This is depends on the pins, you and so on.
I dissolve all base metals first. I also process pins in plastic which leaves separating the foils. A plastic kitchen strainer with slots big enough for foils to pass through, not pins, will work. Use a spray bottle with water.
Gold recovery from plated pins (magnetic mostly) is more effective with a sulfuric stripping cell than other methods. Less waste, high recovery rate if done properly, reusable acid with minimal loss (since acid from washwater can be reclaimed as well).
The Sulfuric stripping cell do not produce much waste at all if operated correctly, since it do not dissolve base metals.
I can understand it would work that way for gold-plated kovar or steel, since conc sulfuric will not react with them, but what about brass or copper-core pins? Sulfuric reacts with those metals.
Concentrated Sulfuric at 95%+ will not.
). Heat to 77F, pour over pins and stir nicely. You will get the gold off in something like 30-60 seconds and not touch the metal underneath. Very impressive when happens. If you want to undedtand how it works get a copy of 1980 Hydrometallurgy magazin and read it or google for patents and article on the formulation
Bruh with this process I would be afraid of making witchbrew 2.0Guys, the brass and SS pins substreate if you dissolve it, it will leave you with metals in solution that are water pollutants if over 0.5 ppm. Zn, Cr, Ni in acidic solution ...and going to electroplating will not work, only waste more $ and is slow process. If you want to play that's a different story, but if you want to make a bit of money thee rule is simple: if a gram of gold is $ 60 and it cost you $60.5 to get it, go and buy pure gold and keep it until is valued at 70+ and sale it.
Simple and effective options are few:
1. Write and balance the reactions of copper, zinc and iron with sodium nitrate assuming the reaction takes place. Calculate how much sodium nitrate you need to use for whatever pounds of pins you have. Add 20+% more to conpensate for the contained water. Take a crucible like porcelan and mix the pins with the powder, cover with some more and put a lead on it. Heat at 350 C (670F) and let it work over night, or up to 24 hours if you have a lot of pins or less if you can heat at 600-700 C. Next day let it cool to under 220 F and dump in water. You'll get the base metals in neutral solution and you'll have "husks" of the gold pins. Rinse and and causting to water to precipitate metal hydroxide and use as fungicide in the garden. What you do with the gold if your fault if you wife finds out.
2. This is a bit of woodo description that follows, but if you want to be scientific you need and ORP to keep the solution potential in check. Prepare a solution of 12-15% sulfuric acid, like drain cleanner, add hydrogen peroxide and for each gram of expected gold add 1.5 g of thiourea, like hair removal (
Interesting, have you checked our waste treatment thread?Guys, the brass and SS pins substreate if you dissolve it, it will leave you with metals in solution that are water pollutants if over 0.5 ppm. Zn, Cr, Ni in acidic solution ...and going to electroplating will not work, only waste more $ and is slow process. If you want to play that's a different story, but if you want to make a bit of money thee rule is simple: if a gram of gold is $ 60 and it cost you $60.5 to get it, go and buy pure gold and keep it until is valued at 70+ and sale it.
Simple and effective options are few:
1. Write and balance the reactions of copper, zinc and iron with sodium nitrate assuming the reaction takes place. Calculate how much sodium nitrate you need to use for whatever pounds of pins you have. Add 20+% more to conpensate for the contained water. Take a crucible like porcelan and mix the pins with the powder, cover with some more and put a lead on it. Heat at 350 C (670F) and let it work over night, or up to 24 hours if you have a lot of pins or less if you can heat at 600-700 C. Next day let it cool to under 220 F and dump in water. You'll get the base metals in neutral solution and you'll have "husks" of the gold pins. Rinse and and causting to water to precipitate metal hydroxide and use as fungicide in the garden. What you do with the gold if your fault if you wife finds out.
2. This is a bit of woodo description that follows, but if you want to be scientific you need and ORP to keep the solution potential in check. Prepare a solution of 12-15% sulfuric acid, like drain cleanner, add hydrogen peroxide and for each gram of expected gold add 1.5 g of thiourea, like hair removal (
TedInteresting, have you checked our waste treatment thread?
https://goldrefiningforum.com/threads/dealing-with-waste.10539/
Another ironic twist is that after telling us how dangerous our waste is, you recommend a chemical
that may or may not be a powerful carcinogenic substance.
Breathe slowly mate
Edit to add link.
i guess if lowes home depot and the cosmetic sections of Walmart sale them for public it doesn't mean you can drink them or expose your skin to it too long before evolution respond to pressure and turns you into a bold monkey or "hairy Man" of Australia. You never know what you get playing.. .Did you read the waste disposal thread?
Ah, I've never used sulfuric at a concentration that high before. It's rather hard to get in NJ. The purest I can get is from Rooto, and that has the organic inhibitors in it, so you have to add a little water and heat to make it do much of anything to metal.
