# Abrasive Mill



## stoneware (Nov 2, 2022)

Treadmill from landfill, propane tank for the drum.

The abrasive action on low grade gold plated junk will rub off then collected for further refining.

All thats left to do in mount the second roller, control module and find an inner tube to cut and stretch over the drum to give some traction.


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## kreinhardt (Nov 2, 2022)

Are you using abrasive media in your tumbler or just letting junk work on itself?


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## stoneware (Nov 2, 2022)

kreinhardt said:


> Are you using abrasive media in your tumbler or just letting junk work on itself?


Any boards that the big paper shredder could not handle were broken down, it's this shred that will do the work.

Lots of low grade pins that I would not otherwise bother with are going into the mill.

I figure a couple of hours in the mill then when it comes time to empty I'll discharge the load into a large plastic tub. Then rinse the barrel out with water.

A drop of dish soap to eliminate float, then screen out the chaff.

I anticipate some solder to also abrade free of the boards, a weak hot hcl should look after the tin - leaving me with what little silver maybe alloyed with the solder.

I'm working at installing the idler roller and control box this evening.

Have more gold plated junk from a box with a couple hundred insulin pumps a neighbor dropped off the other day and some more mother boards to strip. Before the mill goes into action.


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## goldshark (Nov 2, 2022)

I like your ingenuity, let us all know how it works out. You may need to add some silica sand. Crushed will be more aggressive then beach sand.Good luck!


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## stoneware (Nov 2, 2022)

goldshark said:


> I like your ingenuity, let us all know how it works out. You may need to add some silica sand. Crushed will be more aggressive then beach sand.Good luck!


No other media required, the trick is to run the mill dry.


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## goldshark (Nov 2, 2022)

Let us know how it works out. You can add media, such as glass bottles after smashing on the ground, dry. My experience with metal on metal, especially soft metals, is that it will just agglomerate onto other particles, not really eroding off all the base metals. You may end up with a thicker deposition on certain pieces, but no real separation from base metals into individual PM particles. Glass or Silica is a relatively non reactive grinding media. In other words, it won't consume acids in the dissolution phase, like if steel balls were to be used.


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## stoneware (Nov 2, 2022)

The tank used is designed for liquid propane, the welded factory seam needs to be ground down a bit.

After the seam is smoothed out I'll cut a piece of the treadmill belting then use some spray on adhesive to hold it in place.

The center shell overlaps the end bells, you need to fill the gap inside the tank with silicon or similar filler otherwise some of your gold will find its way into the crevices.

Most treadmill motors, the pulley is threaded on. If you run the motor reversed chances are the pulley will come off. 

The mill I'm using has a keyway with set screws.


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## malphorian1973 (Nov 3, 2022)

This is nice man! If you decide it works well enough to build an upgraded version (bigger and more power) I have a really nice 110/220 power supply with control knobs on it that controls the speed and torque of the motor. It's for sale but I would give you the deal. Anyways, I would love to see a video of this in full operation start to finish. I am really interested in yields. Keep thinking outside the box my friend.


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## stoneware (Nov 3, 2022)

Welds ground down, silicon has cured, belting inside to warm up making it more flexible - purchased Gorilla adhesive

Removed old paint and roughed up the surface for the adhesive.


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## stoneware (Nov 4, 2022)

A bug on the first loaded run. there's about 60 pounds in the drum and the drive roller slips against the belting.


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## stoneware (Nov 4, 2022)

Cut an old bicycle inner tube into 2" long pieces, they're a bear to get stretched over the roller but managed to get three on before giving up.

On Monday when I have access to a metal lathe I'll turn a tapered cone that fits over the stub. This should make it much easier to roll the tube sections onto the roller.

Also added a blocker to keep the end of the drum from rubbing against the plastic pulley.


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## goldshark (Nov 5, 2022)

Maybe try a long strip of bicycle tubing wrapped around, with contact cement to glue them on. It might be easier than trying to get the short sections over the hub.Wrap it like a golf club handle. IE, one piece of rubber on an angle so as not to overlap a lot, on the next spiral wrap.


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## stoneware (Nov 5, 2022)

Found a tube slightly larger in diameter than the first one, cut to length then ran some soapy water inside.

Nice tight fit.


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## stoneware (Nov 5, 2022)

When the drive roller is new it has knurling on the center section to give it traction. Once worn it will slip against the belt.

Had the tubing on the drive roller had not been so thin would have welded dibbits onto the surface.

Another idea was to drill small holes then insert screws and let the heads grip the rubber coating on the drum.


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## stoneware (Nov 5, 2022)

With the e-waste acquired yesterday and what I have on hand to process I'll likely have enough material for a small load.

No lift bar inside the drum so the ideal load would be 50% to meet this requirement I'll toss in some chaff from the first load.


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## stoneware (Nov 5, 2022)

I'm going to run this load five hours.

The blocker is doing a fine job of keeping the end of the drum from rubbing against the pulley.

I may have to add a metal surface to it to keep if from wearing.


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## eaglekeeper (Nov 5, 2022)

That could be used as a ball mill as well, Add ball bearings and increase the speed a little and now you have a ball mill.


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## stoneware (Nov 5, 2022)

I also have a ball mill, electric motor is going to be swapped out for a small gasoline engine.

Trailer mounted so I'm able to do my milling away from my neighbors, makes a lot of noise.


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## stoneware (Nov 5, 2022)

I'm going to scoop off the float.


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## stoneware (Nov 5, 2022)

One of the larger pieces tossed in with the shred, only the gold was removed, solder mask and copper untouched.

I did the damage to the end trying to feed it through the paper shredder.


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## stoneware (Nov 6, 2022)

Your gold will be in the mud, process as you would jewelers bench sweeps.

Surprisingly its rather easy to filter, the only solvent used was tap water.

Total cost of the build was the purchase of the Gorilla adhesive, less than $20.00

This concludes my participation in this thread, the abrasive mill in my opinion is a success.


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## stoneware (Nov 7, 2022)

malphorian1973 said:


> This is nice man! If you decide it works well enough to build an upgraded version (bigger and more power) I have a really nice 110/220 power supply with control knobs on it that controls the speed and torque of the motor. It's for sale but I would give you the deal. Anyways, I would love to see a video of this in full operation start to finish. I am really interested in yields. Keep thinking outside the box my friend.


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## stoneware (Nov 9, 2022)




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## stoneware (Nov 9, 2022)

HCL wash, rinsed and dried 159.7 grams from less than half a 20 liter pail.

Gold, palladium. silver with perhaps a bit of lead expected on the final refine.Edit


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## stoneware (Nov 9, 2022)

Most of the palladium was easy to extract.

My palladium is splitting water, oxygen bubbles.


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## stoneware (Nov 10, 2022)

Bottom dregs, palladium with a bit of gold.

Plastic tub tare weight, 18.1 grams
Palladium Net, 33.5 grams


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## Yggdrasil (Nov 10, 2022)

stoneware said:


> Bottom dregs, palladium with a bit of gold.
> 
> Plastic tub tare weight, 18.1 grams
> Palladium Net, 33.5 grams
> ...


