Non-Chemical ? about recovery of Au wire from flat pack ash

[kurt]

Ok – I have incinerated & crushed about 10 lbs of flat packs - removed all magnetic material - then removed other base metals (copper, brass) using nitric – crushed, sifted & washed numerous times & have reduced the amount of ash from about a gallon to about a quart. The quart of material I now have is crushed to around 80 or 100 grit fine with a relatively high gold wire concentration but still way to much ash to recover the gold using AR.

So how do I go about recovering my gold wire from the remaining ash to where I can then process with AR? --- Any help – or a link to a thread where this has been discussed before would be awesome. (I’m having trouble finding info when I do a search)

I guess my real question is – is there another way to recover the wires from the ash – or do I just keep crushing & washing till I have more wire then ash. That is what I have done in the past – but then again, in the past I was only dealing with about a pound of flat packs at a time. This is my first attempt at a larger batch & I have another 20 lb ready to incinerate & just guessing another 20 – 30 lb to strip from boards

Thanks Kurt

 

[Claudie]

I don't have an answer to your question. I am wondering if you have been keeping track of your yields with these "flatpacks" and if so, would you please share the results with the rest of us?

 

[dtectr]

A couple thoughts -
Did you separate the lids from the backing? I believe most wires are in the thermoset plastic lid, with gold foils on the fiberglass backing. The powdered fiberglass has been a real mess for me to deal with in the small experimental batches I've run. Though it would be NO FUN to do so, it may take less time & materials in the long run if the fiberglass were a nonissue.

I believe that lazersteve recommended crushing ceramics to around 200 mesh or so (1/16th" would be approximate) to give access to the gold wires. That may be true for the lids.

Just my dos centavos.

Oh, I'd be interested in yields, as well, if you'd be so kind.

Good luck.
dtectr

 

[gold4mike]

I haven't done this yet so keep that in mind but this is how I would proceed. (I welcome any critique from those more knowledgeable than I)

Put the ash in a beaker, dissolve all that will in HCl, decant or filter, repeat.

Once you believe you have all the base metals out, add HCl again, then either small increments of nitric until no more reaction, or small increments of Sodium Nitrate until no more reaction.

Filter to remove undissolved solids, kill the excess nitric using evaporation method or small gold button, precipitate.

Wash the powder three times with HCl, then with water.

Refine again to desired fineness.

 

[kurt]

Claudie – No I have not tracked yield results – at least not results that would be conclusive because all the small batches I have done up till now were done before finding this forum so I was following a “lot” of mis info. Before finding this forum, I knew nothing about the need to evaporate & remove any free nitric from AR before preciping with SMB, nor did I know anything about testing with stannous. So I am sure I lost value & yes even though I did track those results they would be “totally” unreliable. Also – on this batch, I will not be able to post any real conclusive results because I have dipped into the starting material I incinerated to run some small lot experiments with info I have learned on this forum. (I incinerated this 10 lb batch just before finding this forum which is why I am doing small lot experiments out of it – want to be sure I am doing what I have learned here right before running & messing up the whole batch) All I can really say at this point is that I am WAY more impressed with the results I am getting from what I have learned on this forum, then the results I was getting before.

dtectr – yes I separate the fiberglass back from the plastic lid on that type of chip (flat pack) This10 lb that I incinerated is a combined lot of “ALL” types of chips (flat packs) fiberglass backed (with fiber back removed) RAM chips & other – no CPU’s though. --- once I have finished with this 10 lb – I will run some batches based on type of chip & post the results. --- It may be awhile because I am still working on figuring it all out with this 10 lb

gold4mike – actually if you us nitric instead of HCL to remove the copper/brass base metals before processing with AR you will be able to recover a fair amount of silver &/or maybe some palladium. Not sure yet about the Pl – I need to re-dissolve the Ag I cemented out of this batch - test with stannous & see if there is Pl as well as Ag to be recovered from IC chips.

