Russians outwit Americans in patent resuscitation! You must love headlines like this. I use it to introduce the following that popped up one day in my e-mail inbox.

Cyclotec, an engineering team from St. Petersburg, Russia has developed an innovative ultra fine grinding machine - based on a U.S patent from 1886!! (a 120 years old U.S patent!!).

The Planetary Centrifuge Model (PCM) operates on a principle similar to a ball mill. In addition to rotation around a longitudinal axis, the drum also rotates around an axis of the motion of transport (e.g. planets rotating around the sun). The motion of transport “replaces” gravity acceleration (G) acting upon the balls in the ball mill, with a centripetal acceleration of the motion of transport, acting upon the balls in the PCM––and exceeding gravity acceleration by 10 to 300 Gs.

Here is a figure for those who love applied mathematics:



  • A- Center shaft revolution
  • B- Center cylinder revolution
  • R- Radius of revolution
  • r- inside radius of cylinder
  • W1- Angular speed of revolution of center shaft
  • W2-Angular speed of cylinder revolution

Problems that have so far hindered emergence of a commercial PCM include:

  1. Failure of planetary gear at high load high speed operation,
  2. Complexity of design for continuous even feed and discharge of material;
  3. Removal of excessive heat from the drums;
  4. Provisions for dust removal.

The technology has potential for processing materials of mineral/ceramic origin, and is well-suited for mobile applications. From a scientific perspective, Cyclotec claims an improvement for ground materials properties by reducing particle size to a molecular level, and by making the substance mechanically active. Due to the energy intensity (which exceeds 2000 kW/m3 of grinding volume, comparing to 30 kWh/m3 in ball mill) mechanical activation effect causes for significant acceleration of chemical & upgrading processes.

PCM technology includes two additional parameters for broader control of the grinding process:

a] Centrifugal speed (no critical speed limitation!)
b] Ratio of angular speeds

Here are additional advantages of this technology and its commercial application equipment:

  1. Extremely Compact footprint (1.5 t/h capacity achieved in four drums five liter volume each!)
    Low weight (
    1.5 t/h model weights 1.2 tons)
  2. Significant energy saving: at least twice less power draw in size range smaller then 400 mesh
    (20 micron silica sand product, feed F80 500 micron top size one mm, less than 50 kW/ton)
  3.  Unmatched reduction ratio- (feed 5mm, product 20 micron class)
  4. Extended run time. (high speed, high efficiency planetary gear with planned life span)
    Low wear rate since there is no impact- milling achieved by attrition. Although acceleration rate is high, linear speed is moderate not exceeding 8 m/s.
  5. Ability to operate under superior centrifugal loads - no critical speed limitation.
  6. Simplicity of continuous even feed and discharge of the raw & grinded materials.
  7. Simplicity of removal of the excessive heat and dust.
  8. No vibration – no need for foundation.
  9. Simplicity of the design – we practically have four ball mills united together- meaning simple production adaptation.
  10. Maintenance – easy & simple – complete disassembly & assembly takes six hours by one person.(liners change would require four hours, if there is spare set of drums 2 hours).
  11. Grinding Media charge – effortless and could be done without stopping the grinding process.
  12. Autogenious Grinding – great potential for the realization of the technology of AG with various materials – extremely low power draw comparing to existing grinding processes/technologies, eliminating contamination.

Feed size capability up to 70 millimeters, with drastic improvement in critical class limitation

  1. Versatility –PCM mill could be operated either in dry or wet grinding process.
  2. Intense Mechanical activation (milled granite could be a partial cement substitute, milled slag could replace cement on a pound to pound basis, self ignition of stored milled coal)
  3. Practically Immediate stabilization of the grinding process (about one minute!)
  4. The design could be applied either in continuous or batch mode(for sub micron/nano applications) Potential for large scale production of sub micron product
  5. Grinding process – We already provide milling services to local companies – demonstration possible anytime.

See this link for a video:

For more information contact:
Ezry Akkerman
Marketing Director
Cyclotec /Leotec group
Tel: 007-812-303-91-58
Fax: 007-812-714-91-75