2277 Longyang Rd. Pudong, Shanghai, China info@mixingchina.com

Fluid energy mills, Stirred media mills

    You are currently here!
  • Home
  • Blog Fluid energy mills, Stirred media mills

Fluid energy mills, Stirred media mills

June 25, 2023 nflg 0 Comments

Fluid energy mills Description

The general principle of operation in a fluid energy mill is that the mineral to be ground is fed into a grinding chamber in a high speed, high pressure and, often, high temperature jet of air (or other gas). The particles collide violently and this causes comminution to take place. Various designs of fluid energy mill exist, the most common being the microniser. This mill has a shallow circular grinding chamber and a series of peripheral jets set tangentially to a common circle. The turbulence causes bombardment which effects a rapid reduction in particle size. A centrifugal classification system keeps larger particles within the chamber while allowing fine particles to leave. In a well designed fluid energy mill there will be almost no contact between the charge and the mill lining.

Fluid energy mills Characteristics

Suitable for hard or soft materials to be reduces to 0.02mm or less. This method of milling tends to be energy intensive and slow but is suitable where the product is highly sensitive to heat or contamination from grinding media.

Typical jet mill performance

Mineral Product size Production

(Kg / hr)

Fluid use
Alumina 100% – 0.0075mm

50% – 0.003mm

5500 2850 kg/hr steam at 7000 kPa and 400oC
Feldspar 90% – 0.0075mm 3600 85 m3 /min air at 7000 kPa and 20oC
Graphite 90% – 0.01mm 25 2m3 / min air at 7000kPa and 20oC
Mica 95% – 0.075mm 725 20m3 / min air at 7000kPa and 425oC

Stirred media mills Description

Stirred media mills are usually constructed in the form of a cylindrical drum inside which there are a series of rods, arms or perforated discs which are rotated on a central shaft. The drum is loaded with grinding media, such as metal balls or glass sand. The media and the charge is ‘stirred’ together and thus the grinding takes place.

Stirred media mills Characteristics

Suited primarily to the very fine grinding of soft materials. Usually used with wet grinding but can be used for dry grinding also. Product size is as small as 0.005mm.

leave a comment