Gold not a precipitate in the solution

[hosseini]

hi
1-add a HCL and H2O2 and finger in the Beaker.

2-after filter the solution add a household bleach.

3-add a sodium metabisulfite in solution for precipitate.

but not precipitate gold in the solution.

whats my wrong

thanks for your help

my solution photo
http://s9.picofile.com/file/8271239368/426132135_120009_1.jpg

 

[upcyclist]

We'll need more details before we can be of much help. I can see from your pic that your solution is yellow. I can't see if it's got gold or not--just that it's yellow.

Did you test your solution before you added SMB with stannous chloride to confirm it contained gold?
Did you test it after you added SMB to see if there was still any gold in solution?

My first suspicion is that you have too much nitric in your solution, and that consumed the SMB before it could precipitate gold. But it's just a suspicion. We'd need to know more about your process AND your source material before we can help more.

My first suggestion: put your solution away for a bit while we talk about it. If you just start adding more reagents haphazardly, you'll end up with a mess and our advice will be to "cement it on copper and start over".

 

[kurtak]

My first suspicion is that you have too much nitric in your solution

He didn't use nitric - he used HCl - H2O2 - & bleach

So - though he did not use nitric - the problem is still probably "to much" oxidizer

hosseini

having to much oxidizer in your solution will prevent the gold from precipitating back out of solution --- with to much oxidizer you have to do what is called denoxing the solution before the gold will drop out

Also - as upcyclist said - you need to test your solution so you if &/or where the gold is - stannous choride is used for testing - it made by dissolving tin in HCl

How much HCL & how much H2O2 did you use during that part of the treatment ?

Did the gold dissolve during the HCL & H2O2 treatment - or - did it dissolve "after" the bleach treatment ?

We can help you - but as upcyclist said - we need more info

Kurt

 

[upcyclist]

Doh--I stand corrected. I had nitric on the brain from a different thread. I guess posting details helps most when I read details

 

[4metals]

Kurt and Upcyclist are most likely right but even after you get rid of the excess oxidizer, the gold contained on a single finger is quite small and you may not notice it even if it did drop from solution.

And you did not say that you tested your solution with stannous chloride. If it's there, stannous will indicate its presence down to quantities you may not see even when they do precipitate.

 

[hosseini]

thanks for your answer.

1-i not use nitric acid
2-i tested solution with sncl2 ( Black Color )
3-after use HCL and H2O2 i see the Piece of gold in solution
4-gold dissolve after the bleach treatment in the solution

i think use a too many bleach in solution.

There is a solution to fix the problem? Or solution should be discarded?

thanks

 

[hosseini]

Kurt and Upcyclist are most likely right but even after you get rid of the excess oxidizer, the gold contained on a single finger is quite small and you may not notice it even if it did drop from solution.

And you did not say that you tested your solution with stannous chloride. If it's there, stannous will indicate its presence down to quantities you may not see even when they do precipitate.

add more solution in beaker. my solution 250 ml

how i can get rid of the excess oxidize?

 

[4metals]

Heat.

But without stannous chloride to test the solution you will add nothing but frustration to the process.

 

[hosseini]

Heat.

But without stannous chloride to test the solution you will add nothing but frustration to the process.

i will heat the solution.I hope the problem is resolved

many thanks for your help.

 

[anachronism]

I may have missed missed the question being asked, but how much base material did you start with in this solution?

 

[hosseini]

I may have missed missed the question being asked, but how much base material did you start with in this solution?

base material : 1 pound of finger.( modem.graphic card.ram and cell phone )
my new solution 250 ml