# Stuck solution



## cly9412 (Dec 21, 2011)

OK I have processed about a pound or 2 of ceramic cpu's in 1500 ml of poormans ar.I have allways been sucessful doing this but this time it's stuck.No i didnt use nitric to get rid of the waste meatles first.But it has always worked fine.What is the process for evaporating down the solution and if that dosent work.What is the process for cementing all the meatles out and starting over.


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## ericrm (Dec 21, 2011)

put copper in until nothing disolve anymore
test with stannous to be sure
beware your gold will probably be black powder at the bottom


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## Harold_V (Dec 22, 2011)

cly9412 said:


> OK I have processed about a pound or 2 of ceramic cpu's in 1500 ml of poormans ar.I have allways been sucessful doing this but this time it's stuck.No i didnt use nitric to get rid of the waste meatles first.But it has always worked fine.What is the process for evaporating down the solution and if that dosent work.What is the process for cementing all the meatles out and starting over.


How do you know it is *stuck*? I saw no mention of testing with stannous chloride. How do you know if you have gold in solution? Don't you think you should make that determination before you spend time evaporating? I sure as hell would. 

This may just be the experience you need to understand that your ignoring the removal of base metals isn't smart. 

Harold


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## cly9412 (Dec 25, 2011)

Harold_V said:


> cly9412 said:
> 
> 
> > OK I have processed about a pound or 2 of ceramic cpu's in 1500 ml of poormans ar.I have allways been sucessful doing this but this time it's stuck.No i didnt use nitric to get rid of the waste meatles first.But it has always worked fine.What is the process for evaporating down the solution and if that dosent work.What is the process for cementing all the meatles out and starting over.
> ...


Harold.I didnt mention it but I have checked it with stannous cloride and it has a positive test.I did the math on the cpu's that I had and there should be atleast 2 to 3 grams in my solution.


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## cly9412 (Dec 25, 2011)

What if I put to much water in it.Should I evaporate it off and then add fresh muratic in it and try droping the gold again.And if that dosent work cement with copper.


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## samuel-a (Dec 25, 2011)

cly9412 

Let's strat over...

Please tell us exactly, how many cpu's did you process? 

What type of cpu's?

Did you use heat?

how much of each chemical did you use?


This way, we could estimate better what happend (or didn't) and help others that may find themselves in similar situation.


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## cly9412 (Dec 25, 2011)

Ok I had 6 crix 686 that should have .18 gr of gold in them.I had 6 Intel's that have .48gr in them and there were about 10 pentiums that have .10 gr in them.Any that had a gold back on them I took the back off and did'nt put in the solution.
Then I used 1500 ml of muratic and 3 oz of subzero.I let them set overnight.I did not use any heat while they were dissolving.The next day when I checked the solution all the parts had not dissolved so I poored off the solution and set the undissolved parts to the side and continued the process with what had dissolved.
After pooring off the solution in was dark green just like it has allways been because of the other metals.Then I used a buckner funnle with a hand vacume pump the filter.Once it was filterd I put it into a 3000 ml beaker and heated it up to a light boil.Once it had a light boil I used urea to nutralize.After I had put several hand fulls of urea in.It keep fizzing so I added probly 8 to 16 oz of water and then another pinch off urea.The fizzing finaly stoped.
Then with heat applied I added 2 oz of storm persiptant.There were no brown fumes so I reduced the heat and let it set overnight.When I went out the next morning I tested the solution with my SC and it turned a brownish black like there was still alot of gold in it.So I poored off the solution and no gold had fell.The only thing that had fell was the urea and storm no brown mud.Now there is some black mud in there.I know my process is'nt the correct way by leaving in the unwanted meatles but it has allways worked for me.I'm wandering if it is the colder temutures that is effecting it.One other question besides the obvious problems. Is should shold I filter then add urea and test for gold.Or should I add urea then filter and test for gold?


