Help! I messed up.

[jwlrymkr]

After successfully refining a small test batch of gold scraps, I decided to do a larger batch.
I did the inquartation (I think correctly) with silver and then dissolved it using dilute nitric. Everything went well and I got a nice "spongy" batch of gold in the bottom of the beaker. Then, here is where things went wrong.
I either didn't rinse my gold well enough, or I didn't let the nitric acid fully dissolve all the silver and base metals. After I dissolved the gold in the aqua regia, I was left with a very muddy opaque solution and it was very difficult to filter even using vacuum.
I am stuck now and not sure where to go from here. Do I go ahead and try to precipitate the gold out of solution or do I need to back up somewhere?
Here are a couple of pictures to show the color of the gold solution and mud that is trapped. If my calculations are correct, I should end up with around 3oz of pure when it is all said and done.
Any help is greatly appreciated.
Ken

 

[Yggdrasil]

AgCl comes to my mind.
So you did not completely disdolve the silver. That is my guess.
Just filter and go on as planned.

 

[jwlrymkr]

Thanks! I left it to settle overnight and will get back to it tomorrow. I suppose worst case is that I have to start over again. I just hope I'm not losing a lot of gold.

 

[snail]

You can’t lose gold until you dispose of Solutions and sediments..
It’s all still there in some recoverable form.

 

[orvi]

Just continue as usual, and filter very carefully - no solids should be present after filtration in the liquid.
You can test the liquid like this:
Take like 0,5 ml of the filtered liquid to the test tube or anything similar, and dilute it with 3 times more volume of water.
If the solution build opalescence or precipitate, it contain dissolved silver chloride = you did not leached the silver completely from the inquarted material.

 

[BlackLabel]

Just continue as usual, and filter very carefully - no solids should be present after filtration in the liquid.
You can test the liquid like this:
Take like 0,5 ml of the filtered liquid to the test tube or anything similar, and dilute it with 3 times more volume of water.
If the solution build opalescence or precipitate, it contain dissolved silver chloride = you did not leached the silver completely from the inquarted material.

This only works if your tap water has chlorine in it. In the USA, you can smell the chlorine. Here in Germany, it won’t work.
I‘d suggest to put in a few drops of hydrochloric acid.

 

[nickvc]

This only works if your tap water has chlorine in it. In the USA, you can smell the chlorine. Here in Germany, it won’t work.
I‘d suggest to put in a few drops of hydrochloric acid.

Not actually true AR can and will hold some silver in solution at full strength but dilute it and the silver will start to precipitate hence why many use ice or dilute their solutions before filtering.

 

[orvi]

This only works if your tap water has chlorine in it. In the USA, you can smell the chlorine. Here in Germany, it won’t work.
I‘d suggest to put in a few drops of hydrochloric acid.

I assume that solution with dissolved gold by standard AR process is full of chlorides, both as free excess HCl and also HAuCl4 of course. Silver chloride tend to dissolve in not negligible quantites in these kind of solutions.
Many times when processing pins/processors/karat/transistors - there is some silver as plating on the legs, surface plating, brazing, "underpins" from old CPUs, as alloy in karat... And it will be present in nearly anything you process.

Carried with chloride solutions whole way through the process, when eventually at the end, you drop the gold from the solution - and AgCl is somehow entrapped on vast surface area of this precipitate.

Easy way how to get rid of good portion of AgCl is to lower the concentration of free Cl- in the solution = dilute it with water. Diluted stuff cannot hold so much silver chloride and drop majority as insoluble AgCl precipitate.

Turned around, this phenomena could also be used for detection of silver chloride and to some extent also lead chloride. Diluting some mL of solution with ordinary tap water and preferably chilling it down result in precipitation of these compounds, if present in significant quantity.

 

[Abdoulapapatte]

tu as bien raison , ici au vu des photos que je ne peux voir qu'en petit actuellement , je dirais que tu as du faire un alliage en dessous du 1/4 d'or (250/1000), deux choisis à dire amis raffineur.
j'imagine que tu as déjà trouvé une solution et au passage je suis nouveau sur le forum mais je manie l'alchimie depuis quelque temps , ce que je te conseille :

comme dis précédemment , tu dois rincer la solution car l'argent est un parasite embêtant , pour le faire partir, rien de mieux que le rinçage , comme tu es parti d'une solution hno3 , (A nitric) tu as donc dans ta solution
1 ) d'une part l'or, gros level sous forme de poudre noir au fond de ton bécher, et dans ta solution
2 ) un épais mentaux blanc en solution, ou une solution légèrement opaque, blanchâtre(Ag+/Ag trace)
3) (X) alliage inconnus dissous en solution , tout métal sensible a l'aqua regia (cu,ag, al, zn Fe pd pt ............)
réduction des métaux .

REPONSE:
, je te parle par rapport à mon expérience personnel et je ne parle pas sur ce que je ne sais pas , je tiens à t'informer que mon résultat n'est pas inventé , mais bien vérifier par plusieurs modèles de spectromètre de masse à rayonnement ionisant de type niton xrf portatif, ou quand je vais dans un change vendre ma production dans un bureau de change.

l'erreur ici est surement le rinçage car tu as fais une quartation de l'or à l'argent, donc même avec une eau sans chlore , tu aurais eux par la suite de l'argent à l'intérieur et l'acide chloridrique n'attaque pas l'argent métal mais il se lie avec lui pour l'ancien l'AgCl (chlorure d'argent).
quand tu as fais ton aqua regia tu as forcement utilisé hcl et donc l'argent dissous est apparu car mal rincer voir , mal dissous par l'acide.
SOLUTION :
1) liquide séparer/ solide (primordial)
2) traiter ton liquide / récupérer ton or en neutralisant l'acidité (urée ) , puis en le précipitant (SMB)
3)traiter les solides avec de nouveau de l'aqua régia, il doit te rester une fine couche dans le fond du bécher, pas de panique avec une nouvelle solution fraîche d'aqua regia tu pourras finir le travail. et tu peux chauffer car agcl est tres dure a dissoudre dans l'eau regia.
4) filtrage
5) Met ta solution au froid, laisse la reposer pendant un long moment, du style une nuit entière, je te déconseille la filtration sous vide, sauf ci tu as vraiment un excellent filtre, agcl et vraiment poussiéreux.
6) précipitation du reste de ta filtration et récupération de ton or.
UNE FOIS TON OR précipité et rincer , je te conseille de le repasser un peu avec de l'hcl dilué dans un bécher et de faire bouillir 20 30 minute à +- 85C° histoire d'avoir 9980/1000
7) fais moi une belle photos de ton petit bouton d'or .

8) ci tu as des question hésite pas à me demander.

pour le chlorure d'argent ci tu l'as en petite quantité refond le (en lieux ventilés, dégage du gaz)

je ferais prochainement un poste concernant l'affinage de l'or par ce procédé.
m sur le meilleur resultat actuellement et de
9985/1000 pour l'or
1000/1000 pour l'argent (9x5 mais le spectro bloque un 100/100)
780/1000 pour le palladium
platine et rhodium à venir.
quelque photos : argent or palladium
Best regard
VINCENT (french)
good bye

 

[FrugalRefiner]

Abdoulapapatte, you are more likely to get responses if you translate your comments to English before you post them. Most members will not take the time to translate them.

Dave