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Bubble-particle collision mechanism in the contact zone of cyclone flotation |
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Abstract In order to forecast the dynamics and separation efficiency of cyclone flotation processes, a new collision efficiency model of cyclone flotation, which bases on the collision modeling methods in gravity field and the characteristics of cyclone flotation, has been developed by introducing Reynolds number (Re) into all types of collision processes for the first time, such as interception, inertia, diffusion and centrifugal sedimentation in the contact zone. This model indicates that all the collision effect depends on Re, bubble size and particle size. When the particle size is lower than 1 nm, which is close to a molecular diameter, the collision efficiency is mostly controlled by the diffusion collision. When the particle size is between 1nm and 10 nm, the collision efficiency is controlled by both the diffusion collision and the centrifugal settling. When the particle size is between 10nm and 1 μm, the collision efficiency is mostly controlled by the centrifugal settling. However, when the particle size is above 1 μm, the collision efficiency is controlled by the combined effects of interception, centrifugal settling, and inertia effect. This model can perfectly forecast the dynamics and separation efficiency of cyclone flotation processes, which can supply a theory basis for practical application of cyclone flotation.
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Received: 12 August 2012
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