If you us HCL instead of nitric to remove the copper & brass base metals – the Ag will get lost in the ash as Ag chloride

Anyway – what I am really trying to figure out at this point – is a way to “recover” the gold wire out of the ash, once you have washed off as much ash as possible. There comes a point where the ash to wire ratio is such that further attempts at washing results in washing away some of the wire as well. But at that point you still have too much ash because the amount of AR needed to cover the ash is “WAY” more AR then needed to dissolve the gold in the ash. --- So – you end up with a lot more AR to evaporate then need be & it has more free nitric in it then need be. Also – there is no “effective” way to recover “all” of the AR out of the ash – other then washing it out with “a lot” of water – which means even more evaporation then need be.

One thought I have to recover the wire out of the ash is to use mercury to recover the wire as an amalgam. You could then recover the mercury for future use in a retort set up which should then leave you with a gold button that you could then process with AR. You can also just burn the mercury off with nitric which will leave you with the gold wires to then process with AR. I would be careful with that though because I believe when mercury is dissolved in nitric & if you allow it to dry out you end up with mercury fulminate which is a pressure sensitive explosive.

This was how we recovered the gold from crushed ore concentrates when I was involved in some hard rock mining in Northern California about 20 years ago. We were crushing that ore to 600 or 800 fine – so I am thinking it should work here in this case as well. Just a thought & I am certainly open to feed back on this one.

Kurt

 

[glondor]

The easy solution for recovery of pregnant solution from powders is a filter press. How ever it may not be economical for the home refiner to purchase one. Harold has posted some photos and information on his filter press within the last week. Good info on how they work and what type to get.

I guess an alternative would be some type of centrifuge motion with many types of set up options available. Rusty may have more info on this as I believe he had a working system?

GSP has a great thread also on using polyester cloth as a wick system to remove liquid from sludge. Most affordable method for sure. Maybe he could provide more info on what he used this system for and how effective it was. I recall it worked very well, I don't remember if it was used for pregnant solutions or not.

 

[rusty]

My centrifuge along with some gold powder from my first batch of incinerated chips that I'm currently working on.

Gold and other precious metals were precipitated with copper, I'll wash this in dilute sulfuric acid to get rid of any excess copper before AR.

Base along with silver / palladium were removed with 50/50 water/nitric acid, these are waiting to be melted into anodes for the silver cell.

Regards
Rusty

 

[kurt]

glondor - thanks for the info - very useful for sure - however I am not trying to figure out how to recover the fine powders from solution after precipitating. Rather I am trying to figure out an effective way to recover the gold wires from the ash after incinerating, crushing, & washing as much ash as possible off when processing flat packs &/or chips. --- This is all before using AR to dissolve the gold.

The problem is that when washing the ash off - there comes a point were you have a "relitivly" high gold wire to ash concentration, but there is still a lot of ash. - At this point the problem is 2 fold (1) if you try to wash more ash off you are also taking a risk of washing some of the gold wire along with it - there by losing value (2) although at this point you have removed something like 70% of the ash - you still have so much ash that you need to use "way" more AR then needed to dissolve the gold wire because you need enough AR to cover the ash.

Kurt

 

[rusty]

Kurt melt everything into a crude anode then run this as a copper proposition in a cell collect the values as slimes. this is how I intend to proceed with my next batch.

Regards
Rusty

 

[Claudie]

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=38&t=9767
This post goes over a process of separating the metal from the rest.

 

[rusty]

The first step in filtering the mother liquor from incinerated ash from mother board chips, homemade centrifuge.

http://www.youtube.com/watch?v=FCgBPFfUkzw

Regards
Rusty

 

[rusty]

After extracting the mother liquor from my incinerated chip ash. I let the fine sediment settle out, decanted then filtered one more time using coffee filters then added copper to precipitate the precious metals. Black Is Beautiful.

I agree with Kurt it takes plenty of acids to extract the precious metals from ash, not counting the nitric used to leach out base metals, silver and palladium I now have 2 1/2 gallons of pregnant AR that I'm dealing with.

In this instance not necessarily Ashes to Ashes. IMHO well worth the cost of the acids and time involved.

Rusty

 

[rusty]

Cementing has shifted color, now leaning towards brown.

 

[rusty]

It's ash related, after stirring the leach to clear the copper anode of slimes the black powder has now clumped and turned brown. This is one of five jars currently being cemented out.

Source of chips - MB and daughter cards.

