Lost gold! Precipitating gold direct from ap solution?

[Goldfevernick]

Hi guys, this is my first post after weeks or reading. This is THE best place to get info on refining e scrap to gold so massive thanks to everyone involved, and the vids are great

I discovered a few months Go there was money in selling second hand phones, then I heard they contain gold! So there my story begins...... So I've had a few experiments on the go and on my third batch of fingers I added too much hydrogen peroxide to my hydrochloric acid and dissolved the gold to my disappointment.

The result is a pair quantity of gold flakes and a really dark green solution.

My question is as please forgive me for my ignorance but can you not add sodium hypochlorite so drop the gold? Or does the copper in the ap (copper ii chloride) interfere?

I'm just a little concerned to where the gold went!! I save all my used ap in a container so will it settle out in a black powder over time?

Many thanks in advance guys I look forward to your advice and most probably a good scorning!

 

[NobleMetalWorks]

All you have to do is to continue to use your AP solution to saturation. As copper goes into solution, your solution becomes saturated with copper, since gold is lower on the reactivity scale than copper, the gold will cement out of solution as fine black powder. All you have to do then is collect the black powder and process accordingly.

Scott

 

[Goldfevernick]

Ok brilliant thanks for that Scott, so the gold isn't lost its just suspended in the ap. another quick question if I may, the ap solution I have is now a light blue/ light green colour (from the previous 3 batches) , can I re use it without adding any more hydrogen peroxide? Or is it a case of literally add the used solution to my new batch of fingers?

I've got 8kilos of fingers on their way to me so I figured I'd experiment on a small scale first and hopefully irradiate any newbie errors! Cheers again

 

[NobleMetalWorks]

Ok brilliant thanks for that Scott, so the gold isn't lost its just suspended in the ap. another quick question if I may, the ap solution I have is now a light blue/ light green colour (from the previous 3 batches) , can I re use it without adding any more hydrogen peroxide? Or is it a case of literally add the used solution to my new batch of fingers?

I've got 8kilos of fingers on their way to me so I figured I'd experiment on a small scale first and hopefully irradiate any newbie errors! Cheers again

I attach an aquarium pump to an air stone, and use that to generate oxygen in the solution so I don't need to add anymore H2O2, and reduce the possibility of dissolving gold into solution, it's the excess oxygen in solution that allows the gold to be dissolved into solution. In doing this, all I have to do to keep the solution going is remove AP solution, add more DI water/HCl, along with the air pump of course.

You can then recover the copper out of the solution you removed.

Scott

 

[MysticColby]

I think you do need to add small amounts of hydrogen peroxide. I think people also use air bubblers to do the same thing. don't quote me on it.

 

[Palladium]

Why is it people seem to be missing the point about needing air to make the ap process work. Hcl alone will not dissolve copper. We use h2o2 to start the process and from there you never need it again. All we have to do is add air to the solution and it carries on the process. When you start a new batch of ap you don't have to even add h2o2 then, all you have to do is take some of your old ap solution and add a cup full to the new solution and add air. You need a constant source of ox !

 

[Goldfevernick]

Ok cheers guys, and I don't think people are missing the fact they need to add oxygen but there's a vast amount of information/misinformation out there and until a newbie like myself actually asks the question the answer is near impossible to find! So thanks for the info ill now be adding an air pump.

Can I still use the ap(copper ii chloride) when it's dark brown/ black or is that because I need to add oxygen to reactivate it?

 

[butcher]

The document on Laser Steves website explains the copper II chloride leach (miss named the acid peroxide process), this is an etching solution used to etch copper traces from circuit boards when making circuit boards, it is also an alternative leach of copper to the iron chloride etching solution (Ferric chloride), one of the main benefits of CuCl2 over the ferric chloride is that CuCl2 can be regenerated much easier, and can be used over and over as long as it is not contaminated with metals besides copper .

