Air Classifying Mill

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Classifying Mills


  • Product grinding to a final size of 50 mesh to sub-micron
  • Two-stage closed circuit grinding
  • Interstage air classification/air classifying
  • Large access door for quick inspection/cleaning
  • Standard door interlock


  • Perfect for difficult to grind application or with narrow particle distribution curve
  • Screenless screen frame prevents screen damage and wear
  • More uniform particle distribution
  • Simple maintenance
  • Secondary inlet provides additional air for an element of cooling

Prater's CLM is a "classifying impact mill" that is an industry-leading particle size reduction product. The CLM Air Classifying Mill offers the combination of two-stage closed circuit grinding mill with internal air classification, all in one efficient unit. The unique capabilities of the CLM Air Classifying Mill out performs single-stage air classifier mills when handling difficult to grind products and those products requiring a narrow particle distribution.

There are three stages when processing material through a Prater Air Classifying Mill. The initial grinding stage is similar to what is accomplished in the M Series Fine Grinding Mills; however, a secondary inlet provides additional air for the second stage internal air classifier. This additional air also adds an element of cooling to the material being processed. Over-sized particles that are larger than specified are rejected by the classifier and are directed to the third stage, which is a separate part of the grinding rotor. This recycled material is ground again in the mill section, then redirected to the air classifier, allowing only properly sized product to exit the mill.

All Prater Air Classifying Mills come with an automatic door interlock. This device prevents access to mill internals during operation and prevents dangerous motion during access. A large access door on these mills allows for quick inspection and/or cleaning of the main classifier mill rotor as well as the air classifier rotor.

CLM Air Classifying Mill General Dimensions

CLM-1830.515021 in. 533 mm12.875 in. 310mm
CLM-3630-50280035.875 in. 911 mm28.375 in. 721 mm
CLM-5150-755150050 in. 1270 mm42.125 in. 1070 mm
CLM-7675-10010300063.5 in. 1613 mm56 in. 1422 mm
CLM-101125-20015600078.5 in. 1994 mm72.5 in. 1842 mm

*Do not use for engineering purposes. Please request a certified drawing for all layout or construction uses.


  • Activated Carbon
  • Alfalfa Leaves
  • Boric Acid
  • Boron Nitrate
  • Bran
  • Calcium Carbonate
  • Cellulose Insulation
  • Charcoal
  • Chocolate and Malts
  • Clay
  • Coal
  • Cocoa
  • Coffee
  • Coke
  • Copper Sulfate
  • Corn Meal and Corn Starch
  • Dextrose
  • Egg Shells
  • Flour
  • Gelatin
  • GraphiteGypsum
  • Iron Oxide
  • Lactose
  • Limestone
  • Magnesium Hydroxide
  • Oat Hulls
  • Phenolic Resin
  • Physllum Husks
  • Powder Coating
  • Pre-ground Corn
  • Radioactive Materials
  • Resins Rice
  • Salt
  • Sodium Casinate and Sodium Bicarbonate
  • Soy White Flakes (CLM-76)
  • Soya Concentrate and Soya Protein
  • Spice
  • Starch
  • Sugar
  • Talc
  • Toner
  • Wheat
  • Wood Flour
  • Yellow Pigment
  • Zinc Oxide