Gold Refining Karat Scrap Complete Process - VIDEO

[Barren Realms 007]

Or just rinse the silver chloride out with strong HCl to complex the silver and any copper.

Nice thing about the ammonia water rinse is you can see any copper go, but that copper is only going to go if it's copper (II), not copper (I) which is what most of the copper contaminant is. Use strong HCl and you get the copper and the silver removed.

I wrote a post about that rinse somewhere...

Here is a link to your post Lou.

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=49&t=22328&p=233671#p233671

 

[kadriver]

Or just rinse the silver chloride out with strong HCl to complex the silver and any copper.

Nice thing about the ammonia water rinse is you can see any copper go, but that copper is only going to go if it's copper (II), not copper (I) which is what most of the copper contaminant is. Use strong HCl and you get the copper and the silver removed.

I wrote a post about that rinse somewhere...

We don't want to crush the pieces of gold, we want to leave them just as they are for the HCl wash - correct?

kadriver

Irrelevant, I just realized that we are talking about the precipitated gold, not the inquarted gold. Thanks Lou.

kadriver

 

[Barren Realms 007]

Or just rinse the silver chloride out with strong HCl to complex the silver and any copper.

Nice thing about the ammonia water rinse is you can see any copper go, but that copper is only going to go if it's copper (II), not copper (I) which is what most of the copper contaminant is. Use strong HCl and you get the copper and the silver removed.

I wrote a post about that rinse somewhere...

We don't want to crush the pieces of gold, we want to leave them just as they are for the HCl wash - correct?

kadriver

Irrelevant, I just realized that we are talking about the precipitated gold, not the inquarted gold. Thanks Lou.

kadriver

Actually it is a suggestion on both types.

It might be to your advantage to get you some sulfamic acid. When your reaction stalls put a pinch of crystals into your solution. If you get a reaction it can tell you that you have possibly used up all of your HCL and that you need to add more HCL to finish your process. Using sulfamic acid to denoxx your excess nitric also removes the necessary step of adding sulfuric acid the remove any lead because when the sulfamic acid removes the extra nitric it converts it to sulfuric acid and in the same process converts any lead to a sulphate to be filtered out.

 

[Lou]

Yes.

Furthermore, do not boil the HCl, it serves no purpose other than to distill off azeotropic 20% HCl. Remember, this is a gas dissolved in solution!

Regarding the inquarted gold, what you get is dependent entirely on several things:
1. the karat when it goes into acid
2. the concentration of the acid
3. the temperature of the acid.


Higher temperature, lower gold content, higher nitric content, you're more likely to get a broken apart gold that is difficult to filter. Stick to 4-6K and 1:3 c. nitric to DI and it'll look like brown material.
Only after the bulk of the silver/copper/zinc is gone should you give it the hot 1:1 nitric: DI H2O treatment.
If you keep repeating the process until the color is out of the solution, your gold should be in excess of 995. At that point, it can be rinsed with DI until no AgCl positive test, then rinsed with saturated sodium nitrate/borax solution and melted directly.

Lou

 

[goldsilverpro]

Even if I were to use HCl or NH4OH to leach out the AgCl. I would definitely still dilute and filter. It's the only guaranteed method of getting rid of all (or, most all) of the silver. You don't even have to think about it. It makes the dropping of the gold go much smoother. Sometimes I get a bit sloppy on the nitric, like everyone else, but the dropping still goes smooth as silk. I'm sure there's a limit for free nitric, but I rarely, if ever, reached it using normal AR - of course, I'm pretty good at keeping free nitric out of it to start with.

Try it. You'll like it.

 

[Shark]

Thanks to everyone for the parts concerning using the ferrous sulfate. I have just made a successful drop with it for the first time. I tried three other times with no luck. This time I used a better ratio of chemicals (based on Hoke's book and better math) to meet my needs and it dropped so fast I didn't even have time to get the camera. I now have another useful tool in my collection of recovery/refining know how.