Flotation theory

A. N. Clark and D. J. Wilson, Foam Flotation Theory and Applications, Marcel Dekker,... 

Flotation or froth flotation is a physicochemical property-based separation process. It is widely utilised in the area of mineral processing also known as ore dressing and mineral beneftciation for mineral concentration. In addition to the mining and metallurgical industries, flotation also finds appHcations in sewage treatment, water purification, bitumen recovery from tar sands, and coal desulfurization. Nearly one biUion tons of ore are treated by this process aimuaHy in the world. Phosphate rock, precious metals, lead, zinc, copper, molybdenum, and tin-containing ores as well as coal are treated routinely by this process some flotation plants treat 200,000 tons of ore per day (see Mineral recovery and processing). Various aspects of flotation theory and practice have been treated in books and reviews (1 9). 

Compressors and Expanders Selection and Application for the Process Industry, Heinz P. Bloch, Joseph A. Cameron, Frank M. Danowski, Jr., Ralph James, Jr., Judson S. Swearingen, and Marilyn E. Weightman Metering Pumps Selection and Application, James P. Poynton Hydrocarbons from Methanol, Clarence D. Chang Form Flotation Theory and Applications, Ann N. Clarke and David J. Wilson... 

Form Flotation Theory and Applications, Ann N. Clarke and David J. Wilson... 

Clarke, A. N. and Wilson, D. J. Foam Flotation, Theory and Applications. (Marcel Dekker, New York, 1983) Dallavalle, J. M. Micromerities. 2nd edn. (Pitman, London 1948)... 

Only recently the flotation theory has been reduced to the study of attachment of particles to the surface of a bubble. This approach made it possible to analyse the problem of selectivity of large-size particles ( 20 -40nm or more), which is of major importance for ore dressing. 

Main propositions of the Derjaguin-Dukhin micro flotation theory (1961) are confirmed both with respect to the transport stage and to the attachment of small particles on bubble surfaces. This is demonstrated in Sections 10.1 and 10.5, in a monograph by Schulze (1984) and in reviews by Schulze (1989, 1991, 1993). At the same time, it should be pointed out that some propositions have been substantially changed in the process of development during the period of 30 years. Some of them are not so important as they seemed to be earlier others are still not understood. 

Scheludko s theory of thin film formation and stability are a significant contribution to the modem flotation theory (Fijnaut Joosten 1978). Chapters 10 and 11 present a detailed description of this theory especially with respect to the influence of dynamic adsorption layers. 

However, Yoon does not clarify what "sufficiently hydrophobic" means. If this means the presence of an non-zero contact angle, there are no objections to use it in the discussion of the flotation theory by Derjaguin Dukhin (1961, 1984). In this theory the terms hydrophobicity or hydrophilicity are connected with the presence of hydrophobic or hydrophilic component of... 

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