_, never dry, and never sopping wet.

One nitpick but practical thing to mention, best just to use 15% ammonium chloride solution with perhaps 3% HCl, rather than conc. HCl. It is advisable to use a wash bottle rather than a spray bottle because less risk of misting out soluble platinates. 

Another is don't bother removing the filter. Having it inverted like you did is just fine. 

One thing to mention is that the fused quartz dish can just go over a flame without worry--or directly onto the metal elements. This will prevent you from contaminating the platinum with graphite.


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## kadriver (Nov 19, 2017)

gcdrummer02 said:


> is there any reason you chose the calcination route over the formic acid route?




Yes, I was looking at the procedure in Hoke's book. She suggested two ways to reduce to Pt metal, one is calcine, the other is formic acid. Now that I have the calcine experience, I'll try formic acid next.


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## kadriver (Nov 19, 2017)

Lou said:


> Nice video, Kevin! I am typing this as I watch. Very barren filtrate--stannous it to make a point.
> 
> Handle the salt _damp_, never dry, and never sopping wet.
> 
> ...



How about the filtrate, can that ammonium chloride go into my gold refining stock pot? Or should I start another stock pot dedicated to ammonium chloride.

Thanks for the pointers Lou. As I mention before, I'm not looking to become a platinum refiner. Just want to be able to recover my stock pot, and make a few videos on basic Pt refining. Thank you

kadriver


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## kadriver (Nov 19, 2017)

anachronism said:


> Great video mate.
> 
> One thing though- given the choice between cyanide and Platinum I'm choosing cyanide. Platinum is so darned toxic it's unreal and the danger is that you don't see it coming. Even if I had a completely "pro" setup I'd drop the metal as metal impure and let someone else purify it, and if you ask any of the pros on here (apart from Lou who specialises in it and has spend a HUGE amount of money on safety) they'll say the same.
> 
> ...



I hear you Jon. It was kind of spooky doing this experiment. It's like my work area has been nuked and contaminated with radiation. That's what it feels like. I'm not looking to do platinum on a regular basis. I just want to be able to get the PGMs out of my stock pot (because I do jeweler's waste and I know it has Pt in it). And I'd like to make a few videos on the basics. Thank you.

kadriver


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## Lou (Nov 20, 2017)

I'd use the filtrate to precipitate more platinum.


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## cuchugold (Nov 20, 2017)

Lou said:


> One thing to mention is that the fused quartz dish can just go over a flame without worry--or directly onto the metal elements. This will prevent you from contaminating the platinum with graphite.


This is worth repeating. Any hot, powdery Pt or Pt salt can adsorb / absorb / react with gases, carbon and other compounds very easily introducing contaminants into the once pure metal. So no graphite or silicon carbide crucibles should be used, and a vacuum or very controlled atmosphere when melting is desirable. Improper melting has produced many brittle buttons. Sometimes even changes in density of the perceived metal button occur. I.e.: Improperly melted buttons versus forged ones.

Maybe this thread and the other one can be consolidated, for practicality purposes.

I don't like the use of ammonium chloride at all, but it is still very popular.


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## cuchugold (Nov 20, 2017)

cuchugold said:


> I don't like the use of ammonium chloride at all, but it is still very popular.


I don't feel comfortable with this statement, as it may sound secretive or pretentious, when my intentions are, in fact, quite the opposite.

Perhaps an outline on how I'd process KA's materials and stock pot would be more appropiate. Maybe there is even a better way. I prefer processes that are relatively safe, produce little fumes, and can be run with little to none supervision. Sometimes it is not possible to avoid babysitting a reaction, but many times this is possible, at least in part.

Stock Pot: 
1-This is already very fine powder, so no need to alloy.
2-I'd heat this with 50% sulfuric acid for a couple of hours or so till no more reaction is apparent. Any silver that made it this far, as well as palladium, and rhodium will go into solution (solution from 2), as well as any copper contamination. In the powdered solids (from 2) there will be gold, platinum, iridium, ruthenium, and traces of what went into solution.
3-I'd put the solids (from 2) in diluted HCl and chlorate, till no more reaction is apparent. Basically gold and platinum will dissolve (solution from 3), and the rest of the powders can be stored for future play. The solution from 2 treated with NaCl, silver chloride cake filtered and saved, and the rest of solution put in a vessel with copper to cement.
4-If solution from 3 is treated with oxalic acid, or another gold precipitant like SMB. Do not to use ferrous sulphate. The gold drops and what is left in solution is basically 99% platinum, with some contamination. You can cement it and save it or the solution is ready to go for hydrolisis.

Platinum jewellery:
1-If I had some 14-18 Karat gold to refine (like KA usually has), I'd alloy it 3-1 with the Pt jewellery (try to ascertain which type of hardener you have present Ir or Ru, and keep them separate if possible). Then I'd inquart the lot with silver, and part it with nitric acid. The solution will contain silver, platinum, and palladium if any (rare), with traces of other stuff. The solids will be gold, the hardener Ir/Ru, and traces of others. These solids are very easy to process with dilute aqua regia or HCl + chlorate, like you have done before to get the gold, and the hardeners separated.
2-You could heat the solids up with sulfuric as with point 2 of the stock pot, but really Rhodium is rare for you... except in thermocouples maybe. The solution from 2 treated with NaCl to get the cake of silver chloride, and cemented to get the 99% platinum (or less if with possible palladium).
3-The cemented platinum can be saved here, or dissolved for hydrolisis.

Most of these processes are relatively safe, and familiar to KA, and no unsafe salts are produced so far. So no mysteries really. Can it be done safer, faster, or with even less supervision?. Maybe. A little tedious and time consuming, but you can engage in other activities during most of the processing. It's almost like cementing a stock pot, you can watch it if you want, but no real need. Now hydrolisis is another matter...

There may be errors or omissions above, or better sequencing possible, please point them out, and I'll edit them later. The main idea I wish to relate, is that if you look at what you have in front, and think a little, a solution to the problem will readily appear. This concept is so simple, that you'll soon think it was your idea all along, when in reality it is a centuries' old approach.


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