Chip fire - the beads are great

[g_axelsson]

Here's a couple pictures I took of some partially incinerated I.C. chips. The first one is a picture of some of the stuff I screened out to be re-incinerated. These were just ordinary I.C. chips. No processors.



I took a close up picture of the little square metal pieces (?heat sinks?) with wires on the corners to see what the end of those wires looked like.

View attachment 1

I can't tell for sure if this is gold but I would have expected it to be oxidised if it was just copper. I haven't run any tests on these parts yet. They are mostly magnetic.

The square metal plates are part of the lead frame, the mechanical frame the chip is mounted on and the legs which are bonded. The chip is often brazed with silver or palladium braze to fix it on the metal plate before bonding. If the plate is a lot larger than the chip then you are lucky, the leads is formed from the same metal plate and doesn't lead all the way to the center square, so it means longer bonding wires. 8)

Heat spreaders are thicker copper plates, often as large as the package. It sits above the chip and spreads the heat for better cooling. They are not connected to the chip electrically.

Göran

 

[bmgold2]

Thanks Göran,

I can't say how big the chips were from these little square plates. After incinerating them, I dumped them into a mortar and pestle and smashed them up and then screened them to get rid of the bigger pieces. The parts shown in the picture were screened out and then separated with a magnet. They came out as seen. I expect the chip was crushed already. Next time I incinerated some, I'll try to dissect one and see if I can see the chip or the connecting wires. There were no heat spreaders on any of the chips I incinerated.

 

[dannlee]

Love the plates, save the plates, learn more for sure.

Heated the "once-crushed once-ground" magnetic pieces five minutes cherry hot, then slipped hot melting dish into insulated envelope to extend the cool down period.

Ground the dregs again in mortar and pestle. Magnetic separation with water washing, ash silts floated drain to waste. Magnetic pieces now weigh 8 grams.

First picture is after two hour soak in nitric on heat plate. Lots of cloudy white precipitate and turquoise blue acid into the stock pot. There is crushed die glass frit and I'm thinking Pd dust making a nice bullseye effect.

Second picture is after 30 minute soak in HCl with H2O2 added for second half. More blue/green acid & white silt into stock pot. Less bullseye effect, clear cubic silica grains visible under magnifier.

4mm x 7mm Au pay streak. I am very impressed how Kovar holds onto Au & Pd - and adding heat making it let go. Might be a place for it in incinerator exhaust flue, last processed batch wires gets reheated for free.

I've got filtering set up and ready for AR, sorry for the baby steps.

Working on small-scale production line method too for easier & clean incinerator. 8 kilos of chips cleaned and sorted.

 

[bmgold2]

Love the plates, save the plates, learn more for sure.

Heated the "once-crushed once-ground" magnetic pieces five minutes cherry hot, then slipped hot melting dish into insulated envelope to extend the cool down period.

Ground the dregs again in mortar and pestle. Magnetic separation with water washing, ash silts floated drain to waste. Magnetic pieces now weigh 8 grams.

First picture is after two hour soak in nitric on heat plate. Lots of cloudy white precipitate and turquoise blue acid into the stock pot. There is crushed die glass frit and I'm thinking Pd dust making a nice bullseye effect.

Second picture is after 30 minute soak in HCl with H2O2 added for second half. More blue/green acid & white silt into stock pot. Less bullseye effect, clear cubic silica grains visible under magnifier.

4mm x 7mm Au pay streak. I am very impressed how Kovar holds onto Au & Pd - and adding heat making it let go. Might be a place for it in incinerator exhaust flue, last processed batch wires gets reheated for free.

I've got filtering set up and ready for AR, sorry for the baby steps.

Working on small-scale production line method too for easier & clean incinerator. 8 kilos of chips cleaned and sorted.

I've read this and then jumped back to the first page several times just to make sure I understand what you are saying. You ARE talking about the little square plates like was in my picture right?

Heating them and then cooling them slowly (annealing them) caused the gold/silver/palladium to separate from the plates? Did the plates crush up or are they still squares of metal?

So now the silver and at least some of the palladium is in your stock pot?

Sorry if I got this wrong but it sounds like those magnetic plates are worth saving after all. Five minutes of heating sounds cheaper than trying to dissolve the kovar or whatever metal those plates are to get the values off them.

Keep us updated. Great posts. I can't wait to see the gold bead you end up with.

 

[joubjonn]

so that last "pay streak" is from the first magnetic bits separation?

what I mean is that you already got 1 "pay streak" from original incineration of IC's and removing the magnetic pieces and then went back to the mag pieces to get the next batch of gold? that is impressive. I'm glad I saved my magnetics from my last .5kg IC batch.
tell you what, I'm gonna run my mag pieces again

incinerate again, 50/50 nitric bath on heat for 30 min, water wash, incinerate again, magnet and check for gold

sound right?

thanks for the updates. this is becoming a good thread like patnor's original on flat packs.

 

[dannlee]

Apologies for this Sunday-driver thread among road warrior threads… And if comparing my wombly posts to anything – this was a sloppy burn, pictures show that!

