Advancing coarse particle flotation: how the NovaCell™ overcomes liberation challenges

For the successful recovery of coarse and composite particles by flotation, it is crucial to prevent or limit particle detachment. In conventional flotation machines, the strong hydrodynamic forces essential for bubble-particle collisions and attachment frequently lead to unintended detachment. The likelihood of detachment increases as particle size increases and as fractional surface liberation decreases. The NovaCell™ seeks to overcome this problem by using two distinct recovery zones that target coarse and fine particles separately, the former being achieved using a quiescent fluidized bed. Recent NovaCell™ studies have observed improved recovery efficiency at coarser grind sizes when compared to conventional flotation machines ( Morgan et al., 2024 ). This is thought to result from decreased detachment of valuable particles with low surface liberation within the fluidized bed. Experiments were undertaken on a run-of-mine ore using the NovaCell™ and a mechanical cell. The NovaCell™ achieved greater copper recovery compared to the mechanical cell, especially at particle sizes above 100 µm. To explore this further, mineral liberation analysis was conducted on the NovaCell™ products. The flotation response for each size fraction and liberation class was determined, finding effective copper recovery across all size fractions with fractional surface liberation as low as 10 %.