Copper forming on Gold in AP

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nickjam

Member
Joined
Nov 7, 2018
Messages
13
First ever batch. Placed in four days ago. Doing White Distilled Vinegar and Salt (NaCl) with an air bubbler in the container. Total batch 400mL; small to test my ratios and process before I place in a lot of gold.

Material is from 3 cell phones. The pins, the fingers and two boards that had gold around the edge of the board and circles of gold where the keyboards were.

Day 1 - Turned blue and could see small pieces of gold moving around.
Day 2 - Went cloudy white (CuCl) so I drained off some of the liquid and topped back up to 400mL with more vinegar.
Day 3 - Solution was clear with white precipitate covering everything like snow. When stirred no gold flakes present. Took liquid off and began washing everything to get the powder off. Super time consuming and what gold there was had broken down into REALLY small flakes. Added liquid back after it had settled for an hour and restarted the process.
Day 4 - Clear AP again with white powder and this time the boards and pins all had copper where the gold was. When I scrapped at the copper on the boards there was the gold underneath it!?!

Why is the copper attaching to the gold? I am missing something somewhere and here I thought I had the process down pretty clearly.
 
AP is Hcl and either an air bubbler or with a small addition of hydrogen peroxide, I’m not sure what you have but if you are going to try a process use the correct chemicals as changing even one item can make a huge difference to how it works.
Not sure why you are using vinegar instead of Hcl or why you added salt, this formula will dissolve a lot of metals when all you need to do is liberate the gold by dissolving the copper under the gold plating.
 
There are a lot of videos using a "safer" method using vinegar, salt and H2O2. My results seem similar to the other posts on here with the blue color and the white precipitate, until the copper plating began happening. If no one else has a solution I will make a switch to HCl. This is exactly why I did a small batch and I am playing it safe with the process.
 
Nickvc gave you good advice. Please let me add one small tidbit. Bad information on YouTube and other video hosts outnumbers the good information at a ratio of at least 20:1, in my opinion. If you want good information on recovery and refining of gold and other precious metals, get it here, and not from YouTube.

Time for more coffee.
 
Like many newbies you think some idiot on YouTube will give you a simple safe method that anyone can replicate, bear in mind we are dealing with some of the most dangerous elements in the planet once dissolved and some of the most resistant elements to recover.
Read the forum and learn how to do what you want to do safely and with peer knowledge about how to do so responsibly and with little problems.
It takes a lot of reading and a lot of determination to follow the teachings here but if you want to recover and refine precious metals there is no better resource than the forum.
 
I don't have the talent for using the scientific language that nickvc or galenrog have but.... putting metals into solution using vinegar and salt is NOT safe! The good thing is you CAN learn to refine gold, silver and other metals right here. I know it can be done, I am a work a progress to prove it.

Reading this forum can take you far on your goal of refining. It is a vast forum with many years of combined knowledge. It won't happen over night, or even a few weeks, but it will happen so long as you don't give up on it.

Good Luck!
 
Kadriver posted a Youtube video explaining the vinegar and salt method and he is a long time member here.

https://www.youtube.com/watch?v=ouYW_7-Njbs

It does in fact work. Metals in solution should be handled as you would handle refining waste, responsibly.
 
Thank you geedigity...That is in fact, the exact video I watched and have been following to the T.

So, not some YouTube idiot.
Not some obscure method.
Just a different way to arrive at gold flakes to then process to a more refined product.

One thing I have noticed over the weeks reading this forum is responders are so quick to tell people to "read the forum", "this is dangerous". remember it needs O2" "read Hokes" "Laser has all this on his website" and never truly just supply a simple answer.

We are reading and I was so hesitant to post after reading it for a couple weeks but between the crap responses there is some good information.
It is dangerous? Really? Just look at the chemicals we are picking up and read the labels. Think about the metals we are leeching into solution and think about at what PPM we have them in solution! In the end a lack of knowledge of that is a self-correcting problem.
Hokes is great. But does not have all the answers some real world people that have been doing this a while COULD provide.
Lasers site is good, if you like videos and can sort through to find the right stuff Hokes is better.

An answer? Still do not have one:
Anyone have any idea why the copper is coming out of solution and plating onto the gold instead of being removed from behind the gold? I can not figure out why Kadriver could complete it, but mine worked half way and then reversed itself.

Am I possibly misidentifying brass on the board as gold and the copper is plating to that? Has anyone experienced that?

If you don't have an answer that is totally cool. I know how to fix it, but just wanted some ideas on why? The chemistry is not making sense. Thank you.
 
I have not tried vinegar as there are easier ways for me to get gold processed. When I have run into problems such as your describing it has been due to not starting with enough solution to begin with. The vinegar method that kadriver used should not leave small gold flakes. It is an alternate method for Aqua Regia. It should put your gold into solution, where it can be precipitated out at (hopefully) a better quality than what went in. (try a search for "cementation" , that is the proper term for what you have happening. It is a good thing in the right situation)

Material is from 3 cell phones. The pins, the fingers and two boards that had gold around the edge of the board and circles of gold where the keyboards were.

