Help with iron in gold chloride

[Exhail]

HI guys
I have a issue with a solution that I have acquired from a friend who has put it in the too hard basket.
I have been studying the forum for over 4 years and have even produced a few of my own gold nuggets from gold fingers and various cpu and tv parts by using AP and HCL/Cl methods.

Now about this solution, I am told that it's feed material is from the flat white ribbon type of board connectors from the back of plasma and lcd tv's, and that they were placed into AP for processing. When he went to collect the foils the AP solution which had a air stone in it had turned dark brown and thick like runny custard and he need to water the solution down to filter. The only filter material he was able to use was the filter wool that they use in fish tanks which he said worked exceptionally well. After filtering he then torched the material with a LPG gas torch till ash. But this is where I feel he went wrong as he torched the material in a cast iron pot and when he has scrapped the ashes out has added Iron to the ash in the form of rust.

Any way from here he has tried to dissolve the gold from the ash using HCL/Cl and that is as far as he has gotten as he has found it hard to get all the gold to dissolve. I have tested the solution with Stannous and got a strong positive result for gold. The problem is that when the solution has been left to settle there is a layer that has the left over trash from the ash and solids that were in solution and a grey precipitate that is heavy with what looks like undissolved gold foils and gold precipitate.

My plan of attack was to filter of the solution and drop the gold with smb then go through the washing cycle, redissolve and wash. Then I am not real sure if I should wash the remaining precipitate with HCL till wash is clean and colourless then do another HCL/Cl dissolution and do the normal steps.

Was also wondering if the grey precipitate could be silver or some other pgm.
Any advice would be a great help as from what I told there should be around 3-5 grams of gold and if I can recover it I can have it.

Thanks in advance

 

[FrugalRefiner]

My plan of attack was to filter of the solution and drop the gold with smb then go through the washing cycle, redissolve and wash. Then I am not real sure if I should wash the remaining precipitate with HCL till wash is clean and colourless then do another HCL/Cl dissolution and do the normal steps.

Was also wondering if the grey precipitate could be silver or some other pgm.
Any advice would be a great help as from what I told there should be around 3-5 grams of gold and if I can recover it I can have it.

Thanks in advance

I agree with your plan to separate the liquid from the solids as a first step.

You can try SMB to precipitate any gold from the solution, but since you don't really know what's in the solution, you may or may not be successful. Personally, I would probably cement with copper. It's always a good way to recover from an unknown mess, and it will recover gold as well as any PGMs. Then you can refine whatever cements out.

I wouldn't bother washing the solids since you're going to try another dissolution. Just add your HCl and proceed with your bleach additions. Test the solution for any dissolved precious metals and treat the solution as appropriate.

As far as what the precipitate could be, it could be anything. Unknown metals have been dissolved with unknown quantities of acid and bleach, filtered with an unknown type of filter material (there are many types of aquarium filter floss), ashed in an iron pot... Could be anything.

Dave

 

[solar_plasma]

Of course Dave is right, but most likely the grey precipitate after dilluting dark brown CuCl2 leach is CuCl. Hot HCl, best if concentrated, will dissolve it again and form fresh CuCl2 leach.

edit: reading again, I think I misunderstood the process description.