Milling jar media count

[Pretty green flame]

Hey guys, been quite a long time since i've done any proper pyro. Anyway, currently looking into a bigger ball mill, and obviously with size the cost of media goes up.

 

At this moment I have a 15 liter milling jar planned with 17 mm ceramic media. Now I need a rough estimate on the number of spheres.

 

At 50 % volume of the jar, the media should take 7,5 liters. Now the max. packing density for spheres comes to around 0.75 (very optimistic, probably closer to 0.65). I'm guessing this means that the total volume of media is around 5.625 liters (pure ceramic mass).

 

With each ball weighing in at a little under10 grams and a volume of 2,572 ccm (Alumina oxide density 3,87 g/ccm)

 

So the number of ball equals to 5625 / 2,572 = 2187 balls. Is this correct? Or roughly 21 kilos of media?

 

Just looking for a confirmation that this is correct.

 

Thanks,

PGF

Edited January 23, 2013 by Pretty green flame

[AlexPyro66]

That sounds correct the 15 litre jar how much bp will efficiently make .I am planing on making my mill very soon

[Pretty green flame]

That sounds correct the 15 litre jar how much bp will efficiently make .I am planing on making my mill very soon

 

I think it could handle atleast 2 kilos of composition efficiently.

[AlexPyro66]

I think it could handle atleast 2 kilos of composition efficiently.

2kgs are to much for me(right now ) so a 6litre jar will be able to make 1kg

[Mumbles]

I think you're way under estimating the amount of BP you can make PGF. I'd put the estimate around 3-4 kilos. 3 kilos is probably about ideal under the "rules", but with larger mills there is more wiggle room on that number. I made 1 kilo batches in a 1 gallon jar (3.74L). The charcoal you use makes a difference as to how fluffy or dense the final product will be typically.

 

I can't speak to the total number of balls you mentioned, but the mass seems about right.

 

Good to see you around again.

[Pretty green flame]

I think you're way under estimating the amount of BP you can make PGF. I'd put the estimate around 3-4 kilos. 3 kilos is probably about ideal under the "rules", but with larger mills there is more wiggle room on that number. I made 1 kilo batches in a 1 gallon jar (3.74L). The charcoal you use makes a difference as to how fluffy or dense the final product will be typically.

 

I can't speak to the total number of balls you mentioned, but the mass seems about right.

 

Good to see you around again.

 

Thanks mumbles, it's good to be back.

 

It probably was a very low estimate, 3-4 kilos sound about right. Probably even more with denser chemicals. Will give it a shot with 20 kilos of media for a start, will work on from that.

[Col]

You could use the volume and weight of bp from your other mill for a rough guide, For example, if 100g of your bp equates to 150ml volume (post milling), the material charge for the new jar would be around 2.5kg.

[AlexPyro66]

You could use the volume and weight of bp from your other mill for a rough guide, For example, if 100g of your bp equates to 150ml volume (post milling), the material charge for the new jar would be around 2.5kg.

Thats right with a quick calculating seems that a 6litre jar can handle 1,6 kgs of pine bp

[Col]

I`d only use it as a starting point, A very large mill jar will behave differently due to the extra height and sheer volume of media.