Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Grinding and flotation operations are often studied independently, despite the well-established grinding influence on flotation performance. At most, this influence is studied with microflotation of pure minerals, which hinders a thorough evaluation of the problem. Here, we study the relation between grinding condition and flotation without material simplification. Clearlier, we assess if variations in flotation performance after distinct grinding environments are driven by particle size and shape or by variations in pulp properties. Three ores were studied: scheelite, apatite, and fluorite. These were dry-, wet-, and wet conditioned-ground before flotation in a laboratory mechanical cell. Results were evaluated with bulk- and particle-specific methodologies. For each grinding environment, variations in flotation performance (e.g., apatite and scheelite particles float faster after dry and wet conditioned-grinding, respectively) and selectivity (e.g., higher after dry grinding for the fluorite and apatite ores and irrelevant for the scheelite ore) were quantified. Yet, the impact of particle shape is system specific, i.e. entrainment increases for rounder particles in the apatite and scheelite ores while true flotation is higher for these particles in the fluorite ore. We conclude that the selectivity of these semi-soluble salt-type mineral systems is driven by pulp chemistry variations caused by distinct grinding environments.