# AR in an unknown state, please help



## Korvhaal (Dec 15, 2010)

To start I am not a chemist, but I have never coward away from leaning something new and fancy myself a quick learner. I stumbled across Shor, International and started there. I used a SubZero + Muriatic AR to dissolve mostly CPUs and some components off of 2 motherboards. After a day of dissolving the PMs the AR was spent' I pulled a bag out that still had copper and some gold visible. Took my AR and decanted it into another bucket. Added Urea, it didn't really fizz much but I added a little extra, since I found on another forum that it wouldn't really hurt. It was about 35 degrees here in FL so I was not working in a warm environment. The directions from shor did not say anything about heating or dissolving he Urea before adding to the AR so I didn't. Placed SMB in bucket added about 1qt of AR and .......... SMB in bottom of bucket and AR test's with gold in it, still. Unfortunately, I continued to add SMB a Tbsp at a time until it was gone. It now resides in a cup by itself, as I decanted the AR like solution off the top to test a small amount. I am out of Urea and SMB and not sure if I can get it locally. My question is, finally, how do I get there from here. I have AR in a state I am unsure of about 1qt that is brownish and about 3qts that I have from trying to use the remaining SubZero pebbles in the bottom of the bucket that I only applied Urea to and it is the emerald color.
If I need more chemicals, beside Muriatic acid, please advise me where I can get them locally (type of store or product) as I can't have the chemicals sitting around for too much longer.

What a total noob. :roll:


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## lazersteve (Dec 15, 2010)

Dark brown or chocolate colored solutions usually are negative for gold due to base metal saturation, but you can not be sure unless you test with stannous chloride. The fact that you have visible gold in the mix tells me your AR is depleted and any gold that was initially dissolved has likely cemented out as a dark coffee grounds colored powder.

Add a solid buss bar of copper to the brown colored solution and see if any powder accumulates on it overnight. 

My advice is to stop using urea and to start controlling your nitrate additions so you don't have NOx (nitric oxides) left over in the solution. Try the reaction using muriatic acid and sodium nitrate on a small scale just to help you become acquainted with the reaction and how to recognize when it is finished reacting. There should be no metals remaining in the reaction once the job is done and the AR should test positive for gold (if any was present on the scrap) to stannous chloride. 

Steve


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## Korvhaal (Dec 15, 2010)

Sorry, I have 2 different states of AR. One that has no particulates at all just brownish liquid that tests + for gold with stannous chloride, I believe that is what it is, came with the shor kit and has the same color indications.

the other AR is emerald and has floating bits in it that I have not finished processing due to shortage of nitric acid substitute.

But from what you are saying, I need more nitric acid? and try to reprocess some the brown failed to precipitate AR? I am asking also, what is believed to have gone wrong so I can not repeat it on the unfinished solution.

Thanks

PS is there a local source where I may get sodium nitrate ie, fertilizer or hobby store chemistry set?


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## lazersteve (Dec 15, 2010)

Korvhaal said:


> .. and try to reprocess some the brown failed to precipitate AR? I am asking also, what is believed to have gone wrong so I can not repeat it on the unfinished solution....



If you have added the precipitant to the brown solution before testing you are possibly getting a false positive reaction which produces a brown color , not a purple one.

A photo of the test results and the solution would help.

Steve


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## eeTHr (Dec 15, 2010)

korvhaal---

For anyone to recommend local chemical sources, it would help to let us know what your "local" is. You should put some indication of country or state in your personal section.


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## Korvhaal (Dec 15, 2010)

My location is Brevard County Florida about an hour and 20 mins southeast of Orlando


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## Korvhaal (Dec 15, 2010)

The next stupid question, is the SBM that I wasted in the batch, spent? or is the whitish residue on the bottom still usable. If I were to guess, I would say the whitish solids on the bottom is sodium.


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## eeTHr (Dec 16, 2010)

I would think that, since SMB dissolves in water, and that, unless you added so much that it went beyond saturation, that it is not SMB on the bottom. At any rate, I doubt that it would be recoverable if it was. And it's not really worth trying.

I would decant the solution, first of all. And then re-test it with stannous chloride. If it still contains Au, go about getting your Au out of it.


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## Korvhaal (Dec 19, 2010)

I retested the AR and it is white, obviously, silver present. I had at least 20 ceramic processors, so I know I had gold to start. I know, now why the precipitation failed. I should have researched more, but I was unaware the precipitating agent was the SO2, so I did not cover the bucket adequately. From what I am understanding from what has been said and what I have researched, I need to add more nitric and then raise the Ph again and re-precipitate. Am I on the right track?


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## butcher (Dec 19, 2010)

I am confused how you are determining silver in aqua regia?
a white powder can be many salts. lead, copper, silver, urea, tablesalt the list goes on. stannous will not test for silver.

