Preprint 2024-08
Fernando Betancourt, Raimund Bürger, Stefan Diehl, María Carmen Martí, Yolanda Vásquez:
A degenerating convection-diffusion model of a flotation column: theory, numerics and applications
Abstract:
The operation of a froth flotation column can be described by a nonlinear convection-diffusion partial differential equation that incorporates the solids–flux and drift–flux theories as well as a model of foam drainage. The resulting model contains some non-standard ingredients such as discontinuous fluxes and degenerating diffusion accounting for foam drainage. It predicts the bubble and gangue particle volume fractions as functions of height and time. The steady-state (time-independent) version of the model defines so-called operating charts that map conditions on the gas and pulp feed rates that allow for operation with a stationary froth layer. In addition, a robust numerical scheme allows for the efficient simulation of the dynamic (transient) behaviour of the flotation column. Examples, in part for the addition of solid particles, are presented.
