The Lamella High Shear Rate REFLUX™ Classifier
T Orupold, D Starr, T Kenefick
This paper covers the commercial development of gravity separation of fine
particles using a Lamella High Shear Rate REFLUX™ Classifier (REFLUX™
Classifier), focusing primarily on coal applications. The REFLUX™
Classifier is a fluidized bed device that incorporates a system of closely
spaced parallel inclined channels located above the fluidized bed. These
channels make it possible to achieve a significant suppression of the effects
of particle size, resulting in a highly effective separation on the basis of
density. The improved gravity separation performance is shown to be
remarkably high, with a significant reduction in the variation of separation
density with particle size, and a significant reduction in the change in Ecart
probable error (Ep) with size.
The first full commercial-sized units of the REFLUX™ Classifier were
field-tested in late 2009 in coal applications. More recently, the technology
has been applied in fine particle separation in minerals applications and
there are a number of full-sized units operating in chrome applications in
South Africa. Initially, pilot-scaled units (typically the RC™300) were
trialled in iron ore, mineral sands, and manganese plants amongst other
minerals, typically after other technologies failed to achieve the desired
results. Currently a number of laboratories globally are carrying out more
testing in minerals applications.
More than 50 RC™ units are now operating in coal and minerals
applications. This paper introduces the REFLUX™ Classifier technology,
identifies commercial applications, and gives some commercial results.
Keywords: gravity separation, classification, fluidized bed.