Refining Gold from Gold Filled Jewelry

[Oneal58]

Hi Butcher, this is Oneal.
Just wanting to touch base with you. I had a bad experience with UREA neutralizing solution and I have decided to try the method that you described in an earlier post.
I made AR yesterday, dissolved my values from the sulhuric cell and also the gold filled foils.
Reduced by evaporation down to 1/2 of volume, added a few drops of sulphuric to drop what tin/lead/Etc;, that I could. I reduced another 1/2 by evaporation, I was busy but I think that the nitric reaction you were talking about happened while I was busy and I didn't see it happen. I then added back 3/4 distilled water and let AR sit overnight. There was white powder in the bottom of the beaker that I used, a good bit this morning? I decanted by way of siphon and left the particulate in the bottom of the original beaker.
There was so much whitish Tin/silver/lead/Etc;, in the bottom of the original beaker I have decided to run the now dark yellow AR through the method you outlined earlier. Your method of evaporating down to syrup and adding a little HCl. Then run the process a couple of more times.
My question is should I add a few more drops of sulphuric acid before getting AR too near to being a syrup? After these processes I will increase volume by 4 times with distilled water, let sit overnight and drop gold tomorrow?
What is your preference to use the MetaBisulfite to drop the gold, a warm or cold solution?
Any guidance here would be appreciated Butcher.
Thanks Butcher,
Oneal

 

[butcher]

Oneal,
Glad to see you using the evaporation method, make note when evaporating of the first evaporation (if excess nitric) that as solution gets concentrated you should watch reaction carefully, watching for those small bubbles to start to form (point nitric wants to come out all at once), and turn down heat (or just lower heat the first run) also do not leave solution evaporating and cook to salts (burning gold to bottom of vessel).


When dissolving gold many people will make a mistake and use way too much acid for the volume of gold, this would mean a very long evaporation time to concentrate all of this excess acid.
They also tend to add way to much nitric acid (wasting it) and it will take time to remove.

Best approach would use minimum acid needed (HCl), and adding minimum nitric needed in small increments to dissolve gold, this would leave most of the gold saturating the acid and almost no nitric to evaporate, in this perfect mix adding a bit of gold to the evaporation would quickly use up nitric (so one could basically eliminate the excess nitric with just heat and almost no evaporation.
So keep this in mind as you process.


(Not adding urea to contaminate their gold solution)
(Although a prill can be used to see if nitric is still in solution)


The SMB I am normally not too concerned about temperature (others may be), (as long as temperature is not extremely cold or hot, and then I may try and change temperature) (another reason if from dirty solutions I get colloids then I may heat to boil).

but I do keep in mind that if solution is cold it will hold SO2 gas longer (good), but I it may take longer for reaction to take place, (and solution will not mix on its own from heat rising).
If solution is hot my SO2 gas may escape so fast that the reaction (although reaction faster with heat) will not have time to take place, mixing well is more important to me than temperature as long as it is not extremes.


Hope fully that white powder contains some silver, save it rinsed and keep wet, when you’re ready to deal with it we can discuss it.

Sorry if this does not give you clear instruction (it’s just the way I see it others may have a different opinion).

 

[Oneal58]

Thanks Butcher, been evaporating for hours. Got to get back to the old house. Thanks for the information. Getting close, got to go back out. Talk to you a little later. Oneal

 

[Oneal58]

Hi Butcher,
Came back in for just a minute, it's really cold out there.
I have decided due to the amount of particulate drop I had this morning in the bottom of the beaker, to add a few drops of sulphuric again. Maybe 15 more minutes and AR will be syrupy. Add enough HCL to dilute ( a little) evaporate again, same process 2 more times. Then add 4 times volume of distilled hot water. Put up, covered. See what is what tomorrow.
Thanks Butcher,
Oneal
P.S.
Really excited, anticipation is building, want to see what comes out of the sulphuric cell gold plated stripping and the krud filled watch band tops tomorrow when I drop.
If I can come out with a nice looking button (from this dirty stuff) you will probably hear me, as we say down south, give a loud (Holler) in Oregon.
Will let you know, got to go, going to get through this before I stop, even if I see the sunrise tomorrow morning.
Hopefully things will come out good, then I will feel more confident starting on the karat items.
Thanks a million Butcher,
Oneal

