VEM flexible vertical mills with integrated separator

The vertical mill vem for wet material grinding

The vertical mill enables high energy economy, and convinces with low specific wear values. Drying of the feed material, grinding, separating, and material transport take place inside the mill. Therefore, it is  perfectly suited for grinding products with high proportions of high moisture components.

Amount of rollers
matching to your needs
Low specific
Short switching
time for product changeover

Technical details

  • With three or four rollers
  • Excellent start-stop behavior
  • Very good partial load response (performance reduction down to 25 % possible)
  • Low specific energy consumption
  • Available with installed motor sizes of 60 kW-3000 kW
  • Suitable for high mass flows
  • Short switching time for product changeover
  • Combined grinding, drying, and separating plant
VEM vertical mill

more than 
100 ball  mill 
installations worldwide

Why do ball mills have different dimensions?

The diameter of a ball mill has a great influence on the power consumption of the mill and thus on the possible production output. This is because the ratio of the diameter to the grinding path length determines the residence time of the material in the mill and thus the theoretically achievable fineness of the material at the discharge.

Coarser products would be ground too finely in long mills. They require the short residence time in a short mill. Fine products, on the other hand, need a long residence time. By combining a mill with a separator, it is possible to control the product fineness and to return only those fractions that are still too coarse to the mill. For this reason, very long mills are no longer common today.

Common length-to-diameter ratios:

Short mills: L/D <2.5
Normal mills: L/D 2.5 - 3.5
Long mills: L/D 3.5 - 5.5

What is a slide shoe bearing?

When ball mills are supported on individual bearing jewels via races or surfaces on the mill shell, this is referred to as a slide shoe bearing.

This modern bearing is effective and inexpensive because the head linings of the mill do not have to be designed to carry the load. Depending on the mill size, two, three or four sliding shoes are used per bearing side. The mill, with its heavy weight, rests statically on the slide shoe surfaces. To lift the mill a high-pressure pump pumps lubricating oil into the space between the mill shell and the bearing. This process is referred to as hydrostatic lubrication. When the mill rotates the movement of the mill running surface creates hydrodynamic lubrication. A low-pressure pump maintains the oil flow.

The slide shoes are made of a material with emergency running properties to avoid damages at the bearing and the mill shell, if the oil film should be interrupted.

What is the ideal grinding ball filling degree?

The filling level of 30 % often turns out to be the most economical nominal value. However, filling degrees around 24 – 26 % are energetically the better option for most plants, although the production is lower. Hence, the ideal filling degree always depends on the operator's target. For products that are very easy to grind, filling levels around 20 % are often sufficient.

Get your 360°Mill Check now!

The elimination of bottlenecks can lead to significant energy savings. 

Let's find your bottlenecks.

Millcheck Batch
  • Precise separators

  • High quality Diaphragms

    for the optimal equipment of your ball mill

  • Complementary products

    for your process

  • Process optimized mills durable, robust and efficient.

Our service


Competence Center

Precise analysis for the perfect result.

We analyse your product to design the most efficient grinding plant.

  • Technology center for material tests 
  • Laboratory for material analysis
Christian Pfeiffer pilot plant
A story of efficiency

Efficiency in grinding is our heritage and our future.
Since 1925.

Making grinding processes as efficient as possible is a science in itself – one to which we dedicate our entire expertise and spirit of innovation. From the invention of the first MONOBLOC diaphragm to the technical fine-tuning of the separator QDK. How we became what we are today.