Knowing which process to use....

[cejohnsonsr]

The more I read & study, the more I learn how much I still need to learn. I think I just learned the difference between AR & AP. Quite by accident. If I understand correctly, AP would be the process to use for almost everything (basically anything on a board) except ceramic CPUs & high karat material. AR, on the other hand would be more appropriate for the previously mentioned scrap & for the 2nd run on whatever I get from an AP batch. For example, if I run fingers via AP, whatever gold I wind up with should then be refined using the AR method. I'm attaching a photo of both sides of some scrap I have. I intend to process them as I just described. If anyone has any suggestions or other input, please feel free to weigh in.

Thanks,

Ed

 

[jmdlcar]

Hi,

If it was me I would use "Sodium Hydroxide Lye" first to get of the solder mask then I would use AP to refine it. Hope this help you.

Jack

 

[tek4g63]

Hi,

If it was me I would use "Sodium Hydroxide Lye" first to get of the solder mask then I would use AP to refine it. Hope this help you.

Jack

Like Jack has suggested a NaOH bath might be beneficial. But I would just do one if them in the bath first to see if there is any gold under the mask. If there is no gold under the mask then yes I personally would just go with AP to recover the gold. The plating on the boards is likely very thin. So you may not see nice gold foils floating around in your AP but rather a very fine gold glitter.

After you recover the gold foils/ glitter you could use AR to refine the gold. But personally I like the hydrochloric/ bleach process better for foils. Its cheaper and much simpler for someone new. Because excess chlorine is much easier to expel from your solution than excess nitric is. Plus anytime I can avoid producing NoX fumes is a huge plus in my book.

Good luck and keep us posted on your progress.

 

[cejohnsonsr]

Thank you, Jack. That's exactly what I was thinking. What I'm curious about is whether or not I could take the foils, wash & clean very thoroughly to remove as much sludge from the mash as possible, then dissolve in AR along with some ceramic CPUs. I also have a VERY small amount of finished 1st run powder from a test batch of fingers. I only got .26 gr from 144 gr of material. (I think I wasted about half of my yield, but that's another post.) Anyway, I was considering putting that in the AR as well. If I understand this, AP is good for recovery, like getting the foils from fingers & pins & boards like in the pics. AR is good for refining & also for recovering gold from higher value scrap, like ceramic CPUs. It's beginning to seem like maybe a combination of processes would be better & more efficient.

Ed

 

[steyr223]

Hello you got it just a bit backwards
Re read what was said above.
Dont jump to conclusions.

A/p acid peroxcide (murriattic acid/hydrogen peroxide 3%)
Is your recovery process to separate your base metal
From your gold(which you have dissolved with a/p and can pour off)

Now to refine further you either use murriattic acid and
Regular bleach or a/r.
Bleach is preferred as it is much easier
Put your foils in a beaker cover them with hcl(murriattic in California)
Add small amounts of bleach until you see no more foils
Let it sit in the sun for a day with top off to dispell the bleach
Drop/percipitate with smb mixed with twice the volume water

Now as you seen .26 grams... You wont get much with less than
A pound of fingers and keep you cpu's together for a different process
Hope this helps Steyr233 rob

 

[nickvc]

Ed there are more than one way to dissolve your values as has been pointed out and all have there place in a refiners armoury of processes. The one thing I do want to stress is that you don't mix types of material you want to process until you have refined the gold at least once. The reason behind this is logical when you think about it, many types of e scrap have different base metals some of which can be troublesome,to be polite, and you need to remove those first or you can lose values or make a mess of already good powders or foils, mix tin with AR and you really won't be happy at the outcome. To stress this point again process different materials individually, remove the base metals as well as you can before trying any refining, after one refine you can normally then mix the powders precipitated together for the final refining, using AR and then the chlorox method can be beneficial as they do the same job slightly differently removing more of the contaminants.

 

[Palladium]

Don't mix the foils with the ceramic chips. Never mix materials once you have them segregated. You will probably find no gold under the mask. Ap is taught as a more friendlier solution for beginners, but from an experienced stand point all i see is copper and gold there, maybe a nickle barrier or something small. For me it would be ar. The only problem is the boards will lay flat and stick together. Even with stirring a large lot can be difficult. A trick I've found is to break the board ever so slightly by bending it till it barley cracks and warps. This way the acid can get between them to do it's work. If your going to have to ar them chips then ar is in your future anyways.

