EFFECT OF FINE SOLIDS AND FROTHER ON GAS HOLD-UP AND LIQUID-MIXING INA FLOTATION COLUMN

The effect of fine solids and frother addition on gas hold-up and aver age bubble rise velocity in bubble swarm and liquid phase mixing inten sity has been studied in a 0.06 m flotation column. The variables stud ied were frother (pine oil) addition, feed solid concentration, gas an d slurry velocities. The gas hold-up was estimated from the static pre ssure method, while the liquid phase mining intensities were estimated using the pulse technique. In comparison with our previous air-water study [1], frother addition has a drastic effect on bubble characteris tics, while the effect of solids is negligible except at low gas veloc ities for which complete suspension of solids from the gas distributor were not observed. The presence of small quantities of solids on the gas distributor resulted in bubble coalescence even in the presence of frother. In general, frother addition resulted in an increase in the liquid mixing intensity while the presence of solids had the opposite effect Our results indicate that in the presence off-other the bubbly flow regime is maintained over a wider gas velocity range.