Low yield gold pins

[jabukanac]

Hello everyone first i wanna make a point that i am one of many which English is not a first spoken language so i may have some grammar mistakes

anyhow happy holidays to all members before i start my first post (be gentle i am good learner and i do take advise seriously )
after reading for a year or more on this great forum and other sources on WWW i am ready slowly to start my first trial with some chemical e-scrap gold and silver recovery, i have small supply of nitric acid 500ml 78% -2500ml Hcl 32%- peroxide 500ml 3%

this is not a question how can i do low yield gold plated pins the are many other posts covering this ,i need someone with better understanding (than me) about chemistry relating my idea to use small batches of this pins in only Hcl for a long time (or maybe something better excluding sulfuric cell)
i already placed about 400g of this pins in HCl pickle jar after two days i have purple violet solution i do not believe that any gold will go in solution now the interesting part those pins are low yield from ID pins i do not expect as much gold out of this batch just a test run my real question is how to use AP properly with out big mistakes and keep (later dissolved gold) in solution for latter recovery of gold dust i am not ready to do any refining as yet (still reading) i just wanna see if it is possible to get all of the base metals using HCl (or any other combinations) and keep gold in solution for a long period of time Thanks
feel free to make any comments i do not get offended easily

 

[jabukanac]

I forgot there was no solder on my batch of pins but many of this are magnetic using neodymium magnet (not any other magnet) and i did found small pieces of brass pins after few days i can see that many pins are dissolving slowly after few drops of fresh HCl added but no changes to brass pins :roll:

 

[butcher]

It can take quite a bit of HCl to dissolve metal.
If it is just copper the solution can be reused as CuCl2.
HCl will not attack copper or gold, it will attack base metals above Hydrogen in the reactivity series of metals ( https://www.google.com/#q=reactivity+series+of+metals++ ), such as zinc or tin which can be part of the pins as brass.
HCl will attack oxides of copper, and Air, oxygen or hydrogen peroxide mixed in the acid will oxidize the copper, so that HCl can dissolve the copper oxide making CuCl2.

As long as you do not use too much oxidizer, you will not dissolve gold, if the gold is very thin plate it may fall apart as fine powder, thicker plating will leave foils or hollow tubes as the copper is dissolved away from the gold.

You can start the reaction with 3% H2O2 and then use air bubbled into solution through a small air compressor like used in small fish tanks.

Keeping the solution warm can help, but too much heat drives out the needed oxygen.

This is a slow process and will use more acid, and form more waste solution to deal with than the concentrated sulfuric cell, if you reuse your solution as much as possible it can somewhat help in the cost.

This leach will need attention to keep the CuCl in solution as CuCl2, you can learn how on the forum and through study. There is much information on this on the forum, Laser Steve has a document on the copper II chloride on his web site you will surely want to read to better understand the process, and how to keep your leach working.

 

[jabukanac]

Thanks Butcher great advise i was just reading steve's guide great ,, and few hrs ago i added small amount of peroxide it is fuming but not much time is not in question right now as this is a trial to get my self in the gear of recovering and latter refining using AP then HCl+Bleach for now i have small batches one 400gr low yield pins in 300ml Hcl wich is purple solution second batch is 400gr same pins in 400ml HCl +2ml peroxide 3% again purple in color do you know way is the solution purple there is definitely no tin or solder in it as i have cut all pins half way down of the Mb i remember reading in one of the posts extensive talk about this but i am not able to find it again

and second part of my question would be how long can gold be kept in solution long term without loosing any i know it sounds silly but it is only for education purposes not anything else

and yes adding copper bar would be my next part i do wanna reuse solution as long as possible

i will not attempt to dissolve any of my gold yet still reading allot on this great forum ill let you know when i feel ready for that part
i have some success refining about 200gr of silver scrap using Nitric acid which when really well except the part that i have a buttons not a bar i need someone to get me cheep molds and crucibles as i used sliced potato first time works ok in small amounts of powder

 

[butcher]

You will want to go ahead and buy some good melting dishes they are cheap.

