1st Attempt at AR on Ceramic CPUs

[cejohnsonsr]

Hi butcher. I think I'm finally starting to get he hang of this. After looking at your list at the bottom of your reply, I see that I did the 1st one right. I used minimal Nitric. Only 1.5 ml. I think I'm going to have to use sulphuric because that's what I have on hand & I really can't afford to go buy sulfamic. But that should be ok if I understand correctly. I'll just add 4 or 5 drops to the solution when it's evaporated down enough the 1st time. (That may not be right, but I'm printing your last response as a guide while I'm working.) Now my question is, should I go ahead & decant the solution & all the sediments before I begin evaporation or should I just leave all the original material in the beaker & decant after the 3 evaporations?

Ed

Edited to add pics & further comments

I hope you can see these pics ok. I took 1 of the beaker so you could see what I have. Another from the top. There is some scum floating on the surface. I'm not sure if it's copper or kovar (iron?) from the pins or maybe a little of both. There is a also a fine whitish sediment settled on the ceramic pieces. The Q Tip shows the results of the Stannous test. You can see very dark purple near the end of the stick part. The solution is now more green than yellow. The Stannous turned purple to black so quickly that I had to do the test twice & watch closely to see it. I'm hoping that's a good sign. I can also see just a little bit of undissolved gold on a piece of one of the wafers (the glass part from the center of the chip?) that is against the glass. The heat is turned back on. I'm using just a little more heat than yesterday to help it evaporate faster. I will not allow it to boil. Total volume in the beaker is 300 ml so I'm guessing I should evaporate down to about 150 or at least below 200. Then add just enough HCl to cover. Then repeat. Also, I'll add the sulphuric at the end of the 1st evaporation & stir before I add more HCl.

Ed

 

[butcher]

Ed,
Looks like you are doing great, You are getting a handle on it, your stannous test is proving two things, that you have gold in solution, and that you are not over using your oxidizer (nitric acid), Keep up the good work.

From this if you do keep up the good work you will not need the sulfamic to remove free nitric acid, I would still use the H2SO4, to help with the evaporation and for getting lead out of solution later, you would probably not need all three of the evaporation's, but I would do it any way, as it will be good insurance.

It kind of depends on the material I am working on how I do the process, if I can I do the dissolving and the evaporation with the undissolved material left in the reaction vessel, this first concentration can many times dissolve more values into solution, (sometimes when working with large volumes of powders this is not practical), I will normally decant from solids after I have removed oxidizer, through evaporation when possible, then dilute and let settle, it really would not matter which way you done it.

lets look at how much water we have in solution to get a guess of how much we need to evaporate off, we will figure our added water plus (the 32% HCl added has 68% water), (the 70% HNO3 has 30 percent water) and some water forms from the reaction, this volume of water would need vaporized off before our solution concentrates to the point where we would then be vaporizing off free acid, free acid is acid that did not react with the metals to make salts of the metals dissolved in solution, we normally try to have a little free HCl left, but we want to react all of our nitric if possible.

If you have much free nitric acid when you concentrate, you have to be careful of a boil over, which could result in your gold boiling over onto the ground, if you do not use a catch basin, even though you are not boiling while you concentrate your solution, the boiling point of acids change with concentration, and as the acids get concentrate (lose of water) they will come to a point of azeotropic acid (the most concentrated the acid can be and the point of further evaporation the acid make fumes of this concentration on further evaporation, when nitric acid gets to this point there is a subtle change in solution (you will only notice it if you are watching very closely at the point of concentration, and know what you are looking for, as you concentrate you may see some normal bubbling going on as waster evaporates, but once nitric becomes azetropic and just seconds before a boil over occurs, you will see many small bubbles forming at the side of the beaker where liquid meets air, when you see these tiny bubbles form lower your heat but continue to let solution evaporate free HNO3, after a while the majority of the free azeotropic HNO3 leaves solution and you can then raise back up your heat to continue your concentration as normal (this only happens with the first evaporation and when there is a fair bit of free nitric in solution. that the nitric azeotropes and tries to boil out of the heated solution seemingly all at once.

