Grinding PCBs with a blender

[Chumbawamba]

Check this out:

http://www.youtube.com/watch?v=ifzdez7FRbk&feature=channel_page

Are you guys thinking what I think you'll be thinking after you've viewed the above video?

 

[Harold_V]

Well, if you're thinking what I'm thinking, you don't believe, not for one minute, that a blender will stand up to such materials for very long. Not denying he managed to screw up those cell phones, assuming that's what they really were, but imagine dropping in ceramics that are exceedingly abrasive, and what happens to the bearing at the bottom of the blender, to say nothing of the blades that do the work. None of those components will last long enough to warrant the attempt.

There's a reason the big boys incinerate and furnace this stuff---part of which is it works, and it's far more economical.

Not trying to toss a wet blanket on the party, just trying to keep readers from investing in a blender that isn't intended to be a ball mill, in spite of the grandiose claims.

Harold

 

[Chumbawamba]

Hi Harold.

Well, you're probably right. But I thought it might work for small batches for a small-scale hobbyist beginner like yours truly.

So, no, I guess I don't really advocate going out and buying one of these blenders and ruining a perfectly good margarita making machine to use a few times on some cell phone scrap, but being an electronics recycler means you sometimes get interesting stuff. So in that regards, see the photo below of my little friend, Mr. Robot Coupe. Actually, he's rather big as food processors go, standing about 2 feet tall(!) This is a ~$1,000 piece of high-end restaurant gear with one problem: it doesn't work. I haven't had a chance to take it apart yet to see if it's something simple or if the motor is burnt out. If I do get it fixed I'll probably want to sell it to a local restaurant owner as I could probably get at least $500 for it without trying, rather than using it as an industrial PCB shredder.

But anyway, I was also intrigued by the idea I read about in another thread (I think you also suggested it) of using a sink disposal. My question is how fine would the particulate be if the feeder material is printed circuit boards or processors, and does it leave any residue (i.e. dust) buildup in the disposal over time? Seems like a sink disposal would be good for narrow PCBs, like typical PC interface cards, and CPUs. Motherboards would have to be cut down.

Since all my gold scrap is electronic based (board fingers, CPU, RAM, connectors, cell phones, etc.) I am obsessed with finding a cheap and easy to construct grinding solution that will take reasonably sized batches of feeder material and grind it down to a nice processable powder. So far, RobotCoupe and a sink disposal are the most intriguing options.

 

[Harold_V]

I can certainly understand your desire and objective. Trouble is, the forces involved in destroying solid objects aren't generally going to be withstood with equipment made of light duty materials. That's the problem you'd face with almost any household device that comes to mind. They simply are not made to endure that kind of punishment.

While I don't expect that a garbage disposal unit would last long, those I've seen are headed in the right direction. They work like a hammer mill. They don't use knives in the way blenders and processors do. The outer shell is much thicker, although not nearly thick enough to be considered adequate for the likes of e scrap. I would also be very concerned about the anchor points of the hammers, which are not particularly robust.

Again, I'm not suggesting it won't work---but I am suggesting it would yield problems and cut short the experience. I believe you'd achieve mixed results----probably far from satisfactory. What you're likely to experience is loading and binding problems with some of the components, components that may not lend themselves well to being shredded by such minimal forces.

I'd be particularly concerned about ceramic items, such as chips. If they are hard fired, they are tough and not easily destroyed. They are also very abrasive. You should expect accelerated wear on all components, not only from impact, but from abrasion. Overall, I don't see much working well beyond a ball or rod mill. Even a cement mixer isn't ideal---wrong speed and geometry, plus a shell that is far too thin.

Processing e scrap on a level that is economical can be vexing. There is far too much hand work involved to expect to make it profitable without having the ability to incinerate and process by furnace. It is for that reason that I avoided it when I was refining, and it is also for that reason that a great deal of e scrap has found its way to foreign, poverty stricken lands, where labor is a non-issue.

I firmly believe that processing e scrap is a great hobby, but those that are trying to make a living may find it a futile effort. Not trying to discourage even one person, just trying to keep people thinking in the right direction. As always, YMMV, but please give these points some thought.