I do not now why you would get purple, nickle and copper chloride are green, iron chlorides can be green or yellow, Normally your solution will be green If you have enough HCl and oxygen in the solution, forming the CuCL2, when saturated with copper the solution will turn a darker brown color, this is when it normally needs a bit more HCl and 3% H2O2 or air bubbled into it.

As long as you do not use too much H2O2, or stronger than the 3% H2O2, or do not add a strong oxidizer like bleach (NaClO) or Nitrates, you will not dissolve the gold, gold is a pretty unreactive metal, it takes some fairly strong oxidizers to attack it.

Not much need to add copper, you can just add more pins if for some reason, by mistake you did use a oxidizer strong and put gold into solution, the gold ions if they were in solution would cement back out of solution with the copper from the added pins.

As long as the copper chloride does not get too much base metals Lower then copper into solution the solution can be reuse.

Even if it eventually does change to Iron chloride, it can be used with heating to dissolve a lot of copper and other base metals.

Be sure to read the topic dealing with waste in the safety section, so you know how to handle your waste solutions safely.

 

[jabukanac]

Oh just a update few days latter solution is pale green pins dissolving slowly i added small cup of peroxide and Hcl is active again purple was due to non reactive HCl (400ml was not enough to start any reaction and i did not wanna go with any heating or adding to much peroxide just wanna see how long is going to take HCL to get all base metal out i know that will not attack copper that well but with little help HCL+small amount of H2O2 should work and solution is getting some heat from our sun all daylong

Also need some help to point me in the direction of any discussions what would be best way of striping gold plated jewelry specially watch bands and watches i have seen few posts in the past but i am not able to find them again,

Happy new golden year to all

 

[chlaurite]

You will find it helpful to separate out the magnetic pins from the non-magnetic.

The magnetic ones tend to consist of Fe/Ni alloys like Kovar, which contains a good amount of cobalt - And cobalt chlorides (it forms a few different ones) cause nice rich purple solutions. Iron will also "poison" your copper chloride by replacing it with non-renewable ferrous chloride; they also dissolve a lot quicker in HCl than copper pins do.

Non-magnetic pins usually use a Copper-based alloy. They will take quite a long time (months) to fully dissolve in HCl (via the CuCl2 process), but you can keep reusing the resulting solution as long as it has an excess of acid.

Oh, and save the nitric for later, unless you have easy and cheap access to more.

 

[jabukanac]

Thanks Chlaurite that makes sense on purple solution Fe/Ni on this plated pins was suspected and yes all of them are somehow magnetic using neodymium magnet but not so much using large speaker magnet (maybe just a thin plate or Ni plate on this pins i am not sure but i am sure that most of those pins are copper based being used in electronics)
this run is just to test many theories about low yield gold plated pins is it worth the time ,effort, and cost if done properly ( i must say time in this case should not be as much of a problem as those pins usually end up as scrap metal, so for now i have only two batches going
#1 is 400gr low yield pins (i would say somehow magnetic) in around 500ml of HCl 32% solution went in 10 minutes reach purple color after addition of two small cups 3% H2O2 turn green in color for about 24 hrs than reaction slowed down and start getting clear i have added once another cup of peroxide and it is active again and green amount of metals is slowly dissolving i would say that 30% is gone to solution already after 48hrs i am not so sure if solution is asking for small addition of Hcl or just a H2O2 there is no air delivery connected just a open jar lid also no heat applied other than natural sun i know that heat will speed up but as i said time is not important for this batch i just wanna prove to my self that even a small amount of gold is still a gold and it should be recovered

#2 batch is only 400ml of Hcl 32% and about 400gr of low yielded gold pins this one is still purple color and starting to go yellowish green after 48hrs and every 2 to 3 hrs of mixing materials with glass rod i would not change or add any other chemicals in this one just to see if a simple way is going to work in my opinion copper will eventually start to corrode and should star the reaction slowly (with a little help from my friends) mixing stick
i will appreciate any comment about improving my test runs and any opinions how will this end up just don't forget this is not a real recovery attempt that will be done latter with already proven method and my collection of gold finger from memory sticks which is reaching a 22 kg nicely cut fingers and close to 100 cell phone boards (nokia very heavily plated i think) also have about 74 touch pads boards which have large area of gold plate on them (one whole side)

when i am ready to process those i will definitely ask for advice how to do it ( not that i do not know already how to ,from extensive reading numerous books and processes done already , but for only one reason i hate failures specially first time ha ha ha ) and i do not wanna loose any of my precious metals Thank to all good people on this amazing forum i cannot stop reading even old discussions on this site

