or anticipated by monitoring the volumetric underflow ore
concentration. Roping was observed to occur when the
underflow concentration exceeded about 31% (v/v%);
underflow concentrations between 31% and 50% could
not be maintained in this study.
Medium flow behaviour within the cyclone has been
observed to govern the behaviour of various parameters
of importance during the transition to roping, namely:
the underflow ore concentration, slurry flow through the
outlets, and the density differential. This was especially true
at the onset of spigot overloading.
The density differential decreased to exceedingly low values
during the transition to roping, and this parameter
could possibly be useful in detecting and/or avoiding overloading
of the spigot.
The spigot capacity obtained in this study was slightly
higher than that specified by DSM even though a smaller
diameter cyclone was used, and it appears that the specified
spigot capacities (by cyclone manufacturers) could potentially
be increased.