Another AR gold drop problem, 125g gold stuck in diluted smb solution. Help!

[Drbullion]

Brief history,

1. White gold scrap so it has PGM's, I inquarted with silver, used 1:1 Dilluted Nitric Acid %70

2. Went to AR, slowly added nitric, The problem was i did my calculation wrong and only added 1/3 of total AR so I had to add 2/3 more. It all mostly dissolved, what was left behind was garbage,

I cooled it, added some ice and Added SMB but nothing dropped, I ended up adding A LOT of distilled water because I read the water would allow the smb to work and drop gold, it didnt,

Now I have 2/3rds of a gallon of super dilluted AR with gold in solution, I also added WAY too much SMB 11 ounces hoping it would overcome the nitric,

Anyways I am stuck with this what do I do?

Do I boil off for days? Can I just add Sulfamic acid to this diluted mixutre? Will I need to add SMB again even though I used way to much and its still in there.

There is some very fine brown powder on the bottom of the Jar now but I feel like its SMB mostly.

See photos,

 

[FrugalRefiner]

1. White gold scrap so it has PGM's

Not necessarily. A lot of white gold is made with nickel, not PGMs. Nickel is a powerful whitener. Consider that the US 5 cent coin (the nickel) is made with 75% copper and 25% nickel. European white gold is more likely to contain PGMs, and more recently in the US manufacturers are getting away from nickel due to its allergenic nature, but don't just assume there are PGMs present.

Now I have 2/3rds of a gallon of super dilluted AR with gold in solution, I also added WAY too much SMB 11 ounces hoping it would overcome the nitric,

How much gold did you dissolve in this 2/3 gallon of solution?

Dave

 

[Drbullion]

Sorry, there was also Dental Scrap mixed in which had a bit of palladium in it,

The gold sponge weighed in at just over 125g, So I only used 125ml of HCL, then added nitric slowly,

I realized I needed 3x 125 so I then added more after the fact, this made me use too much nitric because I lost track from the wrong calculation,

I easily added more than double to amount of Distilled water Thats why its 2/3 full of a gallon.

There is roughly 125g of gold sponge dissolved into this dilute solution.

Thanks Dave!

 

[Lino1406]

The color is not nickel, probably palladium/gold. To assure, cement a portion with zinc

 

[Drbullion]

I tried to cement with copper but nothing happened.

Will zinc cement it out? I be happy if I could get it to cement so I Can start over.

What if I add sulfamic acid this as is and try to cement out with zinc? Would that work?

Im open to any suggestion how to fix this. Lol

 

[Slochteren]

I would first check with stannous if there is still gold dissolved and if so to get a indication how much.... If copper didn't cement anything and the copper dint dissolve either there is no free nitric anymore...

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[Drbullion]

Stannous shows up brown on the paper, but theres way to much SMB in it too and I read that will show false positives on stannous,

Should I add Nitric back into it and then cement with copper?

 

[Slochteren]

I would not add nitric, I'm not sure but if you get a false positive there is no dissolved gold in your solution.
Get 400 ml and boil it for a while and check again with stannous.

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[Palladium]

The gold sponge weighed in at just over 125g,

How did you arrive at that number? Did you weigh it wet?
If you started with 125 grams then you don't have 125 grams still stuck in solution.
How much does the powder that already dropped weigh?

 

[Drbullion]

Ok Ill boil 400ml down and test it again,

The gold sponge weight was 125g before I moved to AR,

There is some very fine brown powder at the bottom but I don't know what is weighs, but it does not seem like much,

Ill do the stannous test again after boil down.

 

[jarlowski1]

Decant the solution into a different container. Then wash the powder (a very important step) then dry it and weigh the powder. Then you can work on the solution and you can tell if anything else drops.

 

[Shark]

In a 1 gallon jug, that looks like a fair bit of gold powders. The bottom of those jugs is a large area.

 

[goldscraphobby]

Ok Ill boil 400ml down and test it again,

The gold sponge weight was 125g before I moved to AR,

There is some very fine brown powder at the bottom but I don't know what is weighs, but it does not seem like much,

Ill do the stannous test again after boil down.

Looks can be deceiving. The last drop i did looked disappointing. Didnt seem like much but when weighed it was 50grams

 

[Topher_osAUrus]

Id bet that 50g is right on. ...well, assuming its 100% dry, and no accidents happen while melting..

The brown stannous test means you have too much smb in solution (you already knew that part)

Weighing the "sponge" is kinda like wiping before you're done pooping... you just dont know what alls left, ya know?

-for example, there could have been base metals still in the alloyed gold, but the nitric was unable to dissolve it from it being buried deep behind the gold "sponge".. but, AR easily put it in situ because it dissolved the gold "sponge" that passivated the nitric bath.

-its wet.(presumably) ..nitric is not weightless, water is not either.

Just a couple guesses.
I suppose I could say "educated guesses" because I've been there, and done that.
..It sucks, but, the bottom of the beaker tells no lie