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## samuel-a (Dec 25, 2011)

First thing.
I really dislike the usage of the word "should" when it comes to yields... This leads to fixating. IMHO...




cly9412 said:


> The next day when I checked the solution all the parts had not dissolved so I poored off the solution and set the undissolved parts to the side and continued the process with what had dissolved.



That's a first sign.
If not everything had dissolved, it'smore then likely the majority of the gold that did dissoved at first, had cemented back.
Heat would probably have prevented that and help dissolve everything at first shot.



cly9412 said:


> After pooring off the solution in was dark green just like it has allways been because of the other metals.Then I used a buckner funnle with a hand vacume pump the filter.



That's the point where you need to test with SnCl for the first time.
If positive, values are in solution and maybe in solid form (*black *powder, if not everything had dissolved)
If negative, vlues are in solid form in form, probably in main vessel and in the filter.



cly9412 said:


> Once it was filterd I put it into a 3000 ml beaker and heated it up to a light boil.



That's a sure way to lose values in dissolved form.
The De-NOx-ing process refers to a slow evaporation (122-140F) until a syrup like consistency is achieved and re diluting with HCl (repeated twice more).
Urea, in my mind is a sure way to get lost in the process.
To avoid the De-NOx-ing ordeal altogether, add your source of nitrate/nitric incrementally (while the solution is hot) until all metals dissolve.
That way, the exess nitrates/nitric left is negligible and will not bother you further down the process.



cly9412 said:


> When I went out the next morning I tested the solution with my SC and it turned a brownish black like there was still alot of gold in it.



In my mind, you are seeing a false positive result.
Have you read this article? 
Stannous Chloride – Test For Gold, Platinum and Palladium Presence
Check it out and try to determine what you are seeing in your test.

All in all, i think you have no gold in solution, or very little of it.
If you allow the solution to sit for few days, any gold that had been in solution will thinly coat the bottom of the flask, i see no reason why not.
As to the left over solids (and filter), try and run them again in dilute AR and test with SnCl.


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## cly9412 (Dec 25, 2011)

OK I read your link and the test I'm getting is a deep brown just like the picture.My other test have allways been black.So mabey it's a false test.As for the cpu's that were undissolved I just added fresh muratic and more subzero they are all dissolved now.
Mabey that where all my gold still is.


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## cly9412 (Dec 25, 2011)

samuel-a said:


> First thing.
> I really dislike the usage of the word "should" when it comes to yields... This leads to fixating. IMHO...
> 
> 
> ...


I think your right.I just went out and tested my stuck solution and the color is really brown.And is fading slowly.The undisolved solution was completly dissolved so I put it in another beaker and tested it.It is so purple it's almost black.Thats where my gold is.Answer one other question.Should I filter the solution then add my urea or use the urea and then filter.I have allways filtered then added urea.


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## jimdoc (Dec 25, 2011)

Wow more problems with subzero, "storm persiptant" and urea, Shor sounds familiar.

Jim


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## cly9412 (Dec 25, 2011)

jimdoc said:


> Wow more problems with subzero, "storm persiptant" and urea, Shor sounds familiar.
> 
> Jim


And I'm not a total rookie.I have had very good luck this summer but seem to be having issues now.I dont think it's the product as much as it's my misstakes


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## samuel-a (Dec 25, 2011)

cly9412 said:


> Should I filter the solution then add my urea or use the urea and then filter



Doesn't really matter.

Though, probably better doing this before filtering.

The chemistry of Urea is quite interesting, though i'm not sure i fully understand it to provide any useful input at the moment.


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## cly9412 (Dec 26, 2011)

samuel-a said:


> First thing.
> I really dislike the usage of the word "should" when it comes to yields... This leads to fixating. IMHO...
> 
> 
> ...


Thank You Very Much for your time and breakdown of each part of my explanation.Thats what I needed.


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## niteliteone (Dec 26, 2011)

cly9412
Do you filter the urea before you add it to the AuCl :?: 

If not, are you *SURE* it is pure :?:
What happens if the urea doesn't dissolve completely :?: 
Then you would have to get it all out with your rinses. How do you know you got it all :?: 

Any time I add anything to my AuCl solution (except SMB) I will always filter my solution before I drop my gold from solution.

