Process NPK compound fertilizers efficiently

NPK fertilizers or compound fertilizers belong to the so-called mineral compound fertilizers, consisting of the elements nitrogen (N), phosphorus (P) and potassium (K). This compound fertilizer is mainly produced in the manufacturing processes of drum granulation or compaction.

In this process, the above-mentioned components are granulated with additives and water in the first stage, and compacted under high pressure in the second stage. The resulting granulates are then classified and, depending on the screening result, crushed, compacted or granulated again. At this point, high screening efficiency reduces unnecessary waste in productivity.

Screening machines for difficult-to-screen NPK fertilizers

An industrially manufactured product consists of fertilizer in the form of granules. The grain distribution of the multi-component fertilizer is of elementary importance: Only a uniform grain distribution without unwanted dust enables modern fertilizer spreaders to achieve the optimum throwing distance, which can be up to 25 meters. 

The moisture added during production presents the screening machines with the problem of processing sticky and thus difficult-to-screen materials in the further course of production. The screen cloth can easily become clogged and caking can quickly occur. 

Throughout the decades, RHEWUM has developed special solutions for many customers that have proved themselves in practice as well. Our unique screening machines with direct excitation of the screen mesh can easily screen NPK fertilizers without clogging of the screen mesh.

The direct vibration transmission to the screen mesh enables high-frequency oscillation directly on the material and thereby prevents clogging of the screen meshes. In addition, automatic cleaning pulses free the machine's screen mesh from stuck grain during operation and keep it ready for operation. Production can continue even if a single drive fails, thanks to the large number of smaller drives.

The screening machines RHEsono® and RHEmoto® additionally score with a static housing, which not only protects the building and surrounding steel structures, but also allows inspection during operation. Both machines can be realized with up to 5 screening decks for the simultaneous production of several product fractions.

Recommended screening machines for NPK fertilizers



High-frequency vibrations for screening NPK compound fertilizer at separations up to 2 mm (10 Me.)

Show me more


Direct vibration transmission for perfectly screened NPK at separations from 1 to 10 mm (18 Me. to 3/8″)

Show me more


Uniform product distribution and integrated pre-screening optimizes downstream screening process

Show me more

Product examples

  • NPK, compacted
  • NPK, granulated
  • NPK, micro-granulated
  • NPK, stored product
  • Compound fertilizer
  • Coated fertilizer

Your benefits

  • Smooth production flow without production downtimes
  • No recurring cleaning and low maintenance costs
  • Increased efficiency due to higher screening efficiency and production of several products with only one machine