 

[Oneal58]

Hi Butcher,
That's the problem, if I had a piece of pure gold I would have used it a long time ago. I used what little piece of pure gold I had on a test. I hope to have some pure AU from now on though handy. Would have saved a lot of time.
Trying to warm up again, getting really cold out.
Thanks Butcher,
Oneal

 

[philddreamer]

"That's the problem, if I had a piece of pure gold I would have used it a long time ago. I used what little piece of pure gold I had on a test. I hope to have some pure AU from now on though handy. Would have saved a lot of time."

Oneail, have you learned how to calculate the amount of acids required to dissolve your metals yet? If not, it would be a very good idea to learn now. It will cut down the time spent on evaporating the nitric.

To me, the "fun" of this hobby starts when I sit down with my scrap PM's, paper, pencil, my calculator & I start figuring out how much gold I could recover; then calculate how much silver for the inquarting & then how much nitric & distilled water for dissolving the base metals, & how much HCl & nitric will be needed for dissolving the gold, & so on.

Just my dos centavos!

Kindly,

Phil

 

[Oneal58]

Hi Phil,
I just learned how to calculate the quantities of chemicals required to refine X amount of gold this week Phil. I have been studying Hoke's Book again. Not just reading this time like I did the first time but studying it. Doing the test she recommends and trying to follow her to the letter.
Trouble is I have had this gold lot going for the past 3 weeks. I got into all the trouble before I knew what I know now.
But from now on you bet I will (not) add more chemicals than I should. I will weigh every single piece of metal and keep up with every single ml of chemical applied! I would rather re-process some of the material than waste my acid and triple my work.
Believe me when I say, I have learned my lesson.
Thanks Phil, I wish I had of listened better a month ago!
This I can say to all the noob's, listen to the people on this site, don't take any shortcuts. Why? Because they aren't any short cuts!
Oneal

 

[Oneal58]

Hi Butcher, or anyone familar with this process. I finally got down to my 3rd evaporation and had added my 3rd few drops of HCL. I evaporated for another hour after my last add of a few drops of HCL. I had nothing but black syrup in the vessel. So thick it would not even swirl in the container. I had added a few drops of HCL but I thought I had evaporated that off. I thought that the nitric and the few drops of sulphuric was long gone also. When I added water, (made sure it was very hot water) to this little bit of black syrup in my container I got a violent reaction with lots of brown fumes!! I think this was telling me that I still had an acid or a couple of different acids still left in that black syrup in the bottom of that container.
My question is, why did this happen? Should I have waited for the vessel to cool before diluting with hot water. I thought the acids were long gone, I had no reactions going on in the vessel and no smell of anykind. But when I put that hot water in there it started jumping out of the tall beaker. I am just glad I was using a tall beaker. Some still jumped out of the beaker. There must have been acids left in that black syrup that I missed somehow? Is this right? I am glad I was standing behind a partition I had made for just this purpose or it would have got me!
What did I do wrong, didn't heat the black syrup long enough to drive off acids. I was aware of this, but the syrup was starting to get hard, I had to stop Evaporating? Every indication said that the acids were gone? What happened, I do not want that to happen again!
Thanks, Oneal

 

[niteliteone]

