recovering dissolved gold in AP solution

[jimmyreece]

having added to much peroxide or being left to sit in the sun to long, all the gold foil in a AP solution has dissolved. now the gold would just cement its self on to the copper powder that is in the solution which is the black and brown powder, is this correct?

 

[glorycloud]

Is your AP solution a nice clear emerald green color? Keep using the
AP solution you have on more fingers until it gears a dark brownish color
as more and more copper goes into solution pushing your gold that may have
dissolved out of solution.

When you add a drop or two of water and you get an immediate white
cloud in the AP, then your solution is saturated with copper II chloride
and your gold should be found at the bottom of your bucket.

You can also drop a clean copper pipe or bus bar and it should do the
job as well. I was always cheap and I reused my AP solution as much
as possible.

 

[jimmyreece]

the solution is brown and saturated. the powders that have settled ( brown and black). this is pms, mostly pms or greatly mixed with other metals that have precipitated also ?
concerning the actions of an hcl or AP solutions, the acid dissolves base metals. now all of what is disolved, does that stay in solution or should i assume any or all precipitated powders are a heavy contaminated mixture of all metals ?

 

[jimmyreece]

when you say it should do the job as well, do you mean push the gold out of solution or cement the gold on to the copper pipe or buss bar ?

 

[eeTHr]

jimmy---

Remember the purpose of whatever process you are doing.

The purpose of AP is to dissolve the copper, and leave the gold. If you are processing card edge fingers, that's the case.

So, if the copper is dissolved, and the gold is still solid, what would the sediment on the bottom of the container be?

Particles of gold which are very fine, yet larger than colloidal particles, will be black. Unrefined gold particles larger than those are usually brown. You can have both black and brown gold particles in a process like what you are using.

The gold then needs refining, because there will be a little bit of contaminants.

And there may be a little dissolved gold in your solution, but if you reuse the solution for your next batch, it will not be lost, as the copper will continually push it out. After you use the solution so much that it becomes saturated with copper, it should test clean of Au. Or if you want to, you can cement the last bit of Au out of your solution with copper, but you will shorten the life of the solution. Then, Lazer Steve has a way of rejuvenating the saturated solution, anyway.

 

[jimmyreece]

thank you. you just anwered all my questions i had with the AP process

 

[Geo]

i had the same question but slightly different.i put whole boards in AP because the material im working with has many boards that are plated on both sides with some really thick gold.almost all of them bears the HP logo and are military grade.ive had a couple of problems right away, some of the boards had a kind of solder mask that would not dissolve in NaOH solution so i used a steel wire brush to remove as much as i could hoping the AP would work underneath.the next was some of the boards had a coating of silver solder over the gold,i tried sulf+nitric bath but it saturated too quickly to be useful so i put them in as is.im now on batch two in a very large bucket with 4 1/2 gallons of HCI and 1 gallon of peroxide.each with as many boards as would fit with the second almost complete.the first batch has over 1OZT of material back in foil and black and brown powder.im concerned about how much gold could be in solution.ill have one more batch after this one with material on hand.can you re-activate the solution with the addition of NaOH in solution? if not ill squeeze the last of my gold out and leech the copper then neutralize the solution.

 

[Palladium]

If you used nitric and went to hcl you probably have dissolved some of your gold. For me that's also way to much h202 for the ap process. You only need enough to oxidize the copper at the beginning of the process to get it going. After it starts etching the copper the process is self sustaining as long as you use an air bubble to add oxygen to the solution. Are these boards clean of all components?

 

[Geo]

If you used nitric and went to hcl you probably have dissolved some of your gold. For me that's also way to much h202 for the ap process. You only need enough to oxidize the copper at the beginning of the process to get it going. After it starts etching the copper the process is self sustaining as long as you use an air bubble to add oxygen to the solution. Are these boards clean of all components?

the boards that had the silver that went into sulf+nitric were washed before they went into the bucket.all the boards were depopulated with a chisel and hammer.i put 2 quarts H2O2 in the first batch and 2 quarts into the next with the same solution now it is so green its almost brown.id like to use the same solution to do the last batch of boards but im sure its saturated.i tried a little experiment with a quart of the solution.i put it in a fruit jar and placed the jar in a tupperware bin and added 1/4 cup NaOh.the reaction was pretty dramatic with alot of fizzing and heat but no color change.

 

[martyn111]

i tried a little experiment with a quart of the solution.i put it in a fruit jar and placed the jar in a tupperware bin and added 1/4 cup NaOh.the reaction was pretty dramatic with alot of fizzing and heat but no color change.