 

[cejohnsonsr]

Hi again, butcher. I posted an uupdate earlier, but I don't see it or the pic. After the 1st evaporation I added the sulphuric & a little while later (about 25 ml) it did start to bubble so I reduced the heat. Also some grey/black scum formed on the top. It almost skinned the whole surface & started to dry on top. When I gave it a swish & a stir it broke up. Looked almost like the ceramic materiel. Can that stuff digest a little bit? Anyway, it broke up & either sank or dissolved. It's gone now. But now there is some whitish/greyish scum on top. Almost looks like fractals or maybe salt? I don't know any other way to describe it. I'm working on the 3rd evaporation now. About 75 ml left to go. Then I'll decant through coffee filters. I'm guessing I should rinse the material with boiling hot water & check with stannous after maybe the 2nd rinse? Then I'll let it sit & settle until tomorrow. If it takes much water to rinse I'll evaporate a little off before I chill with a couple of ice cubes. After anything else (silver etc..) precipitates I'll filter again & drop with SMB.

Can't thank you enough for your help. I remember when I 1st started this batch I was pretty sure I had lost everything. I have a much better understanding of what has to be done now. And with gold prices so far down, maybe I'll be able to get my hands on enough good material to do a real batch or 2!

Ed

 

[butcher]

After you last evaporation and you turn off the heat I would add another splash Of HCl, let it sit covered, if you see something floating on top try a stir and let it settle if it will, after it cools and everything that is not dissolved settles then I would decant to another clean vessel, (no need to filter at this point), I use a suction tool and a small plastic pipette to transfer the liquid without disturbing the powders, after you remove this liquid give the remaining solids a dose of water and stir, let it settle again and decant this water into the vessel with your gold (we want 3 to 4 times as much water as we had gold solution, so add this volume to your gold solution, I let it sit overnight in the cold outdoors But you could chill it in a fridge if you wished, the silver and lead will precipitate overnight and the solution should loose that murky look and clear up, in the morning decant the solution from the white powders, filtering the solution into another clean vessel.

Do your stannous test, Bow your head, and pray for lots of gold, and precipitate your gold, smile and wonder at the brown powder which forms, let it sit (overnight if your patient enough), then decant the solution (testing it for values), grab your notes with Harold's gold wash procedure, do your hot washes, dry melt the gold, take a picture to show it to us, and then go out back and bury your gold in a spot in the ground you will not forget where it is for those hard times ahead.

 

[cejohnsonsr]

Well I don't know what to think now. I did as I said I would. Got a lot of sickly green looking mud on the filter. Solution is the same color but clear. A little white powder settled almost immediately. But stannous test is now negative. I don't get it. I tested at every stage & got strong positives every time. Now nothing. I don't know what to do now. Put it all back together? I don't know. The mud was the only thing that got a stannous reaction but I wouldn't call it purple. I'm stumped.

Ed

 

[cejohnsonsr]

I think I know what went wrong & I'm pretty sure it happened in the very beginning & it's my own fault. That sickly looking pale greenish mud in the filter is tungsten. The original batch of CPUs I broke up included a Pentium Pro & an AMD K5. Between the 1st run through AR, in which I used way too much Nitric Acid, the intervening spent sitting in 50/50 H2O/HCl & this final attempt in AR, the tungsten in those 2 heat spreaders completely digested. (Is that the right term for when the metal becomes powder?) Anyway, I bet that's what happened. Palladium mentioned this right after the 1st failed attempt. So, given my skill level (or rather the lack thereof) I guess my only options are to either hang onto this filter until someday when I might be able to separate gold from tungsten or, since there's not really much gold here anyway, throw the whole thing away consider it a lesson learned the hard way.

Anyone have any final thoughts on this subject?

 

[butcher]

Ed,
No need to panic, you still have your values; we just need to determine, where the gold is and what is going on.

I am unsure where you are, did you do all three evaporation's, did you evaporate them down far enough, before you decanted, did you then dilute and let everything settle overnight, before decanting again?

When you talk about having material in your filter it leads me to believe that you did it differently Than I do, I normally leave all insoluble material behind only decanting and filtering the clear liquid.

Can you fill me in on what you have done so far and maybe some more of the details, volumes, how far evaporated, colors...

There can be a couple of reasons your solution may not test for gold with the stannous chloride, you do not have gold in solution, or there is oxidizer remaining that will not let the gold reduce back to metal in the stannous test, another possibility your stannous chloride has oxidized and is no longer useful.

Reviewing a few things here,
You are working with CPU's that have base metals involved if all of the base metals are not removed, or they are not completely dissolved, they can reduce the gold back out of solution onto the remaining metal, or out of solution as powders.