Copper is not a very reactive metal being so low on the reactivity series of metal, and being below hydrogen in the reactivity series, HCl will not attack copper, but HCl will dissolve copper oxide, so we need to oxidize the copper to get it to dissolve in HCl, this will form CuCl2 (the light green solution), this CuCl2 which is a strong enough oxidizer to dissolve copper, this then forms copper I chloride (the darker brown solution), which when saturated with copper begins to lose its ability to dissolve more copper in solution, as it is changing more and more into copper I chloride eventually when saturated the copper I chloride precipitates the white powder of copper I chloride, this solution can be rejuvenated.

Copper II chloride dissolves copper forming copper I chloride, it will need oxygen (or dilute H2O2 which supplies oxygen and water) and some HCl to keep the solution in a state of copper II chloride so that it can keep dissolving more copper into solution, as we continue to dissolve copper and rejuvenate the solution it also grows in volume.

When the solution changes to dark brown it is low on oxygen, and is beginning to be loaded with copper I chloride, being saturate with copper the etch will slow down on its ability to dissolve more copper (unless strongly heated), the copper I chloride which will begin to precipitate as a white powder when saturated, at this point if water is added you will precipitate the copper I chloride, or if oxygen or dilute hydrogen peroxide is added (which is basically oxygen and water), the solution will change back to light green copper II chloride, some small additions of HCl may be needed, if you have copper I chloride the HCl will change the CuCl copper I chloride back into CuCl2 copper II chloride.

I agree with the above statement 3% H2O2 is not needed, and air or oxygen is all that is needed after the solution has formed copper II chloride, I often use additions of 3% H2O2 instead of bubbling air into solution, to rejuvenate the solution and give it oxygen, you can use either method, but it is much better to just add the air, this way you take less of a chance of introducing too much oxygen to the solution and put gold into solution (which is not our goal), and also you are not increasing the volume of solution as much with as much water.

If the oxygen content is too high in solution it can oxidize the gold,and put gold into solution, with just using the air you will not be able to oxidize the gold, like you can with over use of H2O2 additions.

More concentrated solutions of H2O2 can oxidize gold or PGM to put them into solution with HCl.

Actually the dark brown solution if strongly heated can put a lot more copper into solution, there are times in recovery where I find this very handy, I can lower the volume of a solution of copper chloride, dissolve copper and form copper I chloride powders when cooled (which just need HCl to put these powder back into solution as CuCl2).

Copper chloride can also be used to dissolve other metal besides copper, but this eventually changes the solution from being a copper chloride into being a chloride of the other metals you are putting into solution, I will use this with my excess copper chloride solution that is destined for waste any way, this way I can get some more use out of the solution, depending on what I am working on, there are times where I can use the last two methods mentioned to form a copper I chloride powder which is less in volume and can be stored for use later, and get copper or other base metals dissolved, some times these copper I chloride powders will also contain gold foils or silver foils or silver chlorides, I can get back these more valuable metals when I put those copper I chloride powders back into solution as CuCl2 later with HCl additions.

 

[bswartzwelder]

Everything you ask has been asked on this forum too many times to count. Even the things you didn't ask about (like bubbling air through your AP solution) has been covered numerous times. The search engine(s) on the forum are your friend. When I first joined the forum, I was admonished (more than once) to read. Read Hoke, read the forum, use the search engine, quit asking the same questions which have already been asked and covered. I started by reading the Data section (all of it), then the Chemical Processes section (all of it), then the Other Processes section (yes, all of it). Then, one day, I noticed some brown stains on my fingers. I had washed my hands profusely, so what could this be? I returned to the forum and started doing ...guess what... READING. Before this, I had found all the answers to my questions and I WAS AN EXPERT, so my reading days were over. I HAVE NEVER BEEN SO WRONG IN MY LIFE. I freely admit it. I wasn't the expert I thought I was, and the more I learned, the more I realized I needed to learn more. Then I started reading the most important parts of the forum, the Safety section, and the Legal Things section. I should have probably read them first, but in my ignorance (which was blissful), I was just happy to collect PM's and start buying the tools and things I knew I would be needing later. Small purchases don't throw up a red flag to the wife like larger ones do. I have read about the necessity of doing things outdoors, in a well ventilated area, or under a fume hood.

