Non-Chemical Help: Newbie, Ball Mill, & Processors

[moremetal]

Hi everyone,
I'm a complete newbie to all this... so any help would be appreciated. I am attempting to run my first batch of computer processors for gold recovery (first batch of anything for that matter). Here's what I've done so far:
1. obtained a sprinkling of computer processors, 49 of them to be exact
2. bought a ball mill (see this link for the model I'm using: http://www.pyrocreations.com/inc/sdetail/11955/11960), and a AR kit from Shore International
3. cut up the processors into quarters using a bolt cutter. I set aside the metal backs, and only used the ceramic/plastic/gold boards in the ball mill.
4. loaded the ball mill last night with 50 1/2" chrome-plated steel balls, 50 3/4" chrome-plated steel balls, and the 49 processors that had been cut into quarters, and had the stainless steel backs set aside). (You can view a list of the 49 different processors by opening the attached spreadsheet).
5. Ran the ball mill for about 9 or 10 hours.

I opened the ball mill this morning, and to my surprise, the processors are still pretty much in their original size from nearly 10 hours ago. Of course everything is covered with fine black dust... and the corners are all worn... but I was expecting an overnight run with the ball mill to pretty much do the job.

I'd say the ball mill was filled 1/3 full with the processors and the balls (grinding media). The ball mill is a single speed ball mill (i.e., I don't see a way to adjust the speed)

Any tips on how long I should expect to run the ball mill on a batch like this?
Any tips on proper preparation of the processors prior to placing them in the ball mill?
Did I miss anything I should have done prior to using the ball mill?

Thanks in advance!
Jeff

 

[publius]

The mill you bought is for grinding/mixing black powder. More than likely, the balls do not fall onto the processors but roll over them as they would with the powder.

See if you can get your money back from Shor... :roll: Down load CM Hoke's book and put you e-scrap away until you have read it through at least 3 times.

 

[jack_burton]

To answer your ball mill questions, best bet is to do a search on the forums, lots of threads on the topic.

Here's a short synopsis of what I've learned from here:
1. Ball mills (like the one you have there) that grind are ill suited for eWaste.
2. You want a ball mill that will CRUSH, not GRIND.
3. For a small cylinder like you have, this might mean running it as slow as 15RPM.
4. Larger balls mills, like up to 55 gallon drum size, will RARELY run more than 60RPM.
5. You want the balls inside the mill to reach apex travelling slowly enough in the mill that they DROP down on the material.

FYI, your method will still work, but it might take a week or many weeks to grind down the CPUs. A correct ball mill would crush those in 30 minutes.

Good luck and welcome to the forums!

 

[publius]

you would be much better off smashing those chips with a hammer in an iron anvil. Rock polishers, which is what you have, as better suited to the purpose (polishing rocks). Take Jack_Burton's advise and get (or make) a proper ball mill.