precipitates with smb

[Geo]

thats just it,SMB is pretty selective. nothing else should precipitate BECAUSE of the SMB.have you tried the process and waited the amount of time taken without adding SMB to see if anything self precipitates due to other factors,temp change maybe.have you tested the extra weight to see what it is? since it came from AR, then AR should dissolve it and test for values. have you tried to dissolve any of the powder with hcl/cl to see if any solids are left behind.

 

[Dr. Poe]

i have an Ar solution with some gold-----i expect 3grams of gold( this is an example) ,so i add 3grams of smb-----the brown gold precipitates is 7grams-----what is the additional 4grams of brown material? this happens often to me------what is smb precipitating additionally with the gold?
thanks for coments?
Arthur

Tellurium. Dr. Poe :|

If that be the case, shouldn't it be driven off as red fumes if incinerated? (Or am I thinking selenium?)

Harold

Yes, Harold, you are thinking of selenium. Remember that they usually occur together. Dr. Poe

 

[arthur kierski]

Geo,thanks for the recomendations----some of them i did---others i will do and pass to you what happened-----
regards
Arthur

 

[g_axelsson]

In my quest of reading every post on the forum I ran into this one which I think I could add some ideas to.

Arthur, did you ever discover where the extra weight came from?

I have run into a similar problem when precipitating gold from dirty solutions and forgetting to get rid of led before filtering the gold chloride.
I have an idea of what happened, the SMB is quite specific in precipitating gold from chloride solutions as it is producing SO₂ that precipitating the gold. But the SMB also creates sulfuric acid or at least sulphate ions in the solution. If you have dissolved lead chloride SMB will precipitate lead sulphate with the gold. When mixed it can be hard to see that the powder consists of brown gold and white lead sulphate.
If there still is some nitric acid SMB can also precipitate a palladium salt.

In my case I only needed to redissolve the gold, filter and precipitate it again with SMB. The second time it came out decent, less than I wanted but close to expectations. :mrgreen:

Göran

Edited : Changed chloride to sulphate where I did an error. No one else caught my mistake so it doesn't affect the following posts.

 

[arthur kierski]

Goran;you are correct-----the excess powder is(was lead,silver and some more gold)----i did almost all the sugestions in the threads,and concluded ,what you have found in your experiments----

thanks and regards
Arthur

 

[JHS]

Hi Arthur,
this may or may not sound dumb but,are you sure that you calculated the gold amount correctly.
is it possible that there is more gold than you expected.
if it's all brown,i would melt it,just to see the results.
just a thought.
john

 

[arthur kierski]

JHS,unfortunatelly the gold found was only what was found-----
thanks and regards
Arthur