Role of froth processes on flotation

The importance of various froth processes on the performance of flotation cells has been long before recognized. The froth and its stability, the entrainment and the drainage of particles are important factors which affect the grade of the product and recovery of the valuable mineral. The paper highlights the need for a deeper understanding of various phenomena taking place in the froth phase. A distinction is made between the two phase froth and the three phase froth which is encountered in flotation. Some important aspects related to the structure, stability, drainage, contamination of froth by gangue particles, secondary concentration processes, etc. are discussed. A brief review of literature pertaining to mathematical modeling of flotation kinetics involving forth phenomena is presented. Froth models have been broadly divided into two categories: (i) multi-phase froth models, and (ii) models based on microscopic considerations. For case of discussion the former category is further subdivided into: (a) models considering perfect mixing in the phases, (b) models considering plug flow in the froth phase, and (c) steady state models.