Fiber CPU's - That's how i do them

[Dude4ever]

but should I decant the water boil through a filter also?

Yes, the preceeding water wash and the following acids wash would be considered as one.

Remember that micron scale gold particles may easly be washed away, that's why, it is advised to filter any liquid that comes in contact with the gold.
Either filter it all, or combine all washes and allow to settle for few days, later siphon the majority of liquid.


Dude4ever, you are on the right track. I'm looking forward seeing your results.

Thanks Sam

Now I have filtered the solutions, and I came up with nice gold foils, some minor "debris" and some very fine black powder
I have read that this powder could be gold that got dissolved, and then re-precipitated because of copper saturation of the solution, comments?

Stannous test did not show any colour at all on the cotton swabs; I dipped the tip of the swab in the different solutions(3), it showed a yellowish greenish colour, when I dripped a drop of stannous (freshly made, chilled), it turned clear/white again and stayed that way

I have to take some pictures, my SMB hasn't arrived at the pharmacy yet but I will dry the foils and powder, and weight them before proceeding with AR. But what about just preparing a HCl-NaOCl solution, and pour it slowly over the batch in the filter? I need to get familiar with the AR process though.

 

[maynman1751]

I will dry the foils and powder

Dude! just keep the powder and foils in a little bit of water or HCl.....don't dry. Or, you could just go ahead and dissolve with HCl/Cl. I'm not sure if you will get complete dissolution through a filter. If you go that way make sure you rinse the filter well with water to get all the values. Then keep the filter for incineration later when you have enough to do.

 

[butcher]

What would I do is (crush foil tubes with glass rod, this also lets me know if these tubes are hollow or if they still have metals inside, it also helps to keep them from floating around), the powders and foils after rinsing well, incinerate them red hot but do not melt them, if you used a filter just burn it too, cool add HCl to cover and boil, dilute with just a little water (not too much) lower heat but keep very warm, let powder settle, and siphon off the liquid while solutions are hot. Then boiling water washes decanting hot, till color of liquid is clear.

The incineration would oxidize tin from solder, the HCl boil would help to remove base metals and tin oxides, the boiling hot water will also help to remove lead chlorides.
This helps to clean up the powders and foils before dissolving the gold, keeping some of the unwanted materials out of your gold solutions, and improving your final product.

HCl and bleach would be my choice to dissolve the fine foils.

 

[Dude4ever]

OK, interesting.

So if I understand what you mean correctly, first crush up the foils, then I should burn the filter and incinerate the foils and the ashes, and then add everything to a flask and HCl - boil - siphon, then water boils and finally dissolving?

In my other flasks that I poured the excess leach of acid/peroxide into, there were visible tiny gold flakes that floated around, I tried at first to carefully siphon out most of the liquid to ease filtering, but flakes did come over, and that flask stood untouched for 2 days before this. Would not crushing the foils make the siphoning a pain in the a** regarding the tiny flakes?? And with the ashes and all in the solution, wouldn't it be hard to spot if this happens?

This is a very small batch, so I think the burning of the filter is unnecessary - this time (Heard of ash-free filters? expensive, but it turns only to gases when combusted)
But guys, what about spraying the filter clean into my flask with water and dry it so I can put it somewhere for incinerating (Can I use a butane torch?)?
Then wash it with acid and water, and then dry it and weigh it? I have a pocket-diamond-scale that measures 0.000g with a tolerance of 0.002g, so I want to weigh larger and larger batches, and log the results before and after dissolving and precipitating.

Thanks ;-)

 

[butcher]

Gold is heavy even as powders or foils, and tends to sink, the small tubes from the pins can hold air or gas this is why I would smash them (less likely to try and float), oils (even from your fingers, or dirty glass ware) can make gold float, incineration helps as well as clean vessels, surface tension of water will sometimes allow small flakes of gold to float, a fine mist from a water bottle will usually sink these.

If you do not want to burn the filter now you can clean the filter paper off into a vessel (but I would save the filter paper to burn later).

If all you have is a tiny bit of gold I would save it up until I got more, I feel tiny amounts of gold through the processes are more of a chance to lose small amounts, than processing one Larger batch.

 

[Dude4ever]

Here is the results so far:



Big question: Can I incinerate this batch inside a erlenmeyer? (my research suggests that borosilicate glass can withstand 500 degrees celsius for a short period of time).
This does not seem like enough heat to me, but maybe sufficient to remove the impurities?