Where did that Pd come from?


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## stoneware (Nov 10, 2022)

Yggdrasil said:


> Where did that Pd come from?


Probably off of the ram fed through the paper shredder and some from mother boards.

Inside Ethernet metal case, and under the cpu.

I use a small hatchet to depopulate onto a large metal sheet, just pick out aluminum caps and small transformers. and heat spreaders.

Most of the palladium with a trace of gold stays on the bottom of the rinse water bucket.

Me and the woman are going on a couple of dump runs, if I have the time will post on something new I want to try.

Muriatic 4 liters $22.99 Canadian, just placed and order for nitric, waiting on the invoice. 

Below is the reply I received from my supplier, its a good thing the value of gold has also increased.

I will send you a quote as soon as I get the freight rate. The acids have gone up considerably since you have ordered.


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## Yggdrasil (Nov 10, 2022)

stoneware said:


> Probably off of the ram fed through the paper shredder and some from mother boards.
> 
> Inside Ethernet metal case, and under the cpu.
> 
> ...


So this abrasive mill of yours actually grinds MLCCs and other components to dust?
Interesting


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## stoneware (Nov 10, 2022)

Yggdrasil said:


> So this abrasive mill of yours actually grinds MLCCs and other components to dust?
> Interesting



Is there any reason they would not turn to dust.

From post number 3 in this thread.

Lots of low grade pins that I would not otherwise bother with are going into the mill.

A quote from lasersteve,

The proof is in the pudding.


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## Yggdrasil (Nov 10, 2022)

stoneware said:


> Is there any reason they would not turn to dust.
> 
> From post number 3 in this thread.
> 
> ...


I was thinking that since it was mainly for grinding off plating, 
it would not have time enough to grind component down other than the surface that is.


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## stoneware (Nov 10, 2022)

stoneware said:


> Below is the reply I received from my supplier, its a good thing the value of gold has also increased.
> 
> I will send you a quote as soon as I get the freight rate. The acids have gone up considerably since you have ordered.


Not sure why she was concerned about the price increase, shipping was double the cost of my purchase.

After placing a call, yea I'm shocked, that price 77.00 is per 2.5 liter bottle.

Canadian funds, 4 x 2.5 liter nitric.

NI7110-2.5L 1NITRIC ACID ACS 69 - 70% 4/CS 77.00


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## stoneware (Nov 10, 2022)

Yggdrasil said:


> I was thinking that since it was mainly for grinding off plating,
> it would not have time enough to grind component down other than the surface that is.


Larger caps will be laying on the bottom of the rinse tub, incineration takes care of those.

Small caps the size of fly shit do not withstand physical abrasion.


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## stoneware (Nov 10, 2022)

Yikes, at $491.30 with shipping on 4 x 2.5 liters of nitric, I need to use it sparingly.

I did make the purchase, but also intend to change my game plan.


10-Nov-2022Interac eTransfer Outgoing To: Alphachem 
Reference Number 20221110080949666939-$254.3010-Nov-2022Interac eTransfer Outgoing To: Alphachem 
Reference Number 20221110072533666512-$237.00


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## stoneware (Nov 10, 2022)

In theory the vibration would seperate the material according to specific gravity.

This prototype is much too aggressive, perhaps less water would keep the mud from churning over.

Maybe a dimmer switch to slow the motor down, perhaps to much spring.

Fan motor from a fridge, cut off all the blades but one.

Caution turn your sound down.


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## stoneware (Nov 10, 2022)

Anyone see the problem with my vibratory separator. Why the heavies are not setteling onto the bottom.


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## eaglekeeper (Nov 10, 2022)

I think speed is too aggressive... Try different orientations of the motor... that might change the direction of the vibrations...just a guess. There's probably someone here that's made something that works.


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## goldshark (Nov 10, 2022)

You need a jig. All you are doing with the present configuration, is basically creating "liquefaction". You are allowing the heavies to settle, but not stratify according to specific gravity. The super fine stuff may stay in the liquid part, due to the agitation.


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## stoneware (Nov 16, 2022)

Preparing another load of shred for the mill, whole ram, cpu's chips and low grade pins.


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## Golddigger76 (Nov 16, 2022)

stoneware said:


> Anyone see the problem with my vibratory separator. Why the heavies are not setteling onto the bottom.



Maybe try a funnel instead of a flat bottomed container. A funnel will also fit into the pour hole on the bucket lid.
I would think the heaviest material would go to the bottom and stay there, the flat container gives the material way to much room to move around. 
Test it with different speeds and different amounts of water


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## Ohiogoldfever (Nov 17, 2022)

If we look at this like it were material in a gold pan you would want a shearing side to side action to get the material moving back and forth while remaining fluidized or in suspension. It allows bits to slide under another or plinko 
It’s way between and below another. 

If you vibrate a gold pan full of semi round objects it won’t sort it’s self completely. 

The vibrating action only really acts to compact the bits. Allowing themselves to be sorted to be as close to one another as possible. Just like using a concrete vibrator to compact and work the work open spaces (bubbles) out of a poured wall.


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## malphorian1973 (Nov 17, 2022)

stoneware said:


> Preparing another load of shred for the mill, whole ram, cpu's chips and low grade pins.
> 
> View attachment 53154
> 
> View attachment 53155


How do you get your material shredded to this point? Do you use an industrial paper shredder? I thought I read in your post somewhere something about a paper shredder. If yes, do you have a pic or two of said shredder? I have a very large, heavy duty paper shredder myself and I was wondering if they compared. I LOVE this system and would really like to build one if I find it feasible. Thank you in advance for your time.


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## goldshark (Nov 17, 2022)

To stratify according to specific gravity, you need to allow for the settling in a fluid state. A funnel kind of works. An upward flow of water will provide the flow, suspension, only allowing what is heavier than the specific gravity created by the pressure/flow volume relative to the up flowing column of water. Increasing the flow through a given orrifce (size of opening of funnel bottom) will allow for the heaviest particles only, to settle through the up flowing column, if dialed in correctly. This is extremely temperamental, due to a variety of circumstances including particle shape and size, variation in flow rates, and the rapid decrease in suspension rates due to the increasing area of the funnel. 
This is why a mineral jig is much more efficient. By creating a large surface area, and the addition of a specific gravity media bed, it recovers the heavies that exceed the media bed in a clean separation, and allows the middlings to accumulate above the media bed. hopefully you can understand what I am saying. If not, please look for an old copy of the Mining Engineers Handbook, written by Peele, 1941 publish date.
Since you haven't stated what size you are grinding to, it is tough to give a recommendation on concentrating equipment for your product. Sieve test with assays would be very beneficial to finding what your optimal liberation size is.
If fine grinding, you may need a couple of flotation cells installed in the spare bedroom.


