Linatex Flat Bottom Classifier


The Linatex® flat bottom classifier is a well proven performer for the hydraulic classification of particles by size or density. The classifier reliably extracts light or small particles from slurry at high efficiency, whilst displacing a minimum of heavy or coarse particles to the overflow.
  • Extremely efficient washing of soluble or colloidal species from granular particles by virtue of counter-current plug flow washing
  • High sharpness, little misplaced material via direct bed measurement
  • Multiple discharge valves on large units, to continue an even bed draw down without valve blockages or channeling
  • Multiple water injection nozzles result in uniform flow even at minimal flow rates
  • No moving parts are exposed to process slurry, meaning little maintenance is required and a long operating life is achievable
  • Low headroom design results in low capital installation and maintenance costs and easier inspection
  • Zero bypass, no fines in underflow
  • Proven performance in hydraulic classification 200
  • Coal/ash separations by density
  • Silica/heavy mineral separation by density
  • Removal of deleterious material from sand
  • including lignite, coal, wood, plastic/paper, clay/silt and mica
  • Alternative to cycloning:
    • where fines must not be present in the
    • for removing large amounts of clays and slimes
    • for sharp classification in mill circuits
    • at cut sizes coarser than usual applications for cyclones, typically between 100 and 1000 microns
  • Slurry enters the Linatex® flat bottom classifier through an adjustable central feed well (1) which uniformly distributes solids to a settling chamber (2).
  • A controlled flow of clean water is injected to a distribution chamber (3) under the settling chamber.
  • The clean water permeates a series of injection nozzles which are individually replaceable (4) and flows upward through the settling chamber, discharging over the overflow weir (5).
  • The interaction between the rising current and the settling solids creates a fluidized bed. This inhibits the settling of finer sized or lower density material, while allowing the heavier/coarser particles to pass easily to the bottom of the chamber via the hindered settling process.
  • A sensor (6) located near the top of the fluidized solids monitors the height and specific gravity of the slurry and causes multiple discharge valve(s) (7) to open when a set point is reached.
  • Solids are quickly discharged from the classifier in frequent, discrete pulses via the discharge valve(s).
  • The on/off nature of the discharge avoids situations which cause valve blockages or bed channeling behavior (rat-holing) in other classifier types.
  • The pulsing of the bed also assists in removing entrained fines or light particles from the settled bed.
  • The finer or lower specific gravity solids which overflow the weir are typically directed to a densifying hydrocyclone, sieve bend or dewatering screen.
  • Continuous underflow discharge is also available to simplify downstream operations.
    The higher density or coarser solids which discharge from the underflow may be stockpiled, further dewatered, conveyed or gravity-fed to the next process stage.