Simply reliable: Meet
the Ball mill BAM

With the highest efficiency in cement grinding.

The BAM Ball Mill convinces thanks to their simple principle and low maintenance needs: They are robust, durable and extremely reliable in operation.

internals made of rolled steel
low wear and tear
sleep well while BAM keeps turning

Technical details

  • Available as an end discharge mill, airflow mill, or wet mill
  • Slide shoe bearings reduce the strain on mill shells and installations: heavy and expensive cast head walls are not needed
  • Optionally also with trunnion bearings or roller bearings
  • Lateral gear drive and pinion
  • Centralized lubrication system
  • Large reinforced manholes (540 x 640 mm) for optimum maintenance and installation conditions
  • Available with installed motor sizes of: 300 kW–10,000 kW
  • Solid, reliable and long-lasting

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.

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  • 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.

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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.