# Plastic ball mill for MLCC capacitors?



## 924T (Apr 16, 2014)

Howdy, all!

I know the rock tumbler 'ball mills' that have the plastic jars as the polishing/grinding drums are
worthless for I.C. chips, but now that I've become tuned in to MLCC capacitors and SMD resistors
as a source of Silver and a bit of Palladium, and have been scraping them off with a screwdriver, 
and have have accidentally reduced some to dust by taking a bad angle of approach with the screwdriver,

I'm thinking that they're so brittle that a plastic drummed ball mill just might work to reduce the
MLCC's to powder.

It's an attractive thought for me, because the plastic drums have screw-on lids, which would contain
the dust, making the grinding process less of a health hazard than some of the manual smashing techniques.

Has anybody tried grinding the MLCC's this way, and if so, how well did it work?

I'm open to any suggestions for a safe way to do this (I really don't want to ingest ceramic dust, much less
powdered Ruthenium, etc.).

Cheers,

Mike


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## 4metals (Apr 16, 2014)

Do you mean one of these?


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## g_axelsson (Apr 16, 2014)

A rock tumbler is NOT a ball mill!

A ball mill works on the principle of the milling media follows the drum up but falling down from the top and crushing what's been milled between the balls. A proper ball mill have rubber lined inside and doesn't crush against the side of the drum.

A rock tumbler works on the principle of slow movement that gets the rocks grinding against each other together with an abrasive media over long time. That grinds off the sharp edges without damaging the smooth surface. There are no impacts that can crush in a rock tumbler.

MLCC:s are not so fragile. They are hard and brittle but quite tough. My guess is that it would take a really long time to grind it to a powder.

Göran


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## solar_plasma (Apr 16, 2014)

> It's an attractive thought for me, because the plastic drums have screw-on lids, which would contain
> the dust, making the grinding process less of a health hazard than some of the manual smashing techniques.



I always wondered, if it wouldn't be smart just to put some water to the mlcc's when milling, just enough to avoid dust. Any thoughts?


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## 924T (Apr 24, 2014)

4metals,

Yes, that's the beauty I was considering!

I'm betting that one of the really large (glass) dill pickle jars from WalMart would work with
that roller system, too--------not as a ball mill, but for a chemical process that would benefit
from movement of the solution and the material being leached. If so, then you would be able
to visually track the progress of the reaction.

Cheers,

Mike


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## 924T (Apr 24, 2014)

g_axelsson,

You're absolutely correct----I think the only hope for making something like the plastic drum rock tumbler
work as a ball mill would be to put a variable speed motor on it to permit getting the RPM optimized for
getting steel balls to drop onto the MLCC's.

I suppose one could cut off the end of the plastic drum, find a piece of steel pipe the would fit inside
of it, fit the pipe in, and then use a plastic welder to reattach the cut end of the drum, but one would
most likely be better off just fabricating ends for the steel pipe and running that instead of the
plastic drum.

We're finally without any snow on the ground here! Are you able to see the grass now in Ulmea?

Cheers,

Mike


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## butcher (Apr 24, 2014)

924T said:


> I'm betting that one of the really large (glass) dill pickle jars from WalMart would work with
> that roller system, too--------not as a ball mill, but for a chemical process that would benefit
> from movement of the solution and the material being leached. If so, then you would be able
> to visually track the progress of the reaction.



My concern with this idea is, if the jar is sealed acidic gases formed from the reaction, could pressurize the jar making a dangerous situation


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## 924T (Apr 24, 2014)

solar_plasma,

I've been wondering the same thing, that wet grinding the MLCC's should keep the dust hazard way down,
if the moisture doesn't somehow interfere with the grinding process.

I've got a very small lab-size hammer mill (only 2 hammers, 11" diameter, 3400 RPM) that might work
for grinding MLCC's, but these capacitors are so very small that they might just drop through the mill
unscathed---------------any ideas on that?

I did look up the factory specs, and it will wet grind, but to a lower mesh size (<150), and the factory
manual states that the material can't just be damp, it has to be like a slurry, or it will clog up the mill.

So, I'm unsure as to whether I should try MLCC's in it, or not.

I would very much like to get the MLCC's to around -300 mesh, and then try running them on my
small wave table, to see if the metals could be separated from the ceramics that way. I figured
that reducing the amount of bulk being boiled in HCl to remove the Lead and Nickle would be
a prudent thing to do.

I bought the hammer mill and the wave table with the idea of grinding DIP package small I.C."s and
separating the Au out with the wave table, and then I found out on the forum about patnor's incineration
innovations, which pretty much parked the mill and the table.

I was advised by Action Mining NOT to grind I.C.'s with the mill, but got opposite advice from one
of their dealers, who said he'd being doing just that, successfully, for some years----------so I tried it, and
promptly chipped one of the carbide hammers. So, between patnor's information and the chipping
of the hammer, the mill was set aside for a while.

As usual, I'm wide open for commentary and ideas!

Cheers,

Mike


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## 924T (Apr 24, 2014)

butcher,

Yours is a valid concern.

Perhaps a vent tube in the center of the lid, with some wet cloth inserted into the end of the tube
to retard evaporation, would suffice?

Cheers,

Mike


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## g_axelsson (Apr 24, 2014)

924T said:


> We're finally without any snow on the ground here! Are you able to see the grass now in Ulmea?
> 
> Cheers,
> 
> Mike


Hi Mike,

well, it's been a very mild and short winter, the shortest I've ever experienced in my life. The last snow disappeared a month ago, flowers appeared a couple of weeks ago and I'm already starting up refining outside.
Two years ago we had more snow in one day than we had this whole winter... I think you got our snow too this year.

:mrgreen: 

Göran


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## justme2 (Apr 24, 2014)

I haveneed of a ball mill and have thought about design or alternative less expensive methods. I have a cement mixer from harbor freight and have been looking at the design. I notice the blades are raised off the inside walls slightly. I believe that is to let some of the material flow through these slots to get a better and quicker mix.

A smaller version could be built from a 2 gal galvanize bucket or something similar. possibly 2 or 3 3 gal stacked inside each other for strength, this would also reduce the noise factor. the blades could be set above the inside walls just far enough to let the material through but, catch the balls.

Hand method could be the pedal sprocket from a bicycle or could be run with the pedal sprocket, wheel sprocket,chain and, small motor like a wash machine or drier motor. Just one of my many crazy ideas.


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## 924T (May 3, 2014)

After calling quite a few friends in quest of some large diameter steel pipe (15"-18" diameter), I found out today
that there is supposedly a pipe manufacturer within 50 miles of here, so I'm going to pursue that lead.

My question is, for milling say 5 Kg of MLCC's at a time, would the 18" diameter be adequate for the task as a
ball mill drum (with plates welded to both ends)?

Any suggestions as to what length would be optimum?

Cheers,

Mike


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## Smack (May 4, 2014)

I got a section of 18" for mine from the local scrap metal yard, they do resell too.


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## solar_plasma (May 4, 2014)

Have you seen Zoltan's thread about using a brake drum making a ball mill? Might be an option for you.

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=38&t=17471&view=previous


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