Separating Gold Precipitate from Base Metal Precipitates

[Nova02]

Hello, everyone!

I'm new to gold refining, and for my first experiment am doing a small batch of about an ounce of gold filled scrap (1/5 12k, 1/10 10k, 1/20 10k, etc) which I unfortunately did not check for steel/tin content. I decided to use the AP method but used 20-30% H2O2 with it (Pequa Cess-Flo from Home Depot), which dissolved some of my gold. The solution has saturated with base metals, though, and a stannous test shows no more dissolved gold in solution, which I believe means the gold has precipitated. I have sediment (sludge) on the bottom of my vessel, and if I assume the worst (given my previous error), I'm assuming it has iron, tin, and copper precipitates in it. How can I separate these other precipitates from the gold?

Could I poor off the AP solution and start anew with weaker H2O2/HCl solution to just dissolve the base metal precipitates, leaving the gold behind, or is there some precipitate that would inhibit this (I've heard about AP-dissolved steel making a slimy precipitate that gunks up everything)?

I've scoured the forums, and from what I can tell, tin and iron tend to be a pain to filter out or remove. What if I selectively dissolve them using something they're soluble in (copper (i) chloride is soluble in HCl, while copper (ii) chloride is soluble in water)? I could do rinses with water for the water-solubles, rinses with HCl for stuff like copper (i) chloride, and so on until the gold is left over?

I'm very interested to learn about what y'all think, as I'm finding this forum and the concepts within fascinating! Please help me learn about this process.

 

[Shark]

Welcome to GRF.

Would you have a picture of your solution? Iron in AP isn't that big of a deal. But seeing it could make it easier to decide your next move

 

[Yggdrasil]

Hello, everyone!

I'm new to gold refining, and for my first experiment am doing a small batch of about an ounce of gold filled scrap (1/5 12k, 1/10 10k, 1/20 10k, etc) which I unfortunately did not check for steel/tin content. I decided to use the AP method but used 20-30% H2O2 with it (Pequa Cess-Flo from Home Depot), which dissolved some of my gold. The solution has saturated with base metals, though, and a stannous test shows no more dissolved gold in solution, which I believe means the gold has precipitated. I have sediment (sludge) on the bottom of my vessel, and if I assume the worst (given my previous error), I'm assuming it has iron, tin, and copper precipitates in it. How can I separate these other precipitates from the gold?

Could I poor off the AP solution and start anew with weaker H2O2/HCl solution to just dissolve the base metal precipitates, leaving the gold behind, or is there some precipitate that would inhibit this (I've heard about AP-dissolved steel making a slimy precipitate that gunks up everything)?

I've scoured the forums, and from what I can tell, tin and iron tend to be a pain to filter out or remove. What if I selectively dissolve them using something they're soluble in (copper (i) chloride is soluble in HCl, while copper (ii) chloride is soluble in water)? I could do rinses with water for the water-solubles, rinses with HCl for stuff like copper (i) chloride, and so on until the gold is left over?

I'm very interested to learn about what y'all think, as I'm finding this forum and the concepts within fascinating! Please help me learn about this process.

AP is actually a Cupric Chloride etch and need no Peroxide at all.
All you need is some Copper, HCl and Air(Aquarium bubbler).
Amd you ar right, your Gold is in the gunk in the bottom as it cements out on the base metals.
Your first mistake was to not separate the magnetic from the non magnetic.
Next was to use way to strong Peroxide.
Pour off yor liquid, separate the magnetic and restart with HCl and an air bubbler.

 

[Ronei]

I’ve been down this road before. If I were you, I'd pour off the AP solution and start fresh with a weaker H2O2/HCl mix. It should help dissolve most of the base metals like copper and iron without hitting your gold too much. Tin can be a pain, but the diluted HCl should help clear out a lot of that. Just make sure to filter it well to keep your gold safe. It’s a bit of trial and error, but you’ll get the hang of it!

 

[Yggdrasil]

I’ve been down this road before. If I were you, I'd pour off the AP solution and start fresh with a weaker H2O2/HCl mix. It should help dissolve most of the base metals like copper and iron without hitting your gold too much. Tin can be a pain, but the diluted HCl should help clear out a lot of that. Just make sure to filter it well to keep your gold safe. It’s a bit of trial and error, but you’ll get the hang of it!

If you had read my reply, you would have learned that there is actually no need for Peroxide at all, only HCl and an aquarium bubbler.

You would benefit from studying this:

We ask our new members to do 3 things.
1. Read C.M. Hokes book on refining jewelers scrap, it gives an easy introduction to the most important chemistry regarding refining.
It is free here on the forum: https://goldrefiningforum.com/phpBB3/viewtopic.php?f=54&t=19798
2. Then read the safety section of the forum: https://goldrefiningforum.com/forums/safety.47/
3. And then read about "Dealing with waste" in the forum: https://goldrefiningforum.com/threads/dealing-with-waste.10539/

Suggested reading:
https://goldrefiningforum.com/forums/the-library.101/
https://goldrefiningforum.com/threads/when-in-doubt-cement-it-out.30236/
https://goldrefiningforum.com/threa...le-read-this-before-you-post-about-ore.33333/


Forum rules is here.
https://goldrefiningforum.com/threads/gold-refining-forum-rules.31182/

 

[Martijn]

I’ve been down this road before. If I were you, I'd pour off the AP solution and start fresh with a weaker H2O2/HCl mix. It should help dissolve most of the base metals like copper and iron without hitting your gold too much. Tin can be a pain, but the diluted HCl should help clear out a lot of that. Just make sure to filter it well to keep your gold safe. It’s a bit of trial and error, but you’ll get the hang of it!

Why advice him to pour off active leach solution, continue with weak HCl, and start over with H2O2 when he has perfectly good AP?