Not so sure what happened!

[zan13898]

Hey, and i just wanna say beforehand, im just doing this cuz i like chemistry, and this is just a hobby, not hoping to make a profit or something!

Now, i basically do laptop and computer repairing and had a lot of RAM sticks (DDR2 and DDR3) Faulty, about 30 pieces!, so decided to snip the gold teeth and stuff from it and try an extract gold from it...(how cool would that be?). Now, i have a cousin who had a lot of old pentium? something CPUs and we both decided to remove their pins and remove gold from that as well!, about 2KG of CPU so quite a bit of pins we extracted!

the only chemicals we had was very dilute stain remover, guessing 10% HCL solution
Bleach, which is basically sodium hypochlorite, which is yellow coloured, maybe cuz of the chlorine?
sodium metabisulphite we ordered from ebay, food grade!

Now, we added all the pins to HCL solution and started the bubbler to see if we can dissolve the base metals and separate all the gold!, left it outside, i know it only gives of hydrogen gas but im extremely careful and left it outside!, few days later, stirring every day we noticed the solution getting purple, maybe silver dissolving? and pins have turned to silver to blackish colour!

anyway, someone told me that the acid so weak, itll probably take months and constant stirring and we decided to move to the next step!, even though we know the gold wont be pure this way!

so went far away, and added fresh HCL to the pins and Gold teeth from RAM sticks, and added bleach gradually ( note we were both wearing gas mask and eye protection as we know it gives out chlorine gas!) while keep mixing gently!, the HCL solution was cold too!...anyway, we put the cap back on and after some mixing, the solution was all green....actually dark green!...it should be gold coloured but im guessing it dissolved copper as well!....anyway, the thing is, there is still a lot of gold on those RAM teeths and some gold foils floating around and CPU pins are again gold coloured!(atleast some of them!), Is everything wrong? its been 6 hours since we added the bleach!

PS, when is say i capped the bottle after adding the bleach, we constantly look for pressure to make sure it wont burst!, and frankly its deflated even, i guess the liquid absorbed the rest of the chlorine as well!

Thnks for any help and trust me, im being safe as much as possible!, although some more tips would be appreciated to make it more safer...

 

[butcher]

Base metals will cement the dissolved gold.

Bleach is a base or caustic solution of water and chlorine, which will neutralize some of the HCl in solution producing chloride salts.

The chlorine gas will dissolve some of the gold, as the base metal dissolves it will replace the gold ions in solution basically cementing a black gold powder, along with other salts of insoluble metal chlorides which are involved.

Because the acidic HCl contains a lot of water, and the bleach also contains a lot of water and water is normally a product the solution will normally contain a diluted solution, evaporation or concentration will normally produce much more salts, the dilute acid HCl and NaClO will also produce salts, the HCl being more dilute much of the acid is neutralized, which may not leave much acid for the formation of much chlorine as noted in the second part of the equation below:

NaOCl + HCl = NaCl + HOCl
HOCl + HCl = H2O + Cl2
NaOCl + 2 HCl = Cl2 + H2O + NaCl

leaving more HOCl in solution
https://en.wikipedia.org/wiki/Hypochlorous_acid

Excess bleach and the diluted acid solution can raise the pH...

 

[zan13898]

i think i got some of it...at this moment im not really sure why its green still!...and im sure it not basic cuz when i add just more HCL, it dosent fizz, meaning its still acidic!

what should my next step be?, sorry im asking very dumb questions and but ive put in a lot of work and research and im tired now....most people just say go with nitric acid and i find that to be too dangerous!

 

[zan13898]

and @butcher, thnks for replying man!, really appreciate it!

 

[butcher]

At this point, you're in a recovery mode, recovery of a little gold from a large amount and diversity of base metals, you are not anywhere near to refining gold, with the large volume of base metals, and the dilute acid, you have many options, this is only one suggestion.

Add more HCl, (your dilute HCl can be somewhat concentrated by slow evaporation removing some of the H2O before you use it).


(You could go for putting more gold into solution but the base metals will just continue to cement it back out of solution, so adding a strong oxidizer like bleach would not be my choice, not only are you converting the HCl in solution to salt your dissolving gold the cementing it back out as powder, and making the solution more basic and this is not a very effective way to dissolve base metals...) I would change course and dissolve base metals without dissolving the gold...



Eventually, the soluble base metal will saturate the solution, iron and copper will color the solution, nickel will somewhat, other base metals in solution can also give colors many will not.

With acid added you can bubble in air from a fish tank air compressor, and basically convert your solution to a copper/iron chloride solution, which will put more base metals in solution, CuCl2 in solution will dissolve copper and base metals in solution the air gives a weak oxidizer which is not strong enough to dissolve the gold or the cemented gold, the solution will darken from green to brown as more copper goes into solution, as CuCl₂ dissolves copper forming CuCl, and once saturate or if diluted it will precipitate CuCl as a white powder with other insoluble chloride salts, HCl and air can rejuvenate the solution back to a green solution of CuCl₂ capable of dissolving the CuCl powders and converting the CuCl in solution back into CuCl₂, which will take more copper and base metals into solution...