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## stoneware (Nov 17, 2022)

goldshark said:


> To stratify according to specific gravity, you need to allow for the settling in a fluid state. A funnel kind of works. An upward flow of water will provide the flow, suspension, only allowing what is heavier than the specific gravity created by the pressure/flow volume relative to the up flowing column of water. Increasing the flow through a given orrifce (size of opening of funnel bottom) will allow for the heaviest particles only, to settle through the up flowing column, if dialed in correctly. This is extremely temperamental, due to a variety of circumstances including particle shape and size, variation in flow rates, and the rapid decrease in suspension rates due to the increasing area of the funnel.
> This is why a mineral jig is much more efficient. By creating a large surface area, and the addition of a specific gravity media bed, it recovers the heavies that exceed the media bed in a clean separation, and allows the middlings to accumulate above the media bed. hopefully you can understand what I am saying. If not, please look for an old copy of the Mining Engineers Handbook, written by Peele, 1941 publish date.
> Since you haven't stated what size you are grinding to, it is tough to give a recommendation on concentrating equipment for your product. Sieve test with assays would be very beneficial to finding what your optimal liberation size is.
> If fine grinding, you may need a couple of flotation cells installed in the spare bedroom.


I totally agree jig would work better. Just experimenting killing some time waiting on my nitric to show up.

The acid arrived late this afternoon, no more time to play.


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## stoneware (Nov 17, 2022)

malphorian1973 said:


> How do you get your material shredded to this point? Do you use an industrial paper shredder? I thought I read in your post somewhere something about a paper shredder. If yes, do you have a pic or two of said shredder? I have a very large, heavy duty paper shredder myself and I was wondering if they compared. I LOVE this system and would really like to build one if I find it feasible. Thank you in advance for your time.


Worked good when the blades were still sharp, this second load of shred has almost killed it.

Was a landfill score, had a massive paper jam.

I liked it so much that I'm going to build a larger more powerful unit that will handle a whole motherboard - minus the heat sinks.

Also want to shred my plastic waste.


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## stoneware (Nov 17, 2022)

Actively looking for opensource cut files for CNC laser, something similar to the one in the tube video would meet my needs
.


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## goldshark (Nov 18, 2022)

You may want to try a hammer mill. They can be constructed fairly cheap, great input to output size reduction, much greater life than a paper shredder. Why reinvent the wheel? Watch a youtube video on basic construction and operating procedures.
The above machine is great for grinding cars and other recyclables, but the sticker shock will give you a coronary. I saw one at Mine Expo last year for a small table top size (500 lbs.) cost was in the $25,000 range. If you are on a budget, a well built grizzly and a 2 pound hammer will smash a 60 pound lot in a half an hour. Drink a couple cups of coffee for faster through put.


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## stoneware (Nov 19, 2022)

goldshark said:


> You may want to try a hammer mill. They can be constructed fairly cheap, great input to output size reduction, much greater life than a paper shredder. Why reinvent the wheel? Watch a youtube video on basic construction and operating procedures.
> The above machine is great for grinding cars and other recyclables, but the sticker shock will give you a coronary. I saw one at Mine Expo last year for a small table top size (500 lbs.) cost was in the $25,000 range. If you are on a budget, a well built grizzly and a 2 pound hammer will smash a 60 pound lot in a half an hour. Drink a couple cups of coffee for faster through put.


This thread is too demonstrate the benefits of abrasion on low grade gold plated scrap.

The paper shredder is a joke, but it did last long enough to make a second load which will be on the rollers tomorrow morning.

I'm confident that I can build a decent shredder for under $500.00, the municipality discards the leading edge of their grader blades on a regular basis.

This is some of the best abrasion resistant steel money can buy, or get for next to free. There's enough steel left to make cutter blades for a shredder.

The colony will not cut rusted or painted steel on their laser, but somewhere in this province there has to be a water jet.

I've owned four hammer mills, the 2 hp not enough, a 5 hp a bit better the 10 hp would dim the lights in my shop during start up.

The last hammer mill was the real McCoy, came from a feed mill, PTO driven from a tractor and my little Case with a gasoline engine could power it up and keep the hammers spinning. That is if you did not feed the mill to much at any given time.

Paid $100.00 for the feed mill.

Was using that hammer mill to chop copper wire, then with a large hydraulic press making briquettes.

With the scrap price of copper everyone has become a cord cutter, so insulated wire is almost non-existent.

I no longer chase it.


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## stoneware (Nov 19, 2022)

I no longer live on the rural property, I'm now surrounded by neighbors. A hammer mill even with the cyclone is dusty and lots of noise.

The people at city hall would shut me down within the first week, the shredder on the other hand, is in my opinion better suited to my current living arrangement.

Smaller foot print, less horse power with less noise and no dust. I'll be able to reduce my plastic waste into unrecognizable shred.

Computer and other metal case's into shred will make for a good compact load, scrap yard is an hours drive and fuel is not getting any cheaper.

Two months ago gave the hammer mill away, then less than a week ago gave the old Case tractor to another fellow with big dreams.

You can only store so many toys on a quarter acre lot and it's already started to fill up. Fortunately my back yard is secluded from the street.

I have a double garage that I've rewired, insulated and paneled, just need to add a heat source to make it a comfortable man cave.


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## stoneware (Nov 20, 2022)

I ran the last and final load wet, until one of the experts says that I'm wrong I'll claim the float as precious metals.

Used a paint brush to skim off the float, less water.

Tomorrow I'll dry and weigh it up, there will be more laying on the bottom of the tub.

The waste water passed through an activated charcoal filter to collect any colloidal gold., created by over milling.


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## Yggdrasil (Nov 20, 2022)

stoneware said:


> I ran the last and final load wet, until one of the experts says that I'm wrong I'll claim the float as precious metals.
> 
> Used a paint brush to skim off the float, less water.
> 
> ...


I can't say much regarding the float or not  
But a fine filter might do better than AC, the AC do not have much affinity towards non ionic (metal) Gold, do it?
And it is quite coarse filter wise.


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## stoneware (Nov 20, 2022)

Yggdrasil said:


> I can't say much regarding the float or not
> But a fine filter might do better than AC, the AC do not have much affinity towards non ionic (metal) Gold, do it?
> And it is quite coarse filter wise.


Then I'll do as before, acidify the water then add some scrap aluminum, last time recovered about half a gram.


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## orvi (Nov 20, 2022)

Interesting toppic, that is for sure. I was thinking that quite a bit of gold would be smeared onto the plastic/solder and components on the board. Clearly, I was wrong and it can be done  I will watch tis thread, since I always wanted some big equipment to run some lowgrade stuff at volume... 

But unfortunately, I lack the space needed - on the balcony of one-bedroom flat, I cannot quite build up the impact mill or such  I think neighbors won't be very supportive on this venture


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## stoneware (Nov 20, 2022)

Yggdrasil said:


> I can't say much regarding the float or not
> But a fine filter might do better than AC, the AC do not have much affinity towards non ionic (metal) Gold, do it?
> And it is quite coarse filter wise.


It's been mentioned in numerous threads, make sure incineration is complete un-burnt carbon left behind will in later process's lock up values.

AC ( activated carbon ) in my opinion is the holy grail, hospitals administer it orally for accidental poisoning or drug overdose. No home should be without it.

Below a water filter fitted with an AC filter, a small pump will be used to feed the filter.


