New Insight into the Effect of Particle Surface Roughness on Flotation Efficiency: An Experimental and Theoretical Analysis

The significance of the roughness of particles in flotation has been recognized for several decades. In this study, to investigate the effect of particle roughness, a series of rod milling with different grinding durations is performed on the quartz particles. Subsequently, the particle roundness, wetting rate, and floatability are measured. Finally, the flotation kinetic experiments are conducted based on a fixed particle size, and the interaction energy between rough particles and bubbles is calculated based on extended DLVO (E-DLVO) theory. Results show that by increasing the grinding time, the hydrophobic particle surface roughness increases, and the improved flotation rate constant increases. While the results of the E-DLVO calculation show that the interaction energy barrier between particles and bubbles decreases significantly as the roughness increases, the theoretical calculation and the experimental results confirm that an increase in the particle surface roughness decreases the interaction energy barrier between particle bubbles and increases the flotation rate.