Investigation the hydrodynamic conditions of batch column flotation of Bama zinc concentrate using Response Surface Methodology (RSM) - Central Composite Design (CCD)

Performance of a column flotation cell depends on the hydrodynamic conditions (gas holdup، density of the collection zone and density of the froth zone) of the process. Present work has been carried out to observe the effect of column operating variables (gas flow rate (0. 78-1. 3 cm/s)، wash water rate (0. 1-0. 2 cm/s)، feed flow rate (0. 39-0. 91 cm/s) and froth height (45-65cm)) on hydrodynamic conditions in a batch flotation column (400cm height & 10cm diameter) using the zinc rougher concentrate of Irankooh plant. Response Surface Methodology (RSM) was used to design and analysis of experiments as well as process modeling. Results showed that Gas holdup increased and density of collection zone decreased with increasing feed flow rate، gas flow rate، wash water rate and froth height. Also، with increasing wash water rate and gas flow rate، density of froth zone increased and it decreased with increasing feed flow rate and froth height. Froth height and wash water rate were the most significant factors affecting gas holdup and density of collection zone responses. Feed rate and wash water rate were the most significant factors affecting froth zone density. When wash water rate increased from 0. 1-0. 2 cm/s، gas holdup changed from 15. 01-19. 97% and density of collection zone changed from 0. 88- 0. 79 g/cm3. Also gas holdup increased from 15. 85-19. 13 and density of collection zone changed from 0. 86- 0. 81 g/cm3 when hieght froth increased from 45-65 cm. Froth zone density decreased from 0. 47- 0. 3 g/cm3 with increasing in gas rate from 0. 39-0. 91 cm/s. When wash water rate increased from 0. 1-0. 2 cm/s، froth zone density increased from 0. 34 to 0. 44 g/cm3. Two linear and a quadratic models were derived for prediction of gas holdup، density of collection zone and froth zone density.