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## stoneware (Nov 20, 2022)

The foam float was reduced to 10 grams which looked very much like copper but when subjected to hot nitric got unexpected but pleasant results.

To those new to refining, what's missing from the hot nitric are the nitrous oxide fumes which are forever present when reacting with base metals.

When adding nitric acid to finely divided metal powders its advisable to have plenty of head room in the vessel as nitric will react with base metals violently possibly boiling over the top.

Right now just waiting for the leach to cool down, want to see if there's any color from perhaps copper.

The add either table salt or HCl ( hydrochloric acid ) to see if there's any silver present.

The engineer of a steam powered ship would take a water sample from the boiler then by adding a small addition of silver nitrate could tell by the formation of silver chloride if the boiler was taking on sea water.

The large cabinet is destined to be my fume hood.


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## stoneware (Nov 20, 2022)

It was fiber from the boards clogging up the 100 mesh sieve.


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## stoneware (Nov 21, 2022)

Running the load wet in a confined space was a bad idea the foam cushioned the bits and pieces from fully abrading.

Going to run the load again dry.


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## stoneware (Nov 21, 2022)

A Harbor Freight cement mixer would accomplish the same job with the benefit of easier off loading.


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## stoneware (Nov 21, 2022)

My shredder is looking up, water jet operation cost $175.00 an hour, AR 450 3/8" $55.00 square ft.

Asked if i had off the shelf gears with round diameter holes if they could be cut into a hex profile - no problem

Large gear reducers often show up at the scrap yard, mostly discarded because of a motor burn out.

One shredder I looked at used a 40:1 reducer, each cutter had .005 shim between each cutter tp prevent binding.

Not going to bother with trying use grader blade cutting edges, the price of AR is reasonable.


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## stoneware (Nov 21, 2022)

From the second load, 211.2 plus another 10 grams from the foam - lots of base metals in this lot.


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## Ohiogoldfever (Nov 21, 2022)

stoneware said:


> A Harbor Freight cement mixer would accomplish the same job with the benefit of easier off loading.
> 
> View attachment 53231



I have this mixer. Picked it up a couple months ago when laying the block foundation for my garage addition. It will be used for grinding whenever I get to it.


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## stoneware (Nov 21, 2022)

Ohiogoldfever said:


> I have this mixer. Picked it up a couple months ago when laying the block foundation for my garage addition. It will be used for grinding whenever I get to it.


The first load, ran the shred through the paper shredder twice, good gold recovery.

2nd load shred only made it through the paper shredder once before it died, gold recovery was fair. Still a lot of gold plated material encapsulated in plastic and metal casings.

Dry run was also much better, the foam was very thick and it cushioned the material, keeping it from being abraded.

Usually passing a flame over foam will collapse it, or spraying water onto it. First tried the flame all it did was heat the metal foam red hot leaving the cell structure intact - water also a waste of time.

Two days dealing with the foam, mind you that 10 grams is good quality gold / possibly some palladium and silver.

I have the cons from the first run in aqua regia at the moment, from the first hot nitric wash we know there's no copper. The leach is green, think it's safe to assume - gold, palladium and silver to be present.

First metals to give up to the leach have actually left most of the un-reacted gold a beautiful tan color. Once I have some decent weather will proceed to the final refining stages.

2nd batch of cons has a lot of base metals present, it's currently in sulfuric acid.

Worried about breaking my glassware from thermo shock working outdoors so the leaches are currently at ambient temperature which is below freezing.

No heat in my shop yet so I moved everything into my kitchen. Time to haul out the junk.

What you have seen in this thread of my gold concentrates all came from what you see in the 20 liter pail.


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## stoneware (Nov 21, 2022)

First load into the mill ran five hours dry, 2nd load four hours dry then another four hours wet.

I've kept the water from my wet run to be used as rinse on the shred coming out of the mill when I rerun the crap in the 20 liter pail.

Just have to figure out someway to make the shred a bit smaller to expose the gold.

Ohiogoldfever if you give your mixer a work out perhaps you would consider append your results to this thread.


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## goldshark (Nov 21, 2022)

I think you have maybe discovered the path to floatation , using the reagents already combined in the make up of the boards. Perhaps a person like Deano can shed some light on the chemistry of what is happening. It would be a great idea if electronics manufacturers could take the reprocessing into consideration, making recovery a simple, green step.


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## stoneware (Nov 22, 2022)

This is the gold from the last load, used dilute sulfuric to remove base metals. Nice thing about sulfuric acid is that it's not voilent coming into contact with finely divided base metals.

Even though it's below freezing outside I could not resist, coffee carafe in a hot water bath protects it from thermoshock.

Filtering out the leach elements now using distilled water, this is not refined gold. I like to have my cons as clean as possible before going to the refining stage. Less chance of a boil over when the cons are clean.

Bottom image the heavies, 20 grams.


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## stoneware (Nov 22, 2022)

Sulfuric acid used to remove base metals, maybe some silver and palladium present.

Plating out the metals, easier to work with concentrates.

The recovered metals, good candidate for smelting.


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## stoneware (Nov 23, 2022)

My observations are, and my theory is,

Top to bottom, stainless steel anode, once the metal ions below nickel had been depleted, the anode became sacrificial. Refer to electromotive series chart.

The liquor now contains nickle ions causing the color change.

Image 1, Starting point, green liquor.

Image 2, Precious metals stripped out, liquor is now blue.

To remove the nickle ions, I'll switch out the stainless steel anode for a carbon electrode.

Image 3. nothing exciting here just the collected filtrate.

Image 4, incinerated filtrate, observation - gold on filter paper the whitish substance un-burnt sulfur residue from the acid.

Image 5, the recovered metal.

Image 6, the weight.

Image 7, Electromotive series of metals, how can you use it to your advantage. Metal precipitants and electrolysis come to mind.

Most of us use copper to cement silver any metals below copper will be recovered in your silver cell as slime.


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## stoneware (Nov 23, 2022)

While stripping out the metal ions had copper been present is would have been visible in the precipitate as copper metal.

During incineration I did notice some purple in the filter paper, this would have been gold.


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## stoneware (Nov 24, 2022)

Had a good day, picked up my acids got to speak with the chemist and learned how to precipitate palladium as palladium(II) sulfate.

On the way home stopped in at my favorite scrap yard and picked up a couple of gear reducers. The stainless one shown below is 40:1

The food plant where these come from discard the whole unit when a motor burns out, any single phase pump style motor will fit the flange.

In addition to the two reducers, picked up some screens used in a hammer mill, these came from the ethanol plant. I'm guessing AR 450 or AR 500 metal.

I'm very pleased with how quickly I'm able to gather up the most difficult and expensive parts for my shredder build.

Most heavy construction and farm equipment uses AR plate or sheet, Danny is going to give me a call when either some 1/4" or 3/8" material hits the yard.

He is also going to promote the collection of e-waste, he already has some mother boards but they were inside the shop behind bins that would have to be moved to access the boards. He said the crew would be back tomorrow.


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## stoneware (Nov 25, 2022)

Your probably wondering how I can couple the gear reducer to a hexagonal shaft 

Lovejoy manufactures couplers to connect dissimilar shafts.


