Some gold still in solution

[Psyk0siss]

This is my first time doing gold recovery from boards. Everything looked great until I added SMB and I got almost nothing to precipitate. After reading some more about why, I'm thinking too much excess nitric acid? I heated my solution to try to evaluate off excess acid and diluted with distilled water while continuing to add SMB. I got more gold out but I'm adding WAY more SMB than should be needed (I did a very small test batch so in thinking maybe 1/8g gold, I've added probably 30g SMB).

I've still slightly yellow tinted solution, any suggestions?

 

[FrugalRefiner]

What does a stannous chloride test show?

Dave

 

[Psyk0siss]

I don't have any yet, the order is still shipping.

Should I filter out the solids and save the leftover liquid for when it arrives?

Out of curiosity, if it's not gold, why would the yellow color come from?

 

[g_axelsson]

What did you start with, how much and how did you treat it.... for a starter. We can't read your mind.

Göran

 

[Topher_osAUrus]

Yellow could come from iron, or tungsten or some other things...

Should have stannous before even starting to refine, in my humble opinion.

How is one to finish a job, if they do not possess all the required tools of the trade?

 

[g_axelsson]

Having hydrochloric acid and circuit boards is enough. Heat the board until the tin dissolves, hit it hard at an angle against a flat surface, collect the solder and put it in the acid. Voila! Stannous!

Just for giggles I once made stannous from some circuit boards I put in HCl, worked like a charm.

Göran