Ball Mill Critical Speed & Working Principle

[@beaujest4461]

Excellent photography that demonstrates the principle of critical speed. Because I am ignorant of many of the details of ball mill design and operation, I am curious about some other issues which you may be able to advise on. Such as: > Is there an optimum relationship between enclosure diameter and ball diameter or total volume of balls? >Is there a quantitative method for determining the size and volume of balls? i.e. ratio of volume of balls to volume of enclosure. >Is there any advantage in using roller bearings in place of the spherical ball bearings? >Is the running time required to produce high percentage of fine particles affected by the amount of raw material to be ground compared to the volume of enclosure or volume of balls? i.e. how can we know when we are overloading the ball mill with too much raw material input? Too much raw material could act to cushion the interaction between the balls and thus increase the run time exponentially. My interest is in small DIY mills for ceramics. I assume the principles involved are the same as for large industrial machines. Thank you for your time and effort in producing this video.

[@911Metallurgy]

Great many questions to ask on www.911metallurgist.com/grinding/

[@Dennis-et9vq]

You add a term- Critical-with no explanation of what that means? You also do not make it clear the motion showed is full speed or not. Can't you say the best speed for your container?

[@michaelwalker4456]

so do the correct rpms change for the diameter of the barrel and the diameter of the steel balls. For instance if i were to up size the barrel to an 18" inside diameter, what media size should i use and what rpm should i run? or is it a matter of watching it and trying to get that perfect grinding action?

[@yashmehan3944]

i read about your channel, and felt you are educating. Great video, and subbed. may you get further in your career and educating. :) best of luck! thanks for the video!

[@ElGatoLoco698]

I was considering building a ball mill out of some old printer parts. Never considered ball on ball vs. ball on shell grinding.

[@911Metallurgy]

Fine grinding is in majority ball/ball pinch/nip abrasion.

[@911Metallurgy]

sub-critical speed to critical, not over: 75 to 80%

[@sonalibhalla9199]

Had a good review !!

[@lowercherty]

I don't understand your definition of critical speed. At what Bond and others defined as critical speed there should be balls against the wall all the way around. Also it looks like your lifters are very shallow or non existent.

[@911Metallurgy]

Review carefully all of www.911metallurgist.com/grinding/formula-derivation/

[@lowercherty]

911 Metallurgy Corp. That's how I learned it all those years ago. That's not what the movie shows when it talks about critical and supercritical speed. It may be turning at critical speed or faster, but I also suspect there are no lifters in the mill because of the minimal activity of the charge in the mill. It corresponds to the end stage of what I've seen with liner's that were extremely worn to the point where the lifters were worn to nothing.

[@tsegytsetsegdelger]

B Laquisha

[@911Metallurgy]

correct - no liners = worn liners --> higher speed

[@safiqulislam7721]

Good concept....

[@metsdark]

Thanks !

[@arunsinghbais4741]

Superb

[@jangdajee7461]

good

[@naseemabbas5402]

nice

[@TastyLier]

superb 👌

[@rohitsahoo9070]

ceutics ka har chaperter ko hindi me dekhaye

[@faiyajdheka7646]

Good

[@vinodahirwar026]

Sir har chapter Hind me dekhay plz

[@subhashgulwani9550]

nice thanks

[@kandukurisatyanarayanaredd9436]

like that video