Can I ask what you were trying to achieve by adding the NaOH to your solution?
If you were trying to drop gold from solution shouldn't you have been using either SMB or SO2?

Also to quote Harold on many occasions, if you are going from nitric to hydrochloric or vice versa and don't want to dissolve values, Incineration is the way, washing will not remove all of the first acid.

 

[butcher]

Something is wrong.

 

[Geo]

i tried a little experiment with a quart of the solution.i put it in a fruit jar and placed the jar in a tupperware bin and added 1/4 cup NaOh.the reaction was pretty dramatic with alot of fizzing and heat but no color change.

Can I ask what you were trying to achieve by adding the NaOH to your solution?
If you were trying to drop gold from solution shouldn't you have been using either SMB or SO2?

Also to quote Harold on many occasions, if you are going from nitric to hydrochloric or vice versa and don't want to dissolve values, Incineration is the way, washing will not remove all of the first acid.

actually i was trying to remove some of the copper from the solution so that i might re-use it.it didnt work too well.its no big deal, i still have all the solution and have filtered several times and still cant get all the fine gold particles out.i was wondering if i cant get all the fine gold out should i take the solution in small increments and add nitric by the dropper till i dissolve all the fine gold and drop with SMB?

 

[Barren Realms 007]

If your solution is saturated with copper (white cloud developes when you add a drop of water) let it set and your gold should settle to the bottom. If you have any floaters spray them with a mist of water and they should settle to the bottom as well. Then siphon off your solution and process the material in the bottom.

HMMM how many times has this been stated on the forum?

 

[Geo]

another thing i wasnt thinking about when i put the boards in with the solder mask in place was all the slime in my foils and powder,do i rinse in water a few times and incenerate before HCI-CI?

 

[Geo]

i tried the water and it didnt do anything till i was rinsing the foils out of the bucket go figure then it turned white

 

[Barren Realms 007]

i tried the water and it didnt do anything till i was rinsing the foils out of the bucket go figure then it turned white

The white you see doing this is possibly tin that was in your solder.

 

[jimmyreece]

so the AP solution is technicaly for copper based metals. and that i asume is why ive read that alot of guys seperate their pins with a magnet.
but after seperating the pins, one can still use the AP method for iron based pins, correct , or just Hcl +0 ?
yes i can see where having them mixed can and already has(for me) cause a problem in the solution.
it looked like the gold,copper and iron had a big turff war. i still have the remains to that battle put away. what would be a good fix for that at that point. nitric ?

 

[Oz]

Ok, we have a few things discussed in this thread, but all of them add up to “is that gold in the bottom of my solution?” or “is there gold in my solution?”.

Why is there no mention of testing with stannous chloride?

Some of the members here do not realize just how good they have it with all of the information that is on this forum, yet they still just often glaze over it.

A case in point. About 6 months ago I was talking to a refinery that does millions in gold a year. I asked how they determine their end point when precipitating. Long story short, they had never even heard of stannous chloride, nor did they have a good way to determine their end point when precipitating. I described its use and manufacture, then even sent them some pure tin. I offered to walk them through by phone the making of their stannous as well as how to use it once they received the tin I had sent. They were excited to receive it and learn how to use it.

I have yet to get that call.

That my friends is “your” gold going out of their door that you are not paid on when you sell to them, because they do not know how to test! You however have been handed all these years of experience on this forum. If you do not do your work in studying what is offered here, do not expect the refinery you sell to to do it for you!

If you truly study what is written here you will be in the position of "knowing" what you are shipping out, and if you are being paid fairly.

Yes, this became a rant. My apologies.

 

[dtectr]

i tried the water and it didnt do anything till i was rinsing the foils out of the bucket go figure then it turned white

The copper chloride (the bad kind) is readily soluble in even very dilute HCl. When most of the HCl is rinsed away, you have only water & copper chloride, which is insoluble in water & immediately precipitates as white mud.

If you remember from lazersteve's video the first rinses were with HCl, for that reason. Try adding a little HCl to the foils/white residue - the solution should clear immediately. You're not going to harm the foils with just HCl & add your rinses to the stock pot.

I use water now, with copper based materials only after several rinses with HCl. And we're not talking gallons at a time - just enough to cover the foils, and remember to give them a good stir to expose any that is trapped between foils.

 

[jimmyreece]

your absolutly right about stannous chloride testing Oz. and i have to admit i was slow to develop the habit of using it too.
and thats when i learned how common it was to have values in both solution and the sediment at the bottom at the same time. for a while i was going by the belief that values were only in one or the other.