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## stoneware (Nov 26, 2022)

Unrefined palladium with a bit of gold, this will be going to EDI in Ontario.

It appears to me the palladium content on e-waste exceeds the gold content.


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## kurtak (Nov 27, 2022)

stoneware - I am sorry but I have to call *total B.S*. on this thread - especially concerning the claims you are making on the recovery of PMs you are getting from the *very small amount of VERY LOW grade boards* you have run through your system

I am not even sure where to start here - but - lets start here -------

At this point you have run one 5 gallon (20 liter) bucket of shredded LOW grade boards through your system

What does that bucket of boards weigh ? --- 25 - 30 pounds (11 - 13.5 kg) --- lets go high & call it 50 pounds (22.72 kg)

On the "average" - one ton (2000 pounds) of *nothing but* modern day *mother boards* (which are higher grade then what you are running) will recover "about" (plus/minus a few grams) 3.5 toz gold (or about 109 grams) 

That means 50 pounds of (modern day) mother boards would give you a recovery of about 2.75 grams gold 

Yet you are posting numbers like -------


stoneware said:


> HCL wash, rinsed and dried *159.7 grams* from less than half a 20 liter pail.
> 
> *Gold, palladium. silver* with perhaps a bit of lead expected on the final refin


(posted Nov 9) --- per the bold print - 159.7 grams (Au/Ag/Pd) from LESS then a bucket (so less the 50 pounds) --- NOT A CHANCE - you will be lucky if there is a gram of all 3 PMs in that 159.7 grams

Then again on Nov 9 you posted ----------


stoneware said:


> Bottom dregs, palladium with a bit of gold.
> 
> Plastic tub tare weight, 18.1 grams
> *Palladium Net, 33.5 grams*


Again per the bold print --- 33.5 grams of Pd from LESS then a bucket (so less then 50 pounds)

Sorry - *but NOT going to happen *- you would be *lucky* if you got that much Pd from a full ton (2000 pounds) of nothing but HIGH grade boards

Then yesterday you posted -----------


stoneware said:


> *Unrefined palladium with a bit of gold,* this will be going to EDI in Ontario.


Again per the bold print (along with pic on scale showing 93.4 grams) from one bucket that MAYBE weighs 50 pounds --- *just NOT going to happen*

Considering the boards you are processing you will be lucky if there is any Pd at all in that 93.4 grams 

And then you say ------------


stoneware said:


> It appears to me the palladium content on e-waste exceeds the gold content.


FACT - even the highest grade of *consumer* circuit boards will NEVER contain more Pd then gold

There are a FEW exceptions - but that would be *OLD* aerospace/military/telecom or *OLD* soviet stuff --- *VERY RARE*

I am going to give you some REAL recovery numbers on batches of boards I have done

All of these batches where done by shredding the boards - incinerating the shredded boards - ball milling after incineration - then smelting - then assaying on the smelt metal

All of these batches had at least 30% & up to 50% HIGH grade boards - high grade being RAM, hard drive, finger cards & telecom boards

Side note; - though these batches had more high grade & mid grade they also had some low grade (like 10 -20%)

All of them had at least 10% & up to 30% OLD stuff (mid 1990s & older) which contain much more PMs then modern stuff

in other words ALL of these batches had MUCH higher grade stuff then you are running in your system

These are the batches 

415 pounds of CBs (Circuit Boards) metal recovery - Au 1.98 ozt - Ag 3.15 ozt - Pd 5.9 grams - Cu 28.8 pounds

602 pounds of CBs - metal recovery - Au 1.26 ozt - Ag 4.57 ozt - Pd 7.46 grams - Cu 43.4 pounds

948 pounds CBs - metal recovery - Au 2.29 ozt - Ag 6.91 - Pd 15.23 grams - Cu 60.9 pounds

1041 pounds CBs - metal recovery - Au 2.53 ozt - Ag 7.8 ozt - Pd 19.28 grams - Cu 84.3 pounds

1632 pounds CBs - metal recovery - Au 5.22 ozt - Ag 9.18 ozt - Pd 1.01 ozt - Cu 114.3 pounds 

Note; - the silver runs "about" 2-3 times higher then gold & the Pd runs "about" 1/4-1/3 of gold

So - considering the VERY low grade material you are running through your system (IMO) you will be LUCKY if you even recover 1 grams of gold (let alone 2 grams) *maybe* 1 or 2 grams silver & if you are *really lucky* maybe *a "trace"* of Pd from the 50 pounds (or less) CBs in your bucket 

stoneware - please understand - I am in no way trying to be rude &/or disrespectful --- just trying to give you a reality check here

50 pounds (or less) of very low grade stuff is *at best* only give you a couple grams of PMs - let alone troy ounces of PMs

Kurt


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## kurtak (Nov 27, 2022)

AND - just to add to my last post

The only PM you are going to recover with your system is the gold "plated" *on surfaces* of the board &/or pins

NO gold from bond wires inside IC chips (maybe a trace from broken chips)

Little or NO silver because the silver is found *inside* of components - *not surfaces*

Same with palladium - its found *inside* components - *not on surfaces*

All the abrasion in the world is not going scrape PMs off something the PMs are *inside of*

So MOST of the PMs are still left inside what the abrasion can't get to

Its a system designed to leave MOST of the values behind

It might work if you put nothing but gold plated pins &/or close cut fingers in it

But CBs - even shredded - is going to leave most of the PMs behind

Kurt


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## stoneware (Nov 27, 2022)

kurtak said:


> AND - just to add to my last post
> 
> The only PM you are going to recover with your system is the gold "plated" *on surfaces* of the board &/or pins
> 
> ...


The glaciers did a pretty good job of reshaping the earth.

Using the small hatchet mother boards were depopulated, do you suppose those small surface mounted caps may have survived the beating.

Those that did were incinerated.

As for the Pd with the gold content, figured too much gold so It's in AR. Now waiting on the weather to change. This type of work is done outdoors.

You may recall the concentrates were pr-cleaned of base metals.

Now that you've added your two cents. it's time for you to replicate the process and give us some real data


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## stoneware (Nov 27, 2022)

Junk like this went through the shredder, to recover the gold you have to expose it.


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## stoneware (Nov 27, 2022)

Gold from plasma TV's went into the mill, Pd caps from PSU's


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## goldshark (Nov 27, 2022)

kurtak said:


> AND - just to add to my last post
> 
> The only PM you are going to recover with your system is the gold "plated" *on surfaces* of the board &/or pins
> 
> ...


Kurt, maybe he started with one of those rare PM lined special propane tanks. Then it would make sense.


