Are there any mistakes to my method for a first-timer gold recovery and refining?

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Joined
Dec 10, 2020
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8
Hi all,

Im looking to do my first recovery and crude refining! This is my current equipment list and method and im looking to see if I'm missing any important steps or equipment. Is anyone able to identify any major errors in this method? Note: I will move the reaction steps outside since I don’t have access to a fume hood and I will also be wearing long sleeves, pants and covered shoes. and I'm not going to bother with some drops of sulfuric acid for lead contamination, this is my first attempt and I just want to get some practice getting the crude stuff.

EQUIPMENT NEEDED:
  • Breathing mask (P100)
  • Heavy Duty Gloves: pvc or rubber (not latex or nitrile gloves)
  • Safety Glasses: Any pair will work as long as It is safety rated and solvent rated.

  • Gold-plated pins
  • Beakers/jars
  • Watch glass
  • Glass/ceramic Funnel
  • filter paper

  • HCl (32%)
  • Hydrogen peroxide (3%)
  • Household bleach
  • Sodium metabisulfite (SMB)

  • Stannous crystals
  • Tin metal
  • Dropper bottle

MAKING STANNOUS TESTING SOLUTION:
  1. Take about a gram of the stannous chloride crystals in the dropping bottle
  2. Add a gram or less of tin metal
  3. Fill the bottle with 25ml of tap water
  4. Add a little hydrochloric acid, about 25 or 30 drops to the 50mL bottle.
(This gives a milky liquid which is ready to use. The tin metal will dissolve very slowly, and it serves to keep the solution in good condition.)


RECOVERING GOLD FROM PINS:
  1. Make a solution of 2 parts HCL acid to 1 part hydrogen peroxide
  2. Add solution to beaker full of gold pins
  3. Put on medium heat and cover with watch glass
  4. Stir occasionally until all base metals are in solution
  5. Filter gold flakes from solution
  6. Stannous test on waste solution for any PGMs present

REFINING GOLD FLAKES:
  1. Put gold flakes in a clean beaker and add 25 parts HCL for 1 part house-hold bleach
  2. Continue to add some bleach slowly until all gold is dissolved
  3. Filter solution into a clean beaker
  4. Perform a stannous test to check for gold in solution
  5. Add SMB to solution until no more precipitate forms
  6. Do a stannous test to check for any gold left in solution.

Lastly, Melt and pour the gold!

Heres the pins I'll be using (It's about 400g and yes, some of it will probably be brass)
Screen Shot 2022-02-25 at 7.04.20 pm.png
 
Your AP solution will be far too heavy on oxidizer.. you only need a little peroxide to kick start the reaction or better still an aquarium pump to add oxygen to the solution, be aware that this can take some time to work , heating the solution will speed it up but comes at extra cost in electricity and a lot more fume production .
My advice for what it’s worth is read a lot of threads covering the use of AP and rethink your process.
 
Sounds like a plan.
Take nickv's advise.
Breathing mask is questionable. Aim for fume hood, scrubber and other preventive measures.

Heavy duty gloves are not needed imo, except for spills and emergencies. You need to feel what youre doing and not bump things over with clumsy thick gloves.

Strange as it sounds, but you don't need hydrogen peroxide to make Acid Peroxide. Because its actually the copper chloride doing the work. Its a bit of a misleading name.

Martijn.
 
My advice for what it’s worth is read a lot of threads covering the use of AP and rethink your process.
I looked at lazersteve's posts on AP (how its actually CuCl2) and its just confused me. If all you need to start up the AP solution is a bit of copper, HCl and some peroxide, why are there so many posts (lazersteve included) also mentioning the 2:1 HCl and H2O2 ratio? Lazersteve's website also doesn't work for me.

So my base metal removal solution should contain HCl, a bit of copper, and a touch of peroxide to kick off the copper to CuCl2? once ive made this solution, I just add the pins and then add more HCl if the reaction stops? (some posts also mention adding water. i assume this is if there is still lots of free HCl thats been concentrated from evaporation if i heat it).

