AP Colour Question

[user 72646]

Hi

I have an AP made from hcl and hydrogen peroxide.

It is soaking mixed pc and phone parts for gold foil separation.

The bubbler is on and the solution has gone very dark.

Does this colour change signify that the AP is working/active?

Or is the bubbler just kicking up debris?

MM

 

[Shark]

Using up the oxygen faster than the pump can provide. Just leave it running, if it isn’t fully overload with pins and other excess base metals. Some pictures occasionally would really help.

 

[Martijn]

Hi

I have an AP made from hcl and hydrogen peroxide.

It is soaking mixed pc and phone parts for gold foil separation.

The bubbler is on and the solution has gone very dark.

Does this colour change signify that the AP is working/active?

Or is the bubbler just kicking up debris?

MM

Green is fresh good copper 2 chloride, darker is more copper 1 chloride. When that gets saturated, it precipitates out as white slimy gelly stuff. You want it to be green, not dark.

 

[user 72646]

Thank for the reference!

 

[Shark]

This dark color is why pins don’t work very well in AP. It uses up large amounts of oxygen on base metals. This is also part of why it is used on fingers, and very clean boards of the right type, it works best on the finger/ board materials. It is also best to use a large excess of HCl for AP as it leaves plenty of room to hold these metals in solution. Lazersteve had some great information posted about it and did have some more including videos on his web sight. Be worth looking into if it is still available.

 

[user 72646]

Hi

Using up the oxygen faster than the pump can provide. Just leave it running, if it isn’t fully overload with pins and other excess base metals. Some pictures occasionally would really help.

Hi

The pictures look like I have 1gram Copper Chloride per litre of solution, it is a greenish colour.
It has been bubbling for 4-5 days, i have seen a couple of foils in solution, and some items look like some plating has been dislodged.

**using up oxygen faster than the pump can provide*** are you referng to? the AP?

So when the AP is active is uses oxygen and the pump keeps that activity in the AP because it is fuelling with Oxygen?

Thanks

MM

 

[Shark]

**using up oxygen faster than the pump can provide*** are you referng to? the AP?

So when the AP is active is uses oxygen and the pump keeps that activity in the AP because it is fuelling with Oxygen?

In simple terms, yes. The oxygen is needed to oxidize the base metals. In the case of fingers and most boards this is mainly copper. Once the metals are oxidized, the acid (HCl) can go to work eating those metals away. This has the effect of allowing the gold foils to float loose. This is why I said using AP in excess is preferred, it keeps more solution to hold the oxygen with out depleting it. It is also the reason you see all the YouTube videos of people using peroxide, very wrongly in way to much quantity. A little will give a sudden green color back to the AP and speed it up but there is a down side. It can dissolve your gold if too much peroxide is used. An air pump can keep it working with out the gold dissolving. Even though some gold may go into solution it won’t stay, the copper in the solution will force the gold back out, but in a fine brownish colored “sand”. This has the effect of confusing the newer people and can panic them into thinking their gold is gone when it is just hiding from them. If most would allow the pump to run until it returns the solution back to a greenish color before proceeding they would be on the right track. This very dark color can mean there is not enough solution as well. In extreme cases of over saturation adding more HCl would bring it back into balance. You must have enough HCl to hold the amount of base metals you are trying to remove. An excess of AP will aid in a better volume of oxygen to be held in solution. This better balance means it works faster and cleaner.

There are pages on pages of information on the forum about this. It is well worth the effort to search it out.

 

[user 72646]

Interesting that a kind of drop/precipitation" may be occurring in the AP when excess HCL is present.

Just to clarify

Copper in solution can precipitate dissolved gold back out of solution to make brown sands which can be refined in AR.

Is there any movement on purity of the gold after the drop out of solution?
Could sands be processed (AR) with recovered foils?


MM

 

[Shark]

It is not a drop/precipitation so much as it is the effect of cementation. As the gold goes into solution the copper ( or base metal) on the boards cement it back out. This is very fine powders so fine that the gold appears brown. Due to particle size it does not reflect light so we don’t see the yellow gold but only brown dust. This repeats itself until there are no base metals to cement the gold out, or there is mainly copper in solution to keep the gold from going into solution to begin with.

Most will decant the AP from the foils and wash with water until they are working with fairly clean foils/gold, then go to AR. Some will filter the AP and then add the filter and contents to AR. Each has its uses, experience will teach when one is preferred over the other.

AP or copper (ll) chloride is the more proper name, can be a powerful solution when working with the right materials. To the beginner it is the easiest solution to learn and very useful to the advanced users as well.

When your AP goes very dark, take a spoonful and add a drop of peroxide at a time and see if it turns green. If it turns green add oxygen to the solution. If no, add HCl. For real in-depth understanding look up the information that Lazersteve has about it. It is well worth the read.

 

[Martijn]

Interesting that a kind of drop/precipitation" may be occurring in the AP when excess HCL is present.

You misunderstood, exces H2O2 can dissolve gold. Gold in solution will also cement out on more reactive metals like copper with tiny amounts of free HCL. An excess of HCl is used to convert dark CuCl1 to green CuCl2 as shark said.

 

[snail]

If my memory serves me well I believe Lazer Steve gave a tip in the extensive postings on the process. If a drop of creates a white cloud the solution is saturated with copper and more acid is needed.

 

[Martijn]

If my memory serves me well I believe Lazer Steve gave a tip in the extensive postings on the process. If a drop of creates a white cloud the solution is saturated with copper and more acid is needed.

You mean a drop of water i assume?

 

[Yggdrasil]

You mean a drop of water i assume?

