cloudy again

[onewally]

ive been working hard to getting my process so i have been running small batchs, with same process. I m working on the thrid run right now and when i got to the part before adding smb when i add water to it, it gets cloudy? Last run though it stayed clear, but every time when i add smb it does what its spoused to.

 

[martyn111]

A bit more information would be helpful.
What was your starting material?
How much material?
Which process are you using?
How much acid was used?
One possibility is that the solution could benefit from a final filtering before adding the SMB, the cloudiness could be silver chloride, depending on which process you have employed.
Update us and we will help from there.

 

[Marcel]

H2O itself is a precipitant. It will precipitate Cu(I)Cl for instance and AgCl as well (I think). So I think like Martyn, that the solution now should be filtered, then acified a bit and precipitated again. There may be gold that already dropped in the filter together with the AgCl. Then you would have to rinse the filter with amonia (I use hot water plus only bit ammonia 10:1). The AgCl will dissolve and pass through the filter while the gold remains in there. If any was already precipitated with SMB in the first try.
Marcel

 

[onewally]

Im useing hcl first to remove solder mask and clean connectors (first batch was fingers), from about 50 pda and cellphone boards 535 grams, then 3 gallons of hcl+peroxide with air running in it. I let it run 8 days untill the liquid went from dark brown green to a lighter green, filter wash with some hcl rinse with water, then hcl+bleach(at this point all is how it should be)

then i go to dillute the aucl and thats when it goes cloudy.

I let it sit for a few hrs then i add smb.

 

[martyn111]

I let it sit for a few hrs then i add smb.

Rather than letting it sit for a few hours, filter the solution to remove the cloudiness (also read as contaminant) and then proceed with precipitation of your gold. The cleaner the gold powder the less you are relying on the washing proceedure to remove the contaminants.

 

[steyr223]

Hello
I took it that you add the smb dry directly to
Your diluted AuCl.
I have done this,also without diluting
but I seem to have more text book reactions
when adding the smb to an equal amount of H20
Stirring well, then adding that to my AuCl

Just a thought
also what does your water look like
Mine is usually cloudy out of the tap.

Hope this helps
Steyr223 rob

 

[onewally]

i have been useing smb powder i got from brewing store and adding dry to diluted AuCl(1:3 water).

 

[butcher]

The cloudy color after diluting makes me think there is an insoluble salt in the mix, (like silver chloride) the nice yellow color does not indicate copper (very good).
I would let the solution sit overnight or until it cleared (you will probably get an insoluble powder formed on the bottom my guess silver and lead chlorides), decant the clear yellow solution and filter the clear liquid before using SMB to precipitate the gold.

 

[onewally]

at first that was what i was thinking even though by the time they hit the ap there was no soilder left, i also was wondering if it could be cause some of the pins were in plastic, and one or two peices didnt like the hcl and got messy i tryed to clean it all out.

thanks for all the help.

 

[onewally]

should i be useing distilled water or tap (city water) when im diluiting? when diluting the AuCl i thought tap was fine.

 

[qst42know]

Anyone working on e-scrap should be using a bit of sulfuric to rid the solution of lead before it is filtered clear.

Lead chloride can be carried through an HCL process.