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## kurtak (Nov 28, 2022)

Hi stoneware

As I said yesterday - in no way am I trying to be rude &/or disrespectful

I am simply saying that the expectations you have for PM value recovery with your system are unrealistic - very unrealistic

To clarify - at the same time - I am NOT saying that your system won't recover value - it will

The question is - is the amount of values you can recover with this system worth the cost

Cost = time - energy (electricity) - chems - & dealing with waste

In other words - is the expected recovery worth the above cost

In order to determine that we need to look at the purpose of the system &/or the feed stock intend to be run in the system

So at least as I understand the purpose of your system *(and please correct me if I am wrong)* it is to recover the values left behind on CBs AFTER you have removed the higher grade components (such as IC chips - fingers - fully plated pin - etc.) as that stuff is processed through other systems/processes

In other words - chase the values left after high grading (depopulation) the boards

So - in order to come up with an expectation of recovery - for the "feed stock" to be run through your system we need to consider that feed stock & how we get to that feed stock

That means we first need to look at the values of CBs as a whole (where the values are on a whole CB) --- we need some sort of base line on expected recovery of values from whole CBs --- we need an example

We will focus on the gold

Yesterday I gave you the example of modern day mother boards --- modern day mother boards on average will give you "about" 3.5 ozt gold per ton --- that is full recovery by way of shred - incinerate - ball mill - smelt the whole CB

That means the full gold recovery of 1 pound modern day mother boards has an expectation of .05 gram gold ---- one mother board weighs about one pound

Now lets "high grade" that mother board (take off the IC chips & fully plated pins) to process by "other" means (bonding wire recovery from chips & gold foil recovery from fully plated pins)

This removes about 2/3 of the value from the boards as that is where most of the value is

That means (after depopulation) you are left with 1/3 the value of the whole board - for your feed stock

1/3 of .05 gram = .016 gram

That means if you run 50 pounds of this feed stock through your system (& got 100% recovery) you would end up with .83 gram 999 refined gold

Lets round that up to 1 gram --- 1 gram gold at current spot = $56.45

So is the cost of your time (several days to shred, mill, sift, water separate, chem work & deal with waste) energy (electric to run shredder, run mill, water pump, hot plate) chem & dealing with waste - is that cost worth it to get to $56.45 of 999 refined gold --- add in Ag & Pd we *may* get that up to $100 (based on *known* recovery from 1 ton boards) - so even at $100 - is it worth the cost ?

Even something like high grade telecom boards - about 90% of the gold value is in the IC chips & fully plated pins - so after high grading them (depopulating) - your feed stock is low graded to about 10% of its original whole board value

Stoneware - I do commend you on your build & all of your effort - *your build is absolutely awesome* - BUT - as a system for the recovery of value - it will ALWAYS be a system that will cost more then values it can possibly recover --- no matter how much you tweak it !!!!

The values in your feed stock (edit to add; - & be profitable) simply are not there

Kurt


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## stoneware (Nov 28, 2022)

Kurt your assuming that I had shred the whole mother board, which is not the case. 

The boards were cherry picked, the parts were fed through the shredder to expose the gold and other precious metals.

Abrasion works even the refineries use the method on appropriate material.

Personally I don't care if your a none believer nor do I care if anyone uses the method in the future.

You say the cost of equipment, electricity and waste chemical's make the process prohibitive.

The only waste I have from the milling process is 20 liters of water used to rinse the shred free of values. This water will be recycled in the next batch.

Now that I'm into the acid stage there will be some nasty waste to deal with but that's the nature of the hobby.


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## stoneware (Nov 28, 2022)

In this thread the discussion was about removing silver plate the most economical way.


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## stoneware (Nov 28, 2022)

For those interested in real science.

Experimental abrasion of detrital gold, read from page 203/212,

https://pubs.usgs.gov/journal/1975/vol3issue2/report.pdf


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## MicheleM (Nov 29, 2022)

stoneware said:


> Unrefined palladium with a bit of gold, this will be going to EDI in Ontario.
> 
> It appears to me the palladium content on e-waste exceeds the gold content.
> 
> ...


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## stoneware (Nov 29, 2022)

Cheap shot MicheleM

Palladium content in projection televisions, Hammond organs and PSU's where no gold is present, will change the percentage of gold in your concentrates.


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## kurtak (Nov 29, 2022)

stoneware said:


> Personally I don't care if your a none believer


stoneware --- it's not that I am a "non believer" in the concept of the ability to remove metal by abrasion

In fact quite the opposite - I fully understand how metal removal by abrasion works

It works on the physical force of friction when two sold objects are rubbed together - that is the basic concept

How effective the abrasion is depends on the physical characteristics of the object being rubbed together such as hardness &/or texture of the objects

Example; - if I take two polished copper bars & rub them together I won't remove very much metal from the surface of the two copper bars & that is because both bars are the same hardness & being polished have no real texture - I won't get a whole lot of copper powder abraded away from the copper bars

On the other hand - if I take a copper bar & rub it with a piece of 2000 alumina grit sandpaper I will get a nice pile of copper powder & that is because the alumina grit (alumina is a VERY hard ceramic) provides both hardness & texture to abrade copper from the softer copper bar ---at 2000 grit the alumina sandpaper will abrade copper in such a way that it will also polish the copper

That is why I use my vibrating tumbler to polish my brass for reloading ammo as well as polishing the sterling jewelry I make using crushed walnut shells as the "abrasive" polishing media - the walnut shell is harder then the brass/silver & as well the walnut shell has texture so it abrades brass/silver from the surface of the metal which polishes the metal & there will be metal powder in the walnut shell polishing media

I know that you understand this & that I don't need to explain it to you --- I post all of the above to show that I also fully understand the concept of abrasion

So in no way am I saying that your abrasive mill won't work & in fact I posted that yesterday when I said ----


kurtak said:


> To clarify - at the same time - I am NOT saying that your system won't recover value - it will



Rather - my issue here - is the very unrealistic expectation of PM recovery you are posting about here with your abrasive mill --- & that is especially true when I consider the feed stock you are running in your mill

Example; - you posted ---------


stoneware said:


> Unrefined palladium with a bit of gold, this will be going to EDI in Ontario.
> 
> It appears to me the palladium content on e-waste exceeds the gold content.



along with that you posted a pic of your scale read out of this powder (also pictured) to be 93.4 grams of unrefined palladium --- recovered from (about) 50 pounds of CBs run through your system

93.4 grams equals 3 ozt of Pd recovered from 50 pounds of CBs

that is not only unrealistic - but in fact outragedly unrealistic

it takes one full ton (2000 pounds) of CBs to get about (plus/minus) 1 ozt Pd

Yet you claim to be recovering 3 times that much Pd from only 50 pounds of CBs

So your claim is not just unrealistic - but unrealistic to the point of outrageous

And I am sorry - but the same holds true for the recovery expectations for gold & silver

That is because your feed stock (shedded CBs) is *very low grade* to start with (you can not recover 10 grams of gold from something that only contains 1 gram of gold to start with) & your system is not 100% efficient (in fact far from it) meaning you will suffer at least some loss at every step in the process

Bottom line - if the feed stock is low grade to start with the cost of processing is likely going to exceed the value of recovery --- so your feed stock needs to be high enough grade that the recovered value exceeds the cost to process

Your feed stock is not high enough grade to exceed processing cost

How do I know that --- because I spent 10 years making a living (making a profit) handling CBs by the ton - like 2 - 4 ton per month every month 