 

[cejohnsonsr]

Hello everyone. Thanks for all the responses. I'm really learning quite a bit tonight between this thread & 1 other. I really appreciate it.

steyr223, when you say, "smb mixed with twice the volume water", could you be a little more specific? I read that I should use about 1 gr of SMB per gr of gold I expect to recover. So does that mean if I expect to recover 5 gr of gold I should mix 5 gr of SMB with 10 ml of water. I've been a little confused about exactly how much SMB & water to mix together. My 1st attempt at AP I just added the powder 1 teaspoon at a time until I got a reaction.

Palladium, I promise not to mix materials. When you say, "no gold under the mask", do you mean no gold on the board? I'm not sure how that's possible. I can see the gold. The scrap I have is samples & rejects. A lot of it has 1 side etched & the other still completely covered. Also, the weight leads me to believe it's pretty good scrap. I could be wrong. I'm very new to this. But I hope I'm right! I had been thinking about how I was going to get the boards to stand up in the AP bucket. I like your idea a lot! I'll let you know how it works out. I do have quite a bit of ceramic CPUs to process so I'm sure AR is in my future, but I've decided to hold off a bit until I get a little better with the AP process. 1 thing at a time. Right?

I'm trying to keep accurate records so I can report back on my yields, problems, successes, etc...

Thanks again,

Ed

 

[tek4g63]

Don't mix the foils with the ceramic chips. Never mix materials once you have them segregated. You will probably find no gold under the mask. Ap is taught as a more friendlier solution for beginners, but from an experienced stand point all i see is copper and gold there, maybe a nickle barrier or something small. For me it would be ar. The only problem is the boards will lay flat and stick together. Even with stirring a large lot can be difficult. A trick I've found is to break the board ever so slightly by bending it till it barley cracks and warps. This way the acid can get between them to do it's work. If your going to have to ar them chips then ar is in your future anyways.

Palladium, you are far more experienced then myself, so please excuse my ignorance. But if AR was the first step, to dissolve all metals, wouldn't there be a high likely hood that the fiberglass PCB will soak up some gold bearing solution? With a ton of washing I'm sure that you could free most of it, but the likely hood of loss seems great to me. As we are already trying to squeeze pennies of gold out of ounces of material, why let the trash steal some of your pennies?

To save some time? But how much time? With boards like that if he could keep them from sticking together they would not take very long soaking in AP to remove the base metals. And during that time you would be freed up to tend to other matters. Not to mention that when you did dissolve the gold afterwards it would be a much cleaner and easier to work with solution.

It is very possible that I am way off base and if that is the case then I am truly sorry. I just see a bigger chance of losses and complications, especially for new members, if AR is used from the start. Please correct me if I am wrong, because I'm still quite fresh at this and if there is a better way then what I'm doing now you better believe that I'll adopt it. 8)

Thad

 

[necromancer]

your doing good for a member here less then 30 days, please let us know how much you have to process and your yield

thanks

remember "SAFTEY FIRST"

 

[Geo]

Palladium, you are far more experienced then myself, so please excuse my ignorance. But if AR was the first step, to dissolve all metals, wouldn't there be a high likely hood that the fiberglass PCB will soak up some gold bearing solution? With a ton of washing I'm sure that you could free most of it, but the likely hood of loss seems great to me. As we are already trying to squeeze pennies of gold out of ounces of material, why let the trash steal some of your pennies?

To save some time? But how much time? With boards like that if he could keep them from sticking together they would not take very long soaking in AP to remove the base metals. And during that time you would be freed up to tend to other matters. Not to mention that when you did dissolve the gold afterwards it would be a much cleaner and easier to work with solution.

It is very possible that I am way off base and if that is the case then I am truly sorry. I just see a bigger chance of losses and complications, especially for new members, if AR is used from the start. Please correct me if I am wrong, because I'm still quite fresh at this and if there is a better way then what I'm doing now you better believe that I'll adopt it. 8)

Thad

not likely as the fiberglass is encased in resin epoxy. pretty much water tight. a good rinse should get it all. there should be only a few circumstances where you would process whole boards in AR as its better to remove any foils and process only them. the main reason for this is the tin content in the solder. tin oxide in AR is a monster of a problem.it makes the solution hard to filter and can cause colloids to form. a colloid will not precipitate with SMB.

 

[tek4g63]

Thank you geo.

I just know that when I do fingers in AP the stripped fingers seem to have soaked up a lot of solution in the cut/ broken off edge and a little around all other edges. I can tell by color. I've never tried washing them completely clean looking again because after I spray off the foils I throw them in a bucket of water with a little baking soda and that's where they sit until I dig them out and trash them. I just know that the edges never rinse completely clean when spraying off the foils.

