4. Conclusions
This study has established that the onset of rope discharge
at the underflow represents the point at which the
spigot capacity of the dense medium cyclone was reached.
The type of flow at the spigot was monitored, and related
to the spigot loading (and consequently the spigot capacity).
During the onset of roping some of the sinks particles,
which were supposed to exit at the underflow, were displaced
to the overflow, and thus increased the separation
density.
A critical underflow ore concentration at which spigot
overloading occurs has been observed. The quantity of
the critical underflow ore concentration observed in this
study was about 50% (v/v), and it remained constant with
further addition of ore into the cyclone. It has been established
that the onset of spigot overloading can be predicted