I made my money by

Selling boards by the ton --- I sold all the low to mid grade stuff because trying to process it cost more then I could recover from it --- you CAN NOT make money processing 50 to 100 pound of this stuff at a time --- to make money processing this stuff you NEED to process it by the ton(s)

Sending boards by the ton to board smelters --- I sent my mid to mid/high grade stuff to a smelter because sending this stuff to the smelter paid a bit better then selling it to board buyers --- & again with this stuff - you CAN NOT make money processing 50 to 100 pound of this stuff at a time --- to make money processing this stuff you NEED to process it in batches by the ton(s)

And then I actually processed *(only the very highest grade stuff)* in large leaching or smelting batches (30 to 60 pound batches)

I think I know what I am taking about when I say - abrading LOW grade feed stock will cost more then you can recover

On the other hand - if you abraded *only* HIGH grade stuff - like gold plated fingers &/or fully plated pins you would make money

You will understand this when you finally actually recover the small amount of values from your acidic leach solutions --- it will not be even close to what you expect - you will be lucy to make what one day of work at a regular job pays you

I speak from years of experience --- making money --- handling CBs

You need to ether process VERY HIGH grade stuff --- or you have to process ton(s) of low grade stuff it in order to make money processing CBs

Kurt


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## MicheleM (Nov 29, 2022)

stoneware said:


> Cheap shot MicheleM
> 
> Palladium content in projection televisions, Hammond organs and PSU's where no gold is present, will change the percentage of gold in your concentrates.


Clearly you don't know what you're talking about, even the colors are wrong. Anyway it's your time being wasted not mine.


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## stoneware (Nov 29, 2022)

Kurt you were concerned about the cost of electricity.


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## stoneware (Nov 29, 2022)

MicheleM said:


> Clearly you don't know what you're talking about, even the colors are wrong. Anyway it's your time being wasted not mine.


You might be right, the mud could be copper.


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## ChopperGreg (Nov 29, 2022)

stoneware said:


> In this thread the discussion was about removing silver plate the most economical way.
> View attachment 53365


Link?


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## stoneware (Nov 29, 2022)

ChopperGreg said:


> Link?


Best Ball Mill Media for Plated Silver Removal​Link


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## goldshark (Nov 30, 2022)

Are you sure that you're not displaying a Pumpkin Pie? It would be funny if you pulled the wool over everyone's eyes at Thanksgiving, and nobody knew the difference.


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## Yggdrasil (Nov 30, 2022)

Just my two cents.
I really do not like abrasion much, it is simple and fast but rarely complete.

Back in the days I was working with machining and welding Stainless Steel.

One always had to acid treat the weld seems to remove the oxide film.

Stainless aren’t very stainless unless it’s clean, even a paint spot can give rise to corrosion.

Anyway the acid paste was a nasty concoction containing amongst other HF, so we started glass bead blasting resulting in a fantastic finish… for a while. 
But since abrading are not complete it started corroding after a while any way.

Upon investigation we found out that the blasting left behind quite a bit of invisible oxide layer in specks. It actually just pushed it around.

So for abrading you need to remove quite a bit more than you believe to be complete.


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## kurtak (Nov 30, 2022)

stoneware said:


> Kurt you were concerned about the cost of electricity.


It's not that the cost of electricity in & of it's self is a big concern but the fact is that it is a cost none the less which is in addition to all the other cost

So if you run 50 pounds of very low grade material that is going to only recover a gram of gold then the cost of the electricity is only one cost factored into over all cost

This is why the grade of the material that you run in a system - any system - has to be high enough grade material that it will cover all cost plus some for profit on top of the investment cost 

To put it somewhat in perspective lets use a hypothetical example

Lets start with 50 pounds of very low grade feed stock - so low grade that it only has 1 gram of gold in it & we will assume 100% recover (which NEVER happens) but lets assume that anyway We are talking about the kind of stuff you are running in your abrasive mill)

Lets call that 1 gram worth $55 at spot price (which again you are not going to get)

Now lets say running the shredder - the mill & hot plate only adds 5 dollars to your electric bill

The 1 gram gold is now worth $50

But then you also use another $10 in chem to get to that nice 999 refined gold button

The 1 gram is now worth $40

But - because you in fact will not get spot price & in fact will not get 100% recovery we can now figure in another $5 - $10 in loss

You now have a gold button (a bit shy of 1 full gram) worth $30 - $35 --- lets go with $35 for your actual gold value

Now lets look at the BIG cost - the cost of your time

1 day to shred 50 pound CBs - no time to run mill as you can do other things while the mill runs - 1 day to sift/wash the powders out of the shredded CBs - then - at least - 2 more days for all chem work - filtering - gold drop - wash chem out of gold drop - dry gold drop - melt gold into button

So - *at least* 4 days time (factored at 8 hour day) equals *at least* 32 hours of your time (probably more like 6 - 7 days)

Lets say your day job pays you $20/hour - that means the 32 hours time value is $640

Now I know you are going to say - "but Kurt this just a hobby so I don't care about my time" --- but lets be real here --- this hobby &/or any other hobby you do - you at least want to some kind of value return for the time spent at that hobby

So lets say your hobby time is worth $5 --- in order to have that feeling that the time you just spent on the hobby had some value --- 32 hours X $5/hr = $160 --- to recover $30 - $35 worth gold

AND - that is not the only time cost for that $30 - $35 of gold because you had to take time to run around in you car - put gas in your car (actual money spent on gas) to drag electronic stuff home - & the time to tear CBs out of the electronics to get your feed stock --- so even more time 

And you have ended up with a pile junk in your back yard from tearing down electronics & a bucket full of TOXIC waste from chem work in your back yard --- to process 50 pounds of CBs

I know - now you are going to tell me --- "but Kurt I am cherry picking the higher value stuff like IC chip, fingers, fully plated pin, etc. to process also --- & I get that

BUT - processing all of that is also going to take MORE (MUCH MORE) of all the above - on the same 50 pounds of boards 

50 pounds of modern day mother boards will give you right at 3 grams of gold (IF you recover 100%) which is worth (about) $165 --- the fact is - you will NEVER recover 100% with back yard refining - at best 2/3 so you are down to 2 grams worth $110

Ya but Kurt some of the boards are going to be higher grade

OK - lets double that to $220

Ya but Kurt what about the silver & palladium (to be honest you are not going to see much here *maybe* $100)

But - lets double it again to $440 

Ya but Kurt I can sell the iron - aluminum & copper/brass to the scrap yard

OK - lets add another $100 --- for a total of $540 from processing 50 pounds of CBs

To get that $540 dollars in value it is going to cost you (about) one month in time - $10 - $15 in electric & (about) $100 in chem - with 2-3 buckets of TOXIC waste in your back yard 

So --- $540 actual recovered metal value minus $100 actual cost = $440

So --- is a month of your time - the mess you create in your back yard - & the buckets of TOXIC waste you end up with in your back yard worth that $440 in metal you recover from processing 50 pounds of consumer grade CBs ???? 

