Processing Gold

[Wonka]

Nothing seems to be working for me so I’m gonna run through the process. Please let me know where I’m going wrong at.
1. 50/50 nitric cover chips with water then 50% nitric. Wait until there no reaction left. Usually takes days.
2. Pour off nitric and then rinse chips.
3. Pour in HCL to cover chips then add nitric a small amount at a time until there is no reaction left. Then add about 50 ML more. Do I let it sit for awhile here or pour off immediately? And if I do for how long?
4. Filter AR until it’s clear. What do I do with any particles left in the filter?
5. Mix sodium metabisolphite with water. Use until there is no more reaction.
6. Filter.
7. Wash the precipitate with hot water.
8. Put in a 50/50 nitric bath and heat for 10 mins.
9. Pour off and wash.
10. Let dry and smelt.
Between 8-9 is where things keep going wrong. It always seems like there contaminants in the gold powder. I hate the dissolved silver in nitric looks just like AR or gold. Make me think there’s gold in it.
Ok
11. Pour 50-100 ML of HCL in pour off to form silver chloride.
12. Let settle and wash. Repeat until water is clear.
13. Add sodium hydroxide until mixture turns a silvery blacking color.
14. Wash
15. Add some type of suger.
16. Wash and dry. Then smelt.
Here I have another question. What’s stopping copper from turning into chloride? Sometimes during the frist nitric dissolve, at the beginning of all of this, I get different types of chlorides. White green yellow.
I somehow did this wrong before. All kinds of copper ended up in it. I did forget to wash it tho after I added suger but at that point I would think it’s to late.

Yes I have stannus chloride.
Yes I test everything.
My gold always looks like brown mud and black mud mixed. I’m sure there’s silver in it and I’m sure there’s copper in it. I don’t think the wash with nitric of the precipitation is working properly. How long do you let it set in the nitric wash?

 

[Golddigger76]

Can you please elaborate on what type of chips you are processing ?
There's many different types and many different ways they need to be processed.

 

[Golddigger76]

Just reading through your description of what you have done I can see a few things that need to be worked on.

Without knowing what chips, if you incinerated, broken or ground them into a size that the gold bonding wires can be reached by the acid, ect.
It's going to be a guessing game that can be addressed after you answer.

Here are some things that I would like to point out that doesn't seem right:
When adding nitric to hydrochloric to make aqua regia do not be rushed and add small amounts of nitric as in a few drops at a time when you are getting close to dissolving your gold followed by enough time for the reaction to complete.
50 ml of nitric is overkill when there's not much visible metals to put in solution so you'll need to drive it off with heat/time or denox with sulfamic acid.
If you denox with sulfamic you can filter After that's done.
As far as particles in the filter goes, if there's visible gold your aqua regia stage was not complete and you've gotten ahead of yourself, and if it is not visible gold depending on the feedstock it mostly go into my waste bucket.
Washing:
A hot water wash doesn't cut it, more like 4, 5, or 6.
I wash with water until I can no longer see colors like green copper in the acid or any cloudiness and then another time or two and do not do a dilute nitric bath at all after the multiple washing with water.
You need to be very thorough with washing out your precipitated gold.
Guess what....
It's not ready to smelt or melt but it's melting at this point.
If your goal is to truly refine this gold to pure as possible you are going to need to do a second refining.
If my first is with aqua regia, my second is usually with hydrochloric and bleach and best to precipitate with iron sulfate or something different than smb if that's what you used to precipitate the first time.
Twice refined with aqua regia and precipitated with smb works fine as long as you are washing your gold powder thoroughly.
Refining it a second time should get out most impurities.

 

[FrugalRefiner]

OK, I'll try this. Your post doesn't mention what the feedstock is, but I'll try to respond in a generic way.

Nothing seems to be working for me so I’m gonna run through the process. Please let me know where I’m going wrong at.
1. 50/50 nitric cover chips with water then 50% nitric. Wait until there no reaction left. Usually takes days.

This would be a leach step to remove base metals like copper. That's fine

2. Pour off nitric and then rinse chips.

Ceramic chips? Epoxy chips? How were they prepared?

3. Pour in HCL to cover chips then add nitric a small amount at a time until there is no reaction left. Then add about 50 ML more. Do I let it sit for awhile here or pour off immediately? And if I do for how long?

