Ball shaper

Rotor impact mill


Efficiently processing shredder fractions


Efficiently processing shredder fractions

The BHS rotor impact mill is a high-performance crusher with a vertical shaft that addresses the needs of the recycling industry. The mill’s unique impeller rotor works together with a toothed anvil ring to subject the inserted material to severe mechanical stress. Material compounds are crushed and separated selectively, entangled materials are isolated, and brittle-hard materials are crushed very finely. At the same time, metals are shaped into balls and cleaned. Watch the video to find out how to optimally prepare shredder fractions for separation by disaggregating composite material and pelletizing metals with the RPMX rotor impact mill.



Unique crushing principle

  • Impeller rotor is one of its kind worldwide
  • High energy load to the feed material thanks to centrifugal forces
  • Impact and shearing forces produce intensive shredding results
  • Rotation results in a nearly constant gap 

Future-proof investment

  • Flexible use for variety of tasks thanks to variable peripheral speed of the rotor and adjustable gap between horseshoe hammers and anvil ring
  • Effective processing of fine off-spec particle sizes

Selective crushing

  • Brittle materials such as glass and minerals are finely shredded and/or pulverized via impact and shearing forces

Shaping of metals into balls

  • Possible to pelletize even ductile materials due to high levels of stress being applied between the horseshoe-shaped hammers and the fixed anvil ring 

Separation of composite materials

  • Multi-stage application of stress cleans metals and separates out various materials
  • Example of cable recycling: Efficient removal of the plastic sheathing from the conductor

Machine operation

  • Optimum settings achieved thanks to adjustable rotor speed and annular gap
  • Easy to retool


Easy maintenance and high availability

  •  Parts subjected to stress are protected by easily replaceable wear parts
  • Materials used in wear parts are optimized for the relevant application 

Unit ready for operation

  • Ready-to-install unit consisting of machine and drive train mounted on a base frame
  • Unimpeded access thanks to large cover that can be raised hydraulically and pivoted by 360°

Reliable greasing

  • Low-maintenance, reliable operation thanks to a recirculating oil lubrication system with cooling and integrated monitoring 

Vibration absorption

  • Rubber spring elements absorb vibrations generated during operation
  • An electronic vibration monitor causes the machine to shut down if excessive vibrations are registered

Technical systems


Rotor impact mill of type RPMV – the ball shaper

The feed material is loaded into the top center of the machine. When it impacts the rotor, the material is accelerated towards the outside by means of centrifugal forces; there, the horseshoe-shaped hammers engage it and throw it against the anvil ring, In the milling gap, it is crushed as a result of the impact and shearing forces. The material leaves the rotor through the gap and falls down through two outlet chutes.

Rotor impact mill of type RPMX – the turbo-ball shaper

The material is selectively transported into the gap between the anvil ring and hammer from above by means of the rotor cover plate. In this way, the full height of the grinding gap is utilized, resulting in a longer retention time and a higher stress frequency. An intense ball shaping effect is achieved in combination with a high circumferential speed, a narrow grinding gap of 4 to 6 mm and a specially toothed anvil ring.

Operating principle of the RMPV (side view)

Operating principle of the RPMV (top view)


Rotor impact mill available in two models

The RPMV is a rotor impact mill used in the recycling industry. The ball shaper, which has proven itself for many years in a wide range of applications in the recycling industry, sets a new standard with the RPMX. The RPMX rotor impact mill is a turbo-ball shaper. It is used in the reclamation of materials from fine fractions containing metal (such as stainless steel and cable strands) that had previously been considered difficult to process.

Rotor impact mill of type RPMV – the ball shaper

Rotor impact mill of type RPMV

Rotor impact mill of type RPMV – the ball shaper

The RPMV has proven itself in separating composites, crushing brittle components and shaping metals into balls with particle sizes from 5 to 30 mm.

Rotor impact mill of type RPMX – the turbo-ball shaper

Rotor impact mill of type RPMX with rotor cover plate

Rotor impact mill of type RPMX – the turbo-ball shaper

A higher circumferential speed and the considerably smaller grinding gap characterize the RPMX. This feature set makes it ideal for ball shaping and separating composite parts with particle sizes from 0 to 15 mm.


Advantages of the Rotor

  • Replaceable crushing tools
    The anvil ring elements are suspended on the mill housing (RPMV) or bolted on (RPMX). The horseshoe-shaped impact hammers are mounted to the rotor and are held on the rotor pegs by centrifugal force. Both the anvil ring and the impact hammers are easily replaced.
  • Adjustable gap
    A set of replaceable spacers is used to configure the ring gap. The ongoing wear and tear of the impact hammers causes the gap width to change; this can be easily corrected by replacing spacers in different sizes (shown in red in the illustration).


  • Optimized service life
    The rotor direction can be reversed, allowing both sides of the impact hammers to be fully utilized.


Spacers for increasing degrees of wear



Options & accessories

Rotor impact mill of type RPMX

Electro-hydraulic cover opening

An electrohydraulic lid opener can be installed as an option to ensure quick opening of the machine lid for maintenance and inspection purposes.

Installation in electrical terminal box

If required, all electrical wiring can be bundled in a terminal box for easy installation.

Intensive cooling

In the event of high ambient temperatures or if the material to be processed is hot, a supplementary lubrication unit featuring a larger storage volume and stronger cooling power can be provided.

Air cannon

In order to reduce material deposits in the outlet area, the mill can be optionally equipped with air cannons.


The use of a crane is recommended when replacing wear parts.

Control unit

To provide an alternative means of operation, the machine can be shipped with a PLC controller (including touch panel) and a frequency converter if required. This allows for autonomous operation and monitoring of the machine’s functions. The PLC controller can also be used to operate additional system components, such as in-/outlets, a dust removal system, a sorting unit, etc.