When you concentrate your solutions acids and metals can form salts of that metal and acid, nitric for example can form nitrate salts, these nitrate salts when added to acid can reform nitric acid, this is one reason we need several evaporations to remove the nitric from solution.

If we do not take the evaporations down far enough, where we would not still have water in solution, or stopping evaporation while we still have dilute nitric acid in solution, we will not remove all of the free nitric acid, unless we bring the remaining acid down to its azeotrope mixture, and keep the evaporation going until most of that nitric vapors off at 68% nitric in the vapors and continue until all of the free 68% nitric acid liquid has left solution as vapor, before we add HCl (32% acid & 68% H2O), or we add water and re-dilute the solution containing free nitric, we will not get all of the free nitric out of solution during the evaporation process.

OK lets try to determine what is going on,

Lets take a small sample of solution, in a test tube of something we can evaporate the small volume down in, just working with a few milliliters in our test, (or we could just add a little sulfamic acid to a few drops in a spot plate and skip the evaporation process), we can evaporate this small volume much easier to see if nitric may be the cause, we can do the same three evaporation process again on this test solution, an electric hair dryer, a candle or small alcohol lamp can be used as a heat source for the test tube , or even a small coffee mug warmer electric hot plate and our ceramic spot plate can be used to do the evaporations and test in, we can use a pipette to add a drop to re-wet between evaporations, the idea here is to remove free nitric acid from a very small volume of our liquid and retest it with stannous chloride on a Q tip or with ferrous sulfate crystal in a spot plate.

We can test our stannous with our known gold solution to verify our stannous chloride is still working.

We can do a small test leach of the powders and remaining CPU, we can add these remains to our ceramic corning casserole dish, heat them on low heat till about dry add a few milliliters of HCl a few drops of NaClO (bleach), stir it up, just a little heat and then a few milliliters of water, and then test the leach with our stannous chloride on a Q tip.

 

[FrugalRefiner]

Anyone have any final thoughts on this subject?

Now you begin to see the wisdom of those who say take your time, study, read Hoke's book until you understand what she teaches, do the acquaintance experiments, start out with some small, test batches.

Many people like to quote Edison who said he learned a thousand ways not to make a light bulb through his mistakes. I say that if I study what he did, I don't have to repeat those mistakes myself.

Dave

 

[cejohnsonsr]

Hi butcher. Hope you won't take this the wrong way. I'm not giving up. I'll read what you wrote & respond when I'm able. But I'm not really able to continue for a little while. I'm a disabled veteran, in poor health, living on a fixed & very limited income. I had hoped that this might be a way to improve my means eventually. I had also hoped to at least be able to make enough to continue to learn. I put just about everything I had into this. Not that it was all that much. So far, after about 3 months I have 2.24 grams of impure gold powder & I've exhausted my resources. I really can't do anything else but read & study until I find some more $. One thing I can tell you is the stannous chloride is good. I just made it a few days ago. 1 gram tin powder & 30 ml HCl.

I admit to being more than a little disappointed with my progress so far, but I'm not giving up. I just need to back off for a few days & take stock. I'll continue as soon as I'm able.

Thanks for all your help. I really have learned quite a bit.

Ed

 

[butcher]

Ed,
I would not look at your situation at this point as a bad thing, sometimes when we get deep in a forest we may get lost in all of those trees, so many trees we cannot see our way out, if we tried harder to get out the more lost we can become, sometimes it may just be best to find a rock and just sit there a while enjoying the forest, then when we are not truing so hard to find the way out we see the sun and the trees shadow on the ground, then we realize when we came into this forest the sun was not in our eyes, it was warming our back along our hike into this forest, so when we are not struggling to find an answer the answer comes to us.

for me this is a hobby, not a way to make a living, with electronic scrap on a small scale, I do not see how you could make a living unless some one gave you tons of decent material.
I have told people who come here thinking the can make a living from electronic scrap that they could make better pay working at their McDonald's hamburger joint, this is not to say you cannot accumulate a little gold, some of these new members got mad at me for crushing their dreams of getting rich of of a few pounds of electronic trash, reminds me of miners with gold colored glasses giving up their good job, spending the last bit of their money on equipment to mine fools gold, and then taking it to a refiner and wondering why the refiner cheated them, and no matter how hard you try to tell them they are wasting their time mining that material they cannot or will not see it, they only see riches, they only see the trees in their forest and keep looking for a way out, but fail to sit quietly and see that ray of sunlight.

