The role of hydrodynamic and surface forces in bubble-particle interaction

In modeling flotation, the process of bubble-particle interaction is usuall y divided into three subprocesses, including collision, adhesion and detach ment. Of these, the hydrodynamics of bubble-particle collision has been stu died most extensively by many investigators, and the results are useful for the design and scale-up of flotation cells. The process of adhesion, on th e other hand, is least understood because it is essentially controlled by t he chemistry of the system, which is complex and difficult to model mathema tically. However, it is possible to determine the probability of the bubble -particle adhesion from the induction times that can be measured experiment ally under different chemical environments. Furthermore, the new informatio n reported in the literature on the hydrophobic forces of both particles an d bubbles allow prediction of adhesion probabilities using various surface chemistry parameters. Consideration of both the hydrodynamic and surface fo rce parameters is essential in predicting flotation rates from first princi ples. (C) 2000 Elsevier Science B.V. All rights reserved.