# Crushing rocks



## djui5 (Mar 5, 2011)

I've been using a Mortar/Pestle to crush rocks for processing but it's getting a bit tedious to get them all in a powder form. A friend brought a tumbler over and it works to powder some of the rock but won't crush it all up. What are you all using to crush up your rocks? I'm looking for ideas here.


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## seawolf (Mar 5, 2011)

I have not used this but I have seen it listed. 12" piece of 2" pipe with a flat bar welded on one end. 24" piece of 1" round bar for a ram. Crush the rock down and pour into proper size screen to sort it out. Still slow but maybe a little less tedious.
Thinking about an air chisel also.


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## shaftsinkerawc (Mar 5, 2011)

I use an electric jackhammer inside a capped 8" pipe to crush to minus 1". Then run through a Keene Bucket Impact Mill. Your options are only limited by your resources available.


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## Richard36 (Mar 5, 2011)

I built a drum style hammer mill out of an old water pressure tank that I use to crush rocks.
Two horizontal strikes, and 8 vertical. It will crush a 3lb coffee can of 2" rock down to a mesh consistency similar to a 20% sugar and 80% flour mix in around 3 to 5 minutes time.

It's powered up by a horizontal shaft 3 1/2 hp Briggs and Straton.
It works well. 

Sincerely, Rick. "The Rock Man".


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## Barren Realms 007 (Mar 5, 2011)

Richard36 said:


> I built a drum style hammer mill out of an old water pressure tank that I use to crush rocks.
> Two horizontal strikes, and 8 vertical. It will crush a 3lb coffee can of 2" rock down to a mesh consistency similar to a 20% sugar and 80% flour mix in around 3 to 5 minutes time.
> 
> It's powered up by a horizontal shaft 3 1/2 hp Briggs and Straton.
> ...



How about some pictures of the thing?


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## Richard36 (Mar 6, 2011)

Barren Realms 007 said:


> Richard36 said:
> 
> 
> > I built a drum style hammer mill out of an old water pressure tank that I use to crush rocks.
> ...



I suppose I'll post a few photos of it. Sort of reluctant to do so though.
There isn't anything like it on the market as far as a small sampling mill that will actually crush enough material to be of use, and the closest there is as far as feed and discharge ratios go costs over $5000 from Keene Engineering. 

I'll post some photos of it soon.

Sincerely, Rick. "The Rock Man".


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## nickvc (Mar 6, 2011)

You could use an old electric concrete mixer and some steel balls and other shaped pieces of steel. Cover the front with heavy duty plastic sheeting and tie down with either elastic ropes as you use to tie down luggage on your roof rack on your car or copper wire twisted round the rim, If you want to deaden the noise slightly stand it on a piece of rubber matting.
I have used these for years as cheap ball mills and while not perfect they do the job for very little cost just don't overload them.


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## Irons (Mar 6, 2011)

nickvc said:


> You could use an old electric concrete mixer and some steel balls and other shaped pieces of steel. Cover the front with heavy duty plastic sheeting and tie down with either elastic ropes as you use to tie down luggage on your roof rack on your car or copper wire twisted round the rim, If you want to deaden the noise slightly stand it on a piece of rubber matting.
> I have used these for years as cheap ball mills and while not perfect they do the job for very little cost just don't overload them.



You mean like this? 8) 

http://www.youtube.com/watch?v=ASfcnMpbKrs&feature=related


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## Richard36 (Mar 6, 2011)

Thanks Irons.
The other videos that come up with this link are interesting, 
especially all those showing various ore types.

Sincerely, Rick. "The Rock Man".


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## drifter (Mar 7, 2011)

Here's a little prospecting mill I made up....

lately i've just been doing quick and dirty runs - any decent colours then i'd do a weighted sample and rerun the oversize. 










click pic for a vid of the proto running.




These are some pics of the first prototype, The hammers are a little different now














I've posted the cad files for the thing on this site ....

http://www.prelovedplacer.com/forums/index.php?topic=397.0


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## nickvc (Mar 7, 2011)

Irons yes that's exactly what I mean but they're using water so the front doesn't need a cover to keep the dust down. It can be run indoors,shed or outbuilding, but as I suggested stand it on rubber matting to keep the noise down and if run dry put a plastic sheet cover over the front. Cheap and cheerful but it works :lol:


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## Irons (Mar 7, 2011)

Richard36 said:


> Thanks Irons.
> The other videos that come up with this link are interesting,
> especially all those showing various ore types.
> 
> Sincerely, Rick. "The Rock Man".



Perhaps this might interest you as well:

http://www.youtube.com/watch?v=2DJfHLHJBWM&NR=1


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## Richard36 (Mar 7, 2011)

Irons said:


> Richard36 said:
> 
> 
> > Thanks Irons.
> ...



Thanks again.
That's the machine I need in order to crush 10 inch rocks into 3/4 minus 
as feed material for my hammer mill. Cool crusher.

Sincerely, Rick. "The Rock Man".


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## djui5 (Mar 8, 2011)

Thanks everyone.


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## turtlesteve (Mar 8, 2011)

djui,

I saw your post in the gallery and it looks like the material you want to crush is a gold-bearing agate or jasper/chert of some type. I might suggest cooking the rock before you crush it - this will reduce the fracture toughness of the rock and make it easier to break. Actually, native Americans routinely cooked chert and agate in fires to soften it before making arrowheads.

Steve


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## djui5 (Mar 9, 2011)

Thanks Steve. I'm working with a lot of different types of ore though. Roasting them is a good idea, I hadn't thought of that.


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