gold not identifed with stanous(coloidal?)

[arthur kierski]

reading one of the threads ,Dr Poe told the forum of gold not identified by Stanous chloride and that many experienced members lost gold because of this-----i did an experiment and obtained gold from a solution that did not showded gold with stanous--------here goes my experiment: i had a used powder from which i withdrew gold and pd----the only thing that could be left (in my thoughts)would be agcl-----i passed nh4oh thru this powder which became a red liquid,to these liquid i added hcl and in this case no agcl was present----the liquid acidified with hcl became yellow and was tested with stanous and no gold result was found-----to this solution(yellow) i added active carbon, filtrated , and to the powderleft(black) i burned in my furnace until the black collor became brown----this brown powder was magnetic----i passed thru hcl and dried the powder and it was not more magnetic ----this powder was passed thru ar and the result was gold-----tested with stanou chloride ---beautiful,almost black pink=gold + perhaps pd-----the gold was precipitated with smb----and tomorrow i will see if the liquid contains pd(i will test it with stanous and dmg)----
the experiment gave gold as result-----confirming what Dr Poe had said in that thread---- i think that i threw a lot of gold in the many years of refining-----thanks for any remarks
Arthur

 

[artart47]

Hi Arthur!
I've got a similar solution. It is a solution (AP) that i used to depopulate cell boards and had become saturated so I was filtering it. several times It was necessary to rinse the filter. the filtrate and the powder that was in thebottom of the bucket, when contacted by water, would turn from dark to a chalky blue grey. Ikept trying to creat a salt that would be solualbe so i could remove it. the solution is loaded wiith gold flecks and I suspect that much of the very thin gold plating from the boards is in there too.
I washed it with hot HCl, washed with H2O nothing dissolved.
H2SO4 then hot H2O same result
Then I washed it with Amonia, The powder turned a mauve/rose colored and the solution a dark mauve.
I've gotten alot of imput from respected members and I'm experimenting with a small sample to check out what they told me, but something tells me something is going on with this jar. Glondor responded to my post with..."tin? colloidal gold?" I just made stannis chloride last night and tested it, it works! ( tested the stannis, not the soluton) I'm gonna test to see if i get a gold .result I found your post facinating and wonder if I have the same thing going on.
My post is in the "help needed" "mauve powder/mauve solution"
Later artart47

 

[arthur kierski]

Artart 47, i will read your thread with care and see if we have similar problems(solutions?)
regards
Arthur

 

[Dr. Poe]

Yes, the stannous chloride test will give a false negative if the gold isn't ionic (colloidal) or if the solvent held gold ions of super high stability such as sodium thiosulfate or gold thiomercaptans (British Anti-Lewisite [anti-mustard gas]). Add one more: if the stannous chloride is too pure (contains no trace amounts of stannic ion). 8) Dr. Poe

 

[dtectr]

Yes, the stannous chloride test will give a false negative if the gold isn't ionic (colloidal).... Add one more: if the stannous chloride is too pure (contains no trace amounts of stannic ion). 8) Dr. Poe

Is this one reason to keep solution "fresh" with undissolved metallic tin?

 

[Dr. Poe]

Yes, the stannous chloride test will give a false negative if the gold isn't ionic (colloidal).... Add one more: if the stannous chloride is too pure (contains no trace amounts of stannic ion). 8) Dr. Poe

Is this one reason to keep solution "fresh" with undissolved metallic tin?

No, too fresh (just made)--all stannous/ no stannic at all---False negative
Slight exposure to atmospheric oxygen---some stannic forms---just right
Long exposure to air---too much stannic/too little stannous---too old--false readings
Keeping a metallic strip of tin keeps most in a stannous state by slowing down oxidation.
If the strip contacts all stannous (by stirring), no stannic at all remains, again false negatives.
Understand? Dr. Poe

 

[ericrm]

Yes, the stannous chloride test will give a false negative if the gold isn't ionic (colloidal).... Add one more: if the stannous chloride is too pure (contains no trace amounts of stannic ion). 8) Dr. Poe

Is this one reason to keep solution "fresh" with undissolved metallic tin?

No, too fresh (just made)--all stannous/ no stannic at all---False negative
Slight exposure to atmospheric oxygen---some stannic forms---just right
Long exposure to air---too much stannic/too little stannous---too old--false readings
Keeping a metallic strip of tin keeps most in a stannous state by slowing down oxidation.
If the strip contacts all stannous (by stirring), no stannic at all remains, again false negatives.
Understand? Dr. Poe

now im scared of my fresh stannous chloride...
can someone explain or destroy what dr poe said???

 

[Harold_V]

now im scared of my fresh stannous chloride...
can someone explain or destroy what dr poe said???

I refined for more than 20 years, making my stannous chloride from stannous chloride crystals. It never failed to provide proper indications of the presence of gold, in particular when it was freshly made. As it oxidized, yes, it falls off, but that it does is indicated by the color of the solution, which turns a pale opaque yellow. I never relied on the solution without first testing with a standard solution, which was very much a part of the reagents I kept on hand.

I can't address the issue of making the testing solution with metals instead of the salt----but I have serious doubts about the report, as those who follow that procedure appear to enjoy success.


"Dr." Poe was banned from this forum for spreading all too many wives' tales, to say nothing of posting seriously controversial (and doubtful) data. None of us were ever clear on his motive, but we are better off for his absence. My advice to you is to keep a standard solution on hand, and verify your test solution. That's just good refining practice, anyway.

If you work with clean solutions, discarding an acidic solution that has no indication of yellow, or green, if it contains copper and/or nickel, would appear to me to be perfectly safe. That would not be true of a basic solution, however (cyanide). If you have the least doubt, send the solution to your stock pot.

Harold

 

[Geo]

Harold is absolutely correct. keep a standard test solution to test you stannous chloride against. i learned the hard way about testing test solutions. thankfully, i was putting all waste solution in my stock pot so i really didnt lose anything. 1 grain of gold dissolved in 20-30 ml's of solution should work great for a standard test solution.

 

[ericrm]

thanks harold and geo
i had never had probleme with fresh stannous chloride eater... and i have a tested gold bearing solution on hand... the thing is i was so sure about the quality of my stannous chloride that i very rarely test it when fresh...
but it seem that im ok (i have finally understand the real advantage of the stock pot, so if anything was ever missed i will get it back at the end anyway... 8)