Greatings from Zoran

 

[butcher]

jabukanac,

Basically it is not the HCl and H2O2 that does the work in this leach (they are just used to make the leach), the leach is copper II chloride CuCl2, that dissolves copper (forming copper I chloride CuCl in the process of dissolving more copper, then we can be rejuvenate the CuCl back to CuCl2).
When the leach solution is a green color (CuCl2 it is working, when it changes dark brown CuCl, it needs rejuvenating).
If you bubble in air after you get the leach going, you will have a less of a chance of adding too much H2O2 (oxidizer), with the air you are not taking the chance of adding too much oxidizer, which would dissolve the gold.

If you can get some memory fingers, get some and experiment with them, getting the gold foils off the close cut fingers, dissolving the thin copper under the gold plating, this will work faster, and is a good learning tool, to help you learn to use the copper II chloride leach, by leaching copper (without dissolving your gold), and learning to regenerate your leach solution...

 

[jabukanac]

Thanks Butcher i had some understanding about that (good to here confirmation from someone with extensive experience)
so first batch is what i should be carefull not to stuff up (has small amount of H2O2 added ) reason i am having two batches one with H2O2 one without is to learn different reactions visually i know air bubble should speed up the process and i will start one more batch with same amount of everything and added air so i can compare that one with the rest

regarding fingers that would be my next batch but only fingers in AP solution nothing else (keep it simple and foolproof)
and another batch, one with large plated cell boards (which i previously successfully striped with solution of sodium hydroxide to expose heavy plated areas)
this should give me fairly good idea (again with help of good people from this forum) how to do it properly and safe i appreciate any help in keeping me on the right track and i do go back to hoke's to read more and check things from time to time

i would appreciate if anyone can give me suggestion how much material to use in first batch of refining nice cut of memory fingers in HCl+Cl solution
just to be safe not to waist anything including acids (just to clarify how many grams of gold fingers to use i can work out acid mixtures latter)

Thanks Zoran

 

[Plasmajunkie]

So how did it all go? I'm going crazy clipping excess non plated solid's from the pin's and all of the plastic's.I guess it's all money though.Is using reagent grade HNO3 a waste on these pin's, I only ask because it does the job very quickly.I just cant help but wonder how much will be dissolved into solution.I'm glad I was able to find this forum and all of the updated info it provides.Processes already tackled and innovation's that Tesla would smile at.

 

[jabukanac]

So how did it all go? I'm going crazy clipping excess non plated solid's from the pin's and all of the plastic's.I guess it's all money though.Is using reagent grade HNO3 a waste on these pin's, I only ask because it does the job very quickly.I just cant help but wonder how much will be dissolved into solution.I'm glad I was able to find this forum and all of the updated info it provides.Processes already tackled and innovation's that Tesla would smile at.

i have found that just a HCL with H2o2 does poorly on pins in regards to Nitric i have no desire to waist money returns are not justified (using pins to much base metals not much gold)

but i will tell you that i did this with great pleasure just watching how can those pins be profitable with no much effort other than your time so here i go step by step and results

