Is it safe to discard the solution?

[Renaldas]

You can see the results of SnCl2 test. Gold have been precipitated by SMB, remaining precious metals - by copper wire.

 

[samuel-a]

gold is leaving a purplish stain that doesn't come off after 1 min or even 10 min.

that doesn't seems to be the case.

 

[lazersteve]

If you have already precipitated the gold with SMB then don't forget the possibility of false positives:

False Positives with Stannous Chloride

Steve

 

[Renaldas]

If you have already precipitated the gold with SMB then don't forget the possibility of false positives:

False Positives with Stannous Chloride

Steve

It happens only with SMB, or also with other precipitants, as FeSO4 or ascorbic acid?
When I put copper wire into my solution and leave it there for a long enough time, a little bit of wire dissolves, but there is no precipitate, as it happens when solution contains Au, Pd or Pt.
By the way, copper as precipitant works better in concentrated solutions with acidic pH, or it is not necessary?

 

[lazersteve]

It happens only with SMB, or also with other precipitants, as FeSO4 or ascorbic acid?

Only with SMB, if you read the document specified in the link provided it will explain the reason why this happens.

When I put copper wire into my solution and leave it there for a long enough time, a little bit of wire dissolves, but there is no precipitate, as it happens when solution contains Au, Pd or Pt.By the way, copper as precipitant works better in concentrated solutions with acidic pH, or it is not necessary?

Copper cementing reactions work best in an acid solution (pH 3-5).

Steve

 

[qst42know]

Thin copper wire is not the best choice for cementing solutions. PM's deposited on wire may be slowing the reaction. Bar, plate, or heavy sheet would be preferred. You may not be putting enough copper into solution to drop all your values.

Stirring your solution with an air pump while cementing has also been recommended.

 

[Renaldas]

Just tested another huge lot I want to discard. It shows a nice blue color change, it dissapeared after several minutes. Palladium?

Will post photos as soon as possible.

Look here:
http://www.youtube.com/watch?v=uwsIbL2d218

 

[Harold_V]

Palladium?

DMG is your friend.

Harold

 

[Renaldas]

Palladium?

DMG is your friend.

Harold

It is quite expensive ... What amount of palladium can precipitate 1 gr of DMG?

 

[jimdoc]

Palladium?

DMG is your friend.

Harold

It is quite expensive ... What amount of palladium can precipitate 1 gr of DMG?

DMG is for testing only.It will answer your question of if you have palladium.Sodium Chlorate is for precipitating
palladium.

Jim