I always try to get my gold as pure as I can so that means I need to remove anything that might cause a problem before I drop my gold.

Hope this helps. 8) 
Tom C.


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## Dr. Poe (Dec 30, 2011)

When I use urea to rid the solution of nitrogen, I heat the solution first to 160F. I add urea a teaspoon at a time. Once it disappears, I test with a single bead. If the bead reacts, I add another teaspoon. I repeat this action as many times as is needed. I've never had much success using urea in cold solutions. If you need the solution to be cold, have the patience to wait an hour or two after dispelling the nitric.
Dr. Poe


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## butcher (Dec 30, 2011)

In my mind if you need urea for much more than fertilizing the grass your doing something wrong.


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## nickvc (Dec 30, 2011)

butcher said:


> In my mind if you need urea for much more than fertilizing the grass your doing something wrong.




It can have it's uses and I used it extensively when I was refining commercially because the information now so freely available on here just wasn't easy to come by. I refined much on a toll basis but fast returns of metal were required and frequently in karat form so speed was of the essence, not sure I'd use it now I know better but it was a case of needs must at the time. Even now with some jobs where you have an unknown amount of values to dissolve and over use of nitric is almost inevitable I will use it, it's never caused me problems and for speed it's hard to beat unless you have a few buttons spare to consume the nitric but for most of the processes talked about on the forum I agree it's use is for just testing to see if all the nitric has been used before attempting to precipitate your values or whether evaporation is needed.


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## butcher (Dec 30, 2011)

I used urea a lot when I first started recovering and refining, I also learned a lot of other bad habits back then, until I realized the common sense in what GSP and Harold have taught, I kept a baby food jar full and may still use a prill for testing, but the sack of urea goes on my grass, even for fertilizer that stuff is not that great. :lol:

Edit to add: we all have our opinion this is just mine, but I think new members should really consider learning better techniques early in this game, and to start learning to rely on urea, in my mind is a big mistake and a bad habit I wished I would have learned long before I did, my opinion and I am sticking to it, use urea to fertilize the lawn and learn better techniques.


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## nickvc (Dec 30, 2011)

The killer punch I reckon is that nitric is expensive to buy and hard to make so why waste it.
As you said there are many better methods outlined here on the forum for people to follow that avoids it's use except perhaps for a prill to test with.


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## Harold_V (Dec 30, 2011)

nickvc said:


> butcher said:
> 
> 
> > In my mind if you need urea for much more than fertilizing the grass your doing something wrong.
> ...


All I can say is I refined for more than 20 years, strictly on a toll basis. _I never used urea once, nor would I endorse its use_. Following GSP's advice to use nitric sparingly, or using it according to a formula, then adding a gold button to consume any residual acid is what I endorse, and for reasons specified by butcher. I was never keen on the idea of adding ANYTHING to my solutions that wasn't necessary, right down to switching from ferrous sulfate to SO2 gas for precipitation. I truly believe that one learns better habits by learning to do it the right (hard?) way. 

Harold


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## Dr. Poe (Dec 31, 2011)

Like I stated before: Urea at 160 degrees F works, cold use of urea gums up the works and one single white bead is sufficient to verify no nitric in solution @ 160F. It's always best to do the math and use the least amount of nitric acid as possible.
But, tell me of a newbie that can do that. Dr. Poe


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## Harold_V (Dec 31, 2011)

Dr. Poe said:


> It's always best to do the math and use the least amount of nitric acid as possible. But, tell me of a newbie that can do that. Dr. Poe


Heh! That's pretty much how Hoke summed it up, albeit by choosing different words. 

The hardest lesson for the new guy to learn appears to be allowing acids to work until they are exhausted. It can be a slow process, certainly made worse by working without added heat. I learned, early on, that heating was my friend.

Harold


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