IF burned to “no black-sand” or “no ash concretions” those second yields would not have been large.

Metal bases & spreader plates? Handpicked from pile first, water washed, and separated for later processing. No plates reheated or acid washed…. Yet. So far I can’t say if super-heat oxidation of kovar does anything but make busy work.

To summarize:
Broke up two laptops' worth of incinerated chips by hand only.
Kept any VISIBLE base metals out of acids, all ‘screened flour’ cleaned by N50 Neo magnets w/ water wash.

Earlier photos show large clumps picked from pile; medium magnetic wires & small clumps screened from pile; and fine ash pile.... (not this post photo).

1st pay-streak photo(s): Started by AP processing the easy grey ashes first.
2nd pay-streak: Wires & small char clumps mortar and pestle ground, then water wash screened, magnet w/ water wash cleaned and then hot AP.
3rd pay-streak photo: Large char lumps came next - re-incinerated, mortar and pestle ground, water wash screened, magnet w/ water wash, hot AP.

4th pay-streak photos: Everything remaining that had not fallen through 0.6mm screen, metals and remaining char pieces (except metal plates) were open flame roasted then given a hard mortar and pestle grind, screened & water washed, N50/50 & AP.

So, what I called wires/magnetics also had screened small unburned black nuggets or thin ash concretions adhering to the wires & dies. If you've ever burned chips you'll know the metals rarely shed the encapsulation we try to remove cleanly.

Even as sloppy as everything progressed – the real surprise was the 4th result. For giggles I’m going to burn the magnetics again, and burn the black sand in the pay-streak jar after AR removes the Au for some more show and tell.

The next lot – maybe five 90’s video cards – the big chips will be broken up, everything ashed in one step, magnetics water washed and then the reburnt.

Photo is everything remaining - the shiny plates / wires washed and ground; the ugly plates and dies unprocessed.

 

[dannlee]

For giggles I’m going to burn the magnetics again

Using water wash through screen to clean chip legs and lead wires boosts visible values for sure, as does water washing grits being removed by magnetic sifting.

So this paystreak was reclaimed mechanically from kovar after another super-heating, but to pretty it up for photos it got one hour of HCl-Peroxide double-boiler simmer cleaning.

The beaker '50' label is 6mm wide.

The magnetic wires were open flame roasted orange hot - they'd clump together, I'd break it up & repeat for five minutes. Small melting dish preheated on gas burner grate with propane torch direct on powders was a large improvement too.

Guess the next step is waste a little nitric removing non-gold metals, there is a scattering of silvery flour seen at top of photo and a small bulls-eye effect from them. For the sake of science I'll do it though 8)

There is some values left in those wires but not much, they're pretty frayed by now. It's neat extracting the last bits with low/no acid cost, I'm not one of those who get nitric for $7 a gallon instead of $100-plus!!

 

[FrugalRefiner]

So this paystreak was reclaimed mechanically from kovar after another super-heating, but to pretty it up for photos it got one hour of HCl-Peroxide double-boiler simmer cleaning.

Be sure to check that cleaning solution for values.

Dave

 

[dannlee]

Checking for values were done religiously, and I've now got a locked/vented cabinet outdoors for my waste stock pot so everything is kept, used washes, grits, filters.

Tried ball-bearings that fit the bottom curve of a beaker as a grinder to reduce the black char hunks by spinning them by hand, ground up some excellent India Ink silts that resist settling out completely. Doing initial filtering of that I just made coffee from it when trying a coffee filter, even got some through Whatman 40's doing the grit & Aqua Regia rinses, reboiling the grits, and washing down the equipment. Next time I'll let the wet filter conform to the buchner funnel under vacuum longer before starting AND do the rinses under vacuum to keep the seal tight.

Vigorous boiling (after the AR) of well rinsed grits turned the distilled water golden - and on the initial add of AR to the grits a very faint blue/green hue appeared before the gold began reacting, so I surely saw those char hunks had soaked up small metal values, good and bad. The grit (and filters) have all been saved so its a project for some other day, but would like to have a quick method to separate the true heavies from mere char WITHOUT chancing loosing micro-values or making black ink.

I did my best to minimize the Nitric used, held it on a simmer for bunches of hours until even the fine champagne bubbles had faded. So, now, yesterday I reduced 300ml AR values to 125ml evaporating it. With all the rinsing of grits/filters/funnels/beakers it sure got diluted but that gold color stayed bright.

Went out last night and bought sulfamic and DEF both just to have on hand. I'll be bribing sugar pod peas and tomatoes soon with the DEF

Here's a shot of total gold reclaimed before the bearing grinding.

And a montage shot of each stage of values reclaimed for comparison.

And a shot of Aqua Regia resting in the sunshine.

 

[joubjonn]

Really appreciate the updates!
I am working on 600grams of mostly ram IC's. PC100 and 133.
Will post updates on this thread later on.
I just made a quick sluice with a 5 gallon bucket, my gold pan and a hose on
Light flow. Found some very very small micro gold in that pan once
The bucket water ran clear. Finest gold I have ever seen. Very little of it though.