Hi Butcher, or anyone familar with this process. I finally got down to my 3rd evaporation and had added my 3rd few drops of HCL. I evaporated for another hour after my last add of a few drops of HCL. I had nothing but black syrup in the vessel. So thick it would not even swirl in the container. I had added a few drops of HCL but I thought I had evaporated that off. I thought that the nitric and the few drops of sulphuric was long gone also. When I added water, (made sure it was very hot water) to this little bit of black syrup in my container I got a violent reaction with lots of brown fumes!! I think this was telling me that I still had an acid or a couple of different acids still left in that black syrup in the bottom of that container.
My question is, why did this happen? Should I have waited for the vessel to cool before diluting with hot water. I thought the acids were long gone, I had no reactions going on in the vessel and no smell of anykind. But when I put that hot water in there it started jumping out of the tall beaker. I am just glad I was using a tall beaker. Some still jumped out of the beaker. There must have been acids left in that black syrup that I missed somehow? Is this right? I am glad I was standing behind a partition I had made for just this purpose or it would have got me!
What did I do wrong, didn't heat the black syrup long enough to drive off acids. I was aware of this, but the syrup was starting to get hard, I had to stop Evaporating? Every indication said that the acids were gone? What happened, I do not want that to happen again!
Thanks, Oneal

Oneal my friend,
Glad to see you are still working on getting this done the right way.
I've been following you but have been quiet since Your in good hands that know more than I do.

It looks like your process of evaporating down to remove excess nitric is not quite right. In this process you are not removing acids. You are only evaporating excess nitric acid out of solution. All others must stay in solution.

From what I have read you are evaporating to far. you want to stop before the solution turns to syrup then double remaining volume with fresh HCl.
(example) You start with 800ml solution. Evaporate down to approx. 200ml. them add back to solution 400ml fresh Hcl. do this 2 more times with 400ml each time. (not a few drops)

Let the solution cool some before adding any water as hot acid solutions are more reactive than cool solutions. Then add the water slowly 25ml at a time. It is not a good thing to add water to concentrated acid to begin with ( as you saw what usually happens) and since your solution was super concentrated from all the evaporation and not enough HCl addition, You had a loaded canon waiting to go off.

Reread Hokes book on evaporating excess nitric and write down the proceedure so you have it at your bench when you do this the next time. it's a good thing you had that shield to stop the acid from splashing on you.

Hot super concentrated acids are really dangrous and We don't like it when our family gets hurt. again I'm glad you are OK. Be careful.

I hope I got this right if not can anybody correct anything I got wrong so i can learn the best way too.

Goodnight Oneal and all.
Tom C

 

[butcher]

Oneal,
Here is my take on the situation, when solution is first made you had water, HCl, nitric, gold, (possibly silver lead and some other base metals).

When you first begin to evaporate the majority of vapors is water (and gases of reaction), then as you proceed and most of water is gone then the nitric vapors come off, the nitric in solution concentrate (with HCL), when nitric and HCL get concentrated nitric fume are much more concentrated (I believe this is the point nitric will boil over if temperature is not lowered then when most of the nitric vapors off), not all of nitric escapes as I think a portion will azeotrope with HCL), then HCL also concentrates (gold bonds most of the chlorides as a gold salt) any free HCL will vapor off leaving gold salt solution. if driven to dry powder I believe the gold would reduce to metal as the chloride gases off, (but some gold would also become volatile in these fumes and vapor a good portion of valueable gold up in smoke).

The above description is way overly simplified (to give an idea of what happens). The fumes are not purely one gas, and there are combinations of gases forming and escaping.

Now I did not mention the sulfuric acid you added, sulfuric acid has a very high boiling point, and will not evaporate with the temperatures your using.

I think you may have added more H2SO4 than needed, and you went down to a very thick syrup, with your gold chloride salts so most all of the free HCl was evaporated and you concentrated the sulfuric acid solution (gold salts) then you added water to concentrated sulfuric acid.


Now think about the rule about adding water to concentrate sulfuric (and warning how it is so violent of a reaction).

Here if you had added some HCL (20%HCL in which 80% is water), you would have diluted solution and the sulfuric acid, so water reaction might not have been so violent.

