Production of sharp-sized grades from naturally moist sands, Remscheid
Meike Schulz, RHEWUM GmbH
Screening surface after three month of continuous operation with a magnetic drive.
The requirements of the premixed plaster industry for the production of up to five sharp-sized fractions mean dealing with various processes in order to meet the needs of this difficult to screen material.
The requirements of the premixed plaster industry for the production of up to five sharp-sized fractions mean dealing with various processes in order to meet the needs of this difficult to screen material. An Italian manufacturer of different grain sizes for well-known producers of premixed plasters approached RHEWUM with the objective of sizing 80 t/h crushed dolomite flour into the fractions 10.0 mm, 3.5 mm, 2.25 mm, 1.6 mm and 1.0 mm. The moisture and the clay content cause trouble in the processing. Tests showed that screening cloth of applicated linear motion vibrating screens blinded immediately (see figure below). The optimal solution in this case was a combination of different processes: The feed material is separated at 10.0 mm in the feed section on co-vibrating strainer bars.
Screening surface after three month of operation with an unbalance motor.
The feed is sized at 3.5 and 2.25 mm on a screen driven by an unbalance motor – a simple and cost-effective alternative to electromagnetic drives. Critical cuts at 1.6 and 1.0 mm are performed on a directly excited screen with electromagnetic drive. An additionally installed electrical screening surface heating with a required maximum power of 30 kW permits the heating of the screening surface to above 100° C and prevents the caking of the screening surface.
Find the detailed article from Sigurd Schuetz here or in the current ZKG Drymix Mortar Special 2017.