I think everything else is right. Ive watched many youtube videos on this process (especially sreetips).
 
This is a work around method designed to leech base metals but if you add too much peroxide it can and will dissolve gold..
Most members set this up in a bucket with a lid with a few small holes in it and add an aquarium pump which negates the need for any peroxide, it’s not a quick method but should work well given time, you need to separate any steel plated pins before you use it.
 
Breathing mask is questionable. Aim for fume hood, scrubber and other preventive measures.

Heavy duty gloves are not needed imo, except for spills and emergencies.
thanks for the tips. I dont have access to any fume hoods, and open outdoor environment is all i have. Id also be wearing the p100 mask, a face shield, and have a fan blowing any fumes away from me (and being upwind of the fan and natures wind). If i got a little more serious i could make a mini fume hood from a clear plastic box with a computer fan and hose pulling the air to an area with no metals or people.

it didnt mean to say heavy duty, that was from a post that i originally copied some stuff from and i think it just refers to some dish washing gloves labled as heavy duty. I was just going to use the generic rubber gloves others use (i will definitely test some solution on the gloves to make sure they are safe).
 
Most plastic gloves are safe and simple disposable nitrile or pvc gloves will fo fine. Please keep in mind that there can be a permeation time for an acid or toxic solution to go through a glove.
Dispose when contaminated and wear new gloves. In time you will get better in keeping your hands and gloves clean.
 
you need to separate any steel plated pins before you use it.
The majority of the pins in the picture i posted are from recent computers and other pieces of technology (no more than 10 years old). I don’t know if that has something to do with it but they are about 95% magnetic.. only the odd gold-plated pin is not magnetic. I searched for the key terms like "steel pins" in the forum and not much help was found. I know steel (iron) is more reactive than copper and so if i put the CuCl2 solution (AP) into this batch it will cement out the copper from solution as the iron replaces it. Once all the iron is dissolved and some copper starts to be dissolve, ill be back to where i started and continue the recovery like normal. I assume the iron just means the seperating base metals from the gold is just going to cost nothing more than time and HCl (similar to if it was all just copper alloys, just a slight detour where copper precipitates). Is this correct or have i, during my research, somehow completely missed any special steps needed to recover gold from steel pins?
 
EQUIPMENT NEEDED:
  • Breathing mask (P100)

Do NOT trust ANY breathing mask !!!!!!!!!!!

they ARE NOT designed for long term &/or ongoing exposure to fumes !!!!!!!!!!

they are designed for ONE TIME use when there is an accident that fills a room with fumes & you need to go in to fix/clean up the problem cause the fume problem

once the filter material in the filter cartridge has been used - that one time - they are no longer effective & need to be replaced

That means each & every time you go to use the mask you need to replace the cartridges !!!

some fumes - like Nox (nitric acid) they will NOT filter AT ALL (unless they are designed specifically for that) & are VERY limited in filtering HCl fumes

So I repeat --- DO NOT TRUST these type masks !!!!!!!!!

They only give you a false sense of safety !!!!!!!!

You may not smell the fumes with a mask - but that does NOT mean the fumes are not going through the filters to your lungs ---- they ARE !!!!!!!!

Kurt
 
Can you explain which P100 mask you have?
I've done some more digging since I realised there are 2 types of p100 masks...
I got my hands on: 3M™ Particulate Filter 2091/07000(AAD), P100
But ive seen others getting: 3M™ Multi Gas/Vapor Cartridge/Filter 60926, P100

I assume the former are not suitable for AP vapour protection.
 
When I was a kid, my Dad was a superintendent at a plant that made pigments for the paint industry. I used to go and hang out with the Chemist that manned the Quality Assurance Lab. I remember him telling me that the only mask you can really trust is an SCBA type.
 