I have come to learn that the people on this forum are some of the best friends I have in this old world. I trust them with my life, my family's lives and the lives of our pets and neighbors. God knows (and the people on this forum know) I've made my share of mistakes. Some small, and others which have cost me quite a few dollars in lost PM's. The best advice anyone can offer is to educate yourself. I know I didn't mention reading Hoke above, but I would sit down after catching up on the forum and read her words of wisdom. Her book is a free download on the forum, but I purchased a hard copy to read in my spare time. With nice weather here for now, I have been repairing my latest screw up and see the light at the end of the tunnel. While sitting in my lawn chair watching the dogs in the yard, and watching my poormas AR EVAPORATE (MAN, THAT'S A SLOW PROCESS), and drinking my own concoction of diet green tea and apple cider, I sit back and read. I have read Hoke previously, but it just seemed like a good thing to be doing. It has been a rewarding experience, even if I already know how this movie will end. So, I leave you with the challenge to sit back and enjoy the book of the month (HOKE) and the forum. Welcome aboard.

Oh, by the way, for what it's worth, I used the airline tubing I bought when I bought my aquarium air pump, cut it into two pieces, and crimped one end of each piece shut. I then formed a Tic-Tac-Toe arrangement in the bottom of my inner bucket and tied it to the bottom. Then, I used a hot paper clip and punched a series of holes into the tubing which would be submerged. When the free ends are connected to the two outlets on the air pump, they produce sheets of bubbles all across the bottom of the bucket. Most people here use two buckets (one inside the other), with a lot of holes drilled in the inner bucket to allow the AP to flow through. Complete directions are here on the forum, and they're free. There are also some personal modifications you may like to use, some you may not, but give yourself the benefit of the doubt by reading what others have done. Even if a thread does not sound like it would be of interest, at least scan the replies because that's where the true gold is.

Good luck, and be safe,
Bert

 

[Goldfevernick]

As I stated I've been reading the site for a few weeks and used the search engines but the amount of information available is unbelievable and I wouldn't ask a question if i knew or could find the answer to it! Asking as a newbie was a last resort as I knew all the fountains of knowledge would moan at me for asking questions that have been asked 100's of time but As suggested I've added an air stone to my setup, I don't think the fish liked it anyway...

So now I have my air stone in place the O2 to replenish my solution thus omitting the need to add h2o2, but still need to add hydrochloric acid if I've understood correctly, and I'm reading hokes's book but as chemistry isn't my strongest science it's all a bit over my head!

Once again thanks for the info I think I'm starting to understand!

 

[butcher]

When you see the white powder of copper I chloride a little more HCl will put it back into solution as CuCl2.

There are several metals that will form white powders as chlorides, the most common you will most likely see are silver chloride, lead chloride, copper I chloride, and sodium chloride (common salt).

sodium chloride is water soluble even in cold water this will separate it from the others.

Copper I chloride will dissolve in HCl forming the dark brown or green(color depending on saturation) solution of copper II chloride, this will separate it from the others.

This leave lead and silver chloride to deal with.

lead chloride is not very soluble at all in cold water, but in boiling hot water the lead chloride will dissolve into the clear solution, (so it can be removed from the silver chloride), upon cooling the solution the lead chloride will again precipitate out of solution.

silver chloride will not dissolve in water cold or hot, it will not dissolve in HCl (or nitric), but can be a bit fluffy and can take some time to settle so keeping this in mind when separating the other metal chlorides is useful, giving the silver time to settle before decanting the other metal chloride solutions.

Once silver chloride is rinsed of strong acids it is very light sensitive, and light will darken the white powder changing the color to violet or almost black, the light is reducing the crystals of silver chloride exposed to light back into silver metal, the light only seeing the crystals on the surface does not do that good of a job reducing all of the silver chloride back to metal, so we normally use one of the other common methods to do this.

Ammonia solutions will dissolve silver chloride (but will not dissolve silver metal), the ammonia solution is basic, and if we add an acid (HCl is normally used) we again precipitate silver from the solution, silver in ammonium solutions can be dangerous if dried, so any time we do this we always re acidify the solution and precipitate out the silver to keep from having any problems, I keep my ammonia waste separate from my other waste as a precaution.