Shhh, it is the magic ingredient, we don't speak or write about

 

[snail]

 

[user 72646]

It is not a drop/precipitation so much as it is the effect of cementation. As the gold goes into solution the copper ( or base metal) on the boards cement it back out. This is very fine powders so fine that the gold appears brown. Due to particle size it does not reflect light so we don’t see the yellow gold but only brown dust. This repeats itself until there are no base metals to cement the gold out, or there is mainly copper in solution to keep the gold from going into solution to begin with.

Most will decant the AP from the foils and wash with water until they are working with fairly clean foils/gold, then go to AR. Some will filter the AP and then add the filter and contents to AR. Each has its uses, experience will teach when one is preferred over the other.

AP or copper (ll) chloride is the more proper name, can be a powerful solution when working with the right materials. To the beginner it is the easiest solution to learn and very useful to the advanced users as well.

When your AP goes very dark, take a spoonful and add a drop of peroxide at a time and see if it turns green. If it turns green add oxygen to the solution. If no, add HCl. For real in-depth understanding look up the information that Lazersteve has about it. It is well worth the read.

Hi Shark,

Did some filtering and I see an example of the light brown sands...!!
Thanks for the tip.
The filters are golden brown-yellow with a grey paste (tin)?.
I am filtering half of the AP to drop for any dissolved gold that have remained in solution (small experiment), and using the other half again on stubborn components with bubbler.

The sands are about 1-3grams roughly from 1.2 kilos of mixed materials.
Gonna process filters with HCL and Peroxide on a little heat., then smb?
MM

 

[Yggdrasil]

Hi Shark,

Did some filtering and I see an example of the light brown sands...!!
Thanks for the tip.
The filters are golden brown-yellow with a grey paste (tin)?.
I am filtering half of the AP to drop for any dissolved gold that have remained in solution (small experiment), and using the other half again on stubborn components with bubbler.

The sands are about 1-3grams roughly from 1.2 kilos of mixed materials.
Gonna process filters with HCL and Peroxide on a little heat., then smb?
MM

AP will not dissolve any Gold to speak of. So there should not be any Gold in solution.
There might be different Copper and Tin compounds though.
The sands will be a mix of Tin and what ever foils whole or in powder from the PCBs.
HCl and Peroxide 10% or higher will be fine for that.
HCl and Bleach too, just make sure the pH is kept low.

 

[Yggdrasil]

Hi Shark,

Did some filtering and I see an example of the light brown sands...!!
Thanks for the tip.
The filters are golden brown-yellow with a grey paste (tin)?.
I am filtering half of the AP to drop for any dissolved gold that have remained in solution (small experiment), and using the other half again on stubborn components with bubbler.

The sands are about 1-3grams roughly from 1.2 kilos of mixed materials.
Gonna process filters with HCL and Peroxide on a little heat., then smb?
MM

It is wise to process just one kind of material at any given time.
Then you get the data and feel for that particular feed stock.

 

[user 72646]

AP will not dissolve any Gold to speak of. So there should not be any Gold in solution.
There might be different Copper and Tin compounds though.
The sands will be a mix of Tin and what ever foils whole or in powder from the PCBs.
HCl and Peroxide 10% or higher will be fine for that.
HCl and Bleach too, just make sure the pH is kept low.

Hi Yggdrasil

The AP started as HCL and Bleach on a bubbler.

Then I was advised that bleach only lasts 24 hours.

This 24 hour period is where some gold dissolved?

The copper in solution replaces gold in solution and creates a brown sand?

I discussed this with a senior member in forum. Is it plausible given some gold had to have dissolved in acid bleach and bubbler?

The next stage: I added a little hydrogen peroxide to the remaining HCL in solution, as the bleach I assumed was dead.

Bubbled for 6 days in total 1 day as Hcl and bleach & 5 days as Hcl and Peroxide.

Foils are present and I now have an aqua green blue AP, which I have split one half to use again (stubborn items), the other to see if gold is present then drop with smb, After a few more filters?
MM

 

[Yggdrasil]

Hi Yggdrasil

The AP started as HCL and Bleach on a bubbler.

Then I was advised that bleach only lasts 24 hours.

This 24 hour period is where some gold dissolved?

The copper in solution replaces gold in solution and creates a brown sand?

I discussed this with a senior member in forum. Is it plausible given some gold had to have dissolved in acid bleach and bubbler?

The next stage: I added a little hydrogen peroxide to the remaining HCL in solution, as the bleach I assumed was dead.

Bubbled for 6 days in total 1 day as Hcl and bleach & 5 days as Hcl and Peroxide.

Foils are present and I now have an aqua green blue AP, which I have split one half to use again (stubborn items), the other to see if gold is present then drop with smb, After a few more filters?
MM

You need to be more specific. Bleach or Peroxide?
And there is no need for anything else than HCl and bubbler for AP.
Do not add anything else. Or maybe some green corroded copper.

If any Gold dissolves it may cement out inside the PCBs and will be out of reach with conventional measures.
And if you add metallic copper to a solution with Gold in it, it will cement out the Gold as a fine brown powder.
But the amounts you are talking about here it would barely be visible.

How about your studies?
We asked you to study and then ask advice before you proceeded.

 

[user 72646]

Hi
it was hcl & bleach for 24 hours, then hcl & hydrogen peroxide for 5 days. both with bubbler>
first stage (first 24 hours) would dissolve some gold second stage (5 days) would dislodge foils?

This is where i am currently. My studies have revealed that hcl and hydrogen peroxide dissolves gold as does hcl and bleach?

So i see these two processes as having the capacity to dissolve gold and dislodge foils

i will reprocess electronic items with hcl & bubbler only, to detach any stubborn foils.

MM