If you followed kadrivers video, you should not have used "The pins, the fingers and two boards" in this manner. Most of these are processed separately, using other methods. A very few boards, unless properly prepared, can be run with fingers. And the pins should be dealt with as another separate item. kadriver is a member here, maybe he could help point you in the right direction. Most video's are not meant to be step by step "how to" video's, but a general guide. A video that walked through every step and every possible error that could arise would cost millions of dollars, if not more. Knowing what to expect when a process doesn't work out right is a big step in fixing the situation. Then when all else fails, ask away, I still have to at times my self and most likely always will. But I still enjoy it.

Good Luck!
 
Forgive me for sounding rude but why use a method that few bother with if the alternative is one that is well used and documented if your aim is to recover the gold for later refining. If you think that the vinegar and salt is a safer method because it uses common household chemicals you are wrong, you will still be producing chlorine gas and be left with a toxic solution containing a mix of metals, there is no safe way to do much of what we all do here on the forum as it usually produces toxic gases and or solutions.

As to why the copper is cementing out I imagine that the solution has found an easier metal to dissolve so has cemented the copper so it can dissolve more of the new metal, adding more vinegar should help once the new metal has dissolved the solution should go back to dissolving the copper.
If you are working solely with cell phone scrap I believe you will encounter many problems for little return, the problem been that much of the value is encapsulated not visible plating and the only way to recover them economically is smelting. I recall several threads where members were trying to refine cell scrap but can’t remember much success but I could well be wrong.
As to why we suggest people stop processing and read see my comments about toxic fumes and solutions above and the reason we advise to read Hoke is that it was written for non chemists to learn to refine jewelers scrap which helps teach the member the chemical terms and language we use, no it is not much help with e scrap as it didn’t exist in the 1930s but if you can understand that book you will follow all discussed here much more easily and without the need for constant questions on simple processes.
 
Acetic acid is not a good choice to work with. Copper acetate have only a small solubility (7-20g/liter depending on temperature) so the pale blue sludge locks up a lot of the gold as seen in kadriver's videos. The material he worked with is the easiest, pins and whole circuit boards will make it a lot harder. The low solubility of copper acetate also creates a lot more waste from the process, leading to more work and cost to clean up afterwards.

The fact that he managed to dissolve the gold at the end is quite fascinating. I was unable to find any data on the solubility of gold acetate, the only thing I found was that it is slightly soluble in water. That makes it very easy to lose gold in the process.
Thinking about it, 0.8g gold out of half a kilo of fingers is on the low side.

Most members goes for the easy and cheap process instead of complicated and expensive so there isn't a lot of experience of this process. That is why you don't get a lot of response.

The recommendation is to learn the basic processes first before trying to invent new ones.

If you continue insisting on the acetic acid road I think you will mostly be on your own.

Göran
 
Thank you for the constructive comments. I see now that he was only working with fingers and understand how the boards and pins would lock the process up something fierce. After a rinse off and a HCl bath I will place them into my other containers to finished them up the old fashioned way.

Forgive me for sounding rude but why use a method that few bother with if the alternative is one that is well used and documented if your aim is to recover the gold for later refining.

Two reasons. The HCl ones are going fine. Saw a new method where a small spill or mistake would require minimal cleanup vs. dealing with HCl cleanup. No one is perfect! I really didn't care about the NaCl pulling other metals since I was only grabbing the gold flakes to refine. However, now, I am glad I did such a small batch because to try and recover the gold is going to be time consuming. Maybe some rainy day I will make an attempt! Disposal. With vinegar I could easily let the sun cook off the water and waste disposal would be a minimum if it worked.

Most video's are not meant to be step by step "how to" video's, but a general guide. A video that walked through every step and every possible error that could arise would cost millions of dollars, if not more.

Amen. I did find this guy as well that has a lot of videos that show different mistakes.
https://www.youtube.com/channel/UCbzpmTi8lr_JDoKr9saAb1w
 
nickjam said:
Disposal. With vinegar I could easily let the sun cook off the water and waste disposal would be a minimum if it worked.
Unfortunately, that's not true at all. Even if all you did was dissolve a little copper in vinegar, you now have hazardous waste to deal with. Once the copper is dissolved, it creates copper acetate in solution. Drying it would leave you with crystals of copper acetate. If you add water, you once again have copper acetate in solution, and just about any copper compound is toxic to nearly all forms of life. It is hazardous waste that must be disposed of properly. Incidentally, copper acetate is a permeator, so if you get a drop on your skin, the copper will be absorbed into your system, even through intact skin.

All of the same applies to copper dissolved in HCl. You can evaporate the waste solution just as easily, and end up with dried copper chloride instead of copper acetate, and they are both equally toxic, and must be disposed of in the same way.

When you add salt to vinegar, you have a combination of both acetic acid and hydrochloric acid. It just complicates things.

I can buy a gallon of HCl for about $4.00. A gallon of vinegar might be a bit cheaper, but the vinegar is going to be around 7%, while the HCl is going to be around 32%. I get a LOT more bang for my buck by buying HCl.

I believe when kadriver created that video, it was just to demonstrate that it was possible, not that it was recommended.

We all have to start our education somewhere, and we all make mistakes along the way. The forum is full of examples of others who have done the same. As others have said, this is the best source of information. Take your time and study. Gather more scrap as you do. Continue to try out processes recommended here on a small scale. As you become more familiar with what to expect, you can scale up to larger batches.

Dave
 
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