Reread Steves post, as I understand He suggests cement with copper, and I agree, 
do not oxidize with nitric acid again,
slight acidic with HCl is helpful, if needed.

after cementing I would incenerate and treat powders as a base metal with some gold, starting over after I spent more time reading and learning the processes, gathering supplies, working with HOKE's suggestion's on getting aquanted.

It takes less time to study and produce gold than it does to try and recover from botched expieriments.


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## Korvhaal (Dec 27, 2010)

Sorry, thought I put in there I tested with stannous and it turns white every time and thank you all for your help. I have to research the cementing process. I am currently trying to get time to read Hoke's. Probably, should have done than over the Christmas break, back to the grind stone.


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## lazersteve (Dec 27, 2010)

You can watch a cementing video on my website in the silver section.

Steve


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## Korvhaal (Dec 28, 2010)

Okay, I have read a good portion of Hoke's, at least that which applies. I am working with all computer scrap. Mostly, ceramic CPUs some fingers and some pins. I still have a good portion of AR left over from my original batch that is saturated with precious metals. I finally, got some sodium bisulfite and again tried to precipitate it last night..... still no Au. Though, the process looked different, or I am seeing it different (more understanding). I ended up this time with a syrupy brown solution with a coke colored liquid on top and a white powder on the bottom. I am sure that the nitric acid is neutralized, I see no brown fumes and I have some Urea left and it doesn't react at all. My AR is not translucent and I filtered it twice. I am wondering if I have something in the solution that I need to get out of it before I can precipitate the gold. I have been watching different videos on Steve's website and YouTube and have seen nothing that compares to my solution. My wife just got a camera for Christmas, so I will upload a picture or 2. Would I want to remove the silver before or after the gold? Hoke's obviously, precipitates the gold first.
I am cementing the other batch as per Steve's suggestion, now.


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## Korvhaal (Dec 28, 2010)

Disregard the silver before gold question. I temporarily, lost my faculties. I am beginning to believe the nitric is still active. Pictures still to come.......


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## Anonymous (Dec 28, 2010)

I kinda of have the same problem. I am using black sand concentrates from panning and crushed ore. The area I am getting my concentrates and ore come from a very rich area. This area was a hard rock mine getting vein Au and placer pits. It is an inactive gold mine that supplied gold to a (now closed) mint during the 1800’s – early 1900’s. I know the ore and concentrates contain Au because I can see it with the naked eye, bright and shinny. There is also lots of micro Au you can see through a 10x microscope (bright and shinny). You can also see what I believe are gold oxides(?). These are a brownish with a somewhat goldish tinge for color. I have used Hydrochloric / Nitric 3/1. I have made several batches. I have heated some for hours. I have let the AR set in the material for up to a week. 
I just cover the material with AR. The AR turns a golden yellow it makes me think of a Canary. It becomes active and gets warm. I have steamed the mixture (material and AR) till about half gone. I added Urea until it no longer fizzes then I add a bit more and let it sit for 30-45 minutes. I test the Ph after the Urea. It tests about 1+. I use Caustic Soda to adjust the Ph up to about 2 – 3 )solution warms again. The solution is filtered again to remove any Caustic Soda that may not have dissolved. The solution is a maple syrup color when the Ph reaches 2-3. I add SMB (sodium metabisulfite) slowly and stir. I add about 4 tps to about half of a gallon of solution. The solution becomes thicker and more dense looking. It quickly starts to fall to the bottom of the container as a very light to burnt umber colored powder. I let it rest till it stops falling. I pull out a sample and it looks similar to what I think are the oxides in the ore / concentrates. I filter the solution from the precipitate. Dry the powder on a filter on a low heat 100 – 150 *F. When it dries I place about a Tbls in a cast iron pan with about a Tbls of Boric Acid. Acid melts with the heat from Acetylene torch. The mixture is heated until it is white hot and in a liquid puddle (small oval shape). The mixture melts down to just above half of the combined volume of the powder and Boric Acid. I place the cooled oval in a solution of HCL and wait. The HCL becomes active and bubbles from the mass. I bubbles away to nothing or if I look at the mass through the microscope you can see what look like golden strings and bubbles in the dark colored mass. It is sometimes a dark peach color. 
I have purchased Stannous Chloride and put a gram in 10-15 ml of HCL and warm the mixture. After the Stannous Chloride dissolves, I add 1/1 distilled water (clear). I let it cool and have tested the solution and powder. Each time the result is a yellow stain similar to the color of the AR just prior to the addition of the Urea. I can see it but cant get it.. I have ordered CW Ammen’s book “Recovery and Refining Precious Metals”. It is on the way. I have read almost ALL of the post on this site and have visited other sites and found the process I have described above. 
Any Help for me??
Sorry this is so long but wanted to make sure I got all of my steps in here.
Thanks 
Vlaw513


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## Harold_V (Dec 29, 2010)

vlaw513 said:


> Any Help for me??


