If someone wanted to mill a bunch of different samples of something like BP say 10-20g, would a small container of about 2-2.5" diameter by 2.5" tall
work for milling? It would fill the container about 1/4 full, maybe 1/5. I just don't know if there is a minimum diameter that works for milling. I
figure something larger might not allow for enough contact but am concerned as to whether there is some practical limitation to size due to some
physics related to ball milling. As far as rotational speed, that can be adjusted to whatever is ideal for the process. PHILOU Zrealone - 20-2-2017 at 02:38
Like anything related to dynamic and flow of liquids or dusts ... scaling up or down is not easy matter.
There is somewhere on this forum a document that was posted by another user about the dimensional study and rotational speed of ball millers...but I
can't find it back...maybe someone else will be able to do that.
I think that the best is to try...doesn't cost much and you will get an answer faster.
But I really think that below a certain level ball milling becomes less efficient than hand:
-pestel and mortar
-grinding between two hard planes (like spatula and granit surface..as it is done into pharmacy)RogueRose - 20-2-2017 at 06:40
Like anything related to dynamic and flow of liquids or dusts ... scaling up or down is not easy matter.
There is somewhere on this forum a document that was posted by another user about the dimensional study and rotational speed of ball millers...but I
can't find it back...maybe someone else will be able to do that.
I think that the best is to try...doesn't cost much and you will get an answer faster.
But I really think that below a certain level ball milling becomes less efficient than hand:
-pestel and mortar
-grinding between two hard planes (like spatula and granit surface..as it is done into pharmacy)
Can the particles get as small in a mortar & pestel as with a ball mill?
The reason I was thinking about the small container was b/c I could place 6-8 on the mill at a time, for different mixtures or recipes. Fulmen - 20-2-2017 at 08:22
Lloyd Sponenburgh published a booklet some years ago that covered everything you need to know about ball mills for BP. I'm sure you can find it if you
do a search for it.
Can the particles get as small in a mortar & pestel as with a ball mill?
The reason I was thinking about the small container was b/c I could place 6-8 on the mill at a time, for different mixtures or recipes.
Yes by hand and with the proper tools you can go as small/fine as with a ball mill.
I understand the idea...nice...so you can get exactly the same ball milling time and conditions in parallel.wg48 - 20-2-2017 at 17:45
In a tumbler type ball mill your small diameter would mean the balls are not falling very far and its rotating slowly compared to a larger diameter. I
guess you could off set that effect by using dense media. It may take a long time to mill your material.
Perhaps you need a planetary or vibratory ball mill. A vibratory mill should be easy to build compared to a planetary one. The noise could be high
though but apparently they are very quick. If the vibration is linear so the jar does not rotate perhaps it could be used to make hydrides easily.