It was the first pan fry of the IC's, after a 5 min hand crunch in the bucket of water
Ran that through a strainer and the big bits are being burnt again now.

 

[dannlee]

Sigh. Teeniest pipe award maybe?



Getting the routine down, walk through steps before committing, get the equipment tuned up and clean up routine set...

I have golden yellow borax in melting dish, did not make a pellet of powder and spent 15 minutes chasing the bead around trying to catch the visible metal flier speckles.

Went back and cleaned everything the dropped gold had touched and siphoned off AR after a 24-hour settling and added 15% additional powder cleaned up to the earlier micro-bead today.

This was done with a $3 butane pen torch with the dish pre-warmed on cooking burner - bead not quite big enough to jump clear of borax so slightly lumpy.

I'll rerun the filters, char sand and such tomorrow maybe - amazing losses for small batches! I've ordered a digital scale to satisfy mass curiosity.
..

 

[joubjonn]

I'm very curious to see what my post AR saved cons from chip processing will yield

my theory is that all that surface area on the material during pre-filter AR certainly traps what I think could be significant gold. I plan on incinerating it all again and doing another AR leach. AR is the way to go by the way. bleach just takes too long and you have to add way too much to get it to attack the gold that sits at the bottom of the beaker under layers of material. maybe if I could find some higher strength hypochlorite it wouldn't be so weak.

my filters must have some good stuff in them also, I have switched from coffee paper to fiberglass. I find them easier to deal with but not sure yet what the best way would be to leach them.
with the AR I usually just add a few ml of nitric with a small medicine syringe and then throw a few gold buttons in with some heat after filtering, all the nitric gets used up and my buttons get nice and pickled at the same time.

 

[Anonymous]

Hi Dann I may be having a blonde moment, but did you tell us what weight of gold you got ?

 

[joubjonn]

I ended up finding a nice pay streak in my already processed cons. I took three batches of used cons and did another incineration and pan and it looks pretty nice. save those cons. I think they always need another processing. I find IC's to be very challenging. when it comes to incineration, dealing with ash, floating gold, nitric leach, etc. It's just difficult and time consuming for sure. but fun!

 

[dannlee]

On the weight? FedEx Shipping Services say my new 0.01 digital scale delivery will be Thur 4/03/2014. Hope it arrives early.



Yes, I had AR-washed & well 'funnel' rinsed ash that brought distilled water bright yellow after a brief boil. I am trying to keep the chip legs completely out of acid leach steps.

I've ended up desiccating dry my final clean up solution (filters/swabs/evap dish & beaker etch/ash) three times so the second time I added HCl & five drops of nitric to dissolve the purple clay, it dried out again and this time the residues were a copperish gold crystal mat on the floor of the beaker. Very cool stuff, would be nice to have everything done 'reproducible'. The first time they went syrup the golden 'wax' had congealed beaded up alone on the beaker floor, white salt residues and unfiltered ash being left outside the syrup. Neat stuff.

On my cleanup I knew if I got 85% reclaimed it'd be a good lesson - Warm AR rinse through all glassware, a long warm AR soak of the papers w/ rinse and pressing, when/if more volume of waste is happening I'll incinerate in a closed crucible. So far it's been play - we'll see when I get more time invested if its still fun.

More when I have something to report - getting new chip burner together.

 

[joubjonn]

One thing I have been doing is using a little dish soap after incineration. I have seen those little tiny gold wires float on the water before. I think this helps. I really don't like the ash removal part of the process for IC's. I always feel like I'm dumping gold down the drain. Those little wires are difficult. Most of them do sink to the bottom but some don't. I wonder if I would loose more by just going straight to Nitric after removing the magnetic pieces without removing ash would loose in gold compared to rinsing the ash. I thought about trying this out with a batch of BGA chips. That way I don't have to worry about getting rid of the legs.

Also for the legs, I put all my magnetic pieces / some of the metal disks from IC's in AP with a bubbler. I"m thinking I'll let all the iron/copper dissolve and re-claim what's left and save it for later processing. Should have palladium/gold/silver right? I am not skilled enough for palladium refining yet but I could save that for later.

 

[dannlee]

I lost the final AR clean-up. Got busy and left the heat going, evaporated dry three times. And then I could get nothing to drop in the ten minutes I had to give the teeny drab of Au so I'm back on track to give this my full attention, nothing rushed, left undone or half-hearted.

The gold pellet weight is between 0.110 and 0.117 grams - scale would NOT throw the same reading twice in a row until I inspected it and found aluminum metal shavings between load tray and housing. Seems overly vulnerable to temperature changes, even placing it in strong task lighting will cause the grains' zero to drift upwards - placing it in sunshine causes 40 grains gain above 'zero' in less than a minute. I ordered a calibration weight set and have a protected area to use it, if it acts up more it's going back.

I've been accumulating incinerator parts, just have to sit down and commit to one design.

Have cleaned up another 1000g of 1990's networking chips.