Comprehensive assessment of flotation banks through mineralogy, liberation, and particle size at Constancia concentrator

Vallejos P.; Yianatos J.; Medina M.; Sotomayor G. · Minerals Engineering (2026) · DOI: 10.1016/j.mineng.2026.110734

Resumen

This paper presents a chemical and mineralogical kinetic characterization of the rougher and scavenger flotation banks in a copper concentrator plant. Sampling campaigns were carried out to characterize the kinetic responses along the banks, per mineralogical specie, particle size, and liberation class. Additionally, measurements on froth depth and top of froth (TOF) allowed for complementing the study. The results showed that sampling methodologies provided representative samples, while manual froth depth measurements allowed for reliably determining the profiles along the banks (SD < 2.4 cm). Then, TOF results gave useful information regarding entrainment of non-valuable minerals into concentrates, estimating contents of 15–40% in the first cells of the rougher banks of this study. On the other hand, the results confirmed the quasi-linear relationship between the cumulative recovery along a flotation bank and liberation at industrial scale, as well as the classical “elephant curve” relationship with particle size, in both rougher and scavenger banks. These results support the advantage of looking at the liberation as the main driving force for collection. More liberated particles, as well as −106 µm fractions in rougher and 38–53 µm in scavenger, presented faster flotation kinetics. Additionally, although true flotation of activated pyrite was identified in the rougher stage, the scavenger bank showed good control of pyrite flotation. On the other hand, the scavenger performance against entrainment was influenced by the higher content of ultrafine particles produced from regrinding. These findings suggest potential opportunities to enhance metallurgical performance through strategies such as targeting pyrite depression, and improved recovery of ultrafine particles, e.g., using intensified flotation technologies, thereby minimizing losses to tailings.