Re: Size Reduction
Dear Shri Aswath Prabhu,
Possibly, you will have to opt for one stage crushing and two stage grinding. The first stage could be crushing by hammer mill. The type of crusher will also depend upon the capacity MTPH. Subsequently, ball mills grinding can reduce it to 10micron size (ball mill / vibrating tube mill).
I suggest you to refer to manufacturer of crushing / grinding equipment, and they will give you a specific recommendation for your application. The number of stages for crushing and grinding can best be suggested by the experienced manufacturers in this matter.
Your crushing / grinding requirement is not exceptionally uncommon, and hence getting suitable equipment would not be so difficult.
Regards,
Ishwar G Mulani.
Author of Book : Engineering Science and Application Design for Belt Conveyors.
Advisor / Consultant for Bulk Material Handling System & Issues.
Email : parimul@pn2.vsnl.net.in
Tel.: 0091 (0)20 25882916 ■
Grinding To Fine Mesh Size Range
Hello: For this application........the TERTIARY stage of reduction can be easily handled by a VERTICAL SHAFT IMPACTOR.
Fines range can be achieved (MORE OR LESS FINES) by adjustment to VSI SPEED.......to allow you to customize your specification to your own personal needs.
TESTING of your particular product...........would be my recommendation.........and testing hopefully in a production mode would be the best. A guarantee of performance would be supplied by our company or any reputable supplier.
lastly, a vertical shaft impactor........also offers CUBICAL OR ANGULAR product.........vs elongates......which typically are not desirable.
Hope this helps......
George Baker ■
Vertical Shaft Impactor.
Gentlemen
Dear mr George baker.
I find your description of the VERTICAL SHAFT IMPACTOR very interesting- maybe i can use it in my sampling equipment.
Will you please send me a overrview over your products or a link to your homepage ■
Re: Size Reduction
Crush-grind-mill
Jaw crusher, roller mill, media mill is an option.
see www.ultrafinegrind.com
Regards,
Chris Martin ■
Re: Size Reduction
A general comment on your quest:
Most single pass comminution machines can process the product with a 6 times reduction in size. Multiple (recyles) will yield more at the expense of comminution efficiency.
The impact crusher can produce a grinding feed stage of 10/6=1.7 inches. Maybe down to 1.5 inches. This feed size may work with a ball mill recyle circuit.
The 10" initial rock size is too large for a ball mill. The balls have to grab the largest particle size. This works out to require a ball of 20 times the largest rock size as determined by the self-locking taper angle or nip angle between balls or between balls, wall and rock. Maybe you should think about a AG-SAG mill if you are attempting a one stage circuit. The ore surface area liberated will likely create too fine a viscous fluid to yield good comminution with such a circuit. Multiple passes and classifiers will be required.
As stated above, ball mills efficiently break down rock larger than 20 times the input particle size. Working backwards from your 10 micron finished product yields a cylone recyle stage ball mill with a ball size of about 1.2-1.5".
This will not be efficient due to the abundance of fines in the coarse mix. This means you pay more in kW-hrs per ton and pay more in wear of liners. T
he magnitude difference or diference in efficiency depends on: machine types, rock strength and plasticity. By example, if the limestone is soft, then a jaw crusher may not be as efficient as a hammer mill style crusher due to its high elasticity.
As others have stated, you likely need a 3 stage comminution circuit. Crush- mill -mill or some hybrid of this concept.
Lawrence Nordell
www.conveyor-dynamics.com ■
Untitled
Your problem can be solved by pre-crushing the raw material down to a particle size below 2 mm and a one stage fine grinding in a second step by using the agitated media mill MaxxMill in combination with an air classifier in open or closed circuit operation.
Stefan Gerl
MASCHINENFABRIK GUSTAV EIRICH GmbH & Co KG
Wallduerner Str. 50
74736 HARDHEIM, GERMANY
mailto:stefan.gerl@eirich.de
Internet: http://www.eirich.com ■
Size reduction
How do you grind limestone from 10" size to 10 microns?
To my knowledge this cannot be done in a ball mill. If so then how??
my address is mizun@bol.net.in
please reply ■