Said another way, don't quit your day job in favor of refining e scrap.

Harold

 

[Harold_V]

So, no, I guess I don't really advocate going out and buying one of these blenders and ruining a perfectly good margarita making machine

Yum! That's one of my favorite drinks!

I have a killer recipe if you're interested. Got it from the manager of Great Western Chemical years ago. That's where I used to buy all my chemicals when I was refining.

My wife and I do an occasional Mex night, chips, guacamole, stuffed jalapeños, salsa and a blender of margaritas.

Harold

 

[qst42know]

An ideal though I suspect a pricey solution would be a machine designed to do the job of grinding electronic scrap to a flour like consistency.

If you look around some on this site they make machines for the task.

http://www.retsch.com/

 

[goldsilverpro]

Why anyone would want a flour-like consistency in beyond me. I can't see how that would give you any advantage at all. You are increasing the surface area, which is good, but the powdered material traps more solution and is more difficult to work with.

To me, the only parts that need to be broken up are those where the gold is sealed up inside the part, like a ceramic IC. With these, the purpose is to break up the chip and the underlying ceramic into several pieces, so the acid can more quickly penetrate under the chip and go after the gold braze. I would think a hammermill, a ball mill, or maybe a jaw crusher would be the best.

 

[qst42know]

By varying the screens in these machines any desired consistency can be had down to flour like. This outfit makes many types of machines to suit many industries. Including jaw crushers.

 

[Russmith007]

For only about a thousand bucks, you too can have one of these Keene impact crushers.

It does look like it would do a pretty good job on ceramic chips...

http://www.keeneeng.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=RC1&Category_Code=RC

 

[Harold_V]

Why anyone would want a flour-like consistency in beyond me. I can't see how that would give you any advantage at all. You are increasing the surface area, which is good, but the powdered material traps more solution and is more difficult to work with.

The only exception that comes to mind would be if an agitation tank and filter press were incorporated. In such a case, the finer, the better, up to the point of creating clay. I ran such a setup. It was actually to my benefit to reduce the product (gold ore) to powder because it contained miniscule bits of gold, so unless it was reduced to dust, some of it wouldn't be exposed to cyanide. I achieved well over 99% recovery in my instance, but I certainly agree with you for plated pieces. Reducing them in size would work to advantage only to a point.

Harold

 

[jamthe3]

Don't know if this helps or not, but possibly w/ small amounts (especially if you're planning on cutting up boards anyway) maybe something here would do.

http://www.unitednuclear.com/mills.htm

Cheers,
John

 

[Chumbawamba]

Hey Harold.

Every night is Mexican night for me, because I married one

Please do share your recipe. This summer will be good and hot in many ways and having a nice, refreshing, tasty margarita to take the edge off would be just the thing.

 

[Chumbawamba]

Jamthe3,

After checking out the United Nuclear page on ball mills, I now realize there's a (perhaps) better use for mouse balls than as ammunition for an as-yet-to-be-designed firearm.

I've been extracting and collecting the balls from old style computer mice for a few years and have hundreds now. The rubber coating usually comes off without too much trouble--simply cut around the circumference and remove. They would make great media for a ball grinder.

I also now realize that I have a small ball mill. I got it from a food lab a few months back but couldn't quite make out what it was since I'd never seen one before. Cool!

Another idea for making a crusher comes from a friend, who had a friend who made one using chains attached to a vertical shaft. The shaft was affixed to the end of a high-torque electric motor, and a tank surrounds the whole thing. Stick your to-be-grinded crap inside, turn on the motor, and the chains produce a vortex of whipping motion that pulverizes whatever is in there. I'm sure this isn't a new idea, but it sounds like something easy to construct, especially for large target objects.

 

[jamthe3]

You'd be surprised at how many things use bearings of one sort/size or another....at one point or another I've probably gathered and sold several 5 gallon bucketfulls. Been eyeing them closer now...and of course now I find them more seldom...ain't that always the way...LOL!!

John

 

[Harold_V]

A few things for you to ponder:

Do keep in mind that ball size is influenced by what is to be destroyed (or crushed). As the charge increases in size and it's ability to be broken, larger and larger balls are required. That dictates the potential size of the ball mill.

