Numerical simulation and experimental study of impact flow enhancing flotation pulp conditioning

A laboratoryimpact flowconditioningpulpdevice was developed to enhance the adsorption of collectors on the surface of particles using the high-velocity impact flow to achieve an efficientmodification of mineral particlesurface.The flow field of the impact flowconditioningpulp device was calculated using the Fluent software to analyze the fluid distribution characteristics,as well as the fluid dynamics parameters such as fluid velocity,strain rate and Kolmogorov scale (η). Moreover,the collector adsorption density,surface hydrophobicity,and flotation kinetics of mineral particles after pulp conditioning with different impactvelocities were analyzed to verify the effect of impactvelocity on the modification of mineral particles.The results show that thehorizontal and circulating flows were present in the mixing zone of the impact flowconditioningpulp device,which was beneficial to enhance the adsorption of collector and the surface modification of particles. The fluid flow was mainly affected by the radial and axial flow,as well as the radial and axial flowvelocity all increased as the increase of impactvelocity. In the impact section,the strain rate of fluid was higher. In the divergent section,the strain rate of fluid gradually decreased up to the stable value,and the strain rate increased with the fluid flowed to the wall surface. The increase of the impactvelocity may increase the strain rate. In the impact section,the η decreased with the fluid flow. In the divergent section,the η increasedwith the distanceup to the X-axis distance of 20 mm above which the η decreased,and the η decreased with the impactvelocity increased.The collector adsorption density,contact angle,flotation rate constant,and maximum combustible recoveryincreasedwith the impactvelocityincreased to 4 m/s above which thosedecreased,and the optimum impactvelocity of the pulp conditioning was 4 m/s with the collector adsorption density,contact angle,flotation rate constant and maximum combustible recovery were 0.88 mg/g,103.27°,0.0516 s^-1and 94.18% respectively.