Non-Chinese PCBs

All,

I tried smelting 107 grams of shredded non-Chinese motherboards last night in a small induction furnace, and here is the result;
The smelt metals and ashes from melting epoxy and plastic,


After some grinding and removing the metallic buttons which vary in colors from the ash,


Here is final shot after separating the visible metals from the mess


So the total mass from the furnace was 107 grams the net weight of metals 31 grams, now Can I use the goldbug system made by precious metals refining co to separate Cu Au Pd and Ag from dissolving the alloy in AR?


Best regards,
Kevin

Are you receiving your boards shredded Kevin, or are you shredding them yourself?

If you are receiving them shredding is there a reason why you cannot get them complete?

for the sake of you experiment i suggest that you mill your black residue ,than dump it in water to allow a mecanical separation of burned non metalic and the metalic.
im very doubtfull that you manage to recover the gold from the ic that way but im often wrong so...

spaceships said:

Are you receiving your boards shredded Kevin, or are you shredding them yourself?

If you are receiving them shredding is there a reason why you cannot get them complete?

Click to expand...

Spaceships,

No I have them in complete forms, and shred them myself to ease the smelting.


Regards,
Kevin

ericrm said:

for the sake of you experiment i suggest that you mill your black residue ,than dump it in water to allow a mecanical separation of burned non metalic and the metalic.
im very doubtfull that you manage to recover the gold from the ic that way but im often wrong so...

Click to expand...

Last time I smelt gold finger cards, using the same induction furnace, it showed 3200 ppm Au in the bulk metallic parts, and no trace in the ash. I think a much better procedure to separate the metals from the ash would be ball mill follow by passing through a seive 10 micron. Ashes pass through the metals stay on top.

I want to test the metals of interest myself using hcl or nitirc acid.

Best regards,
Kevin

If you're taking in PC motherboards, wouldn't you save yourself a lot of work later by just depopulating the boards and smelting the product you take off the boards?

At the least then you'll be taking the majority of the copper out of the process from the layers in the board out of your melts. At the very least you could remove the known gold bearing items and concentrate your process.

Hi kjavanb,
maybe this is whatyou are looking for?

Pat

spaceships said:

If you're taking in PC motherboards, wouldn't you save yourself a lot of work later by just depopulating the boards and smelting the product you take off the boards?

At the least then you'll be taking the majority of the copper out of the process from the layers in the board out of your melts. At the very least you could remove the known gold bearing items and concentrate your process.

Click to expand...

Copper is a major base metals in most boards, and recovery of it is easy, and most of the precious metals are recovered at the anode in this process. My objective in this experiment is to smelt all metallic components from the entire board, then based on analysis find an optimum solution to recover precious and non-ferrous metals as many as possible. Hence no cherry picking for me.

Pat,

Thanks for the file, I had seen it on Umicore website before. But so many models and boards out there you cant really know exact value for each boards till you test them yourself and this is what I have been doing.

I will continue this post with ICP analysis of 120 elements in these metallic buttons, and will show you.


Regards,
Kevin

Thanks for the reply Kevin

If you're looking at an optimum way to recover the PMs and non ferrous metal then bearing in mind the relatively tiny amount of gold on PC motherboards, if you have a way to concentrate that gold without contaminating it in a massive way you could look at doing that.

Spaceship,

I am getting PCBs in 2000lb lot, so this is no home business for me. Will post yield and results soon.

Regards,
Kevin

Kevin don't worry I wasn't implying that it was a home business. I would suggest though that you look at the yields on these boards in a very detailed manner to make sure that your buy price isn't unrealistic in terms of return.

2000lb is a reasonable lot. PC motherboard is very often refining at less money than it trades for these days, as there is a perceived value between traders that isn't lived up to once it hits a refinery.

I would love to be able to refine our board in the UK however the licencing and H/S requirements make it nigh on impossible.

Try to melt a sample with an equal amount of borax, And also try to get a conical mold to pour in to.

You will be left with a consistent alloy at the bottom and the slag on top.

This might cost a little more than your normal procedure due to the Borax, But it's very efficient and fast.

On the long therm this method would be much more profitable, and also the alloy can directly be separated in an electrolysis cell, if the copper content is <96%. Thus eliminating the need for a remelt, ball milling and recollecting the small alloy beads. You could also calculate the copper content from one crushed sample, and add copper while you are melting the crushed boards. Ensuring an efficient run in the Cell. The copper is recovered from the cell and added to the next batch.

9kuuby9 said:

Try to melt a sample with an equal amount of borax, And also try to get a conical mold to pour in to.

You will be left with a consistent alloy at the bottom and the slag on top.

This might cost a little more than your normal procedure due to the Borax, But it's very efficient and fast.

On the long therm this method would be much more profitable, and also the alloy can directly be separated in an electrolysis cell, if the copper content is <95%. Thus eliminating the need for a remelt, ball milling and recollecting the small alloy beads. You could also calculate the copper content from one crushed sample, and add copper while you are melting the crushed boards. Ensuring an efficient run in the Cell. The copper is recovered from the cell and added to the next batch.

Click to expand...

Thanks a lot on great tips for smelting, as for electrolysis process after that, I have been talking with Precious Metals Processing Consultants, that would eliminate adding extra copper to reach over 95% copper content?

Best regards,
Kevin

kjavanb123 said:

Thanks a lot on great tips for smelting, as for electrolysis process after that, I have been talking with Precious Metals Processing Consultants, that would eliminate adding extra copper to reach over 95% copper content?

Best regards,
Kevin

Click to expand...