Steel structure

To complement the machine, we offer standardized or customized steel add-on solutions such as supports, platforms, railings, and stairs.

Plant technology

We are also able to provide you with complete system solutions that include, for example: Steel construction, bunker and dosing technology, feeding and draining/discharging technology, classifying and separation technology, as well as dust removal systems. We plan the system design in accordance with your requirements and comprehensively coordinate the project with you.

Technical specifications

Performance data
Type Rotor diameter x height Number of hammers Circumferential speed (max.) Drive power (max.)
RPMV 0813 850 x 135 mm 6 65 m/s 75 kW
RPMV 1113 1.150 x 135 mm 8 70 m/s 132 kW
RPMV 1513 1.500 x 135 mm 12 70 m/s 200 kW
RPMX 1116 1.150 x 160 mm 8 90 m/s 315 kW
RPMX 1516 1.500 x 160 mm 12 90 m/s 315 kW
Dimensions and weights
Type A B C D E F Weight 1)
RPMV 0813 2.800 mm / 3.100 mm 2) 1.270 mm 1.975 mm 219 mm 770 mm 2 x 210 mm 4.400 kg
RPMV 1113 4.600 mm 2.000 mm 2.700 mm 406 mm 1.300 mm 2 x 430 mm 7.700 kg
RPMV 1513 4.900 mm 2.120 mm 2.740 mm 610 mm 1.540 mm 2 x 500 mm 12.000 kg
RPMX 1116 4.600 mm 2.000 mm 2.790 mm 406 mm 1.300 mm 2 x 430 mm 8.500 kg
RPMX 1516 4.900 mm 2.120 mm 2.850 mm 610 mm 1.540 mm 2 x 500 mm 12.800 kg

1) Weight for standard design without motor and accessories.
2) Depending on the drive power.

All specifications apply to the standard design. Technical data for customized designs may differ from the specified data. All technical data may change due to development. Subject to modification without notice.



Tests give certainty

Which technical solution is the right one for your recycling process? Don’t leave anything to chance. Our team of specialists will test your material at our test center and develop a solution tailored to your specific needs.


“Rotor impact mill for recycling (RPMV & RPMX)” brochure
“Recycling solutions” overview brochure
Display all

Success stories

Rotorshredder makes recycling meatballs even more efficient

June 2019
BHS-Sonthofen has developed a new procedure for processing meatballs in order to increase the amount of copper recovered. Electric motors and motor armatures represent a small fraction of waste from incineration or large shredders, and it is difficult to cleanly separate them by type. Yet they contain a good deal of valuable copper, whose share is up to 22 percent. This impressive new procedure features a Rotorshredder optimized for this process, subsequent materials separation and copper processing using a rotor impact mill.

Less wear for economically efficient processing of ASR

March 2019
Since March 2019, a BHS-Sonthofen rotor impact mill (type RPMX) has been in operation at Jansen Shredder Recycling BV in Moerdijk, the Netherlands, for the fine processing of automotive shredder residues (ASR). Thanks to years of experience in the processing of metal-bearing waste materials, the experts from Sonthofen found the optimal solution for processing abrasive materials. Wear costs at Jansen have significantly decreased since.

Plant for recycling automotive shredder residues (ASR) in Finland.

July 2017
Kajaanin Romu Oy operates one of Finland’s most cutting-edge plants for recycling scrap in the town of Kajaani, located approximately 500 km northeast of Helsinki. The company commissioned a BHS-Sonthofen plant for processing automotive shredder residue (ASR) fine fractions of particle sizes between 0 and 30 mm. It separates the feed material abundant with valuable metals into ‘light’ and ‘heavy’ fractions in a single pass. This allows the plant operators to economically produce fractions that can be sold profitably. Moreover, the plant significantly reduces the cost of material disposal at landfills.

DHZ AG – Extracting concentrated metals from incinerator bottom ash

July 2016
DHZ AG operates a modern recycling center in Lufingen in the Swiss canton of Zurich. The facility focuses on processing incinerator bottom ash (IBA). BHS-Sonthofen supplemented two existing IBA processing plants with an additional plant that extracts high-quality, heavy and light non-ferrous metal fractions from the coarse concentrate generated upstream. These are of such high quality that they can be sold directly to smelters or to industrial customers.

Don’t let valuables end up at the dump!

January 2016
A metric ton can contain up to 20 grams of gold and up to 200 to 300 grams of silver, as well as platinum and other precious and non-ferrous metals. Heavy non-ferrous fractions of material left over after shredding and processing large automotive, electrical or electronic scrap components still hold a lot of value. Previously, the recyclable materials were deposited in landfills. Based on our unique process, BHS-Sonthofen processing plants can recover these metals.

Technical articles in the media

BHS-Sonthofen supplies rotor mill for ASR processing

June 2020
Sonthofen, Germany-based BHS-Sonthofen says a rotor impact mill (type RPMX) with chilled cast chrome wear parts has proven effective for the processing of automotive shredder residue (ASR) fine materials at Jansen Shredder Recycling BV in Moerdijk, the Netherlands.
recycling today


Vakbeurs Recycling (Gorinchem) 2021

11-16-2021 - 11-18-2021
Booth A112 at Scratch Recycling

IERC 2022

1-19-2022 - 1-21-2022

IFAT 2022

5-30-2022 - 6-3-2022

Satisfied customers worldwide


Find a sales representative

Find your personal contact person on site. We are there for you worldwide.

Find a sales representative

Find your personal contact person on site. We are there for you worldwide.