Backing off and sitting quietly for a while can be a good thing, you have a little experience under your belt now, and with more study, that ray of sunshine will shine on you, and when you are not, fighting to find the answer it will be revealed, as you know this forum and all of the information provided here can help with those answers, their are many ways a man could make use of what is learned here to help make his life better (refining electronic scrap may or may not be that answer).

Ed may the sunshine on you, and may you not be so busy looking for answer that you miss that answer.

 

[cejohnsonsr]

Thanks butcher. I appreciate that. I never expected to get rich doing this. Maybe to make a little $ & have some fun & learn something new. Believe it or not, there was a time when I was working in IS/IT when I could have had several hundred pounds of old memory,ISA cards & Pentium Pro CPUs just for hauling them away. If I had known then what I know now.......... I still think it's possible to make a little $ doing this. I just have to be much better at doing it. Like this batch for instance. I forgot all about the tungsten heat spreaders until right at the very end. And, for the life of me, I don't know why I didn't let it cool & settle before I decanted. Couple of long days, a little bit tired & I out-smarted of myself. I'm going to do like you said & just take a break for a few days then look around & see what I can do. I really do wish I could find some good scrap & be able to buy it for a good price. Sooner or later the VA is going to pay me the pretty penny they owe me. Maybe then I'll be able to afford to buy all the right equipment & do all the experiments from Hoke. I'd like that. In the mean time, I'm broke. LOL! But I can read & study. I've even seen a few posts from folks who made the same mistakes as me. I can help a little & that's a good feeling too. I'll be back in a few days as time & computer access allows. (Mine is still busted.)

Thanks again,

Ed

 

[steyr223]

Evaperate it all the way down .is that where the color
Changes to orange because of concentration
Add hcl to bring it back to yellow 3 times
Mine stays brown it never comes near orange

My material is still in the solution, i have taken
Nothing out almost 200 ic's that were quoted with
Confidence by lou to have .25-35oz /lb

Does anyone have an explanation.

Sorry if i sound frustrated but it seems everyone
Has a different way and just when i think i got it
I dont
Ive tried holkes no change ,butcher no color change
Harold wait till bubbles mark the spot turn it down a notch
And when it bubbles again let cool add hcl and do it again
Still no purple

Sam chimes in .i do what he say then never finishes
Im stuck on the middle waiting

I dont have an entitlememt attitude and you guys have always
Been great ,im definitely not upset with any members or the
Form, im just disappointed

I guess i will chalk this one up as a loss and when the og
Comes back then i will learn from your ptompt answers
Till then
I wish everyone riches of wealth and knowledge.

 

[butcher]

Evaporate it all the way down .is that where the color
Changes to orange because of concentration
Add HCl to bring it back to yellow 3 times
Mine stays brown it never comes near orange

I am guessing you are talking about the evaporation process to get rid of free nitric acid here, gold chloride solution is a clear yellow solution, if it is concentrated its color looks orange or even a red orange.
If your solution is brown it is because other metals like copper are in the solution.

Steyr223, I am having a hard time trying to figure out what your question is, or what you are doing, or having trouble doing, I can see you are frustrated, but I am unsure of what.

Sorry if I sound frustrated but it seems everyone
Has a different way and just when I think I got it
I don't
I’ve tried Hoke's no change, Butcher no color change
Harold wait till bubbles mark the spot turn it down a notch
And when it bubbles again let cool add HCl and do it again
Still no purple

Sam chimes in .i do what he says then never finishes
I'm stuck on the middle waiting

This sounds like you are having trouble De-NOxing an aqua regia solution, and are not getting a positive test for gold, which you are expecting.

We would need a little better understanding of where you are, and what you have done up to this point, and a little better understanding of what your question or concern is before we can help.

Sorry I just do not understand what it is you are having trouble with, or why.
Don't get frustrated, there is an answer, or a solution to the problem, you will find that solution easier if you are not frustrated.

 

[squarecoinman]

I think steyn is referring to this post

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=18197&p=183600#p183600

scm

 

[steyr223]

Sorry guys thank you
I found my gold 8)

Im not sure. How to link but i posted here

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=18197&p=183703#p183703