| The electro-flotation of kaolinite particles of different size fraction were studied in a modified hallimond tube.The paper study on the influence of bubble property which changed with electrolysis conditions such as current intensity and cathode aperture and flotation conditions including reagent species, reagent concentration and pH on the interaction between bubble and kaolinite particles of different size fraction. Furthermore, the paper did more thorough study on the system of particle-bubble interaction by High speed CCD and fitting of particle acquisition probability.Results show that current intensity and cathode aperture had significant effect on the cumulative recovery of kaolinite. As the current intensity increased from 50mA to 150mA,bubble amount increased while bubble size decreased,so flotation rate constant K and theoretical recovery R increased.The flotation cumulative recovery of kaolinite of three size fraction increased with current intensity in the experi-ment.Bubble size increased when cathode aperture increased from 38μm to 420μm. At a certain current intensity, the larger the cathode aperture, the more coarse the particle size,and the better the flotation effect. When the reagent was changed from DDA to 1227, kaolinite flotation effect changed slightly.As the concentration increased from 2×10-5mol/L to 1×10-4mol/L, large bubbles decreased and the bubble size became more even. The cumulative recovery of kaolinite increased meanwhile.As pH increased from 4 to 10,bubble size decreased rapidly.The cumulative recovery of kaolinite decreased as pH increased.And the cumulative recovery of fine particle was higher than the coarse's at pH=10.There was an optimum match between particle size and bubble size.The best acquisition probability was found in the specific range.The optimum match in the experiment was as follows:When the current was 150mA,the flotation of 0～36μm is efficient in the aperture of 38μm and the cumulative recovery reached 84%:the flotation of 38～45μm is efficient in the aperture of 50μm and the cumulative recovery reached 81%: the flotation of 45～74μm is efficient in the aperture of 74μm and the cumulative recovery reached 77%.The research was supported by "National Natural Science Foundation—(50674103) "of China.
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