 

[Geo]

dont incinerate in borosilica glass. use either steel or pyroceram bakeware. pyroceram includes Corningware white casserole dishes with flower patterns.incineration involves heating material to a red hot state for a prolonged period of time.borosilica glass will melt at those temps.

 

[Harold_V]

dont incinerate in borosilica glass. use either steel or pyroceram bakeware. pyroceram includes Corningware white casserole dishes with flower patterns.incineration involves heating material to a red hot state for a prolonged period of time.borosilica glass will melt at those temps.

It won't melt (although that depends on the heat source)---it melts at a much higher temperature (well in excess of red heat), but it isn't stable. It suffers from thermal shock and is readily broken by uneven heat, in particular if the cross sections are quite thick. That's why beakers are made thin, and of relatively uniform cross section.

Harold

 

[Geo]

dont incinerate in borosilica glass. use either steel or pyroceram bakeware. pyroceram includes Corningware white casserole dishes with flower patterns.incineration involves heating material to a red hot state for a prolonged period of time.borosilica glass will melt at those temps.

It won't melt (although that depends on the heat source)---it melts at a much higher temperature (well in excess of red heat), but it isn't stable. It suffers from thermal shock and is readily broken by uneven heat, in particular if the cross sections are quite thick. That's why beakers are made thin, and of relatively uniform cross section.

Harold

thanks Harold, i was taking a stab at it. i know that the glass tubing i use is borosilica glass and it melts at around red hot, i guess it melts due to its smaller diameter. ive never tried heating a beaker that hot and hopefully i never will.

 

[butcher]

don’t incinerate in borosilica glass. use either steel or pyroceram bakeware. pyroceram includes Corningware white casserole dishes with flower patterns.incineration involves heating material to a red hot state for a prolonged period of time.borosilica glass will melt at those temps.

Good stab at it Geo, I agree the borosilicate vessel would be a mistake to use for incineration, I believe you also meant to say stainless steel pan (not regular steel).

I do most of the process in the pyroceram bake ware (corning dish), from incinerating washing and dissolving.

Thermal shock and uneven heating of glassware, makes this grown man cry when he has gold in the glassware.

 

[Harold_V]

thanks Harold, i was taking a stab at it. i know that the glass tubing i use is borosilica glass and it melts at around red hot, i guess it melts due to its smaller diameter. ive never tried heating a beaker that hot and hopefully i never will.

You're actually not far off the mark. It softens @ 1,510° F, but suffers from thermal issues, as I said.

Here's some useful information.

http://en.wikipedia.org/wiki/Borosilicate_glass

Harold

 

[JesseSShaw]

I am new to collecting precious metals from scrap. Since I am out of work and have no income to speak of, I had to try something. This seemed like it could provide some income for me and my family. I figured it is worth a shot since I have basic, scientific comprehension and learn quick. I decided to try this method for fiber CPUs first since it requires only HCL and the method is pretty straight forward. Unfortunately, it didn't work for me. I used 15ml of HCL per gram of pins instead of 12ml. I boiled for three hours each time as suggested. I went through the same process four times until the solution would not saturate any longer. Yes, four times, trying to dissolve all the contaminant metals. The solution wouldn't saturate anymore and yet there is still contaminant metals at the bottom of the flask trapping a lot of the gold. The fourth time I added some H2O2 3% and hoped it wouldn't attack the gold as well but it still wouldn't dissolve all the contaminants. The HCL I used is 31.45% concentration since I don't easily have access to 32% but it should still be strong enough. I included a picture of what I was left with at the end. Any ideas?

 

[Geo]

it takes upwards of one to two days to digest the Kovar in straight hcl. it can be done. when the solution is hot and you see small bubbles being evolved, thats the Kovar being attacked. it is a completely different look than just liquid boiling. when liquid boils, it evolves rather large bubbles where ever the heat is greatest. when the metal is dissolving, tiny bubbles will evolve over where the metal is regardless of heat dispersion.when you were doing the dissolution, was the tiny bubbles visible? if there were some, the reaction was taking place, maybe not as fast as you would have liked, but still progressing.

do not leave solution heating unattended. do not let the reaction run dry. add hcl as needed. cover the reaction. be patient. its takes some time on the larger pins from the big green chips.