Do NOT trust ANY breathing mask !!!!!!!!!!!
they ARE NOT designed for long term &/or ongoing exposure to fumes !!!!!!!!!!
they are designed for ONE TIME use when there is an accident that fills a room with fumes & you need to go in to fix/clean up the problem cause the fume problem
once the filter material in the filter cartridge has been used - that one time - they are no longer effective & need to be replaced
That means each & every time you go to use the mask you need to replace the cartridges !!!
some fumes - like Nox (nitric acid) they will NOT filter AT ALL (unless they are designed specifically for that) & are VERY limited in filtering HCl fumes
So I repeat --- DO NOT TRUST these type masks !!!!!!!!!
They only give you a false sense of safety !!!!!!!!
You may not smell the fumes with a mask - but that does NOT mean the fumes are not going through the filters to your lungs ---- they ARE !!!!!!!!
Kurt
Yeah i read about that and i think someone (probably was you) used those exact words on another thread. I also read the posts about people breathing in fumes and still suffering years later, so i am aware of the dangers of working with these chemicals. My operation will be very small scale and outdoors with wind and a fan blowing fumes away from me.
 
Dust filters are never any good. For vapors and gases.
Cartridge filters have to be suitable for the specific gases you really defenitely are hoping to want to work in. Pun intended...
The cartridges are expensive and last ONE DAY. Depending on your gas concentration.

Prepare to buy a lot of filters.
And know that your not working safe with a mask.
It's false safety. Very dangerous.
 
To make AP without H2O2: let some copper oxidize by keeping it moist every now and then.
Or look for copper with a green layer of oxide.
Like a copper busbar rig hanging in the fume hood over an AP bucket for a couple years..

20220225_170342_mfnr.jpg
Put the copper (without rust and other trash) in HCl to soak the oxide off, filter, add a bubbler and your done.
HCl converts copper oxide into copper chloride.
Consuming more copper will make it more concentrated. And you never have to use H2O2.
Cold AP does not fume very much, but keep it in a fumehood or in a ventilated area.
 
To make AP without H2O2: let some copper oxidize by keeping it moist every now and then.
Or look for copper with a green layer of oxide.
Like a copper busbar rig hanging in the fume hood over an AP bucket for a couple years..

View attachment 48612
Put the copper (without rust and other trash) in HCl to soak the oxide off, filter, add a bubbler and your done.
HCl converts copper oxide into copper chloride.
Consuming more copper will make it more concentrated. And you never have to use H2O2.
Cold AP does not fume very much, but keep it in a fumehood or in a ventilated area.
Copper oxide is NOT green. And you don't need water to produce it. Copper oxide is black and you can just heat copper with a torch to produce CuO layer on your copper.
 
Most plastic gloves are safe and simple disposable nitrile or pvc gloves will fo fine. Please keep in mind that there can be a permeation time for an acid or toxic solution to go through a glove.
Dispose when contaminated and wear new gloves. In time you will get better in keeping your hands and gloves clean.
This is true for many acids, but concentrated nitric acid is not one of them. Both latex and nitrile glove are attacked by concentrated nitric and can actually catch fire. I believe it is NileRed that has a video on the subject.

Probably the most hazardous acid the refiner is likely to encounter is concentrated sulfuric acid - which can char the skin.
 
This is true for many acids, but concentrated nitric acid is not one of them. Both latex and nitrile glove are attacked by concentrated nitric and can actually catch fire. I believe it is NileRed that has a video on the subject.

Probably the most hazardous acid the refiner is likely to encounter is concentrated sulfuric acid - which can char the skin.
Indeed that goes for concentrated and fuming nitric acid. As explained by Nurdrage in this video.
 
This is true for many acids, but concentrated nitric acid is not one of them. Both latex and nitrile glove are attacked by concentrated nitric and can actually catch fire. I believe it is NileRed that has a video on the subject.

Probably the most hazardous acid the refiner is likely to encounter is concentrated sulfuric acid - which can char the skin.

This is true but never underestimate the danger of using lye as that can and will cause as much damage as hot sulphuric
 
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