The stone separating screens, type VSP, are designed to handle soft to medium hard clays (up to a maximum hardness of about 2–3 on the Mohs scale) containing larger stones (up to 300–400 mm).

The VSP stone separating screens are fed directly from the pit or by primary box feeders and carry out the primary crushing of the raw materials, reducing the material to about 80 mm on exit.


The machine is composed by:
1 screening unit;
1 crusher for the hardest clay bodies and reject of big dimensioned stones.

  • Single motorization for each screening unit with same rotation direction, staggered and interpenetrating reciprocally for a correct screening;
  • Set of scrapers for cleaning of gaps;
  • Crushing is carried out by a paddle wheel shaft rotating on an inclined combing system for the transport of clods;
  • The paddle wheel shaft movement, controlled by a hydraulic decelerating unit, allows the automatic reject of stones;
  • Easily removable rack for wearing parts maintenance.

The stone separating mill LSP has the task of separating the clay material from the hard parts present (stones, pebbles, etc.) and  performing the first action of crushing of material (roughing).
This action is carried out by the passage of the material through the existing gap between the two cylinders which are rotating in opposite directions and at different speeds. The stone separation is achieved by means of helical threads cut on the external surface of the slow cylinder.


  • Rollers running at differential speed;
  • Smooth shell complete with hard-facing anti-wear treatment in tungsten carbide with high resistance to mechanical stress;
  • Grooved roll, screw shaped, with anti-wear treatment in tungsten carbide;
  • Shafts are driven by two orthogonal gear-motors SEW type, with oscillating fixing and axial block;
  • The smooth roll gear-motor is installed on a support assembled on the machine structure, while the screw shaped roll one is installed on a mobile support for the recovery of the shell wear;
  • Safety device with automatic stopping of the machine;
  • Interchangeable scrapers made in wear resistant steel, mechanically adjustable from outside of the machine;
  • Mechanical adjustment of working gap between rolls;
  • Protection cover on moving parts.