processing motherboards, is this the way to go?

[mike6]

Gentlemen

I am pleased to report that I am now refining silver efficiently and consistently. I have developed a small client base and am operating my micro refinery on a full time basis.

This development is in no small measure due to the gold refining forum.

I would like to thank, among others, especially, Palladium, GSP, Harold V, Frugal refiner and G Axelsson for taking the time to answer my questions and for sharing their hard won knowledge.

I have not posted over the past few months because I have been researching the concept of urban mining, with specific reference to the recovery of gold from computer scrap.

I have applied the techniques prevalent on the forum, and appropriate to my geographical and financial situation to the recovery of both ceramic and fiber CPU’s, fingers, N/S bridge chips, ceramic and plastic IC’s, and am content that my yields are on par with those reported on the forum.

It is at this point that I request guidance in choosing a horse to back with regard to the final refining process.

At present, I have access to 600lb batches of standard motherboards.

Boards are de populated using a Ryobi multi tool with a wide chisel attachment to “bare board” level

High yield items are sorted and removed for traditional processing.

What remains are connector pins encased in plastic, as well as tiny mlcc’s, capacitors, etc.

I have built a pyrolysis chamber, as well as a ball mill, and am succeeding in separating carbon from metal (precious or otherwise)

It is my intention to smelt the resultant metals with copper and chapman flux, and then again with legend flux in the process described by Jason Gaber at MBMMLLC. (Video on youtube),https://www.youtube.com/watch?v=ko608Ti7lcsproceed with electro refining of the copper, and then to process the slimes for PM’s.

Gentlemen, I cordially invite your constructive participation in this discussion.
Mike

 

[mike6]

Gentlemen

I am concerned that I have some how offended the GRF community in my ignorance.

I am aware that it has been suggested, that when foolish questions are asked, that they simply be ignored.
This seems to be the case with my question regarding the processing of low value items from motherboards, using Chapman flux, and a process rather suited to the removal of flour gold from black sand.

I have delayed trying the process, until some one, more knowledgeable than myself, had a chance to poke a few holes in my experiment.

Despite the fact that the question has been viewed in excess of 100 times, not a single comment has been forth-coming.

If I have made some sort of mistake, I would appreciate it if one of our administrators could point me in the right direction.

Mike

 

[solar_plasma]

I do not believe that anyone is ignoring you and I cannot remember any incident where you might have been ignorant. I remember your beautiful silver cell setup though.

When nobody answers then it might be because they do not feel that they could add anything useful. Those who could maybe just do not feel that they have time to answer your question to their own satisfaction. Maybe it would help, if you could specify some main problems, that can be answered in few sentences.

If I can help by pointing you to some readings about smelting and about electrolytical copper refining, I will gladly do. But I have extremely little practical experience on this matter.

 

[FrugalRefiner]

Mike, speaking only for myself, you have not offended me. I read your post. I did not comment because what you propose is beyond my experience. I do, however, respect the opinions of those who have tried to process whole motherboards when they have suggested that when done on a small scale, it will be very difficult to make any profit, let alone not lose money.

Dave

 

[solar_plasma]

I looked into your old posts. Maybe the discussion about rudeness in the forum has not been really lucky. As a medium long term member I am not amused when people come here thin-skinned, criticize this and that and want to change the way the forum is moderated, since I felt it comfortable just from the beginning and I am thankful for this high quality moderation.

On the other side people did not stop to answer to your posts.

 

[mike6]

Thank you Sir.

I was beginning to feel lonely in cyberspace! I am relieved to hear, that in my absence, I have not become persona non grata.

I guess I was looking for some re assurance that the process actually had merit. I think I may be at that stage of the refining learning curve where I have just enough knowledge to be dangerous! :lol:

I will take your advice and proceed with bench top experimentation, post pics and findings, and when I stumble, call on the GRF paramedics to apply a bandaid.

Thank you for your reply.
Mike

 

[mike6]

Solar Plasma

I am not sure I entirely understand the contents of your previous post. Would you be so kind as to elaborate?

 

[solar_plasma]

Only the third possibility why someone doesn't answer. But I guess the first two are the reasons for not answering (no idea or no time).

