An approach to quantify the true flotation recovery of floatable minerals using natural entrainment tracers and particle-based separation modeling

In froth flotation, overall recovery of the floatable particles consists of true recovery and recovery by entrainment, where entrainment refers to the non-selective recovery of particles in the concentrate. To understand and optimize the flotation process with regard to process conditions, it is essential to distinguish true flotation recovery from overall recovery. The established methods rely on tailored flotation experiments, unrealistic flotation conditions, or using external tracers which can be different in density and crystal structure to the mineral(s) of interest. This study presents an approach to utilize naturally occuring suitable tracers to estimate the entrainment component from overall recovery of individual particles by establishing a relationship between their settling velocity coefficient and recovery probability. Recovery probabilities of individual particles are computed using particle-based separation modelling. The approach is demonstrated for a copper ore, where naturally occurring rutile was used as the tracer to determine the entrained component of the overall recovery of chalcopyrite particles. Laboratory flotation experiments revealed that entrainment accounted for up to 6% of the overall recovery probability of fully liberated chalcopyrite particles in the fine size fractions. This approach provides a practical method for entrainment correction enabling a more accurate evaluation of true flotation recovery.