Study of solid and liquid behavior in large copper flotation cells (130 m²) using radioactive tracers

¹ Nuclear Applications Department, Chile an Commission of Nuclear Energy, PO Box 188-D, Santiago, Chile
² Chemical and Environmental Engineering Department & CASIM, Federico Santa Maria Technical University, PO Box 110-V, Valparaíso, Chile

Abstract

The behavior of the solid and liquid phases, in large flotation cells, was characterized by means of the radioactive tracer technique. The use of radioactive tracers enabled the identification of the Residence Time Distribution, of floatable and non-floatable solid, from continuous (on-line) measuring at the output streams of the flotation cells. For this study, the proper radioactive tracers were selected and applied in order to characterize the different phases; i.e. for liquid phase Br-82 as Ammonium Bromide, for floatable solid recovered in the concentrate Cu-64, and for non-floatable solid in three particle size classes (coarse: >150 μm, intermediate: <150 μm and >45 μm, and fine: <45 μm), Na-24. The experimental results confirmed the strong effect of particle size on the Residence Time Distribution, and mean residence time of solids in larger flotation cells, and consequently in flotation hydrodynamics. From a hydrodynamic point of view, the experimental data confirmed that a single mechanical flotation cells, of large size, can deviate significantly from perfect mixing. The experimental work was developed in a 130 m³ industrial flotation cell of the rougher circuit at El Teniente Division, Codelco-Chile.