2073
Investigating the Multidimensional Separation Behavior of
Particles in a Cyclosizer Setting—A Case Study on Calcite,
Fluorite and Magnesite
Johanna Sygusch, Martin Rudolph
Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Freiberg, Germany
Thomas Wilhelm, Orkun Furat, Volker Schmidt
Ulm University, Institute of Stochastics, Ulm, Germany
ABSTRACT: Particle separation is typically investigated regarding one particulate property only. Virtually all
separation processes, however, act on various particle properties in different ways. Modern particle analytical
modalities enable a statistically meaningful multidimensional particle characterization. Within this study,
individual particle fractions of magnesite, calcite and fluorite (–71 µm) are processed via the turbulent cross-
flow separator cascade Cyclosizer (M16, MARC Technologies Pty Ltd), consisting of 5 hydrocyclones, thus
producing 5 different product streams. Particle characterization is achieved via dynamic image wanalysis from
which information on the particle shape and size is obtained. Using this data, bivariate Tromp functions are
computed, which show the combined effect of the particle descriptors of roundness and areaequivalent diameter
on the separation behavior. While the first cyclones recover predominantly coarse particles with high roundness
values, fine particles with varying roundness are recovered in the latter cyclones.
Keywords: Hydrocyclone, multidimensional separation, multivariate Tromp function, particle size, particle
shape
INTRODUCTION
In the minerals processing industry, hydrocyclones are
a widely used tool with various applications within the
processing stages. They are efficient for the classification
of particles with sizes between 5 µm and 250 µm and are
commonly placed in a milling circuit or for desliming of
the flotation feed, especially for Kaolin processing, where a
high amount of fines leads to several issues for the separa-
tion, e.g., slime coating (Trahar, 1981). The classification
is mainly influenced by the particle size and the particle
density, as both properties affect the settling velocity of
the particles, which determines to a large extent which
streamlines the particles follow. Via the turbulent crossflow
hydroclassification, coarser particles and those with higher
densities tend to follow the outer streamlines and pass the
underflow discharge, whereas finer particles and those with
lighter densities tend to follow the inner upward stream-
line and pass the overflow discharge (Schubert, 1989). The
turbulent flow conditions within the hydrocyclone are
influenced by its dimensions, such as diameter, cone angle
or geometry of the underflow or the feed nozzle, but also
by the pulp density of the feed suspension, as particles are
Investigating the Multidimensional Separation Behavior of
Particles in a Cyclosizer Setting—A Case Study on Calcite,
Fluorite and Magnesite
Johanna Sygusch, Martin Rudolph
Helmholtz-Zentrum Dresden-Rossendorf, Helmholtz Institute Freiberg for Resource Technology, Freiberg, Germany
Thomas Wilhelm, Orkun Furat, Volker Schmidt
Ulm University, Institute of Stochastics, Ulm, Germany
ABSTRACT: Particle separation is typically investigated regarding one particulate property only. Virtually all
separation processes, however, act on various particle properties in different ways. Modern particle analytical
modalities enable a statistically meaningful multidimensional particle characterization. Within this study,
individual particle fractions of magnesite, calcite and fluorite (–71 µm) are processed via the turbulent cross-
flow separator cascade Cyclosizer (M16, MARC Technologies Pty Ltd), consisting of 5 hydrocyclones, thus
producing 5 different product streams. Particle characterization is achieved via dynamic image wanalysis from
which information on the particle shape and size is obtained. Using this data, bivariate Tromp functions are
computed, which show the combined effect of the particle descriptors of roundness and areaequivalent diameter
on the separation behavior. While the first cyclones recover predominantly coarse particles with high roundness
values, fine particles with varying roundness are recovered in the latter cyclones.
Keywords: Hydrocyclone, multidimensional separation, multivariate Tromp function, particle size, particle
shape
INTRODUCTION
In the minerals processing industry, hydrocyclones are
a widely used tool with various applications within the
processing stages. They are efficient for the classification
of particles with sizes between 5 µm and 250 µm and are
commonly placed in a milling circuit or for desliming of
the flotation feed, especially for Kaolin processing, where a
high amount of fines leads to several issues for the separa-
tion, e.g., slime coating (Trahar, 1981). The classification
is mainly influenced by the particle size and the particle
density, as both properties affect the settling velocity of
the particles, which determines to a large extent which
streamlines the particles follow. Via the turbulent crossflow
hydroclassification, coarser particles and those with higher
densities tend to follow the outer streamlines and pass the
underflow discharge, whereas finer particles and those with
lighter densities tend to follow the inner upward stream-
line and pass the overflow discharge (Schubert, 1989). The
turbulent flow conditions within the hydrocyclone are
influenced by its dimensions, such as diameter, cone angle
or geometry of the underflow or the feed nozzle, but also
by the pulp density of the feed suspension, as particles are