Ya but Kurt that's just one 50 pound batch & I plan on doing more then just that one 50 pound batch

Really - OK - then you are starting to approach a fulltime job - if not a fulltime job --- would you work at a fulltime job for $440 a month

Ya but Kurt I am going to improve my system to get better results

OK - lets double it again plus a bit to $1000 a month --- would you work a fulltime job for $1000 a month

The bottom line is that you can not - will not make money *processing* low grade consumer CBs 

Now ask me how you make money *processing* CBs 

Kurt


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## stoneware (Nov 30, 2022)

kurtak said:


> It's not that the cost of electricity in & of it's self is a big concern but the fact is that it is a cost none the less which is in addition to all the other cost
> 
> So if you run 50 pounds of very low grade material that is going to only recover a gram of gold then the cost of the electricity is only one cost factored into over all cost
> 
> ...


I'm retired been on pension for the past 8 years, they pay me to stay at home so people like you have a day job.

What I do is far cheaper than sitting in the pub buying rounds for the freeloaders.


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## goldshark (Nov 30, 2022)

As long as you know the real numbers, and can live with it, it's ok in my book. Everybody needs a putz. Sure beats standing on a street corner begging for change.


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## stoneware (Dec 1, 2022)

Now that the mill is sitting idle, we're preparing 50 pounds of silver plate for abrading.

Garnet will be the abrasive used, as it's imperious the most acids which may become relevant during the final recovery


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## ChopperGreg (Dec 1, 2022)

stoneware said:


> Best Ball Mill Media for Plated Silver Removal​Link


Thank you


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## stoneware (Dec 7, 2022)

Kurt your sales pitch needs boning up, that 20 liter pail contains the goods from over 1000 pounds of various types of boards. 

Surface mounted caps, BGA's, Cpu's and whole ram sticks went through the shredder before tumbling.

I'm not trying to sell anything just sharing information, take it for what its worth, gold is a very soft metal usually platted over nickle to keep the gold from migrating into the copper.

Wave soldering picks up gold, the solder underneath cpu sockets are a good candidate to absorb some gold.

Using the small hatchet, I have it all.

By the way copper rubbing against copper will wear the copper wihtout some sort of lubricant,


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## stoneware (Dec 12, 2022)

The gold is in with the copper,

How would you go about recovering the gold.


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## orvi (Dec 12, 2022)

stoneware said:


> The gold is in with the copper,
> 
> How would you go about recovering the gold.
> 
> View attachment 53687


I will consider to shot this down with XRF in order to find out what you are actually doing. There are far to many assumptions in a row in your recovery venture.
First of all, I can say, that from modern motherboards, most of the gold is in the CPU and (usually) 2 BGA chips. This can comprise sometimes even 40-50% of total gold content on the average motherboard of WinXP computer. Then there are pins and smaller chips+transistors. This era MLCCs are junk for the most part - base metal types, some good ones on the some CPUs. Silver - mostly from caps and RuAg resistors. Really, not much of the stuff to be found here. Value lies in the tin, copper and gold - other precious metals are just added bonus.

And I would say it would be very difficult to get the gold bonding wires from the plastic via abrasion. Smearing is very bad thing which happens all the time when you have soft metal like gold. 

Tested batch of connectors with pins running like 7g/kg gold was shredded to liberate free metal from the plastic. Loss of gold was about 2-10% on the plastic, depending on the type of plastic and shredding method used. No metallic pieces were left in the light fraction. Just smeared gold on the surface of the light stuff. It could even be measured with XRF. Second, once you have soldered something, gold cannot be reclaimed with abrasion.

Pick the cherries if you want to process something and sell the rest as lowgrade. No waste on your side, no hassle due to processing and nice material in your hand to play with. After catching goldfever, most important part to stay sane is to abandon processing unpopulated boards  then, it will go easy. I also wanted to set up bigger shaft furnance scaled to around 100kg/day. I am glad that I never worked it out and never tried to build that thing


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## goldshark (Dec 13, 2022)

My guess, is the Copper is well above the 75% range, so inquartation may work. Try a 1 gram digestion in Nitric, and see what happens. Small amounts will not lead to an excess of HMs. I don't know if you have a good microscope to see if there are foils coating the Copper, but would think this is the case, since you are grinding, and not chemically, or thermally alloying the metals. Mind you, the Au may be only microns thick, so may be difficult to identify on Copper, and the Nitric digestion may produce Au in very thin, flat particles, but should filter in a very fine filter. Please keep us posted on results.


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## Yggdrasil (Dec 13, 2022)

stoneware said:


> The gold is in with the copper,
> 
> How would you go about recovering the gold.
> 
> View attachment 53687


An AP leach will be fast on this kind of powdered copper, making the Gold and possibly Silver accessible for a more targeted smelt or leach.


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## orvi (Dec 13, 2022)

Yggdrasil said:


> An AP leach will be fast on this kind of powdered copper, making the Gold and possibly Silver accessible for a more targeted smelt or leach.


I would personally dissolve this in straight AR and test with stannous. If it is some kind of concentrate, it should show nice black positive. If it fail to make black positive stannous I wouldn´t mess with this anymore.
Any kind of digestion, either in AP or straight nitric would most probably produce ultrafine gold sludge (if gold is there) which would be harder to process and separate via decantation - as I think that in that small concentrations, it would pass filter papers easy


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## stoneware (Dec 16, 2022)

I now have copper sulfate, filtered out, tin sulfate removed after it was dissolved in hot distilled water.

The filtrate left is a very nice chocolate brown with silver sulfate.

I'm going to incinerate the filtrate, my thoughts are that heat will decompose the silver sulfate into metallic silver.

I've added scrap iron for the next incineration.


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## stoneware (Dec 16, 2022)

The mud waiting for incineration, the scrap iron has some redox taking place - silver looking material.

Could be silver or possibly palladium.


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## stoneware (Dec 17, 2022)

The color of the mud after the hot oil of vitriol treatment.

Top image before treatment.


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## stoneware (Dec 17, 2022)

The insoluble.



















t


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## stoneware (Dec 17, 2022)

Incineration of the filter mud, before and after.


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## stoneware (Dec 17, 2022)

Electrically removing tin, anode is in the flower pot.


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## stoneware (Dec 18, 2022)

The material below 146.7 grams after hot nitric digestion.


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## goldshark (Dec 18, 2022)

Not to be too nitpicky, but gr. usually stands for grains, gms. stands for grams.


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## stoneware (Dec 18, 2022)

goldshark said:


> Not to be too nitpicky, but gr. usually stands for grains, gms. stands for grams.


Good catch goldshark.

Scale uses the ( g ) symbol for grams, the scale has been weight tested at its current elevation and recommended ambient temperature and with a pair of 500 g test weights.

This evening with a room temperature of 55 °F the scale is off by half a gram.

Decent scales shipped from the factory are calibrated for sea level. I'm 1,875 ft above.


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## stoneware (Dec 19, 2022)

Tin an interesting metal / oxide, have plenty to experiment with.

Tin (IV) oxide is amphoteric in nature. *It reacts with acid as well as with base*. It reacts with strong acids and forms tin (IV) salts as a product. 

Tin (IV) oxide acts as a reducing agent as in this compound tin is in its highest oxidation state.


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