Thank you for the correction. Now I know. :mrgreen:

 

[Geo]

hcl is a strong bleach. anything that it does not dissolve will lose some color or be discolored. anyone that has spilled a few drops of hcl on denim knows it when they wash next. that wasnt the little woman that splashed bleach on your pants. :lol:

broken fiberglass will soak up some solution but a water rinse will wash it out. fiberglass isnt like cotton and doesnt like to hold fluids easily. you can wick fluids with fiberglass cloth and it can be used a an alternative to filtering.

 

[Fox32]

Steyr, if there was a like button your post would have earned it!

 

[Anonymous]

Hi,

If it was me I would use "Sodium Hydroxide Lye" first to get of the solder mask then I would use AP to refine it. Hope this help you.

Jack

yes you are right but can leve it in long or it will eat your gold if it is thin layer of gold it will eat it just leve it in about 1 min and rub of the mask and use rubber gloves and eye mask to do not get lye on you skin it will eat it of wow

 

[steyr223]

Why thankyou
As far as the smb and volume there
Are many ways.
Normally if i have.say 400 ml of auric
Chloride i mix my smb(which you got rigjt
Gram for gram) with 400 ml of water then i add it
to my auric chloride.
So i end with 800 ml of solution that hopfully
Drops some gold powders
Others add ice to the 400 ml until it =800 ml
Then add the smb directly (after filtering
A second time)
And some even drop(precipitate) with hcl
In place of the water
Some do it upside down in a flotation chamber
And in a vacuum :shock: just kidding :lol:
Hope this helps
Steyr233 rob
Ps just so you know i posted a pic of my latest
This came from 1lb of figers ,6lb of golde plated jewlry ,
100 grams of very deep golden pins, 100 grams
Of ok pc pins, 3lb of boards like yours (100's)
And about another 50 grams of fingers
3 different processes . First lb of fingers= 1.87 grams
Pins and jewelry(done in sulfuric cell)=.82 grams
The rest was the rest

All this from very.low grade stuff 3.2 grams
As you can see a lot of work
But like you i am still perfecting the art(40 more years)

 

[Palladium]

Geo is correct about the fiberglass. Had it been anything besides new rejects i would have recommended different. Washing the fiberglass boards of gold in solution is easier than trying to wash those 10,000 pieces of minute gold from the boards and those little holes. Not to mention how the gold hangs on the rough board edges. I do all my fingers in direct ar also. From a production stand point i can't afford not to run them like that, but from a hobbyist stand point or a newbie i would recommend ap until you master your processes.

 

[lazersteve]

Ed,

Unless you have a very large number of these boards, I would suggest that you simply run them with a pound or more of normal board fingers. Most boards like the one in your photo contain so little gold, you will be chasing a proverbial 'ghost' trying to get the gold out of any solution you choose to use.

I with Ralph (Palladium) on processing fingers. Use AP when learning, use AR when you master the process. You will understand why when you graduate past 5 pounds of fingers in a single batch.

Steve

 

[steyr223]

Now you guys tell me :roll:

One way you can tell if there is
A lot of gold or a little is to put
1 in a jar big enough to hold it
With a/p and a fish pump hose
To bubble it
To clarify the a/p would have to
Be used ,already saturated with copper
(Cu2Cl) ,your old stuff ,not newely mixed

If it is a thin layer it will be gone within
Hours not days like fingers
If it is still not stripped in.a couple days
Your rich
Steyr233 rob

 

[cejohnsonsr]

Steve, I have what was supposed to be 6.6 lb of these boards. Not all like the one in the pic. Different sises & shapes, but all either samples or rejects. Personally I think the raw weight is more than 6.6 but I admit I haven't weighed them. Individually, they "feel" heavy compared to similar size boards even though the normal boards had chips on them & these samples & rejects don't. I also have some similar material. I was thinking if I can get it to all fit in the bucket it might make a good AP batch for my 2nd attempt. I'm going to take everyone's advice & stick with AP for now, even though I do have some ceramic CPUs that I'd like to run & my Nitric Acid finally arrived yesterday (after waiting 18 days!). Actually, I'm glad it didn't come sooner. I probably would have tried a process I'm not yet ready for.

Concerning that 1st AP attempt, I'm going to post a few pics so you can see what I had. Everything went pretty much as expected until I divided & diluted. One beaker dropped & the other didn't. That has me baffled as they were identical. I'd really like to understand what went wrong there & try to correct my mistake (if possible) before i try again. I still have all of the AuCl from both beakers minus the SMB sediment from the nonreactive beaker. I wish I had taken pics of the stannous tests. I realize that even if I get the bad half to drop, we're not talking about much gold. It's really not about quantity at this point. It's about making sure I understand what's happening & that I can perform the process properly & consistently.

Also, I haven't begun reading Hoke yet. Today seems like a good day for that.

Thanks again for all the help & advice.

Ed