1# 400g low yield pins no plastic no solder (cut of )
2#300ml 32%Hcl +5ml 3%H2o2 mixed few times a day (no oxygen bubblerr no heat applied i do not wanna waist any more than necessary energy or chemicals) so this was sitting for a week or so before i made a decision to go further with the same pins plus more

i have filtered this solution out with double coffee filters washed all this in small amount of HCL dust and flakes and then placed back in the coffee pot with some more pins 300g
so now i have my pins in coffee pot all of them and i add new 300ml HCL to start solution activated i do not use any more peroxide but i do add about 100ml of my first AP which is saturated with CuCl almost brown keep mixing few times a day and few days later same process again new hcl 100ml of old solution and 20 days latter i have around 50g of fingers undissolved still sitting in coffee pot and one beaker of 500ml dark green solution containing small gold particles
i have done this purposely so i can use same solution as my leach for ram fingers latter and it did not cost me more than a $2 for HCL i used
i have 40g of dust and flakes which will undergo heavily washes and get ready for refining latter i will get final results posted my educated guess is i would get somewhere between 1-4g of pure gold (not bad considering did not cost me more than $2 dollars and my time)
oh yes just to mention last batch of fingers was from cat 5 cable pins looks like they have more gold on them than IDE pins

 

[bswartzwelder]

Using a small aquarium air pump to bubble air through your AP solution is definitely NOT A WASTE of energy. Most aquarium air bubblers use far less than 10 watts of electricity making it one of the most cost effective methods. Ten watts run for 100 hours is only 1 kilowatt hour of energy. Sure beats stirring the solution by hand, does a much better job, and runs 24 hours a day mixing and rejuvenating your solution as it stirs it with the bubbling action. The amount of chemicals it rejuvenates pays for the energy consumed many times over. It can essentially shave days off the process you're using and you aren't messing around with your hands or body near HCl. My father many times said to be penny wise and not dollar foolish.

The people on the forum endorse one method or another from their own personal experiences. What ever method they are using, you can bet it is a good way to do business. The way you are doing this could take weeks or even longer. Why not work like the pros and do it in a couple of days?

Just my $0.02 worth
Bert

 

[jabukanac]

Using a small aquarium air pump to bubble air through your AP solution is definitely NOT A WASTE of energy. Most aquarium air bubblers use far less than 10 watts of electricity making it one of the most cost effective methods. Ten watts run for 100 hours is only 1 kilowatt hour of energy. Sure beats stirring the solution by hand, does a much better job, and runs 24 hours a day mixing and rejuvenating your solution as it stirs it with the bubbling action. The amount of chemicals it rejuvenates pays for the energy consumed many times over. It can essentially shave days off the process you're using and you aren't messing around with your hands or body near HCl. My father many times said to be penny wise and not dollar foolish.

The people on the forum endorse one method or another from their own personal experiences. What ever method they are using, you can bet it is a good way to do business. The way you are doing this could take weeks or even longer. Why not work like the pros and do it in a couple of days?

Just my $0.02 worth
Bert

Great advise bswartzwelder small air bubbler will rejuvenate solution to the point quicker and in many cases speed up a process but do not forget we are talking pins here which they are most likely different material not just a copper base pins so each material have there reaction point regardless of how much air you push to speed up ,my point i have found refreshing solution to work faster than air bubbles,you said way not work like a pro me personaly becouse i am not even close to a professional and i would not like to tink that i will ever be ,,it is a hobby of mine and will stay that way and i am sure many here feel that way,
anyhow to clear this info and advises yes i do use air bubbler pond pumps connected to small solar panel so does not cost me anything but i use that to refresh my solution when i process fingers such as ram memory or any cards fingers works on depopulated board great to ,,but i think is useless on pins ,,example
1kg of mixed low yield pins will take approximately anywhere from 3 to 4l of HCL and 200ml of H2o2 to disolve base material completely most of gold plated material will not just flake of in fact most of it will be plated back with this mixture or material and most likely we will loose gold as is not easy to be identified so complete dissolving is a must to recover all gold , so i have found that mixing helps moving small gold particles away from sticking on another and refreshed new HCL does the job of keeping gold visible and separate ,also when i mix my beaker i do swap containers and leave pins exposed to air to dry and start oxidation naturally (takes about 2hrs or less ) when new HCL is added Only small amount 200ml to 300ml old solution helps with leaching also oxidation on those pins does a better job than any amount of pushed with bubbler ,if the bubbler does work we will all process solid gold or gold plated jewelry this way

