Date of Award
Doctor of Philosophy
A hydrodynamic study of bubble column flotation for the recovery of titanium and zirconium minerals from oilsand tailings has been carried out in a 0.06 m (i.d.) column. A beneficiation process for these tailings was also developed which ensures the recovery of rare earth minerals.;The optimum conditions for the recovery of these minerals were found to be at a frother concentration of 0.15% (v/v) pine oil and pH range of 8.3 to 11.7. Low recoveries were obtained at frother concentrations exceeding 0.2% (v/v) pine oil.;Individual phase hold-ups were estimated using the static pressure method. Flow regimes were identified using the changes in bubble rise velocity with gas velocity. For all the systems considered here, the liquid hold-up decreased with increasing gas velocity in the chain bubbling and bubbly flow regimes. The addition of a frother generally resulted in a decrease in the liquid hold-up, bubble size and rise velocity. The presence of solids in the column did not have any significant effect on the gas hold-up except for gas velocities at which solids were observed on the gas distributor.;The control of gangue recovery in a bubble column flotation cell is presently accomplished with the addition of wash water near the froth-pulp interface. The results obtained here show that the height of the calming zone may be effectively used to control gangue recovery.;Liquid phase axial mixing coefficients were estimated using the pulse technique. The parameters were estimated in the frequency domain using Parseval's theorem. The isotropic turbulence theory of Baird and Rice was used to provide dimensionally consistent correlations for the chain bubbling and bubbly flow regimes. The variation of the liquid dispersion coefficient with gas velocity was found to agree rather closely with the flow regime mapping. The results obtained indicate that the gas phase Froude number is a useful criterion for characterizing flow regimes in vertical bubble columns. The addition of frother generally resulted in an increase in the liquid dispersion coefficient while the presence of solids had the opposite effect.
Ityokumbul, Mku Thaddeus, "Hydrodynamic Study Of Bubble Column Flotation For The Recovery Of Heavy Minerals From Oilsand Tailings" (1987). Digitized Theses. 1596.