Impact mill info

[Mgumby16]

Hello all. I'm starting an impact mill build and I'm looking for info on what determines how large the feed size can be. Most impact mills I see have a 3 inch feed and at a max maybe 4 inch. So determines the feed size.

Some info on my build. The drum is 18 inches in diameter and 24 inches in length. The motor I will be using is a 5 hp electric motor. I plan on using a 1 inch dia shaft and large steel ball bearings attached at the end of the flail. My thought is that a ball bearing is generally hardened steel and a sphere should be the strongest shape and last longer.

This will be a production unit and hope to not have to replace the flails every few hours

Thanks!

 

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[bobw53]

I've got a few thoughts.

Bearings doesn't sound like the worst idea, a concern that may or may not be valid. Really hard stuff tends to be brittle. Good for wear resistance, not so
good at impacts. Are they just going to shatter? A hammer should tell you pretty quick.

Are you going with chains, or hammer style?

I'm also concerned about 24" of 1" shaft. Especially if its only supported at the ends. I'm thinking an impact mill is basically an engineering mess. All kinds
of funky loads and inherently off balance all the time. 24" of 1" unsupported shaft would scare me.

Good luck, and post up some pics when you get going on it.

 

[jair]

My thoughts , I have built a 16" X4 " impact mill . Using chains , works very well , crushes down to 200. Mesh . An 18" depth not to sure of , I'm thinking 10" may be more productive , 1" shat ? May need to be a little Heavier , impact , welding hard objects to a mild steel ? Make sure and plan , that's a lot of force slinging a round , maybe you have a harden shaft not sure ,

I am still experimenting with hammers . of different types , cleverest worked really well but still wear and cost a lot more , but last longer then chains , trying chains with hard steel cut from cutting edges . Work very well so far. As for cost verses were. Look under GG's chain crushers . Just my input , I'm sure you'll do just fine on your build , that's how people come up with the best equipment , by experimenting , Wish you well and hay! Have fun doing it , that's what makes it the best .

 

[robert2b]

I use a 16" circumference impact mill that is 15" in depth and has a shaft that is 1 and 1/8" in diameter. I use 1/2" chain that is 70 grade. I crush about 6 full 5 gallon buckets of material before I need to flip the chains. The rock is passed through a jaw crusher prior to being pulverized so that I am feeding 1" material into the impact mill.
The chain costs me about $75 for 4 sets of six 3 link lengths of chain. I did the math and figure that for every $1000 worth of gold that I pull out of the quartz I am spending about $80 on chain. This kind of sucks, but with the hardness of the material I am working with I cannot seem to find a better solution. If anyone has a better idea please let me know.

 

[bobw53]

If anyone has a better idea please let me know

I don't know if this is a better idea or not, but it is what I was going to try. McMaster Carr has "cut resistant security chain".
Case hardened. Around the same price as any other chain. Except for of course 1/2". I'm sure you can get it elsewhere for
cheaper.

 

[Mgumby16]

Thanks for the ideas! Sounds like in need to either beef up the shaft or reduce the length of the drum.

I will probably try a 4" feed and see how that works.

As for the hammers I will be experimenting to try and find out what will last the longest. The ball bearing idea may or may not work but I'll give it a try! Lol.

 

[dave wiseman]

Shackles,instead of flail chains.......https://www.google.com/search?q=pic...Ufr91jqmM:&usg=__BZR4R8gAqRIAFidusaXASZaPZug=

 

[jair]

You won't know unless you try , just remember things can come a part.