 

[mike6]

Thanks Solar plasma

I would hate to think that the "thin skinned" among us would be ostracized by the thick skinned for advocating good manners on the GRF, Or God forbid, burned at the stake for not wishing to remain steadfastly in the dark ages.

 

[FrugalRefiner]

Let's try to stay on topic.

Dave

 

[artart47]

Hi Mike ! I just had the thought that it may be helpful to see what is actually left behind on the depopulated boards. There may not be enough values to justify the processing or may-be there is. If it were me ( at my present stage of ignorance) I'd probably do a couple hundred pounds of them so I could smelt the metal content. Then, be able to have someone do an assay. If they end up being low grade sell them off after you depopulate them
Art.

 

[mike6]

Gentlemen
today I began preparing a 3kg (6.6 pounds) batch of motherboard components for the chapman flux experiment.

I am happy to report that the pyrolysis of the sample went well, and all components are brittle enough to be crumbled between two fingers. The capacitors in the mix popped with exactly the same sound as popcorn in an enclosed pot. The pyrolysis chamber flue is vented back into the heat source, so I am not concerned with a buildup of pressure within the chamber.

I attach some pictures of the sample before and after the pyrolysis phase.

My next step will be to introduce the pyrolysed sample into my home made ball mill for crushing and subsequent screening.

I am comfortable with the mechanical preparations, however, the processing of the mish-mash of metals, precious and otherwise that will remain, leaves me apprehensive.

I will use copper shot as the collector metal when I smelt the sample mixed with chapman flux, but do not know what to expect the resultant copper ingot to contain when I scan it with an xrf analyser.

Based on the attached pictures, your opinions would be greatly appreciated.
Mike

 

[upcyclist]

From a non-expert: Are you sure you even need a collector metal added? You've already got a lot of basemetals (copper, tin, steel, etc.) if you're now just seeing what else you can salvage from the "all others" category.

Another thought: if you do need to add collector metal, why not instead pyrolize & pulverize the entire board without depopulating it, and allow the PCB to provide your collector metal? You'd be opting for saving time (omitting a step) and spending more on extra acid (dissolving the copper traces).

In either case, since you are testing a business case, be sure to track your consumption of acids and other materials as well as your time. Actually, if you're testing, try both methods! And tracking your time is important--if you spend an extra $100 on acid but save 20 hours of work (extreme case), it's worth it.

Since you will be getting some very low-grade metals, you could use HCl for an initial processing, before nitric, since it's cheaper, though you'll also have to roast off any remaining HCl before you process with nitric. That'll dissolve the lead/tin/nickel/iron/etc. Forum experts, does this help, or is it better to just go all-nitric? Again, I'm assuming this is a time vs. money tradeoff, and time IS money.

 

[kjavanb123]

In my opinion, since I have been in your path before, if you chose the path of melting everything into a refiner bar, then pyrolyze the entire board, or even better shredd the boards, remove the ferrous, then pyrolsys, following ball mill, seive, melt the top of screen into a bar, and sell the fine ashes passed the sieves to sweep refiners.

Good luck

 

[Anonymous]

Mike what setup did you use to pyrolise those components?


Edit: Also what's the thought process behind pyrolising capacitors and resistors please?

Jon

 

[Geo]

Kevin makes a good point. I would remove the magnetics after milling and before smelting. If not, the flux could get loaded with iron quickly. NoIdea has some good ideas about what to do with the magnetics. He lets it oxidize to collect any precious metals that get collected with the magnet. It takes awhile but it's mostly iron anyway. When you have done enough to make the cleanup worth it, consider it a little bonus.

 

[MarcoP]

Is it me or I see unburned plastic? Left bottom corner, it looks like a laptop battery connector still intact. If so you should prolong the pyrolysis time.

Marco

 

[Pantherlikher]

Would it not be worth the time and effort to separate materials before Pyrolizing everything?
Removing capicitors, copper coils, etc.?
Seems to me you are not removing as much base metal as possible the easiest way. Take them out before hand.

Makes for many piles and takes time but in the end...would it not be worth the effort to process like material instead of everything at once.

A pile like that, my guesstimation would take me a half hour. I'm O.C.D. so very thorough.

B.S.

 

[Geo]

Would it not be worth the time and effort to separate materials before Pyrolizing everything?
Removing capicitors, copper coils, etc.?
Seems to me you are not removing as much base metal as possible the easiest way. Take them out before hand.