Understand that this is not intended to be rude. 
Not a chance in hell. You are most likely processing nothing but garbage---so gold shouldn't be expected. Even if you have gold present, you may be losing it to cementation due to garbage that's included in the process. Hard to say without seeing what you're doing. 

Please do yourself a favor and read Hoke, so you understand what constitutes proper procedures. Much of what you're doing is a waste of time. And, be aware----processing black sand with acid tends to be a losing proposition----especially when what you think is gold is just mica. 

Before you jump to the conclusion that you are, indeed, processing gold bearing material, you'd be well served to recover at least one of the particles you consider to be gold and do a couple simple tests. One of them would be to crush the item. If it shatters, it's not gold. If it flattens, and stays intact, it likely is. 

If you think it is, dissolve it in a test tube, using just one drop of nitric acid, or even less if it's small. I mention a small amount of nitric because too much interferes with the stannous chloride test that will follow. 

Back to the drop of nitric, include no less than three drops of HCl, and four would be better. Heat gently, but do not boil. If the item does not dissolve, it likely isn't gold. If it does, the resulting solution should take on a nice yellow color, and if there's silver present (alloyed with the gold) you should see a white cloud form in the solution. The solution may also shift green if there's copper present. When the particle is dissolved, test a drop of the solution with stannous chloride. If you have gold, it will be displayed as a pink through purple/black reaction. It may or may not last, depending on the amount of free nitric that remains in your solution, so use a bare minimum, as I suggested, and give it time to do its work. 

If you do not have stannous chloride at your disposal, you are working blindly and wasting not only your time, but ours. Be damned sure you have stannous chloride. 

Might not hurt to report what you discover. 

Harold


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## Korvhaal (Dec 29, 2010)

Is a brown foam "head" when you apply the SMB or in my case now, SB the same as brown fumes? Also, I found a chemical with Sodium Bisulfite that has Sodium Hydrosulfite, as well, will that work as a precipitant or will the Sodium Hydrosulfite interfere? From my calculations it won't, but I was hoping for a more experienced opinion.

Thank You Steve, I watched your videos and I am cementing the first failed precipitated portion of the batch and I am also using the AP on some fingers to get some margin of success from this new venture. :lol:


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## Anonymous (Dec 29, 2010)

Thanks Harold_V.

Just getting started with this. I ordered the Stannous Chloride from a chem comp. I've been crushing the ore to 100and processing it..


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## Anonymous (Dec 29, 2010)

Harold, 

You mentioned testing the particulates. I have taken the ore that contains the shinny stuff and put Nitric on them and placed them in a heated environment . The shinny stuff does not dissolve. I have looked at them through the microscope prior to, during and after the application of Nitric. I can see the surrounding stuff dissolving and no reaction to the shinny stuff. I have seen mica and pyrite(s) in the ore and concentrates they are crystaline and are brittle when punctured with a needle. They also dissolve in Nitric. The particulates I see that are what I believe is Au DO NOT dissolve and are not brittle. The concentrates (black sand) contain smooth slivers of flour Au. I have tested these in Nitric. No reaction. The particles I am looking at are VERY small but the concentrates are FULL of these types of particulates. I do not see where my process is a mess. I appreciate constructive criticism and guidance. I do not see where the "mess" could be coming from. The solution has been filtered several times. I have CW Ammen's book on the way to read. 

I have geological surveys and assays that date back since production started. I have recent surveys and assays. I have work product notes from several different foremen that worked at the location. The tailings are what I am working with that during production it was not worth while to process. Now, according to the most recent survey, it is likely worthy to process. 

You are likely correct that I have made a mess with my solution. You are likely correct that the ore contains mica and pyrites, but I assure you that the area I have access to is unique in its geological structure and is unique in the quantity of Au and Ag that is present. I would like to further this conversation with you privately. I see that you are very knowledgeable in this field and are likely an expert. I have read many of your post and see that you are not fooled by someone just posting. If you would be interested in communicating further privately, please feel free. 

Thanks Again
VLAW513


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## Harold_V (Dec 29, 2010)

I am not exempt from being wrong, and I'm always open to more information that may clear the air. 
Sadly, I am not an expert, although I have had many experiences that parallel this one. 

As suggested, I will take this to PM's. 

Harold


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## Korvhaal (Dec 30, 2010)

I believe, I have precipitated my first batch of gold  . My feeling that the nitric was in fact still active was correct. Thank you all for your help and I will be here mulling around if I can be of help from my experiences.


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