Ball size, when too small, does not do the work ----items are destroyed by attrition. That's exactly what you must avoid unless you don't mind the ball mill experiencing as much damage as the charge, and an end product that has been reduced to fine dust.

The maximum ball size I ran was 2", along with an assortment of smaller balls, down to about 3/4", along with a number of rollers from a large bearing. The rollers, as I recall, were less than an inch in diameter, and about an inch long. With this mix I placed one piece of ore in the ball mill that had not been crushed to ½" minus. It was about two inches in size, and only slowly was reduced, eventually being totally crushed, but it remained in the ball mill for days. From this you can, hopefully, come to understand the relationship between charge and ball size.

Considering your objective with chips would be to reduce them in size, but keep the pieces fairly large, I would advise large balls, and a short run in the mill. Otherwise, as the particles get reduced in size, they will be all the easier to reduce to dust, which you should avoid unless you invest in an agitation tank and a filter press.

Balls that have come from computer mouses will likely be useless because they are too small to be effective.

Harold

 

[Harold_V]

Hey Harold.
Every night is Mexican night for me, because I married one

I hope, for your sake, she is a great cook! We enjoy Mexican cuisine immensely. Love those fleshy corn tortillas that are served in Mexico. I was down there in '72 and couldn't get enough of those things.

Please do share your recipe.

The recipe may sound a bit hokey, but don't discount it until you've given them a go. If you like a blended margarita, these are as good as any I've had, anywhere.

For a blender full:

3/4 full of ice
6 ounces tequila
2 ounces triple sec
six ounces 7 Up
six ounces frozen lime concentrate (for making limeade)
I use a lime, saving the hulk for salting the rim of the margarita goblets we use. The juice and pulp go in the blender along with the concentrate.
I like to add a little salt in the blender, as well as salt the rim. Your choice.

Blend until smooth, and enjoy!

Harold

 

[Chumbawamba]

I hope, for your sake, she is a great cook!

Oh, good lord. Pick the region and style and she can usually whip it up and it will be damn good: Mexican (of course) and Thai are her favorites. I'm of Arabic extraction and she's already mastered many of my mother's Syrian recipes (and my mother is an excellent cook in her own right) so yes, I eat well

I'll definitely try the Margarita formula the next time the sun comes out and shines its rays down on us. I'll get and post my wife's Sangria recipe to reciprocate.

Also, thanks very much for the insight on the ball size for a ball mill. That's something that one can only glean from experience. Much obliged!

 

[goldsilverpro]

Here's a couple of old threads on ball mills and other ways of crushing

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=3107&highlight=ball+mill+balls

http://goldrefiningforum.com/phpBB3/viewtopic.php?t=337&postdays=0&postorder=asc&highlight=ball+mill+balls&start=15

The set of rolls that I mention on the 2nd page of the latter link was the best thing I've ever used for breaking up ceramic or plastic ICs. You could feed a lot through them and the crushing was instant. The rolls were about 6" dia x 8"-12" long with a pretty good sized motor. The rolls were set side by side, horizontally and you just fed them from the top. I think there was also a small hopper.

 

[Gorillatactics28]

Even though this post is a decade old I would like to put my experience in as to concrete Harold's thoughts. No blender will stand up to IC chips, ceramic CPUs even if incinerated. I though I knew more than I did because one batch of chips worked. So I went around to all the thrift stores and ended up purchasing 7 older blenders and one commercial blender. Long story short the commercial blender lasted longest and maybe processed 10 pounds of mixed chips and 2 pounds of cellphone boards. The other 7 combined didn't equal this amount. The blades are just not strong enough to deal with the material. Even though blades are replaceable you would put your entire profit into blades. I will say that not one of the machines burned up a motor. Hope this helps prevent someone from making my mistakes and Harold your hypothesis holds merit wish I would have read this thread before I wasted my time and money. Live and learn.

 

[watlarry]

Here's a youtube link to a pretty good diy cheap ball mill. https://www.youtube.com/watch?v=8Z9j7_t4qlU