So, I'm assuming you creating AR to dissolve the gold. If you add your nitric in increments till there is no more reaction, why would you add another 50ml? You're defeating the purpose of adding your nitric incrementally by adding excess nitric at the end. Don't do that.

4. Filter AR until it’s clear. What do I do with any particles left in the filter?

Time out! You didn't mention cooling, diluting, or deNO_Xing or adding sulfuric to precipitate lead. These are all important.

For particles left in the filter, save them up. There may be silver worth recoving.

5. Mix sodium metabisolphite with water. Use until there is no more reaction.
6. Filter.
7. Wash the precipitate with hot water.

Sodium metabisulfate. Spelling of chemical names is important. When I wash, I start with HCl. I follow the washing procedure Lou described in ________________

8. Put in a 50/50 nitric bath and heat for 10 mins.

You'll dissolve some gold. You've come from a chloride based solution (your AR), so there will be some chloride left. Adding nitric will create at least a little bit of AR, which can dissolve a little bit of gold.

9. Pour off and wash.
10. Let dry and smelt.

At this point, you should have a clean precipitate of gold. You would melt it, not smelt it. See _________________

Between 8-9 is where things keep going wrong. It always seems like there contaminants in the gold powder. I hate the dissolved silver in nitric looks just like AR or gold. Make me think there’s gold in it.
Ok

This is where you lose me. By step 8 you should have a clean precipitate of gold. If you chill and dilute the AR before adding your sulfite, there should be no silver in your precipitated gold. You shouldn't have dissolved silver in a nitric wash after dropping your gold.

11. Pour 50-100 ML of HCL in pour off to form silver chloride.

Again, you've dropped the gold from AR. You shouldn't have any silver in any solution that could be dropped as silver chloride. This is not a step that should be following a dissolution and precipitation of gold.

12. Let settle and wash. Repeat until water is clear.
13. Add sodium hydroxide until mixture turns a silvery blacking color.
14. Wash
15. Add some type of suger.
16. Wash and dry. Then smelt.

Here you're describing a process for processing silver chloride, which shouldn't be a problem after refining your gold in AR. Again, you would melt it, not smelt it.

Here I have another question. What’s stopping copper from turning into chloride?

Nothing. Copper goes into solution as CuCl₂. Silver does not stay in solution as a chloride because it is not soluble as a chloride. I know it can be confusing, but you have to learn some chemistry to understand what you're doing.

Sometimes during the frist nitric dissolve, at the beginning of all of this, I get different types of chlorides. White green yellow.

No, if you're doing a nitric dissolve, you won't have chlorides.

I somehow did this wrong before. All kinds of copper ended up in it. I did forget to wash it tho after I added suger but at that point I would think it’s to late.

At this point, I don't know if you're talking about gold or silver. Two different processes, and two different end products.

I think you're confusing processes and combining them when they shouldn't be combined. You're getting there, but keep studying.

Dave

 

[Wonka]

Thanks for the responses guys! I can see some thing I’m doing wrong and I think they’ll help. I appreciate the feedback.

 

[MvK]

Between 8-9 is where things keep going wrong. It always seems like there contaminants in the gold powder.

I also have black particles mixed with the brown gold powder when doing the first step gold recovery. Im not sure but i suspect some other PGM is coming down with the gold. Could also be plain gold but it looks like its taking longer to settle down slowing down my project.

I just wash it off the mud and collect it in a vessel. This 'gold refining waste vessel' will be my collector for several refinings and when theres enough to work with i will refine that seperately.

Leaves you cleaner gold mud to work with for the refining stage.

Also, dont wash the powder in nitric. Use HCL bath and distilled water bath.

 

[Wonka]

Well here my first “big” pour. I did have more problems with this part. The dang graphit crucible kept cooling off to fast and the gold would stick at the top. So I had to repour this like 5 times but I think it turned out ok.

 

[Wonka]

I be posting a walk through of platinum pladdium next. I’m gonna try the ammonia path. Will see how things go.

 

[Yggdrasil]

I be posting a walk through of platinum pladdium next. I’m gonna try the ammonia path. Will see how things go.

It is Palladium not Pladdium, check your spelling.

 

[Yggdrasil]

I be posting a walk through of platinum pladdium next. I’m gonna try the ammonia path. Will see how things go.

Most refiners will shy away from processing PGMs due to their toxicity.
I’d recommend that you stick to Gold and Silver until you master them.
At least until you have a proper lab and can contain the gases, dusts and the liquids from PGMs in a separated area.