I can't tell if I messed up or what???

[g_axelsson]

Decant what solution you have to another beaker and rinse the powder. Add the rinse into the decanted solution. Heat the solution to steaming and see if you get any reaction or color change. After an hour or so, turn off the heat and let the solution cool all the way back down. This will drive off any excess SO2 gas that may be causing the dark test results. If you are still getting the dark test result after heating and cooling, try a little more SMB. If you do not get a precipitate, check for PGM's. Take a small sample in a small bottle or test tube and add to it a small amount (a few crystals or more depending on the size of the sample) of potassium chloride and see if you get a yellow salt. You could test with DMG which would be faster if you have any.

If the pH is high this won't help. Then there is no excess SO₂, only dissolved SMB and that isn't affected by heating.

Göran

 

[g_axelsson]

Grelko, have you tested to add a bit of HCl to your solution with a lot of SMB and almost black stannous test?
HCl doesn't hurt but could be what is missing. It is rarely said but SMB needs an acid to be able to drop gold. (Add acid slowly or you might get a boil over.)

When you get a black result from stannous testing try to dilute your solution. Put a drop of solution in one spot, then add a couple drops of water, mix and take a drop of this to the next spot. Repeat if necessarily in the next spot and so on... I think this is covered in one of Hoke's books.

Göran

 

[Grelko]

Grelko, have you tested to add a bit of HCl to your solution with a lot of SMB and almost black stannous test?
HCl doesn't hurt but could be what is missing. It is rarely said but SMB needs an acid to be able to drop gold. (Add acid slowly or you might get a boil over.)

When you get a black result from stannous testing try to dilute your solution. Put a drop of solution in one spot, then add a couple drops of water, mix and take a drop of this to the next spot. Repeat if necessarily in the next spot and so on... I think this is covered in one of Hoke's books.

Göran

I forgot to check the PH of the solution. I haven't tried adding HCl to it yet. That may just fix the problem.

I remembered reading about the stannous "acquaintance test" in the book, I was going to do that today. Thanks for reminding me.

I have a feeling that it would be orange going towards yellow, like the original solution did when I diluted that, but we shall see.

 

[Grelko]

1. 5 drops solution, 5 drops stannous.

2. 5 drops solution, 5 drops stannous, diluted with 5 drops of water.

3. 5 drops solution, 5 drops stannous, diluted with 10 drops of water.

4. empty.

5. 5 drops solution, 5 drops HCl

6. 5 drops solution, 5 drops HCL, 5 drops stannous. Also, I used a paper towel to soak up the solution in this test. The black precipitate was almost solid and came out in 1 piece.

Edit - The PH is around 5.5

 

[Geo]

Take the solution you have left and make sure it has excess HCl. Add a solid piece of copper and see if anything cements out. It will be easier to cement any values and start over.

 

[g_axelsson]

pH 5.5 is almost neutral. Add some HCl to it.

I was too lazy to calculate the strength of the acid... so I googled it. http://www.oxy.com/OurBusinesses/Chemicals/Products/Documents/hydrochloricacid/tech-calculated_ph_values_HCl.pdf
pH 5.5 is 0.00001150 % HCl in water (by weight)!
In fact, you probably would lower the pH by putting your hands into the solution! Do not do this!!!!
Natural skin surface pH is on average below 5, which is beneficial for its resident flora.

Göran

 

[Topher_osAUrus]

Those tests look more brown than purple.

Sure its not a false positive?

 

[Grelko]

Take the solution you have left and make sure it has excess HCl. Add a solid piece of copper and see if anything cements out. It will be easier to cement any values and start over.

I should be able to do this later tonight. I might give it a couple days to see if anything drops (or heat it). If I would have just added copper in the first place, I'd probably be done by now.

pH 5.5 is almost neutral. Add some HCl to it.

I was too lazy to calculate the strength of the acid... so I googled it. http://www.oxy.com/OurBusinesses/Chemicals/Products/Documents/hydrochloricacid/tech-calculated_ph_values_HCl.pdf
pH 5.5 is 0.00001150 % HCl in water (by weight)![/url]

Göran

Thanks for that link (wow, I sure didn't have much HCl in there). I was going to add enough HCl, to see if I can get the PH back down to 1-2, then put in copper.

Those tests look more brown than purple.

Sure its not a false positive?

It has to be, I haven't seen anything besides black/brown stannous results in the last couple days.

Any powder that I get from the 2 beakers, I was going to add to the rest of the material and re-dissolve it (completely this time).

 

[Grelko]

Well.... I know what should be wrong with my solution and why the stannous tests are black/brown.

I started dissolving the rest of the material from the original filter. The solution was almost black until I added about 20ml of water to the HCl/Cl. It turned darker green, but the stannous was still black.

I decanted about 3/4 of the solution to a separate beaker, then added fresh HCl/Cl to see if I could get the rest of the material to dissolve.

This time the solution was light green/yellow and had black pieces floating "burnt filter I'm guessing".