Basically, I would change the process to a copper chloride leach to dissolve the base metals, leaving the gold,
After recovering your gold, then maybe consider concentrating the HCl acid for the process you are attempting now.

 

[FrugalRefiner]

Hey, and i just wanna say beforehand, im just doing this cuz i like chemistry, and this is just a hobby, not hoping to make a profit or something!

Zan, your English is pretty good! But please try to avoid things like "wanna", "cuz", etc. Many of our members have to use translators to read the forum, and things like that do not translate well.

Now, i basically do laptop and computer repairing and had a lot of RAM sticks (DDR2 and DDR3) Faulty, about 30 pieces!, so decided to snip the gold teeth and stuff from it and try an extract gold from it...(how cool would that be?). Now, i have a cousin who had a lot of old pentium? something CPUs and we both decided to remove their pins and remove gold from that as well!, about 2KG of CPU so quite a bit of pins we extracted!

You made a mistake by mixing different types of scrap. Fingers (your "gold teeth" from the RAM) have a much higher percentage of gold compared to the amount of base metal which is mainly copper with a coating of nickel. The pins are different base metals with a much higher base metal percentage. mixing different types of scrap complicates the process.

the only chemicals we had was very dilute stain remover, guessing 10% HCL solution

Never guess at the chemicals you're using. Stain removers could be a variety of chemicals other than HCl.

Now, we added all the pins to HCL solution and started the bubbler to see if we can dissolve the base metals and separate all the gold!, left it outside, i know it only gives of hydrogen gas but im extremely careful and left it outside!, few days later, stirring every day we noticed the solution getting purple, maybe silver dissolving? and pins have turned to silver to blackish colour!

In addition to hydrogen, you probably have HCl and possibly chlorine being evolved.

anyway, someone told me that the acid so weak, itll probably take months and constant stirring and we decided to move to the next step!, even though we know the gold wont be pure this way!

Patience is one of the most important tools for a refiner. Becoming impatient and moving ahead to the next step usually results in a big mess.

so went far away, and added fresh HCL to the pins and Gold teeth from RAM sticks, and added bleach gradually ( note we were both wearing gas mask and eye protection as we know it gives out chlorine gas!) while keep mixing gently!, the HCL solution was cold too!...anyway, we put the cap back on and after some mixing, the solution was all green....actually dark green!...it should be gold coloured but im guessing it dissolved copper as well!....anyway, the thing is, there is still a lot of gold on those RAM teeths and some gold foils floating around and CPU pins are again gold coloured!(atleast some of them!), Is everything wrong? its been 6 hours since we added the bleach!

That impatience bit you in the butt again.

PS, when is say i capped the bottle after adding the bleach, we constantly look for pressure to make sure it wont burst!, and frankly its deflated even, i guess the liquid absorbed the rest of the chlorine as well!

Never cap an active reaction. It is an accident waiting to happen.

Thnks for any help and trust me, im being safe as much as possible!, although some more tips would be appreciated to make it more safer...

In the interest of safety, take a look at the Simple Answers thread.

Study everything in the Safety section of the forum.

Before you start any process, you need to have a complete understanding, or you put yourself, and those around you, in peril. You're guessing too much. Nearly anyone can learn to refine from the information on this forum, but it takes a lot of study. Be patient and you can achieve your goal.

Dave

 

[zan13898]

okay, i can concentrate the HCL to azeotropic no problem, what about all that green liquid thats mostly just basic chlorine water?, that have any gold in it or should i just decant it? also, when im filtering out the green liquid, ill filter out some gold foils, can i use HCL concentrated plus bleach to dissolve them or is there any other safer method?, without chlorine gas!, and nitric acid is not an option....im realizing that im leaving you with no other option but maybe i thought id ask...lol

 

[butcher]

The green liquids color comes from copper and other base metals in solution. This copper chloride will dissolve copper and more base metals above copper involved.

http://goldrecovery.us/goldrecovery/documents/CuCl.pdf

As the copper and other metals go into solution, they will replace the gold in solution.

My advice was not to worry about dissolving gold at this point, but to concentrate on recovering it, and at the same time eliminate as much base metals as possible, using a safer method.

At this point I suggest you let the solution sit (do not cap the solution but cover and store it in a safe location, letting its chemistry takes its course for the time being.

Now your gold is safe, you can learn from your mistakes, before proceeding to recover your values learning about the chemistry in the meantime...

This will give you a chance to study the process I mentioned of using Copper II chloride to dissolve the copper and base metals, also called the copper II chloride leach or the miss-named acid peroxide process.

Through your study, you will gain much understanding of how the reactions work, and an understanding of how to recover from this mess.

Take note of FrugalRefiners safety warnings and do research into the safety of the processes.

The solutions and gases from these reactions are dangerous, understand the dangers involved and how to protect your self and others, you will also need to learn to deal with the toxic solutions safely, read dealing with waste in our safety section, reading this will also give you a better understanding of the chemistry involved here in the processes we are discussing, and a better understanding of many of the chemistry principles involved in recovery and refining...