Makes for many piles and takes time but in the end...would it not be worth the effort to process like material instead of everything at once.

A pile like that, my guesstimation would take me a half hour. I'm O.C.D. so very thorough.

B.S.

The only thing I would recommend that needs to be removed before pyrolosis is aluminum. All heat sinks and as many caps as possible. All the copper needs to stay and he may even need to add more copper to the melt to bring the copper content to 95% for the parting cell. The iron can be removed after incinerating and before smelting. IC legs, brackets, nuts and screws. Some iron will have precious metals still so the iron should be kept and dealt with to recover these small amounts. Depending on how long and how much material is processed, this little amount could add up quickly.

 

[kurtak]

Mike

Sorry but somehow I missed your posting this thread until now - I can & will help you with this process but it will be a while as I am currently to busy to post details so that you can do your smelt properly & with the best possible out come - it may be a week or two before I can get to it but when I do the information will be as complete as I can make it --- For now I will just make a few comments

Kevin suggested sheading & incinerating the whole boards milling & smelting (with some other steps between the milling & smelting) & there is absolutely nothing wrong with his advise - however he is also using a different smelting technique then you intend to use so unless you intend to go with his technique I "do not" suggest the "whole" board process --- it will cause problems down the line with the copper collecting method of smelting --- Kevin is using a silver collecting method along with Pb/PbO in the smelt which deals with the base metal that are other wise a problem in the copper smelt method --- with Kevin's method you NEED "good" fume control along with scrubbing set up in the smelt operation to deal the fumes of the Pb/PbO

Geo posted

The only thing I would recommend that needs to be removed before pyrolosis is aluminum.

He is absolutely right - keep the aluminum out "before" going to incineration - in fact looking at your pics (before & after incineration) there is "a lot" of junk that I would remove before going to incineration - as is there will be junk that needs to be removed after incineration --- the less junk you have "after" the incineration process the less you will need to worry about your gold being dragged out &/or following along with the junk & ending up in your junk instead of in you ash concentrates where you want it to be collected by your copper

Also I "do not" recommend using the chapman flux for your smelting --- why ? --- (1) it has potassium nitrate in it which is a relatively strong oxidized & it will therefore oxidize a fair portion of your copper which will then go off in your slag instead of working as your collector (as is "some" copper is going to end up oxidizing with out any oxidizer so you don't need to ad to the problem by having an oxidizer in the flux) & the potassium nitrate is harder on crucibles (as is the flux you will be using is hard on crucibles - you don't need a component in the flux that makes it harder on crucibles) --- ( there is an exception to this which I will talk about later)

(2) the chapman flux has silica in it which you don't need in the first place & in the second place there will be "some" silica provided by the silicon chips (dies) from your IC chips

(3) also - because some of the SMDs from CBs are made up of ceramics you need cryolite in your flux to "dissolve" the ceramic - chapman flux does not have any cryolite in it so you need to ad it --- cryolite its self is hard on crucibles - adding it to a flux that has potassium nitrate in it & you now have a flux that is even harder on crucibles --- if you don't dissolve the ceramic (with cryolite) you wont recover all the PMs that are tied up in the ceramic SMD components

In other words chapman flux is made for smelting ores & the ingredients in the flux preform tasks (actually chemical reactions in the crucible) that are associated with the smelting of ores --- your material is not ore so you need your flux make up to be more suited to what your are smelting --- in other words you need your flux "chemistry" to be suited to the material you are smelting

For smelting the components harvested from CBs & using copper as your collector you want a basic flux made up of borax & soda ash mixed 50/50 along with a little fluorspar --- you want to use anhydrous borax - not the off the shelf 20 mule team type borax --- mix 1 cup borax + 1 cup soda ash + 1 well rounded table spoon fluorspar (in other words not level but not overly heaping table spoon)

This flux works fine for incinerated CB component provided there are no ceramics - if there are ceramics then you also need to add "some" cryolite

This is all I have time for today - there is a LOT more to know & I will post as much as I can over time as time allows so as to provide as complete information as possible when I am done along with pictures I have taken during some of my smelting & I will be happy to answer any questions you have along the way

I have a question --- what type furnace do you have (gas fired or electric) & what size crucible will it hold ?

Kurt