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The essential features of distinction the particles are size, shape and surface roughness. The classical characterization of particles by using size analysis and geometric shape factors often cannot distinguish the valid differences between individual powders. By means of computer aided-image analysis, some parameters (which are used in estimation the surface roughness, shape and size of particles) can be determined. Detachment process of particles from the gas-liquid interface is a phenomena with important effects on interfacial processes such as flotation. An approach of the determination of detachment forces by a centrifuge method is described. To examine the effect of particle shape and surface roughness in the detachment process, centrifugal experiments on materials with different surface chemistry are carried out. A new approach for the problem of determination the theoretical centrifugal detachment force is introduced. This fundamental includes all forces affected on a particle and it avoides all errors with previous theories. To study the effect of surface roughness and shape of particle on its floatability, flotation tests using a modified Hallimond tube are studied.

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Prof. Dr. Mahmoud M. Ahmed, Assiut Univ. studied in Max-Planck Institute. He is the Head of Mining and Metallurgical Department, Assiut Univ. His study is "Mineral Processing". He has experiences in teaching and research. He is a reviewer at many International Journals. He is a member of Who´s Who . He published many international researches.

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