 

[JesseSShaw]

it takes upwards of one to two days to digest the Kovar in straight hcl. it can be done. when the solution is hot and you see small bubbles being evolved, thats the Kovar being attacked. it is a completely different look than just liquid boiling. when liquid boils, it evolves rather large bubbles where ever the heat is greatest. when the metal is dissolving, tiny bubbles will evolve over where the metal is regardless of heat dispersion.when you were doing the dissolution, was the tiny bubbles visible? if there were some, the reaction was taking place, maybe not as fast as you would have liked, but still progressing.

I understand the difference between boiling and chemical reactions actually. I could tell by the way it was bubbling just as you said. Unfortunately, the reaction stopped after the first process. But I proceeded three more times just to make sure it wasn't reacting any longer. No more tiny bubbles coming off the materials after the first process.

do not leave solution heating unattended. do not let the reaction run dry. add hcl as needed. cover the reaction. be patient. its takes some time on the larger pins from the big green chips.

I Never left it unattended nor let it evaporate too much. For me, that is just logical. :mrgreen: It's unfortunate that some people need to be made aware of that. :| I closed off the opening of the flask with only a tiny opening to cut down on evaporation. I was regularly adjusting the temperature in order to find that happy medium between no boiling and boiling out of control. I processed the batch four times with fresh HCL each time. That is 12 hours of boiling. I would think that would be enough time to complete the dissolution. Am I incorrect in my thinking?

EDIT:
The image I uploaded in my previous post is a little misleading. I took the picture after I had decanted the floating gold foil and micron particles. There is a thin layer of HCL just barely covering the pins in the flask. You just can't see it. My apologies.

 

[Geo]

when iron is dissolved in hcl in the presence of oxygen, it creates ferric chloride. ferric chloride is an etchant for printed circuit boards and will attack the iron aggressively when heated. when the reaction stopped the first time, there was no need to discard the pregnant solution, just add more hcl. when you removed the ferric chloride, you slowed the reaction down. i know it sounds unrealistic, but that's what happens.replace some ferric chloride and the reaction will start back when heated. i cant think of anything that could cause the iron to passivate.

 

[JesseSShaw]

when iron is dissolved in hcl in the presence of oxygen, it creates ferric chloride. ferric chloride is an etchant for printed circuit boards and will attack the iron aggressively when heated. when the reaction stopped the first time, there was no need to discard the pregnant solution, just add more hcl. when you removed the ferric chloride, you slowed the reaction down. i know it sounds unrealistic, but that's what happens.replace some ferric chloride and the reaction will start back when heated. i cant think of anything that could cause the iron to passivate.

Thank you for your quick replies and information. I will try the process again, this time boiling much longer in order to try and generate more ferric chloride. If I don't see a reaction after a few hours then I just might try adding some fresh (not oxidized) iron to the solution so as to manually generate ferric chloride and "kick start" the process again. Will post the results. Thanks again for the information.

:!: EDIT:
I decided to create some ferric chloride right from the start this time. I dissolved a pinch of iron filings in HCL before I tried to dissolve the rest of the pins. It seems to have worked. I am now seeing a reaction as I boil the pins again. I will update in a new post the end results.

 

[gold4mike]

One thing I've noticed when dissolving pins in HCl is that, while the liquid is hot, even at a rolling boil, it appears mostly clear as if no reaction was occurring. I apply heat for an hour or so, then remove from heat and let it sit overnight.

In the morning the liquid will be very dark. I pour this liquid off, add more HCl, heat again, let sit overnight. When I find the liquid clear in the morning I know I've dissolved all that the HCL can dissolve.

Then it's time to move to the next process.

 

[JesseSShaw]

When I find the liquid clear in the morning I know I've dissolved all that the HCL can dissolve.

Were there any undissolved contaminants when the HCL stopped working? What I'm shooting for here is gold that is pure enough to sell without further processing.

 

[eesakiwi]

Jesse, are you just boiling the pins in 35% HCL without anything else in it (ie Hydrogen peroxide).

How much acid are you using?

 

[JesseSShaw]

Jesse, are you just boiling the pins in 35% HCL without anything else in it (ie Hydrogen peroxide).

How much acid are you using?

Refer to my first post on this:
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=9693&p=147064#p146922