Just a little too much sulfuric, and maybe a little thicker syrup than necessary,

Live and learn?

This is just my thinking (not being there and seeing),

 

[Oneal58]

Thanks fellows, I appreciate your help.
I will go back through HOKE'S Evaporation Process (again) before attempting anymore. This scared me, I could have easily been laying up in the Hospital today?
I have taken a couple of pictures of what is left of the solution. It is not nearly as concentrated as it was before I started. It was so yellow I could not even see through it in the beginning. I fear I lost a lot of values in the, now what I call an explosion. How this small coffee pot stood up to the reaction I have no idea, but glad it did. I have some of the solution in the bottom of my dish, floor, wall, partition, Etc;. How do I recover the solution that is in the dish? If I mop it up with filters and just put into my next AR Batch?
This is my question, take a look at the center of the vessel, in the bottom of it. It looks like a mound has formed. Is this mound made of gold there, it sure looks like gold. It is sitting among whitish powdery looking material, probably more tin, lead, Etc;. But this mound, what is it, is it gold that participated out somehow in the reaction. I got you a picture of it, it puzzling me?
Oneal

 

[butcher]

Oneal58,
That is a nice yellow color; looks like you have done a good job of removing the base metals. I am impressed.

Yes it is most likely gold in the bottom of the beaker, gold will not dissolve in sulfuric acid, and when you evaporated to thick syrup you removed most all HCl, and maybe a portion of chlorides that were locked up in gold salts, these chlorides may have exploded off in the violent reaction as chlorine gas when your beaker erupted by adding water to the concentrated sulfuric acid and gold chloride solution, thus reducing to elemental gold.

The other impurities in this gold in the bottom of your beaker can be washed out or the majority of them can be.

I would decant the yellow solution from these gold and impure powders; the yellow solution will hold more pure gold. And we do not want to precipitate the purer gold in solution into the (now reduced gold and lead and silver salts).

After washing the powders (the gold in bottom of your beaker we can return them, to the other gold you will precipitate from this solution later).

After decanting (decant and filter yellow liquid into clean vessel). You can precipitate gold from this pretty yellow liquid. (Wash any precipitated gold using Harold's instructions.

Leave gold powders now reduced in your beaker (gold, silver chloride, lead salts in beaker), add water and boil (raise temperature to boil slowly, we do not want to thermally shock the glass), after boil lower temperature so powders settle well (no moving action from heated beaker stirring solution), then we will decant the solution (lead Chloride dissolved in hot water, precipitates out as white crystals when cool). May need to repeat depending on how much lead we need to wash out.

Now these powder contain gold and silver chloride (here we could re-dissolve gold to remove it from silver chloride, (OR) dissolve silver chloride from the gold, I would choose to dissolve silver chloride,

(But to do this you must follow directions closely as silver compounds in ammonia can be dangerous if allowed to dry), keep wet and acidifying make them safe),

Add ammonium hydroxide to gold and silver chloride salts (household ammonia), (real ammonia is better but harder for me to get), heat solution but (DO NOT COOK DRY). The heat does not need to be too high as ammonia will gas off at low temperatures, this solution will change silver chloride salts to a silver Amine solution (silver will be soluble and we can be wash the silver from the gold), decant this warm solution to clean jar, let it cool in this jar (you may have picked up some gold (which will settle) if so we will separate these.

Silver in this silver amine solution is precipitated by adding HCl, (this acidifies the solution making it safe), this gives you back your silver chloride powders, the solution becomes Ammonium chloride solution (I save all my ammonium chloride solutions to make salts later).


Hot water rinses help in washes.

(What we have done here is very similar to Harold’s washing of gold powders)

I did not give all of minute details here but a general overview of how I might approach this.

