# pt test positive in telephone contacts?



## goaldspektre (Dec 19, 2009)

I recently tested some relay contacts from a 1983 northern telecom switchboard and they tested positive for pt.I would expect pd not pt.I used nitric on them and nothing happened even when i cut them up.I ran them through the sulphuric cell , filtered and washed the powder then dissolved in hcl chlorox which was heated to remove excess cl. The solution was a vivid orange and gave a dark rosey orange stannous test.I waited overnight and re-tested,thinking that leftover traces of chlorine was affecting the test but got the same result.I was thinking I should add ammonium chloride to the solution before I get too excited as I have 20 grams of these deplated contacts.Am I doing the process in a correct manner here or am I getting mis- information on stannous test colours.


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## teclu (Dec 19, 2009)

goaldspektre said:


> I recently tested some relay contacts from a 1983 northern telecom switchboard and they tested positive for pt.I would expect pd not pt.I used nitric on them and nothing happened even when i cut them up.I ran them through the sulphuric cell , filtered and washed the powder then dissolved in hcl chlorox which was heated to remove excess cl. The solution was a vivid orange and gave a dark rosey orange stannous test.I waited overnight and re-tested,thinking that leftover traces of chlorine was affecting the test but got the same result.I was thinking I should add ammonium chloride to the solution before I get too excited as I have 20 grams of these deplated contacts.Am I doing the process in a correct manner here or am I getting mis- information on stannous test colours.




Hello,


Do you have a picture with these relais?, which are the brand name and the part number? 

teclu


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## goaldspektre (Dec 20, 2009)

Hi teclu, I can't find my usb cable for my camera right now.The part number is p0578224 / qun10d / style b .The contacts are rectangular, about 1/8 inch l x 1/32 h x 1/16w.They are soft, shiny grey and didn't dissolve in nitric,h2s04 or hcl-cl.Think they may be tungsten/silver and didn't react to nitric for whatever reason?I would think at most they would be palladium. By the way pat is 3748403 , can.pat 1973.I tried to melt some and without oxygen my mapp gas won't do it.I know pt and tungsten both have high melting points as does pd....without pics thats all i got for info.Ammonia chloride didn't cause precipitation but the acid was diluted with chlorox and pgms' are finiky from what i've read as to how they react. Too bad they aren't easy like gold to refine.


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## Harold_V (Dec 20, 2009)

It doesn't make a lot of sense that the contacts would be platinum, but stranger things have happened. 

Everything you've described indicates they are, indeed, platinum. Palladium will readily dissolve in nitric, and it typically yields a dark brown solution, although once in my refining career I had a customer provide a solution that contained palladium that was a vivid orange color, much like mercurochrome in color. I have no idea why. 

The test results you mentioned are in keeping with platinum. It's easy enough to know if it is. Concentrate the solution, than dissolve some ammonium chloride and add it to the container. If you have platinum, you'll see an immediate reaction, yielding a powder that is anything from yellow to orange. If it's palladium, you won't get a reaction. 

You can also test with DMG. If it's palladium you'll get a canary yellow precipitate. If it's platinum, there will be no reaction. 

Do note that if the solution isn't concentrated, you may get no reaction when adding ammonium chloride, even if it's platinum. Both platinum and palladium won't precipitate from dilute solutions. 

Harold


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## goaldspektre (Dec 20, 2009)

Thanks Harold , I really don't think they are platinum either . After adding the ammonia chloride I remembered reading how both pd and pt have to be concentrated to precipitate.I think i'll source some DMG before proceeding any further.


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## Platdigger (Dec 20, 2009)

Just take a small amount of your solution and concentrate that.

Also, the solution that you all ready added the ammonium chloride to, you could add chlorox
to that, to see if you get any pd.

Also, the chlorox trick, seems to work good in dilute solutions.


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## goaldspektre (Dec 20, 2009)

Saved myself a lot of time with a magnet , the contacts are a ferrous metal . Not worth the time but lesson learned.Thanks for the input guys.


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## Anonymous (Dec 20, 2009)

Being magnetic does not rule out pgms they are paramagnetic if I remember right.

JIm


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## goaldspektre (Dec 20, 2009)

True but I think i'll wait until I have a sizeable amount of material with a known pgm content and then commit my time to that. I can't justify chems and my time to a small amount of unknown material.I also ran some known gold cell powder through hcl-chlorox today and got the same vivid orange colour which is leading me to suspect an impurity in either my acid or bleach or maybe some base metal causes it??? Funny thing happened when I put smb in the solution,some blonde coloured powder fell to the bottom of the beaker.I put heat to it with my torch and it just turned into this metallic yellow "button" shape,what could it be?


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## nickvc (Dec 21, 2009)

As a quick test for platinum points heat them to red heat and allow to cool if they stay the same colour its a good indication you might have Pt then test with acid,the use of a magnet is a must now when testing modern Pt jewellery as its now alloyed with cobalt on a regular basis which makes it magnetic you can use it to seperate Pt lemel from a mixed lemel, note that its usually used in castings not in sheet, wire and old Pt jewellery so its not 100% but it can concentrate values.


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## goaldspektre (Dec 27, 2009)

Ok , so is this what pt will test like with stannous?


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## lazersteve (Dec 27, 2009)

Looks close.

The top left side appears to be purple or green blue, these colors indicate gold or palladium respectively.

This all assumes the spot is completely moist with fresh stannous chloride and the orange color is not the original color of the powder or solution under test.

Steve


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## goaldspektre (Dec 27, 2009)

Thanks Steve,
I concentrated the de-noxxed ar and the spot tested pos for au.After dropping the au with smb does any excess smb taint the stannous test?I wanted to test for pd because the contacts are a soft whitish alloy that easily breaks down in the h2so4 cell but only with electricity not just acid alone?


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## lazersteve (Dec 28, 2009)

Excess SMB can act to precipitate copper salts from solution as well as Palladium if the solution is not properly denoxxed.

Adding tin to a solution saturated with SO2 (the by product of SMB and water/acid) can produce H2S ( and/or Na2S ) which can precipitate many metals from solution giving odd color reactions when testing, most of these reactions result in dark colored powders with some exceptions.

The resulting powders are sulfides. You will smell the faint odor of rotten eggs when this reaction occurs. This odor is H2S and is a very hazardous gas when not properly managed.

See some of my recent posts on this topic.

Steve


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## g_axelsson (Dec 29, 2009)

Poor old Noxx!

Everybody is denoxxing their solutions nowadays. I remember that in the good old days of the forum most people only denoxed their solutions.

:mrgreen: 

/Göran


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## goaldspektre (Dec 29, 2009)

g_axelsson said:


> Poor old Noxx!
> 
> Everybody is denoxxing their solutions nowadays. I remember that in the good old days of the forum most people only denoxed their solutions.
> 
> ...






lol, you're meshuggah!


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