so i do agree bubbler in AP is very good ,not so much for mixed materials or solids
my way of processing is not the best way just very cost and labor efficient ,1.2kg of mixed pins dissolved in only 2l of 32% Hcl 5ml of H202 (first run) and then new solution with only HCLno more than 200ml on naturally oxidated pins works faster than pushing air in solution ,do not forget i am doing this at the same time using my first two solution processing fingers and bards where solution is air bubbled and works great if i keep same solution for this pins i will end up with gallons of chemicals which i would be skeptical in using it again on other things as it will contain many bases dissolved, and we all know some of it can give as headache latter

i know Post is long again butcher did asked me to keep it simple and i will one of this days i promise
but this was my $0.02 cents on top of your $0.02 which will make it $0.04 and not so cheap considering that processing 1kg of this finger will most likely not produce more than 1.80gr of gold
we all have our own ways if i can learn from others i am happy and i like to be happy :lol:

 

[bswartzwelder]

The air bubbler does more than just rejuvenate the solution. It also keeps the solution in constant movement. This movement means the rejuvenated solution is more likely to come into contact with whatever your working with. I haven't heard of it being used with anything other than AP but it is certainly cheaper than refreshing the solution.

Back in the 70's, I used to make printed circuit boards using ferric chloride. It was an extremely slow process until I added an air bubbler. Then the processing time went from hours to minutes.

Having said that, if the pins have a bunch of solder on them, they will destroy the solution very quickly. AP is not the best choice for removing solder.

 

[924T]

bswartzwelder,

What a timely post (for my purposes)----I've been dithering for a week about whether to keep using
Ferric Chloride (I've still got a gallon of it), or switch over to using Copper Chloride, and I had been speculating
about whether or not an air bubbler would accelerate the Ferric Chloride.

I do like the low odor of the Ferric Chloride, but am not keen on its opacity.

A faster Ferric Chloride would make the opacity more of a minor issue, for me.

Also, I think I've figured out why my PM's weren't going through, so I'll PM you soon to see if I got it right.

Cheers,

Mike

 

[butcher]

Old used Copper II chloride solution (reusing the waste), or making and using the ferric chloride leach...

Ferrous chloride FeCl2 can be made dissolving Iron in HCl and water approximate equal volumes of water and acid, (steel wool or transformer laminates).
Fe (s) + 2HCl (aq) + H2O (l) --> FeCl2 (aq) + H2 (g)

Ferrous chloride FeCl2 with excess HCl will oxidize with air to form Ferric chloride, but the reaction can take a long time.
FeCl2 (aq) + 1/4 O2 (g) + HCl (aq) --> FeCl3 (aq) + 1/2 H2O

Now from the ferrous chloride FeCl2, we can make ferric chloride FeCl3, with about equal volume of 3% Hydrogen peroxide H2O2. Heat is generated in the reaction of oxidation of the iron chloride.
FeCl2 (aq) + H2O2 (aq) + HCl (aq) --> FeCl3 + H2O + H + O

Ferric chloride (FeCl3) can etch copper (Cu) or iron (Fe), oxidizing the copper or iron into solution and reducing the ferric chloride (FeCl3) back to ferrous chloride (FeCl2).
2FeCl3 (aq) + Fe (s) --> 3FeCl2 (aq)
Etching copper a two step process.
FeCl3 (aq) + Cu (aq) --> FeCl2 (aq) + CuCl
Then
FeCl3 (aq) + CuCl --> FeCl2 (aq) + CuCl2 (aq)

Now we have discussed the normal leach for copper used to etch copper.
Let add some things to this discussions where we can continue to use this solution.
(This discussion also applies to the old used copper II chloride leach we can no longer use because it has been contaminated with iron or Kovar.)

We can heat this solution (ferrous chloride and cupric chloride (FeCl2 + CuCl2) with more copper, (this copper could be copper we need to dissolve from other metals like silver or gold plating like pins or pieces of copper with silver contact points...), the solution when heated being still acidic eats at the copper with a vengeance, especially as it gets concentrated, heating it to a fairly thick dark brown solution.
FeCl2 + CuCl2 + Cu (s) --> FeCl2 (aq) + 2 CuCl (aq)
Here we have both ferrous chloride and cuprous chloride dissolved in solution.