I looked up under the bottom of the beaker, to see what needed dissolved and saw 10-15 small MLCCs :lol:

I couldn't see them before, because of all the black powder/chunks at the bottom. When I filtered the original solution, they stayed in the filter, so I had no idea they were even there.

I'm not sure how I got those mixed in with the material, but after I had solution light green/yellow, I tested with stannous and it quickly went orange, then black. The stain looks dark grey/black with a hint of purple.

Edit - Since I still have the other beaker with a piece of copper in it, I should probably combine the solutions, now that I know what went wrong and cement all values.

Edit 2 - These little buggers were the problem.

 

[Grelko]

Ever since I started this hobby, not much of it has worked out right. Either I'm too busy, or it's raining etc.

Atleast I can always count on you guys and the forum for help and great information. Plus, I can count on Copper to do it's job

More dropped out than I thought would, but there's probably a bit of copper in it now.

I'm letting the powder dry out over night, then "completely" incinerating it tomorrow, to make sure I don't have anymore bits of filter in it, if it's not still raining.

I am going to scrape the filter clean once the powder is dry, then add it to my other filters, instead of burning it along with the powder this time.

I thought the stannous was still showing a very slight purple, but it was the flourescent lights (Stannous finally looks clear now) I checked it under different lighting also. By the off chance I missed any PMs, they're in my stock pot.

I'm guessing it looks grey-ish in the picture because the CuCl2 is diluted with stannous and the lighting. Also the solution got stirred up while scraping the copper, so it might be tiny bits of black powder floating around.

Solution on top, stannous test on bottom.



When you guys say it "cements" to the copper, you arent joking. It was hard to get off. I used a tooth brush instead of a wire brush, so that I didn't get any bits of iron mixed in. Afterwards, there was still a tiny bit of black on the copper that wouldn't come off "even after 5 minutes of scrubbing at it", but I'll eventually dissolve that piece someday.

Edit - The tooth brush will never be used for anything besides scraping PMs from copper.



Dirty powder in the filter. So far so good.

 

[Barren Realms 007]

You are developing your patience I see. Nice job. :mrgreen:

Now you need to learn to let the material settle and siphon off the liquid and you will have less filter material to work with and more sediment to work with.

Hobby, home refiner needs to develope a different mind set than a commercial refiner at times.

Your getting there. Patience. :G

 

[Grelko]

You are developing your patience I see. Nice job. :mrgreen:

Now you need to learn to let the material settle and siphon off the liquid and you will have less filter material to work with and more sediment to work with.

Hobby, home refiner needs to develope a different mind set than a commercial refiner at times.

Your getting there. Patience. :G

I have tons of patience haha, I normally do wait and decant the solution, but I was excited to see how much powder dropped to the bottom of the beaker, so I filtered it instead.

I was thinking, if I did happen to have any AgCl mixed in, I probably shouldn't incinerate it just yet. Re-dissolving and filtering it out first would probably work better.

I've been reading for the last hour, about AgCl and I'm thinking, as long as I don't actually melt the powder, I should be ok and not lose any silver as fumes, because it'll turn into silver oxide (Or have I gotten this part wrong?). I know you shouldn't let AgCl dry out.

 

[Barren Realms 007]

You are developing your patience I see. Nice job. :mrgreen:

Now you need to learn to let the material settle and siphon off the liquid and you will have less filter material to work with and more sediment to work with.

Hobby, home refiner needs to develope a different mind set than a commercial refiner at times.

Your getting there. Patience. :G

I have tons of patience haha, I normally do wait and decant the solution, but I was excited to see how much powder dropped to the bottom of the beaker, so I filtered it instead.

I was thinking, if I did happen to have any AgCl mixed in, I probably shouldn't incinerate it just yet. Re-dissolving and filtering it out first would probably work better.

I've been reading for the last hour, about AgCl and I'm thinking, as long as I don't actually melt the powder, I should be ok and not lose any silver as fumes, because it'll turn into silver oxide (Or have I gotten this part wrong?). I know you shouldn't let AgCl dry out.

You are correct in the fact that you have gotten this part about the AgCl loss correct. Once you have put a flame to it you have lost values because of the silver chloride to elemental silver step has been removed. The silver chloride changes it's structure once a flame is put to it. Either covert the silver chloride to elemental silver and remove the silver then the PM's or remove the PM's before converting the silver chloride to elemental silver.

Most of the time as a home refiner or hobby refiner it not an easy decision to make. But once you make the decision or how you will process the silver or silver chloride then stick with that decision so you are limiting the number of processes you are doing to recover values.

 

[Grelko]

You are correct in the fact that you have gotten this part about the AgCl loss correct. Once you have put a flame to it you have lost values because of the silver chloride to elemental silver step has been removed. The silver chloride changes it's structure once a flame is put to it. Either covert the silver chloride to elemental silver and remove the silver then the PM's or remove the PM's before converting the silver chloride to elemental silver.

