The effect of external gas/slurry contact on the flotation of fine particles

An external contractor was investigated in order to evaluate its efficiency in collecting fine particles. For this purpose, a flotation column was equipped with an external flow-through sparger/contactor. The device was fitted on a slurry recycle stream and consisted of a porous stainless steel tube around which an air-tight rigid jacket was sealed. The device acted as a bubble generator and a bubble-particle interaction chamber. Variables including contractor length, pore size, collection tubing length, device placement, column length, and superficial slurry rate (inside the porous tube) were investigated. Size-by-size recovery plots were generated using a Brinkmann particle size analyzer. sults show that the slurry rate plays a significant role in the recovery of fine particles. Other parameters, such as collection tubing length, porous tube length and pore size, all play a role in fine particle recovery to varying extents. It is concluded that a combination of conventional internal bubble-coursing and external contact is ideal for the recovery of a wide range of particle sizes.