Regards
Rusty

 

[dtectr]

It's ash related, after stirring the leach to clear the copper anode of slimes the black powder has now clumped and turned brown. This is one of five jars currently being cemented out.

Source of chips - MB and daughter cards.

Regards
Rusty

Very informative, as always, Gil. What amount of feedstock (approximately) did you process to arrive at that quantity - if you don't mind me asking?

 

[rusty]

It's ash related, after stirring the leach to clear the copper anode of slimes the black powder has now clumped and turned brown. This is one of five jars currently being cemented out.

Source of chips - MB and daughter cards.

Regards
Rusty

Very informative, as always, Gil. What amount of feedstock (approximately) did you process to arrive at that quantity - if you don't mind me asking?

You may recall just before Christmas I came home with a truck load of boards along with a barrel full of plugs which I posted a picture of way back perhaps a 1,000 lbs of boards some were tel comm.

Also recovered a couple of pounds of rough silver now waiting for the silver cell for final treatment and parting of any palladium.

I would love to purchase that 8,000 plus that silver saddle is currently offering for sale. Someone is going to recover some serious values from that lot.

Way back, I ran the barrel of plugs through the hammer mill then ball milled the pulp, It was apparent then that the gold was being abraded off of the pins, now that I have processed the remaining pulp found no gold what so ever. Not to worry the gold from the pins run ion the ball mill is in the Visonware dish above.

Very early I stated on the forum that e-scrap[ should be treated as ore, electrolytes are manageable to keep em healthy, unwanted ions can be stripped from a fouled solution then the electrolyte can be returned to the cell for further use.

Started building that car trailer, now that I have begun will complete the job before returning to this gold project.

Regards
Rusty

 

[rusty]

Just pulled the copper pipe to have a peek, the cement coming down now has a color shift towards gray.

From the list of single electrical potentials I'm assuming the order of things are as follows.

Copper + 0.34 volts first displaces the following metal ions in sequence. I'm curious to know if using an Orp meter would inform you when to halt the cementing of metal ions from the leach leaving tin and lead behind.

Gold + 1 . 3 6 volts
Platinum + 0.90 volts
Silver + 0.80 volts
Tin - 0 . 1 4 volts
Lead -0.12 volts

Just curious.

Edit: After thinking about the gray cement, it has to be either tin or lead as silver would have been caught at the filter as silver chloride.

Regards
Rusty

 

[Claudie]

It's not silver.

 

[rusty]

It's not silver.

Yea I got that, after thinking that silver would have converted into a chloride - it would have stayed in the filter.


Care to venture an educated guess as to what it might be.

Regards
Rusty

 

[butcher]

I would continue cementing, till reaction is completed, and deal with other metals later. Copper would not cement tin, but lead would precipitate with or without the copper.
the gray can be copper I chloride, lead chloride, silver chloride, elemental silver, and so on mixed with your gold powders.
Most of the tin would stay in acidic solution and can be decanted, what does not get out later.
Copper I chloride and lead (insoluble in chloride solution) would be your major problems.

I do not believe you would be able to stop cementing at a certain point and selectively cement only certain metals from solution.

I would wash powders in diluted HCL, and boil in water, lowering heat to let powders settle, decant (I use suction bulb) to remove the soluble lead chloride, let this water & PbCl solution cool and lead again becomes insoluble (here I return the water to the boiling pot and repeat, reusing same water so to keep waste levels to a minimum), once most all lead removed, I use caustic soda and water to wash these powders, neutralizing them converting metals salts to oxides, rinse well then decant and put in square corning dish (some use stainless steel) on hot plate on low till dry( or until raising heat does not cause gassing and bubbles popping splashing out values, raise heat to high, then roast them red hot crushing and stirring well, I use propane torch, my white corning dish can take the torch heat, I just heat it up slowly so not to thermal shock it.

Now you have metals oxidized, a water wash, boil in HCl, boiling hot water rinsing and caustic soda neutralization and rinsing of the salt water (reaction of HCl and caustic soda), repeat incineration to rid any chlorides, now you are ready to treat with nitric and get silver or any Pd, then go for the gold.

But you already knew all this, I just had to comment as I love reading your posts they are alway's very interesting to me.

Edit: do not count out there may be PGM's involved.