Negative stannous but AR keeps dropping gold

[chrundle_the_great]

I have a batch of AR once gold dissolved did stannous came up negative. Denoxed, did stannous still negative. Added 40ml 50/50 H2O/HCL did stannous test was good. Added SMB gold dropped (about 3g) another stannous, negative. Let it sit for a few days to let any residual gold to settle, another stannous, came back positive. Added more SMB, another gram dropped. Stannous test keeps coming back negative because of curiosity keep adding SMB and gold keeps dropping. I've added SMB 6 separate times and it keeps dropping gold but stannous keeps keeps showing up negative. Made new stannous solution tested with my base AR, test was good. The AR I'm dropping gold from still shows negative but when I add SMB it's still dropping gold. What am I missing?

 

[4metals]

What am I missing?

Sounds like it's what you are not missing, free nitric acid. The SMB will drop the gold and if you have any free nitric it will redissolve the gold and continue to allow it to drop and re-dissolve. How did you denox the solution?

 

[FrugalRefiner]

If you keep adding SMB after a negative stannous test, it's possible you are dropping copper instead of gold. Have you tried melting any of the material that keeps dropping to see if it melts up like gold instead of copper? Just a thought.

Dave