 

[Oneal58]

Hi Butcher, thank you for the compliment. I don't want to get my hopes up again just yet though. I have been too confident a couple of times prematurely already? But thanks Butcher for the much needed encouragement.
I am just getting back in today. Had something to take care of this afternoon. Going out to start back up again. Will keep you informed of progress.
Thanks Butcher,
Oneal

 

[Oneal58]

Hi Butcher, or if Butcher is busy anyone who has an idea what I am doing wrong?
I dropped the gold (SMB) and washed good several times in hot steaming water. I added HCL to powders 3 times and heated, decanted, wash, repeated. Last time I washed with distilled hot water several times before adding ammonium hydroxide. Decanted, rinsed several times with steaming hot water. Then 1 final wash in HCl/BOIL decanted rinsed several times with hot steaming distilled water.
Each time the solution would get low I would get this loud popping in the beaker. The Gold is popping like popcorn, I have to keep the beaker covered because the small pieces of gold will jump out the beaker. Sometimes a little nugget will surprise you and shoot off with a loud noise?
I feel that I may have acids (HCL) locked up in the gold somehow or I used too much (SMB) to drop with and it's locked up in the gold? But I washed and heating many times? When heated these pockets of gas/acid are exploding. Every once in a while 1 will pop to the extent I am afraid it may break the beaker I have the gold in? Every picture of gold I have seen on the forum looks like powder after being dropped. The gold that I dropped has very small nugget like structures (characteristics) to them? Why is that?
Am I on base here and what do I do, keep heating untill the popping stops completely?
Thanks Butcher,
Oneal

 

[Oneal58]

Hi Butcher, when melting your gold button. Do most refinners use Borax on this forum? I know it depends on how particulate/crud you have floating on your gold. If your gold is pure enough though that you have no crud. Doesn't the button pick up the borax on the bottom of the button from the melting dish anyway? You have to use warm sulphuric to get this coating of Borax off after the melt, how long does this usually take, to get the Borax off and is there an indicator that will key you in when the Borax is gone.
Thanks Butcher,
Oneal

 

[qst42know]

is there an indicator that will key you in when the Borax is gone.

The borax glass will go milky white and fall off.

Gold is popping like popcorn, I have to keep the beaker covered because the small pieces of gold will jump out the beaker.

Drying too fast causes steam explosions to eject some of your gold. Low heat till mostly dry would help, then drive it hotter.

 

[butcher]

Oneal,
STOP WET THE POWDERS.
Remove from Heat.

You may have made a fumilate,
It does not sound like you have followed Harold's wash procedures correctly.

If this is the case you may have made a very dangerous substance.


The ammonia (metal compound) should be made some what acidic and washed.

Get this into a safe condition or stay away from it.

We can discuss this further later.

 

[Oneal58]

Hi Butcher, checked back over Harold's instructions. I followed them exactly. I cut heat down to a simmer, reaction stopped.
I just got through melting the gold button, didn't use any Borax on it. I didn't see any type particulate or crud on top of the button and went ahead and melted it. I counted to 5 mississippi,is that enough? Picked up the button out of the melting dish and went for the water. The button stuck to my pliers and I missed the water. The button landed on the floor, I picked it up again and made it to the water this time but it was already cooled down.
The buttom looks terrible because of this.
Can I re-melt the button again, causing no harm and maybe using a little Borax this time? Pictures of the ugly button is below. It should have been 5 times bigger but as all of you know I lost a lot of values on several occasions. As Butcher said it, LIVE AND LEARN. I know I can do better the next time, I have already started on another batch. I have developed this fever this afternoon but I don't feel sick, wonder what it could be?
Will it hurt to re-melt it to get a better looking button?
Thanks, Oneal

 

[butcher]

Oneal, you scared the crap out of me, I thought you were in danger, with that gold exploding after adding ammonia.

Edit: Well after cleaning my pants, and looking at your button Good job.
please do more study before making any more gold buttons, I sure would hate to see something happen to my friend.

 

[qst42know]

It looks pretty good even roughed up.

Save the button to add to the next melt.