Copper electrolysis, will need an anode of at least <96% copper content. If it's lower than that, other metals will start to plate on your cathode and you'll start to have many problems after that. Unless the scrap itself contains more than 95% then this would work out without any addition of copper. Their is no other way around this, Unless those Consultants are speaking about another method other than electrolysis. The Copper you'll be adding would be a one-time purchase only, besides the growing number of scrap you'll have to buy more.
But It is always recovered back. So no additional costs here, If the scrap doesn't have a copper content of <95% that is.

Kind regards,

9kuuby9

kjavanb123 said:

ericrm said:

for the sake of you experiment i suggest that you mill your black residue ,than dump it in water to allow a mecanical separation of burned non metalic and the metalic.
im very doubtfull that you manage to recover the gold from the ic that way but im often wrong so...

Click to expand...

Last time I smelt gold finger cards, using the same induction furnace, it showed 3200 ppm Au in the bulk metallic parts, and no trace in the ash. I think a much better procedure to separate the metals from the ash would be ball mill follow by passing through a seive 10 micron. Ashes pass through the metals stay on top.

I want to test the metals of interest myself using hcl or nitirc acid.

Best regards,
Kevin

Click to expand...

that is very surprising to my understanding of the process but number dont lie, how did the ash were tested?

edit : red blood cell are about 12 micron , portland cement is 74 micron i doubt the ash will pass tru 10 micron...

Did I overlook something? I didn't see any yields for nickel. I had thought that gold was plated over top of a nickel plating. Where am I making my mistake?

Bert

bswartzwelder said:

Did I overlook something? I didn't see any yields for nickel. I had thought that gold was plated over top of a nickel plating. Where am I making my mistake?

Bert

Click to expand...

These beads have not been analyzed yet.

Regards
Kevin

The standard way of doing this is to incinerate until all carbon has been removed, ball mill to break up the ash, screen at 10-12 mesh or, maybe, as fine as 20 mesh, melt the metal on top of the screen and cast into bars, sample the ash that goes through the screen (pulps) with a grain sampler, drill the bars, assay the bars and pulps, and ship bars and pulps to a primary copper smelter (usually in Europe).

10 mesh is about 2000 microns. 10 microns is about 1250 mesh. Eric is right, you'll never get that material through a 10 micron screen. I doubt if you could get it through 100 mesh (150 micron). I have screened the ball-milled incinerated ash through a 40 mesh (420 micron) screen and it took quite awhile to do it. And I would imagine that ground incinerated ash would be finer than what you would obtain by grinding the material you have. If you used fluxes in the melt, that would probably even make the problem worse.

I can't see that what you have done will be feasible, at all, on a large scale. Even with shredding, the un-incinerated boards will occupy a lot of space. Even a big furnace wouldn't produce much volume, as opposed to what you could do by incinerating first and then melting only the metallics. As far as fumes go, I would guess you would get as many fumes by direct melting as you would by incineration. Whether you incinerate or don't incinerate before melting, you still end up with a pulp that contains metals. The amount of pulp you are generating by direct melting will be greater because it still retains most of the elemental carbon.

We always used gas furnaces to melt the metallics. If the copper percentage was too low, we had to add copper to reduce the melting point so it would melt in the gas furnace. I'm thinking the copper had to be at least 75-80%. On average, I would guess the copper ran about 80-85% in the final refiner's bars. The remaining percentage was composed of the 20, or so, other metals found in the boards. These impurities will cause all sorts of havoc when you attempt to plate the copper out. What type solution do you plan on using (very important)? I doubt if the gold bug will work with the amount of impurities that will be present. However, you can probably send them some refiners bars and see if they can work out a system for you. The only successful electrolytic system I've seen work on refiners bars was a membrane cell with an anodic membrane (only passes anions) divider using about 10% sulfuric. The membrane prevented the metals from plating out. The PM's remained in the anode sludge and were filtered out. The copper was cemented out of the solution with iron.

GSP,

This induction furnace I used is consuming only 40kw-hour, which is very cheap locally, plus the entire loading to complete smelt takes only 10 minutes, I used borax but not enough, plus I poured the mess into a graphite crucible, rather a colical mold. But isn't this same as incineration both produced ashes and smelted metals.

As for copper percentange, the sample gold finger cards I smelted, it contained 58% Cu, and 38% Zn, and 3200 ppm gold, how would I to remove zinc which will set the alloy copper content to 95% plus purity along with gold and other precious metals? Since it is alloyed I assume pyrometallrugy is out of the question right?

Regards,
Kevin

kjavanb123 said:

GSP,

This induction furnace I used is consuming only 40kw-hour, which is very cheap locally, plus the entire loading to complete smelt takes only 10 minutes, I used borax but not enough, plus I poured the mess into a graphite crucible, rather a colical mold. But isn't this same as incineration both produced ashes and smelted metals.

As for copper percentange, the sample gold finger cards I smelted, it contained 58% Cu, and 38% Zn, and 3200 ppm gold, how would I to remove zinc which will set the alloy copper content to 95% plus purity along with gold and other precious metals? Since it is alloyed I assume pyrometallrugy is out of the question right?

Regards,
Kevin

Click to expand...

The ashes are totally different. Yours are full of carbon and the carbon in the incinerated ashes has essentially been removed by burning. Some carbon in yours has probably been burned off but most is still there. The flux coated it and prevented oxygen from contacting the carbon. Look at the color. The black is carbon. Well incinerated ash will usually be a light gray. Carbon tends to retain PM's.

According to the numbers you gave, I estimate the value of the boards is $12/pound. However, in the grand scheme of things, considering that the values on boards can run all over the map, the sample you ran is so tiny it is meaningless. If you ran 2000# of material, it would be a different story. BTW, at 5 melts/hour in that induction furnace, how long would it take to run 2000#?

Awhile back, I think I posted some patent and book links that gave methods of separating Cu from Zn, electrolytically.