Screening and mixing machine

Our 3-fraction starscreen can also be used as a screening and mixing machine with the appropriate equipment. The wheel, crawler or wheel-crawler tracked machine can then be used to stabilise soil with lime, cement or other aggregates. The drive is diesel-hydraulic.

The coarse screen separates larger particles and loosens up the fine fraction. The fine fraction falls onto a conveyor belt and is then weighed and mixed with the compound from the attached binder container during transfer. At the transfer point, the mixture is additionally mixed by a hammer roller and remaining agglomerates of the soil are beaten smaller. The screened soil mixed with compound is transferred at a height of 2.8 metres by the side discharge conveyor.

The binder container is equipped with a dust extraction system, filter, level indicator and overpressure control. The filters are cleaned one after another by compressed air. The machine is controlled by CANBUS and the program. With the appropriate compound, a relatively dust-free and exact mixing with up to 200 tons per hour is possible.

Versatile potential applications

For soils that need to be moistened during the process, we offer appropriate additional equipment. The machine can also be equipped with a larger compressor.

With further equipment, the machine can also be used for the production of liquid soil. This process takes place in batches and preferably in truck mixers. 5-6 truck mixers can be filled in one hour. About 2500-3000 litres of water are needed for 10 tons of soil mixture. This amount of water is supplied through a 2″ pipe when it is transferred to the truck mixer. The feed is regulated by the CANBUS controller of the machine and the individual batches are recorded on a delivery note according to the regulations.

The method described here has particular advantages for clay soils. The starscreen can screen cohesive soils with relatively fine grain size. Due to the direct processing and mixing by the hammer roller, as well as the crushing of the remaining agglomerates, an optimum mixing is also possible with clay soils. For this reason, the soil can be fluidised on site quickly and at any time, which is a crucial point in regard to the German Soil Protection Act.

The screening and mixing process

Coarse screening takes place in the first step: all material fractions that are larger than 60 mm are being removed and the soil is loosened up. Following this, the soil is weighed and blended with the desired percentage of cement, lime and similar. Using the belt scales/force transducers it can be set how high the percentage of the amount to be blended in (1–10 %) should be. The machine equipped with the patented mobile wheel-crawler chassis can be moved in the terrain (crawler chassis) and by means of an articulated truck without special permit during transportation.


  • Soil stabilization – for the production of stabilized soils in civil engineering/road construction.

  • Earth recycling – Reprocessing of unusable soils.

  • Homogenizing - Production of new construction material on-site in road construction.
  • Immobilizing - Contaminated soils and construction materials require exact dosing of the binding agents to be either reused or properly disposed of.
  • Creating transportability - Materials such as drilling mud that cannot be transported due to their consistency are brought into a state in which they can be transported without any problems.
  • Liquid soil production – Reusing excavated material as liquid soil This saves time and labor costs.


  • High mixing performance of more than 200 t/h.
  • Thanks to the material loosening by coarse screen and hammer roller, optimum mixing (without agglomerates) is possible even in clay soils.
  • With the appropriate equipment, the machine can also be used to produce liquid soil.
  • Flexibility: Deployable as screening and mixing machine or 3-fractions starscreen.
  • Simple handling: Replacement of mixing unit and second screen deck in no time.

Screening and mixing machine

  • Backers Crusher & Screens GmbH

  • Auf dem Bült 40

  • 49767 Twist
  • Germany
  • This email address is being protected from spambots. You need JavaScript enabled to view it.