Most of the time as a home refiner or hobby refiner it not an easy decision to make. But once you make the decision or how you will process the silver or silver chloride then stick with that decision so you are limiting the number of processes you are doing to recover values.

Now, is that the actual flame touching the silver chloride? I have a small crucible that I can heat from the side or bottom, until everything is glowing red, so the flame wouldn't actually be touching any powder.

I'm not 100% sure on refining silver as of yet, so I'd be going after the gold first.

Please correct any mistakes if you see them.

I was going to incinerate the powder, then re-dissolve it with HCl/Cl. I think that cotton fluff "AgCl?" will be at the bottom of the beaker again, so I can filter it out (Would I need ice cubes for anything?). Take the gold bearing solution "possible PGMs from those MLCCs" and heat it, to remove the Cl.

Drop the gold with SMB, settle, filter or decant and rinse it, so I have "cleaner" gold powder. The HCl/Cl and SMB solution might have PGMs in it, so I'll put in a piece of copper to drop them out.

I shouldn't need sulfuric, because there shouldn't be any lead in this. If there was, it would still be in solution, while the copper dropped the PMs out.

The gold powder will be rinsed with "warm/hot" HCl, distilled water a few times each, until clear, then re-dissolved etc, again. I was going to do this until the gold powder is a light "blond" brown.

Add just enough borax to glaze a new melting dish (after heating the dish to get any water out) and after melting, I should have a nice clean button that's possibly 999. :mrgreen:

Any borax that's stuck to the button, I was going to boil off in distilled water, since I don't want to use sulfuric.

Do I even need borax to melt clean gold powder, or can I just melt it into a bead?

 

[Geo]

Place the copper in a container like a butter bowl and let it dry completely. Any precious metals will dry and flake off.

 

[g_axelsson]

Looking good! The copper plate and cemented powder that is.

When I get powder, sediments or foils stuck in a filter I usually wash it down into a beaker with a squirt bottle and the filter paper against the inside of the beaker. With the filter flat against the glass it is easy to wash off most of the content. Then the filter goes into my incineration pile if there was any values in it from start.

That copper piece can be used again for cementing values and when you are finished with it you just put it in the stock pot and let it dissolve.

Göran

 

[Grelko]

Place the copper in a container like a butter bowl and let it dry completely. Any precious metals will dry and flake off.

That's great to know, thank you. I wasn't sure if I'd have to wait until I dissolved it to reclaim any smal pieces that were stuck to it.

Looking good! The copper plate and cemented powder that is.

When I get powder, sediments or foils stuck in a filter I usually wash it down into a beaker with a squirt bottle and the filter paper against the inside of the beaker. With the filter flat against the glass it is easy to wash off most of the content. Then the filter goes into my incineration pile if there was any values in it from start.

That copper piece can be used again for cementing values and when you are finished with it you just put it in the stock pot and let it dissolve.

Göran

I normally just take the filter after it's dry and dump any powder into a container. Fold the two sides and rub them together over a paper plate, or just the container itself and add any powder to the rest of it. Then I add it in with my other filters to incinerate later.

The way you do it should work better, so I'll have to try that next time. My filters look like they still have a thin coating on them.

I was going to continue using that piece of copper until it got too thin, then toss it in the stock pot.

 

[Grelko]

I've been thinking,

Instead of converting AgCl to Ag with Karo and NaOH, if this article is accurate, wouldn't it be easier to do this instead?


Faraday induced the mechanochemical reduction of AgCl with Zn, Sn, Fe and Cu in 1820, using trituration in a mortar.
(I haven't looked for his actual reasearch papers from back then yet.)

The bad news is that the PDF costs almost $40. The good news, is that the sentence above basically explains what he did.

This article says that it'sa a re-visit of the experiment. They use a ball mill etc. I didn't read the PDF to see exactly how it works though.

http://link.springer.com/article/10.1007/s10973-007-8479-8

Other sites explain it a little more, but it looks as if all he did was grind AgCl and one of the other metals in a mortar and it'll convert to Ag without using any chemicals. It seems to be a pressure conversion. Edit - Spontaneous dehydration

Then all you would have to do is rinse it with water, since the chlorides of Zn, Fe, Sn and Cu are soluble in it, but Elemental silver isn't. You could also use acetone for some of these.

Section 1.1.1.2 explains the process a little more.

https://books.google.com/books?id=FldqbSffUMgC&pg=PA3&lpg=PA3&dq=faraday+experiment+with+%22agcl%22+1820&source=bl&ots=-RUheOlt0M&sig=tHMjQ_MebtdGqPUPzG8EnKWUJpw&hl=en&sa=X&ved=0ahUKEwi6y8Wv3oPPAhVFfiYKHTikDQ0Q6AEILTAD#v=onepage&q=faraday%20experiment%20with%20%22agcl%22%201820&f=false

 

[Topher_osAUrus]

Did you look up and see what trituration is?
I believe its much more in depth than just beating up the silver chloride :lol:

 

[Geo]

Silver chloride can be converted with HCl and aluminum, or sulfuric acid and steel.