This leaves us with ferrous chloride and cuprous chloride in solution, If we decant a portion of this solution into a jar and let it cool, Most of the CuCl will settle out as a dark powder (along with any gold flakes, silver chloride, lead chloride if involve...).

Now once cooled and settled we can we can decant the mostly ferrous chloride back to the main solution (we will discuss it more later).

The copper I chloride (cuprous chloride) (CuCl), can be rinsed with Hot boiling water (this will dissolve some salts of the iron and copper chlorides, and lead (this rinse water decanted hot can also be returned to the main solution.
This leaves us with white powders of copper I chloride, silver chloride and gold flakes, now we can save these powders for reuse later.
Or dissolve the CuCl in HCl.
CuCl + HCl --> CuCl2
So now after we let the silver chloride and gold foils settle, we can decant the CuCl2 solution, Which is clean enough to use as a new batch of copper II chloride leach (CuCl2) (miss-named acid peroxide leach, or AP on the forum).

Now back to or FeCl2 ferrous chloride solution if you reread this post from the beginning you can see where the ferrous chloride solution (FeCl2) can be oxidized back to the ferric chloride FeCl3 to leach more copper or iron...

____
Now we can get some other iron products, or byproducts, from these iron solutions with the methods above, iron solutions can hydrolyze and with oxygen can form some insoluble iron oxides or hydroxides in solution, or precipitate from solution. Strong heat can accelerate this. One of these can be a red Iron powder (red rouge powder) (a form of rust), that will not dissolve in acids (even aqua regia)...

4 FeCl2 + 4 H2O + O2 <-- --> 2 Fe2O3 + HCl
Or
heated too strongly
FeCl2 +H2O +1/4 O2 --> 1/2 FeCl2 + 2HCl

6 HCl + Fe2O3 + Fe --> 3 FeCl3 + 3H2O

6 FeCl2 +3/2 O2 + H2O --> 2 FeO.OH + 12 HCl
Then
4 FeCl3 + 8H2O --> FeO.OH +12 HCl
FeCl3 + 3H2O --> Fe(OH)3 + HCl

These iron oxides or hydroxides normally do not cause a problem with the gold recovery processes, the red iron powders do not dissolve easily and even gold can be dissolved from the red powder...

Butcher

 

[solar_plasma]

While rereading this post, I asked myself, what to do with the larger and larger amount of CuCl, which is not used for new CuCl2 and I just wonder, if it could be directly smelted with fx. NaCO3 and C to some Cu, CO2 and NaCl?

And at which temperature will red iron oxide form in the solution? Would a hotplate of a coffeemaker be too hot?

 

[butcher]

I would convert the CuCl to copper metal (adding some acid HCl or H2SO4 and water), using a metal like iron to replace the copper from solution.

Melting the copper I chloride back to metal just seems too much trouble...

A coffee maker hot plate does run at a fairly lower temperature than you can turn a hot plate up to.
I cannot give an answer on temperature where the red rouge Iron forms.

The iron hydroxide (red rouge powder), seems to form from the more insoluble powders on the bottom with heat, I do not know at what temperature they form, but I do know on a hotplate the glass in contact with the burner at the bottom gets much hotter that the rest of the glass or solution.

This thought brings up another, powders sitting on the bottom of the vessel, can get much hotter than the solution or glass which is not in contact with the hotplate, stirring can keep from cooking salts on the bottom, and can help to keep glassware intact, note also that when we have powders sitting on the bottom of a heated vessel that the glassware can be heated even higher than if these powders were not just sitting there, this can cause the bottom of the glassware to become overheated at the bottom (with the upper portion of the glass being cooler) this can cause the glassware to crack at the base and the bottom to break out.

If you hear a popping or cracking sound, with a vessel sitting on a hot plate, do not move the glass vessel, lower heat and use a siphon tool to remove solution, lifting the vessel the bottom of the vessel will stay on the hotplate as acid solution falls out of the pot all over your hotplate, by siphoning out the solution most all of the acid solution can be save, saving you from a big mess.

It is best not to heat a solution strongly if much powder rest on the bottom of the vessel.